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Title: Mars and Its Canals

Author: Percival Lowell

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Language: English

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*** START OF THE PROJECT GUTENBERG EBOOK MARS AND ITS
CANALS ***

MARS AND ITS CANALS

Mars’ Hill

MARS
AND ITS CANALS

BY

PERCIVAL LOWELL

DIRECTOR OF THE OBSERVATORY AT FLAGSTAFF, ARIZONA;
NON-RESIDENT
PROFESSOR OF ASTRONOMY AT THE MASSACHUSETTS
INSTITUTE OF
TECHNOLOGY; FELLOW OF THE AMERICAN ACADEMY OF
ARTS AND
SCIENCES; MEMBRE DE LA SOCIÉTÉ ASTRONOMIQUE DE
FRANCE;
MEMBER OF THE ASTRONOMICAL AND ASTROPHYSICAL
SOCIETY
OF AMERICA; MITGLIED DER ASTRONOMISCHEN
GESELLSCHAFT;
MEMBRE DE LA SOCIÉTÉ BELGE D’ASTRONOMIE;
HONORARY
MEMBER OF THE SOCIEDAD ASTRONOMICA DE
MEXICO;
JANSSEN MEDALIST OF THE SOCIÉTÉ
ASTRONOMIQUE
DE FRANCE, 1904, FOR RESEARCHES ON MARS;
ETC., ETC.

ILLUSTRATED

New York
THE MACMILLAN COMPANY
LONDON: MACMILLAN & CO., Ltd.
1906

All rights reserved

Copyright, 1906,
By THE MACMILLAN COMPANY.

Set up and electrotyped. Published December, 1906.

Norwood Press
J. S. Cushing & Co.—Berwick & Smith Co.
Norwood, Mass., U.S.A.

To

G. V. SCHIAPARELLI

THE COLUMBUS OF A NEW PLANETARY WORLD

THIS INVESTIGATION UPON IT

IS APPRECIATIVELY

INSCRIBED

PREFACE

Eleven years have elapsed since the writer’s first work on Mars was
published in which were recorded the facts gleaned in his research up to
that time and in which was set forth a theory of their explanation.
Continued work in the interval has confirmed the conclusions there stated;
sometimes in quite unexpected ways. Five times during that period Mars
has approached the earth within suitable scanning distance and been
subjected to careful and prolonged scrutiny. Familiarity with the subject,
improved telescopic means, and long-continued training have all combined
to increased efficiency in the procuring of data and to results which have
been proportionate. A mass of new material has thus been collected,—some
of it along old lines, some of it in lines that are themselves new,—and both
have led to the same outcome. In addition to thus pushing inquiry into
advanced portions of the subject, study has been spent in investigation of
the reality of the phenomena upon which so much is based, and in testing
every theory which has been suggested to account for them. From diplopia
to optical interference, each of these has been examined and found
incompatible with the observations. The phenomena are all they have been
stated to be, and more. Each step forward in observation has confirmed the
genuineness of those that went before.
To set forth science in a popular, that is, in a generally understandable,
form is as obligatory as to present it in a more technical manner. If men are
to benefit by it, it must be expressed to their comprehension. To do this
should be feasible for him who is master of his subject and is both the best
test of, and the best training to, that post. Especially vital is it that the
exposition should be done at first hand; for to describe what a man has
himself discovered comes as near as possible to making a reader the co-
discoverer of it. Not only are thus escaped the mistaken glosses of second-
hand knowledge, but an aroma of actuality, which cannot be filtered
through another mind without sensible evaporation, clings to the account of

the pioneer. Nor is it so hard to make any well-grasped matter
comprehensible to a man of good general intelligence as is commonly
supposed. The whole object of science is to synthesize, and so simplify; and
did we but know the uttermost of a subject we could make it singularly
clear. Meanwhile technical phraseology, useful as shorthand to the cult,
becomes meaningless jargon to the uninitiate and is paraded most by the
least profound. But worse still for their employ symbols tend to fictitious
understanding. Formulæ are the anæsthetics of thought, not its stimulants;
and to make any one think is far better worth while than cramming him
with ill-considered, and therefore indigestible, learning.
Even to the technical student, a popular book, if well done, may yield
most valuable results. For nothing in any branch of science is so little
known as its articulation,—how the skeleton of it is put together, and what
may be the mode of attachment of its muscles.

CONTENTS
PAGE

Preface vii

PART I

NATURAL FEATURES

CHAPTER

I. On Exploration 3

II. A Departure-point 12

III. A Bird’s-eye View of Past Martian Discovery 20

IV. The Polar Caps 32

V. Behavior of the Polar Caps 41

VI. Martian Polar Expeditions 54

VII. White Spots 73

VIII. Climate and Weather 82

IX. Mountains and Cloud 96

X. The Blue-green Areas 108

XI. Vegetation 119

XII. Terraqueousness and Terrestriality 128

XIII. The Reddish-ochre Tracts 148

XIV. Summary 159

PART II

NON-NATURAL FEATURES

XV. The Canals 173

XVI. Their System 184

XVII. Gemination of the Canals 192

I. The Diplopic Theory 196

II. The Interference Theory 201

III. The Illusion Theory 202

XVIII. The Double Canals 204

XIX. Canals in the Dark Regions 243

XX. Oases 249

XXI. Carets on the Borders of the Great Diaphragm 265

XXII. The Canals Photographed 271

PART III

THE CANALS IN ACTION

XXIII. Canals: Kinematic 281

XXIV. Canal Development Individually Instanced 304

XXV. Hibernation of the Canals 313

XXVI. Arctic Canals and Polar Rifts 325

XXVII. Oases: Kinematic 330

PART IV

EXPLANATION

XXVIII. Constitution of the Canals and Oases 337

XXIX. Life 348

XXX. Evidence 360

XXXI. The Husbanding of Water 366

XXXII. Conclusion 376

INDEX 385

LIST OF ILLUSTRATIONS
PLATES
Mars’ Hill Frontispiece
PAGE
The Hermitage 8
The San Francisco Peaks 18
Martian Maps by:
I. Beer and Maedler. 1840 26
II. Kaiser. 1864 26
III. Flammarion (Résumé). 1876 27
IV. Green. 1877 27
V. Schiaparelli. 1877 28
VI. Schiaparelli. 1879 28
VII. Schiaparelli. 1881 29
VIII. Schiaparelli. 1884 29
IX. Lowell. 1894 30
X. Lowell. 1896 30
XI. Lowell. 1901 31
XII. Lowell. 1905 31
South Polar Cap. 1905 42
North Polar Cap. 1905 44
Mare Erythraeum, Martian date, December 30 120
Mare Erythraeum, Martian date, January 16 122
Mare Erythraeum, Martian date, February 1 124
Mare Erythraeum, Martian date, February 21 126
Mars, on Mercator’s Projection 384
CUTS APPEARING IN TEXT

South Polar Cap in winter 56
Hellas in winter 59
White south of Nectar and Solis Lacus 59
Northern Cap hooded with vapor 64
Northern Cap unmasked 65
Deposition of frost 70
First northern snow 72
White in Elysium 75
White in the Pons Hectoris 78
Projection on terminator 101
Lines in dark area 117
Map of North America at the close of Archæan time 132
North America at opening of Upper Silurian period 134
Map of North America after the Appalachian revolution 135
North America in the Cretaceous period 136
North America, showing the parts under water in the
137
Tertiary era
Earth’s Desert Areas, Western Hemisphere 156
Earth’s Desert Areas, Eastern Hemisphere 157
Showing the Eumenides-Orcus 183
Martian doubles 206
Martian doubles 207
Mouths of Euphrates and Phison. June, 1903 219
Peculiar development of the Ganges 228
Djihoun, the narrowest double 229
The Sabaeus Sinus, embouchure for the double Hiddekel
232
and Gihon
The Propontis, 1905 247
Fons Immortalis, June 19 254
Utopia Regio. 1903 256
Ascraeus Lucus and Gigas. March 2, 1903 258
Peculiar association of the Luci Ismenii with double canals 260

Lucus Ismenius. March, 1903 262
Showing seasonal change. I 285
Showing seasonal change. II 285
Mean Canal Cartouches 298
Showing development of the Brontes:
I. February 25 306
II. March 30 307
III. April 3 307
IV. May 4 308
V. May 7 308
VI. July 18 309
Cartouches of the Brontes 311
Amenthes alone in February 319
Amenthes feebler and still alone in March 319
Appearance of Thoth with Triton and curved Nepenthes.
320
Amenthes vanished, April 20
Advent of the Lucus Moeris. May 29 321
Amenthes with Thoth-Nepenthes. July 322
Cartouches of Amenthes, Thoth, and their combination 323
Phenology Curves—Earth 342
Phenology Curves—Mars 343

PART I

NATURAL FEATURES

MARS AND ITS CANALS

CHAPTER I
ON EXPLORATION

F rom time immemorial travel and discovery have called with strange
insistence to him who, wondering on the world, felt adventure in his
veins. The leaving familiar sights and faces to push forth into the unknown
has with magnetic force drawn the bold to great endeavor and fired the
thought of those who stayed at home. Spur to enterprise since man first was,
this spirit has urged him over the habitable globe. Linked in part to mere
matter of support it led the more daring of the Aryans to quit the shade of
their beech trees, reposeful as that umbrage may have been, and wander
into Central Asia, so to perplex philologists into believing them to have
originated there; it lured Columbus across the waste of waters and caused
his son to have carved upon his tomb that ringing couplet of which the
simple grandeur still stirs the blood:—

Á Castilla y á Leon
Nuevo mondo dió Colon;

(To Castile and Leon beyond the wave
Another world Columbus gave;)

it drove the early voyagers into the heart of the vast wilderness, there to
endure all hardship so that they might come where their kind had never
stood before; and now it points man to the pole.
Something of the selfsame spirit finds a farther field today outside the
confines of our traversable earth. Science which has caused the world to
shrink and dwindle has been no less busy bringing near what in the past
seemed inaccessibly remote. Beyond our earth man’s penetration has found
it possible to pierce, and in its widening circle of research has latterly been

made aware of another world of strange enticement across the depths of
space. Planetary distances, not mundane ones, are here concerned, and the
globe to be explored, though akin to, is yet very different from, our own.
This other world is the planet Mars. Sundered from us by the ocean of ether,
a fellow-member of our own community of matter there makes its circuit of
the sun upon whose face features show which stamp it as cognate to that on
which we live. In spite of the millions of miles of intervening matterless
void, upon it markings can be made out that distantly resemble our earth’s
topography and grow increasingly suggestive as vision shapes them better;
and yet among the seemingly familiar reveal aspects which are completely
strange. But more than this: over the face of it sweep changes that show it
to be not a dead but a living world, like ours in this, and luring curiosity by
details unknown here to further exploration of its unfamiliar ground.
To observe Mars is to embark upon this enterprise; not in body but in
mind. Though parted by a gulf more impassable than any sea, the telescope
lets us traverse what otherwise had been barred and lands us at last above
the shores we went forth to seek. Real the journey is, though incorporeal in
kind. Since the seeing strange sights is the essence of all far wanderings, it
is as truly travel so the eye arrive as if the body kept it company. Indeed,
sight is our only far viatic sense. Touch and taste both hang on contact,
smell stands indebted to the near and even hearing waits on ponderable
matter where sound soon dissipates away; only sight soars untrammeled of
the grosser adjunct of the flesh to penetrate what were otherwise
unfathomable space.
What the voyager thus finds himself envisaging shares by that very fact
in the expansion of the sense that brought him there. No longer tied by
means of transport to seas his sails may compass or lands his feet may
tread, the traveler reaches a goal removed in kind from his own habitat. He
proves to have adventured, not into unknown parts of a known world, but
into one new to him in its entirety. In extent alone he surveys what dwarfs
the explorer’s conquests on Earth. But size is the least of the surprises there
in store for him. What confronts his gaze finds commonly no counterpart on
Earth. His previous knowledge stands him in scant stead. For he faces what
is so removed from every day experience that analogy no longer offers itself
with safety as a guide. He must build up new conceptions from fresh data
and slowly proceed to deduce the meaning they may contain. Science alone
can help him to interpretation of what he finds, and above all must he wean

himself from human prejudice and earthbound limitation. For he deals here
with ultramundane things. With just enough of cosmogony in common to
make decipherment not despairable this world is yet so different from the
one he personally knows as to whet curiosity at every turn. He is permitted
to perceive what piques inquiry and by patient adding of point to point
promises at last a rational result.
Like mundane exploration, it is arduous too; ad astra per aspera is here
literally true. For it is a journey not devoid of hardship and discomfort by
the way. Its starting-point preludes as much. To get conditions proper for his
work the explorer must forego the haunts of men and even those terrestrial
spots found by them most habitable. Astronomy now demands bodily
abstraction of its devotee. Its deities are gods that veil themselves amid
man-crowded marts and impose withdrawal and seclusion for the
prosecution of their cult as much as any worshiped for other reason in more
primeval times. To see into the beyond requires purity; in the medium now
as formerly in the man. As little air as may be and that only of the best is
obligatory to his enterprise, and the securing it makes him perforce a hermit
from his kind. He must abandon cities and forego plains. Only in places
raised above and aloof from men can he profitably pursue his search, places
where nature never meant him to dwell and admonishes him of the fact by
sundry hints of a more or less distressing character. To stand a mile and a
half nearer the stars is not to stand immune.
Thus it comes about that today besides its temples erected in cities,
monasteries in the wilds are being dedicated to astronomy as in the past to
faith; monasteries made to commune with its spirit, as temples are to
communicate the letter of its law. Pioneers in such profession, those already
in existence are but the precursors of many yet to come as science shall
more and more recognize their need. Advance in knowledge demands what
they alone can give. Primitive, too, they must be as befits the still austere
sincerity of a cult, in which the simplest structures are found to be the best.
Still the very wildness of the life their devotee is forced to lead has in it a
certain fittingness for his post in its primeval detachment from the too
earthbound, in concept as in circumstance. Withdrawn from contact with his
kind, he is by that much raised above human prejudice and limitation. To
sally forth into the untrod wilderness in the cold and dark of a winter’s
small hours of the morning, with the snow feet deep upon the ground and
the frosty stars for mute companionship, is almost to forget one’s self a man

for the solemn awe of one’s surroundings. Fitting portal to communion with
another world, it is through such avenue one enters on his quest where the
common and familiar no longer jostle the unknown and the strange. Nor is
the stillness of the stars invaded when some long unearthly howl, like the
wail of a lost soul, breaks the slumber of the mesa forest, marking the
prowling presence of a stray coyote. Gone as it came, it dies in the distance
on the air that gave it birth; and the gloom of the pines swallows up one’s
vain peering after something palpable, their tops alone decipherable in dark
silhouette against the sky. From amid surroundings that for their height and
their intenancy fringe the absolute silence of space the observer must set
forth who purposes to cross it to another planetary world.

The Hermitage

But the isolation of his journey is not always so forbidding. His coming
back is no less girt with grandeur of a different though equally detached a
kind. Even before the stars begin to dim in warning to him to return, a faint
suffusion as of half-suspected light creeps into the border of the eastern sky.
Against it, along the far pine-clad horizon, mesa after mesa in shaggy lines
of sentineling earth, stands forth dark marshaled in the gloom, informed
with prescience of what is soon to come. Imperceptibly the pallor grows,
blanching the face of night and one by one extinguishing the stars. Slowly
then it takes on color, tingeing ever so faintly to a flush that swells and
deepens as the minutes pass. One had said the sky lay dreaming of the sun
in pale imagery at first that gathers force and feeling till the dreamer turns
thus rosy red in slumbering supposition of reality. Then the blush dies out.

The crimson fades to pink, the pink to ashes. The stars have disappeared
and yet it is not day. It is the supreme moment of the dawn, the hush with
which the Earth awaits its full awakening. For now again the color gathers
in the east, not with the impalpable suffusion it had before but nearer and
more vivid. No longer reflectively remote, rays imminent of the sun strike
the upper air, the most adventurously refrangible turning the underside of a
few stray clouds into flame-hued bars of glowing metal. They burn thus in
the silent east first red, then orange, and then gold, each spectral tint in
prismatic revelation coming to join the next till in a sudden blinding burst
of splendor the solar disk tops the horizon’s rim.
Not less impressive is the journey when the afternoon watch has replaced
the morning vigil by the drawing of the planet nearer to the sun. Lost in the
brilliance of the dazzling sky, the planet lies hid from the senses’ search.
The quest were hopeless did not the mind guide the telescope to its goal. To
theory alone is it visible still, and so to its predicted place the observer sets
his circles, and punctual to the prophecy the planet swings into the field of
view. One must be dulled by long routine to such mastery of mind not to
have the act itself clothe with a sense of charmed withdrawal the object of
his quest.
So much and more there are of traveler’s glimpses by the way,
compensation that offsets the frequent discomfort, and even balking of his
purpose by inopportune cloud. For the best of places is not perfect, and a
storm will sometimes rob him of a region he wished to see. He must learn
to wait upon his opportunities and then no less to wait for mankind’s
acceptance of his results; for in common with most explorers he will
encounter on his return that final penalty of penetration, the certainty at first
of being disbelieved.
In such respect he will be even worse off than were the other world
discoverers of the fifteenth and sixteenth centuries. For they at least could
offer material proof of things that they had seen. Dumb Indians and gold
spoke more convincingly than the lips of the great navigators. To
astronomy, too, that other world was due. Without a knowledge of the
earth’s shape and size got from Francisco of Pisa, Columbus had never
adventured himself upon the deep. But more than this, an astronomer it was,
in the person of Americus Vespucius, who first discovered the new world,
by recognizing it as such; Columbus never dreaming he had lighted upon a
world that was new. Nor does it impair one jot or tittle of his glory that he

knew it not. Nothing can deprive him of the imperishable fame of launching
forth into the void in hope of a beyond, though he found not what he sought
but something stranger still.
So, curiously, has it been with the trans-etherian. To Schiaparelli the
republic of science owes a new and vast domain. His genius first detected
those strange new markings on the Martian disk which have proved the
portal to all that has since been seen, and his courage in the face of
universal condemnation led to exploration of them. He made there voyage
after voyage, much as Columbus did on Earth, with even less of recognition
from home. As with Columbus, too, the full import of his great discovery
lay hid even to him and only by discoveries since is gradually resulting in
recognition of another sentient world.

CHAPTER II
A DEPARTURE-POINT

As the character of the travel is distinctive, so the outcome of the voyage is
unique. If he choose his departure-point aright, the observer will be
vouchsafed an experience without parallel on Earth. To select this setting-
out station is the first step in the journey upon which everything depends.
For it is essential to visual arrival that a departure-point be taken where
definition is at its best. Now, so far as our present knowledge goes, the
conditions most conducive to good seeing turn out to lie in one or other of
the two great desert belts that girdle the globe. Many of us are unaware of
the existence of such belts and yet they are among the most striking features
of physical geography. Could we get off our globe and view it from without
we should mark two sash-like bands of country, to the poleward side of
either tropic, where the surface itself lay patently exposed. Unclothed of
verdure themselves they would stand forth doubly clear by contrast. For
elsewhere cloud would hide to a greater or less extent the actual
configuration of the Earth’s topography to an observer scanning it from
space.
One of these sash-like belts of desert runs through southern California,
Arizona, New Mexico, the Sahara, Arabia Petræa and the Desert of Gobi;
the other traverses Peru, the South African veldt, and Western Australia.
They are desert because in them rain is rare; and even clouds seldom form.
In a twofold way they conduce to astronomic ends. Absence of rain makes
primarily for clear skies and secondarily for steady air; and the one of these
conditions is no less vital to sight than the other. Water vapor is a great
upsetter of atmospheric equilibrium and commotion in the air the spoiler of
definition. Thus from the cloudlessness of their skies man finds in them
most chance of uninterrupted communion with the stars, while by suitably
choosing his spot he here obtains as well that prime desideratum for

planetary work, as near a heavenly equanimity in the air currents over his
head as is practically possible.
From the fact that these regions are desert they are less frequented of
man, and the observer is thus perforce isolated by the nature of the case, the
regions best adapted to mankind being the least suited to astronomic
observations. In addition to what nature has thus done in the matter,
humanity has further differentiated the two classes of sights by processes of
its own contriving. Not only is civilized man actively engaged in defacing
such part of the Earth’s surface as he comes in contact with, he is equally
busy blotting out his sky. In the latter uncommendable pursuit he has in the
last quarter of a century made surprising progress. With a success only too
undesirable his habitat has gradually become canopied by a welkin of his
own fashioning, which has rendered it largely unfit for the more delicate
kinds of astronomic work. Smoke from multiplying factories by rising into
the air and forming the nucleus about which cloud collects has joined with
electric lighting to help put out the stars. These concomitants of advancing
civilization have succeeded above the dreams of the most earth-centred in
shutting off sight of the beyond so that today few city-bred children have
any conception of the glories of the heavens which made of the Chaldean
shepherds astronomers in spite of themselves.
The old world and the new are alike affected by such obliteration. Long
ago London took the lead with fogs proverbial wholly due to smoke, fine
particles of solid matter in suspension making these points of condensation
about which water vapor gathers to form cloud. With the increase of smoke-
emitting chimneys over the world other centres of population have followed
suit till today Europe and eastern North America vie with each other as to
which sky shall be the most obliterate. Even when the obscuration is not
patent to the layman it is evident to the meteorologist or astronomer. By a
certain dimming of the blue, smoke or dust reveals its presence high up
aloft as telltalely as if the thing itself were visible. Some time since the
writer had occasion to traverse Germany in summer from Göttingen to
Cologne and in so doing was impressed by a cloudiness of the sky he felt
sure had not existed when he knew it as a boy. For the change was too
startling and extensive to be wholly laid to the score of the brighter
remembrances of youth. On reaching Cologne he mentioned his suspicion
to Klein, only to find his own inference corroborated; observations made
twenty years ago being impracticable today. Two years later in Milan

Celoria told the same story, the study of Mars having ceased to be possible
there for like cause. Factory smoke and electric lights had combined to veil
the planet at about the time Schiaparelli gave up his observations because of
failing sight. With a certain poetic fitness the sky had itself been blotted just
at the time the master’s eye had dimmed.
America is not behind in this race for sky extinction. In the neighborhood
of its great cities and spreading into the country round about the heavens
have ceased to be favorable to research. Not till we pass beyond the
Missouri do the stars shine out as they shone before the white man came.
Few astronomers even fully appreciate how much this means, so used
does man get to slowly changing conditions. It amounts, indeed, between
Washington and Arizona to a whole magnitude in the stars which may be
seen. At the Naval Observatory of the former sixty-four stars were mapped
in a region where with a slightly smaller glass one hundred and seventy-two
were charted at Flagstaff.
Besides their immediate use as observing stations these desert belts
possess mediate interest on their own account in a branch of the very study
their cloudlessness helps to promote, the branch here considered, the study
of the planet Mars. They help explain what they permit to be visible. For in
the physical history of the Earth’s development they are among the latest
phenomena and mark the beginning of that stage of world evolution into
which Mars is already well advanced. They are symptomatic of the passing
of a terraqueous globe into a purely terrestrial one. Desertism, the state into
which every planetary body must eventually come and for which, therefore,
it becomes necessary to coin a word, has there made its first appearance
upon the Earth. Standing as it does for the approach of age in planetary
existence, it may be likened to the first gray hairs in man. Or better still it
corresponds to early autumnal frost in the passage of the seasons. For the
beginning to age in a planet means not decrepitude in its inhabitants but the
very maturing of this its fruit. Evolution of mind in its denizens continues
long after desolation in their habitat has set in. Indeed, advance in brain-
power seriously develops only when material conditions cease to be bodily
propitious and the loss of corporeal facilities renders its acquisition
necessary to life.
The resemblance, distant but distinctive, of the climatic conditions
necessary on earth for the best scanning of Mars with those which prove to
be actually existent on that other world has a bearing on the subject worth

considerable attention. It helps directly to an understanding and
interpretation of the Martian state of things. Though partial only, the
features and traits of our arid zones are sufficiently like what prevails on
Mars to make them in some sort exponent of physical conditions and action
there. Much that is hard of appreciation in a low, humid land shows itself an
everyday possibility in a high and dry one. The terrible necessity of water to
all forms of life, animal or vegetal, so that in the simple thought of the
aborigines rain is the only god worth great propitiation upon the due
observance of which everything depends, brings to one a deeper realization
of what is really vital and what but accessory at best. One begins to
conceive what must be the controlling principle of a world where water is
only with difficulty to be had, and rain unknown.
But in addition to the fundamental importance of water, the relative
irrelevancy of some other conditions usually deemed indispensable to
organic existence there find illustration too. On the high plateau of northern
Arizona and on the still higher volcanic cones that rise from them as a base
into now disintegrating peaks, the thin cold air proves no bar to life. To the
fauna there air is a very secondary consideration to water, and because the
latter is scarce in the lowlands and more abundant higher up, animals
ascend after it, making their home at unusual elevations with no discomfort
to themselves. Deer range to heights where the barometric pressure is but
three fifths that of their generic habitat. Bear do the like, the brown bear of
northern American sea-level being here met with two miles above it. Nor is
either animal a depauperate form. Man himself contrives to live in comfort
and propagate his kind where at first he finds it hard to breathe. Nor are
these valiant exceptions; as Merriam has ably shown in his account of the
San Francisco peak region for the Smithsonian Institution—a most
interesting report, by the way—the other animals are equally adaptive to the
zones of more northern latitudes on the American continent, zones
paralleled in their flora and fauna by the zones of altitude up this peak. All
which shows that paucity of air is nothing like the barrier to life we
ordinarily suppose and is not for an instant to be compared with dearth of
water. If in a comparatively short time an animal or plant accustomed to
thirty inches of barometric pressure can contrive to subsist sensibly
unchanged at eighteen, it would be rash to set limits to what time may not
do. And this the more for another instructive fact discovered in this region
by Merriam: that the existence of a species was determined not by the mean

temperature of its habitat but by the maximum temperature during the time
of procreation. A short warm season in summer alone decides whether the
species shall survive and flourish; that it has afterward to hibernate for six
months at a time does not in the least negative the result.

The San Francisco Peaks

That the point of departure should thus prove of twofold importance,
speeding the observer on his journey and furnishing him with a vade mecum
on arrival, is as curious as opportune. Without such furtherance, to the
bodily eye on the one hand and the mind’s eye on the other, the voyage
were less conclusive in advent and less satisfactory in attent.

CHAPTER III
A BIRD’S-EYE VIEW OF PAST MARTIAN DISCOVERY

W ith Mars discovery has from the start waited on apparent disk. To this
end every optical advance has contributed from the time of Galileo’s
opera-glass to the present day. For apparent distance stands determined by
the size of the eye. But although it is the telescopic eye that has increased,
not the distance that has diminished, the effect has been kin to being carried
nearer the planet and so to a scanning of its disk with constantly increasing
particularity. Mankind has to all intents and purposes been journeying
Marsward through the years. Any historic account of the planet, therefore,
becomes a chronicle of seeming bodily approach.
Perhaps no vivider way of making this evident and at the same time no
better preface to the present work could be devised than by putting before
the eye in orderly succession the maps made of Mars by the leading
areographers of their day, since the planet first began to be charted sixty-
five years ago. The procedure is as much as possible like standing at the
telescope and seeing the phenomena steadily disclose.
Seen thus in order the facts speak for themselves. They show that from
first to last no doubt concerning what was seen existed in the minds of those
competent to judge by systematic study of the planet at first hand, and
furthermore, from their mutual corroboration, that this confidence was well
placed. For, far from there being any conflict of authorities in the case,
those entitled to an opinion in the matter prove singularly at one.
Beginning with Maedler in 1840 the gallery of such portraitures of the
planet comprises those by Kaiser, Green and Schiaparelli, continued since
Schiaparelli’s time by the earlier ones of the present writer. To this list has
been added one by Flammarion, which though not solely from his own
work gives so just a representation of what was known at the date, 1876, as
to merit inclusion. The remarkable drawings of Dawes and the excellent

ones of Lockyer in 1862-1864 were never combined into maps by the
observers, and though the former’s were so synthesized by Proctor in 1867,
the result was conformed to what Proctor thought ought to be and so is not
really a transcript of the drawings themselves.
Each of the maps presented marked in its day the point areography had
reached; and each tells its own story better than any amount of text. They
are all made upon Mercator’s projection and omit in consequence the
circumpolar regions. The later ones give, too, only so much of the surface
as was shown at the opposition they record, for Mars, being tipped now one
way, now another, regards the earth differently according to its orbital
position. In comparing them, therefore, the equator must be taken for
medial line. Mercator’s projection has been the customary one for
portraying Mars except for such oppositions as chiefly disclose the arctic
pole. And this, too, with a certain poetic fitness. For it comes by right of
priority to delineation of a new world; seeing that Mercator was the first to
represent in a map the mundane new world in its entirety, by the rather
important addition of North America to the southern continent already
known, and to give the whole the title America with ‘Ame’ at the top of the
map and ‘rica’ at the bottom.
In looking at the maps it is to be remembered that they are what we
should call upside down, south standing at the top and north at the bottom.
Inverted they show because this is the way the telescopic observer always
sees the planet. The disk would seem unnatural to astronomers were it duly
righted. Just the same do men in the southern hemisphere look at our own
Earth topsy-turvy according to our view, the Sun being to the north of them
and the cold to the south. Certain landmarks distinguishable in all the maps
may serve for specific introduction. The V-shaped marking on the equator
pointing to the north is the Syrtis Major, the first marking ever made out
upon the planet and drawn by the great Huyghens in 1659. The isolated oval
patch in latitude 26° south is the Solis Lacus, the pupil of the eye of Mars;
while the forked bay on the equator, discovered by Dawes, is the Sabaeus
Sinus, the dividing tongue of which, the Fastigium Aryn, has been taken for
the origin of longitudes on Mars.
Twelve maps go to make the series. They are as follows:—
Maker Date
I. Map of Beer and Maedler 1840
II. Map of Kaiser 1864

III. Map of Flammarion (Résumé) 1876
IV. Map of Green 1877
V. Map of Schiaparelli 1877
VI. Map of Schiaparelli 1879
VII. Map of Schiaparelli 1881
VIII. Map of Schiaparelli 1884
IX. Map of Lowell 1894
X. Map of Lowell 1896
XI. Map of Lowell 1901
XII. Map of Lowell 1905
If these maps be carefully compared they will be found quite remarkably
confirmatory each of its predecessor. To no one will their inter-resemblance
seem more salient than to draughtsmen themselves. For none know better
how surprisingly, even when two men have the same thing under their very
noses to copy, their two versions will differ. Judgment of position and of
relative size is one cause of variation; focusing of the attention on different
details another. What slight discrepancies affect the maps are traceable to
these two human imperfections. Maps IV and V make a case in point: it was
to his new-found canals that Schiaparelli gave heed to the neglect of a due
toning of his map; while Green, less keen-eyed but more artistic, missed the
delicate canaliform detail to make a speaking portraiture of the whole.
Amid the remarkable continuity of progression here shown, in which
each map will be seen to be at once a review and an advance, we may,
nevertheless, distinguish three stages in the perception of the phenomena.
Thus we may mark:—
I. 1840-
A period of recognition of larger markings only;
1877
II. A period of detection of canals intersecting the bright 1877-
regions or lands; 1892
III. A period of detection of canals traversing the ‘seas’ and 1892-
of oases scattered over the surface; 1905
Each period is here represented by four charts; and each expresses the result
of a more minute and intimate acquaintance with the disk than was possible
to the one that went before. To realize, however, how accurate each was
according to his lights it is only necessary to have the seeing grow steadily

better some evening as one observes. He will find himself recapitulating in
his own person the course taken by discovery for all those who went before,
and in the lapse of an hour live through the observational experience of
sixty years; in much the same way that the embryological growth of an
individual repeats the development historically of the race.
Two verses of Ovid, which the poet puts into the mouth of Pythagoras,
outline with something like prophetic utterance the special discoveries
which mark the three periods apart. Ovid makes Pythagoras say of the then
world:—

Vidi ego, quod fuerat quondam solidissima tellus
Esse fretum; vidi factas ex aequore terras;

—Ovid, Metamorphoses XV, 262.

(Where once was solid ground I’ve seen a strait;
Lands I’ve seen made from out the sea.)

True as the verses are of Earth, the poet could not have penned them
otherwise had he meant to record the course of astronomic detection on
Mars. For they sound like a presentiment of the facts. A surface thought at
first to be part land, part water; the land next seen to be seamed with straits;
and lastly the sea made out to be land. Such is the history of the subject, and
words could not have summed it more succinctly. “Vidi ego, quod fuerat
quondam solidissima tellus esse fretum” rings like Schiaparelli’s own
announcement of the discovery of the ‘canals.’ Indeed, I venture to believe
he would have made it had he chanced to recall the verse. So “vidi factas ex
aequore terras” tells what has since been learned of the character of the
seas.
Of the three periods the first was that of the main or fundamental
markings only. It came in with Beer and Maedler, the inaugurators of
areography. That they planned and executed their survey with but a four-
inch glass shows that there is always room for genius at the top of any
profession and that instruments are not for everything in its instrumentality.
Up to their day the reality of the planet’s features had been questioned by
some people in spite of having been certainly seen and drawn by Huyghens
and others. Beer and Maedler’s labors proved them permanent facts beyond
the possibility of dispute.

The second period was the period of the discovery of the now famous
canals,—a new era in the study of Mars opened by Schiaparelli in 1877
(Map V). Unsuspicious of what he was to stumble on, he seized the then
favorable opposition to make, as he put it, a geodetic survey of the planet’s
surface. He hoped this undertaking feasible to the accuracy of micrometric
measurement. His hopes did not belie him. He found that it was possible to
measure his positions with sufficient exactness to make a skeleton map on
which to embody the markings in detail—and thus to give his map
vertebrate support. But in the course of his work he became aware of
hitherto unrecognized ligaments connecting the seas with one another.
Instead of displaying a broad unity of face the bright areas appeared to be
but groundwork for streaks. The streaks traversed them in all directions,
tesselating the continents into a tilework of islands. Such mosaic was not
only new, but the fashion of the thing was of a new order or kind. Straits,
however, Schiaparelli considered them and gave them the name canali, or
channels. How unfamiliar and seemingly impossible the new detail was is
best evidenced by the prompt and unanimous disbelief with which it was
met.

Map I. Beer and Maedler, 1840.

Map II. Kaiser, 1864.
(From Flammarion’s Mars.)

Map III. Résumé by Flammarion, 1876.
(From Flammarion’s Mars.)

Map IV. Green, 1877.
(From Flammarion’s Mars.)

Unmoved by the universal scepticism which rewarded what was to prove
an epoch-making discovery, Schiaparelli went on, in the judgment of his
critics, from bad to worse—for in 1879 (Map VI) he took up again his
scrutiny of the planet to the detecting of yet more particularity. He re-
observed most of his old canals and discovered half as many more; and as
his map shows he perceived an increased regularity in his lines.
In 1881-1882 (Map VII) he attacked the planet again and with results yet
further out of the common. His lines were still there with more beside. If
they had looked strange before, they now appeared positively unnatural.
Not content with a regularity which seemed to the sceptics to preclude their
being facts, he must needs see them now in duplicate. To the eyes of
disbelief this was the crowning stroke of factitiousness.
In consequence no end of adverse criticism was heaped upon his
observations by those who could not see. But curiously enough,—what did
not attract attention,—the blindness of the critics was as much mental as
bodily. For they failed to perceive that the very unnaturalness which seemed
to them to discredit his observations really proved their genuineness. His
discoveries were so amazing that any change in strangeness simply went to
confirm the universal scepticism and clouded logic. Yet properly viewed, a
pregnant deduction stands forth quite clearly on a study of the maps.

Map V. Schiaparelli, 1877.
(From Schiaparelli’s Memoria.)

Map VI. Schiaparelli, 1879.
(From Schiaparelli’s Memoria.)

Map VII. Schiaparelli, 1881.
(From Schiaparelli’s Memoria.)

Map VIII. Schiaparelli, 1884.
(From Schiaparelli’s Memoria.)

On comparing maps V, VI and VII an eye duly directed is struck by a
difference in the aspect of the lines. In his first map the ‘canals’ are depicted
simply as narrow winding streaks, hardly even roughly regular and by no
means such departures from the plausible as to lie without the
communicatory pale. Indeed, to a modern reader prepared beforehand for
geometric construction they will probably appear no ‘canals’ at all.
Certainly the price of acceptance was not a large one to pay. But like that of
the Sibylline Books it increased with putting off. What he offered the public
in 1879 was much more dearly to be bought. The lines were straighter,
narrower, and in every way less natural than they had seemed two years
before. In 1881-1882 they progressed still more in unaccountability. They
had now become regular rule and compass lines, as straight, as even, and as
precise as any draughtsman could wish and quite what astronomic faith did
not desire. Having thus donned the character, they nevermore put it off.
Now, this curious evolution in depiction points, rightly viewed, to an
absence of design. It shows that Schiaparelli started with no preconceived
idea on the subject. On the contrary, it is clear that he shared to begin with
the prevailing hesitancy to accept anything out of the ordinary. Nor did he
overcome his reluctance except as by degrees he was compelled. For the
canals did not change their characteristics from one opposition to another;
the eye it was that learned to distinguish what it saw, and the brain made
better report as it grew familiar with the messages sent it. In other words, it
is patent from these successive maps that the geometrical character of the

‘canals’ was forced upon Schiaparelli by the things themselves, instead of
being, as his critics took for granted, foisted on them by him. We have since
seen the regularity of the canals so undeniably that we are not now in need
of such inferential support to help us to the truth; but too late, as it is, to be
of controversial moment the deduction is none the less of some
corroboratory force.
With the third period enters what has been done since Schiaparelli’s time.
For that master was obliged, from failing sight, to close his work with the
opposition of 1890. In 1892 W. H. Pickering at Arequipa was the chief
observer of the planet and made two important discoveries: one was the
detection of small round spots scattered over the surface of the planet and
connected with the canal system; the other the perception of what seemed to
him more or less irregular lines traversing the Mare Erythraeum. Both were
notable detections. The first set of phenomena he called lakes, the second
river-systems, sometimes schematically ‘canals,’ but without committing
himself to canaliform characteristics as his drawings make clear. The same
phenomena were seen at that opposition at the Lick, by Schaeberle, Barnard
and others, and called streaks. These discoveries took from the maria their
supposed character of seas—a most important event in knowledge of Mars.

Map IX. Lowell, 1894.

Map X. Lowell, 1896.

Map XI. Lowell, 1901.

Map XII. Lowell, 1905.

The next advance was the detection at Flagstaff in 1894 of their
canaliform characteristics by my then assistant Mr. Douglass, who in place
of the irregular streaks and river-systems of his predecessors found the seas
to be crossed by lines as regular and as regularly connected as the canals in
the light regions. To him they appeared broad and ill defined, but so
habitually did to him the canals in the light areas, while for directness and
uniformity the one set showed as geometrically perfect as the other. All the
dark maria of the southern hemisphere he found to be laced with them and
that they formed a network over the dark regions, counterparting that over
the light. Still more significant was the fact that their points of departure
coincided with the points of arrival of the bright-region canals, so that the
two connected to form in its entirety a single system. After the publication
of his results (Lowell Observatory Annals, Volume I, 1895) Schiaparelli
identified some of those in the Syrtis with what he had himself seen there in
1888 (Memoria, VI, 1899), though his own had not been sufficiently well
seen of him to impress him as canals.
Of other additions to our knowledge since made by the writer the present
book treats; as also of the theory they originally suggested to him and which
his later observations have only gone to confirm.

CHAPTER IV
THE POLAR CAPS

A lmost as soon as magnification gives Mars a disk that disk shows
markings, white spots crowning a globe spread with blue-green patches
on an orange ground. The smallest telescope is capable of this far-off
revelation; while with increased power the picture grows steadily more
articulate and full. With a two and a quarter inch glass the writer saw them
thirty-five years ago.
After the assurance that markings exist the next thing to arrest attention is
that these markings move. The patches of color first made out by the
observer are shortly found by him to have shifted in place upon the planet.
And this not through mistake on his part but through method in the
phenomena; for all do it alike. In orderly rotation the features make their
appearance upon the body’s righthand limb (in the telescopic image), travel
across the central meridian of the disk and vanish over its lefthand border.
One follows another, each rising, culminating and setting in its turn under
the observer’s gaze. A constantly progressing panorama passes majestically
before his sight, new objects replacing the old with a march so steady and
withal so swift that a few minutes will suffice to mark unmistakably the fact
of such procession. But for all this ceaseless turning under his gaze, after a
certain lapse of time it is evident that the same features are being shown
him over again. With such recognition of recurrence comes the first
advance toward acquaintance with the Martian world. For that in all their
journeying their configuration alters not, proves them permanent in place,
part and parcel of the solid surface of that other globe. This surface, then,
lies exposed to view and by its turning shows itself subject, like our earth,
to the vicissitudes of day and night.
In such self-exposure Mars differs from all the four great planets, Jupiter,
Saturn, Uranus and Neptune. Features, indeed, are apparent on the first two

of these globes and dimly on the other two as well, but they lack the
stability of the Martian markings. They are forever exchanging place. In the
case of Jupiter what we see is undoubtedly a cloud-envelop through which
occasional glimpses may possibly be caught of a chaotic nucleus below.
With Saturn it is the same; and the evidence is that the like is true of Uranus
and Neptune. What goes on under their great cloud canopies we can only
surmise. With Mars, however, we are not left to imagination in the matter
but so far as our means permit can actually observe what there takes place.
Except for distance, which, through science, year by year grows less, it is as
if we hovered above the planet in a balloon, with its various features spread
out to our gaze below.
Attention shows these areographic features to be on hand with punctual
precision for their traverse of the disk once every twenty-four hours and
thirty-seven minutes. For over two hundred years this has been the case,
their untiring revolutions having been watched so well that we know the
time they take to the nicety of a couple of hundredths of a second. We thus
become possessed of a knowledge of the length of the Martian day and it is
not a little interesting to find that it very closely counterparts in duration our
own, being only one thirty-fifth the longer of the two. We also find from the
course the markings pursue the axis about which they turn; and just as the
period of the rotation tells us the length of the Martian day so the tilt of the
axis, taken in connection with the form of the orbit, determines the
character of the Martian seasons. Here again we confront a curious
resemblance in the circumstances of the two planets, for the tilt of the
equator to the plane of the orbit is with Mars almost precisely what it is for
the Earth. The more carefully the two are measured the closer the similitude
becomes. Sir William Herschel made the Martian 28°, Schiaparelli reduced
this to 25°, and later determination by the writer puts it nearer 24°. The
latter is the one now adopted in the British Nautical Almanac for observers
of the planet. This is a very close parallelism indeed; so that in general
character the Martian seasons are nearly the counterpart of ours. In length,
however, they differ; first because the year of Mars is almost double the
length of the terrestrial one and secondly because from the greater ellipticity
of Mars’ orbit the seasons are more unequal than is the case with us, some
being run through with great haste, others being lingered on a
disproportionate time. It is usual on the Earth to consider spring as the
period from the vernal equinox, about March 21, to the summer solstice,

about June 20; summer as lasting thence to the autumnal equinox; autumn
from this latter date, about September 20, to the winter solstice on
December 21; and winter from that point on to the next spring equinox
again. On this division our seasons in the northern hemisphere last
respectively: spring, 91 days; summer, 92 days; autumn, 92 days; and
winter, 90 days. On Mars these become, reckoned in our days: spring, 199
days; summer 183 days; autumn, 147 days; and winter, 158 days. If we had
counted them in Martian days they would have totaled about one thirty-fifth
less in number each.
In its days and seasons, then, Mars is wonderfully like the Earth; except
for the length of the year we should hardly know the difference in
reckoning of time could we some morning wake up there instead of here.
Only in one really unimportant respect should we feel strange; in months
we should find ourselves turned topsy-turvy. But lunations have nothing to
do with climate nor with the alternation between night and day; and in these
two important respects we should certainly feel at home.
Though the axis could be determined by the daily march of any marking
and thus the planet’s tropic, temperate and polar regions marked out, the
process is made easier by the presence of white patches covering the
planet’s poles and known, in consequence, as the polar caps. It is from
measures of the patches that the position of the Martian poles has actually
been determined. These polar caps are exactly analogous in general position
to those which bonnet our own Earth. They reproduce the appearance of the
ice and snow of our arctic and antarctic regions seen from space, in a very
remarkable manner. In truth they are things of note in more ways than one
and would claim precedence on many counts. Priority of recognition,
however, alone entitles them to premier consideration. Among the very first
of the disk’s detail to be made out by man, they justly demand description
first.
With peculiar propriety the polar caps have thus the pas. Not only do
they stand first in order of visibility, but they prove to occupy a like position
logically when it comes to an explanation of the planet’s present physical
state. It is not matter of hazard that the most evident of all the planet’s
markings should also be the most fundamental, the fountainhead from
which everything else flows. It is of the essence of the planet’s condition
and furnishes the key to its comprehension. The steps leading to this
conclusion are as interesting as they are cogent. They start at the polar caps’

visibility. For their size first riveted man’s attention and then attention to
them disclosed that most vital of the characteristics of the planet’s surface:
change.
Just as almost all of the features we note are permanent in place, showing
that they belong to the surface, so are they all impermanent in character.
Change is the only absolutely unchanging thing except position about the
features the planet presents to view. It was in the aspect of the polar caps
that this important fact first came to light. Not only did they thus initially
instance a general law, they have turned out to make it; for by themselves
changing they largely cause change in all the rest. But for a long time they
alone exemplified its workings. To Sir William Herschel we owe the first
study of their change in aspect. This eminent observer noted that their
varying size was subject to a regular rhythmic wax and wane timed to the
course of the seasons of the planet’s year. The caps increased in the winter
of their hemisphere and decreased in its summer and being situate in
opposite hemispheres they did this alternately with pendulum-like
precision. His observations were soon abundantly confirmed, for the
phenomena take place upon a vast scale and are thus easy of recognition. At
their maximum spread the caps cover more than one hundred times as much
ground as when they have shrunk to their minimum. In the depth of winter
they stretch over much more than the polar zone, coming down to 60° and
even 50° of latitude north or south as the case may be, thence melting till by
midsummer they span only five or six degrees across.
In this they bear close analogue to the behavior of our own. Ours would
show not otherwise were they viewed from the impersonal standpoint of
space. Very little telescopic aid suffices to disclose the Martian polar
phenomena in this their more salient characteristics and convince an
observer of their likeness to those of the earth. Any one may note what is
there going on by successive observations of the planet with a three-inch
glass. Nor is the change by any means slow. A few days at the proper
Martian season, or at most a couple of weeks, produces conspicuous and
conclusive alterations in the size of these nightcaps of the planet’s winter
sleep. Resembling our own so well they were early surmised to be of like
constitution and composed, therefore, of ice and snow. Plausible on its face,
this view of them was generally adopted and common sense has held to it
ever since. It has encountered, of course, opposition, partly from very
proper conservatism, but chiefly from that earth-centred philosophy which

has doubted most advances since Galileo’s time, and carbonic acid has been
put forward by this school of sceptics to take its place. We shall critically
examine both objections; the latter first, because a certain physical fact
enables us to dispose of it at once. In casual appearance there is not much to
choose between the rival candidates of common sense and uncommon
subtlety, water and frozen carbonic acid gas, both being suitably white and
both going and coming with the temperature. But, upon closer study, in one
point of behavior the two substances act quite unlike, and had half the
ingenuity been expended in testing the theory as in broaching it this fact had
come to light to the suggestors as it did upon examination to the writer and
had served as a touchstone in the case. At pressures of anything like one
atmosphere or less carbonic acid passes at once from the solid to the
gaseous state. Water, on the other hand, lingers in the intermediate stage of
a liquid. Now, as the Martian cap melts it shows surrounded by a deep blue
band which accompanies it in its retreat, shrinking to keep pace with the
shrinkage in the cap. This is clearly the product of the disintegration since it
waits so studiously upon it. The substance composing the cap, then, does
not pass instantaneously or anything like it from the solid to the gaseous
condition.
This badge of blue ribbon about the melting cap, therefore, conclusively
shows that carbonic acid is not what we see and leaves us with the only
alternative we know of: water.

CHAPTER V
BEHAVIOR OF THE POLAR CAPS

A ssured by physical properties that our visual appearances are quite capable
of being what they seem we pass to the phenomena of the cap itself.
Like as are the polar caps of the two planets at first regard, upon further
study very notable differences soon disclose themselves between the earthly
and the Martian ones; and these serve to give us our initial hint of a
different state of things over there from that with which we are conversant
on Earth.
To begin with, the limits between which they fluctuate are out of all
proportion greater on Mars. It is not so much in their maxima that the ice-
sheets of the two planets vary. Our own polar caps are much larger than we
think; indeed, we live in them a good fraction of the time. Our winter snows
are in truth nothing but part and parcel of the polar cap at that season. Now,
in the northern hemisphere snow covers the ground at sea-level more or less
continuously down to 50° of latitude. It stretches thus far even on the
western flanks of the continents, while in the middle of them and on their
eastern sides it extends ten degrees farther yet during the depth of winter.
So that we have a polar cap which is then ninety degrees across. In our
southern hemisphere it is much the same six months later, in the
corresponding winter of its year.
On Mars at their winter maxima the polar caps extend over a similar
stretch of latitude. They do so, however, unequally. The southern one is
considerably the larger. In 1903, 136 days after the winter solstice, in the
Martian calendar February 27, it came down in longitude 225° to 44° of
latitude and may be taken to have then measured ninety-three degrees
across; in 1905, 121 days after the same solstice, it stretched in longitude
235° to latitude 42°, and 158 days later, in longitude 221° to latitude 41°;
values which, supposing it to have been round, imply for it a diameter on

these occasions of ninety-six and ninety-seven degrees. It was then
February 20 and March 10 respectively of the Martian year. These
determinations of its size at the two oppositions agree sufficiently well
considering the great tilt away from us of the south pole at the time and the
horizonward foreshortening of the edge of the snow. It seems from a
consensus of the measures to have been some five degrees wider in 1903
than in 1905, which may mean a colder winter preceding the former date.
The cap was still apparently without a dark contour in both years, showing
that it had not yet begun to melt.

South Polar Cap.
(Lowell Observatory, 1905.)

Less has been learnt of the northern cap. In 1896-1897 when it was
similarly presented skirting the other rim of the disk, a gap occurred in the
observations corresponding to the time by Martian months between
February 24 and March 22. On the former date the cap came down only to

latitude 55° in longitude 352°; on the subsequent one and for several days
after the latitude of the southern limit of the snow was such as to imply a
breadth to it of about eighty degrees. The cap was now bordered by a dark
line, proving that melting had already set in. It cannot, however, at its
maximum have covered much more country than this, in view of its lesser
extent on February 24.
Fair as our knowledge now is of the dimensions of the Martian polar caps
at their maxima, we have much more accurate information with regard to
their minima, and this, too, was obtained much earlier. That we should first
have known their smallest rather than their greatest extent with accuracy
may appear surprising, exactly the opposite being our knowledge of our
own. It is not, however, so surprising as it appears, inasmuch as it is an
inevitable consequence of the planet’s aspect with regard to the sun. When
the tilt of the axis inclines one hemisphere toward the sun, that
hemisphere’s polar cap must melt and dwindle, while at the same time it is
the one best seen, the other being turned away from the sun and therefore
largely from us as well; so that even such part of the latter as is illumined
lies low down toward the horizon of the disk where a slight change of angle
means a great difference in size.
It has thus come about that both the south and the north polar caps have
been repeatedly well seen and measured at their minimum; and the
measures for different Martian years agree well with one another. For the
northern cap six degrees in diameter is about the least value to which it
shrinks. The south one becomes even smaller, being usually not more than
five degrees across, while in 1894 it actually vanished, a thing
unprecedented. Its absence was detected by Douglass at Flagstaff and
shortly after the announcement of its disappearance the fact was
corroborated by Barnard at the Lick. The position the cap would have
occupied was at the time better placed for observation in America than in
Europe, inasmuch as the cap is eccentrically situated with regard to the
geographic pole and its centre was then well on the side of the disk
presented to us while in Europe it was turned away. This, together with the
fact that it undoubtedly came and went more than once about this time,
accounts for its disappearance not having been recognized there, haze left
by it having apparently been mistaken for the cap itself.

North Polar Cap.
(Lowell Observatory, 1905.)

On Earth the minima are much larger. In the northern hemisphere the line
of perpetual snow or pack-ice in longitude 50° east runs about on the 80°
parallel, including within it the southern end of Franz Joseph Land.
Opposite this, in longitude 120° west, above the North American continent,
it reaches down lower still to 75°. So that the cap is then from twenty to
thirty degrees in diameter. In the southern hemisphere it is even larger. In
longitude 170° west the land was found by Ross to be under perpetual snow
in latitude 72°. Cook had reached in longitude 107° east an impassable
barrier of ice in latitude 70° 23′. The season was then midsummer, January
30. So that we are perhaps justified in considering 71° south as about the
average limit of perpetual snow or paleocrystic ice. This would make the
southern cap at its minimum thirty-eight degrees across. Pack-ice with open
spots extends still farther north. The Pagoda in 1845 was stopped by
impenetrable pack-ice in south latitude 68° and the Challenger in 1874
encountered the pack in latitude 65° on the 19th of February, which

corresponds about to our 19th of August, the time at which the sea should
be most open. The limit of perpetual snow is thus lower in the southern than
in the northern hemisphere. Here again, then, the two minima differ, but in
the reverse way from what they do on Mars.
From this we perceive that the variations in size of the caps are much
more striking on Mars than on the Earth and that these are due chiefly to the
difference in the minima, the maxima not varying greatly.
To explain these interesting diversities of behavior in the several polar
caps we shall have to go back a little in general physics in order to get a
proper take off. It is a curious concomitant of the law of gravity that the
amount of heat received by a planet in passing from any point of its path to
a point diametrically opposite is always the same no matter what be the
eccentricity of the orbit. Thus, a planet has as many calories falling upon it
in travelling from its vernal equinox to its autumnal as from the autumnal to
the vernal again, although the time taken in the one journey be very
different from that of the other. This is due to the fact that the angle swept
over by the radius vector, that is, the imaginary bond between it and the sun,
is at all points proportional to the amount of heat received; just as it is of the
gravity undergone, the two forces radiating into space as the inverse square
of the distance. Thus the heat received by a point or a hemisphere, through
any orbital angle, is independent of the eccentricity of the orbit.
But it is not independent of the axial tilt. For the force of the sun’s rays is
modified by their obliquity. The amount of heat received at any point in
consequence of the tilt turns upon the position of the point, and for any
hemisphere taken as a whole it depends upon the degree to which the pole
is tilted to the source of heat. In consequence of being more squarely
presented to its beams, the hemisphere which is directed toward the sun and
therefore is passing through its summer season gets far more insolation than
that which is at the same time in the depth of its winter. For a tilt of twenty-
four degrees, the present received value for the axis of Mars, the two
hemispheres so circumstanced get amounts of heat respectively in the
proportion of sixty-three to thirty-seven.
But, though the summer and winter insolation thus differ, they are the
same for each hemisphere in turn. Consequently the mere amount of heat
received cannot be the cause of any differences detected between the
respective maxima and minima of the two polar caps. If heat were a
substance which could be stored up instead of being a mode of motion, the

effect produced would be in accordance with the quantity applied and the
two caps would behave alike. As it is the total amount has very little to say
in the matter.
Not the amount of heat but the manner in which this heat is made at
home is responsible for the difference we observe. Now, though the total
amount is the same in passing from the vernal to the autumnal equinox as
from the autumnal to the vernal, the time during which it is received in
either case varies from one hemisphere to the other. It is summer in the
former while it is winter in the latter and the difference in the length of the
two seasons due to the eccentricity of the orbit makes a vast difference in
the result. Winter affects the maxima, summer the minima, attained. Of
these opposite variations presented to us by the two caps, the maxima, the
one most difficult to detect, is the easiest to explain, for the difference in the
maxima seems to be due to the surpassing length of the antarctic night.
Owing to the eccentricity of the orbital ellipse pursued by Mars and to
the present position of the planet’s solstices, the southern hemisphere is
farther away from the sun during its winter and is so for a longer time. The
seasons are in length, for the northern hemisphere: spring, 199 days;
summer, 183 days; autumn, 147 days; and winter, 158 days; while for the
southern hemisphere they are: spring, 147 days; summer, 158 days; autumn,
199 days; and winter, 183 days. The arctic polar night is thus 305 of our
days long; the antarctic, 382. Thus for 77 more days than happens to its
fellow the southern pole never sees the sun. Now, since the total sunlight
from equinox to equinox is the same in both hemispheres, its distribution by
days must be different. In the southern hemisphere the same amount is
crowded into a smaller compass in the proportion of 305 to 382; that being
that hemisphere’s relative ratio of days. But since during winter the cap
increases, there is a daily excess of accumulation over dissipation of snow
and each twenty-four hours must on the average add its tithe to the sum
total. Since the northern days are the warmer each adds less than do the
southern ones; and furthermore there are fewer of them. On both these
scores the amount of the deposition about the northern pole should be less
than about the southern one. Consequently, the snow-sheet there should be
the less extensive and show a relatively smaller maximum, which explains
what we see.
With the minima the action is otherwise. Inasmuch as the greater heat
received during the daylight hours by the southern hemisphere is exactly

offset by the shortness of its season, it would seem at first as if there could
be no difference in the total effect upon the two ice-caps.
But further consideration discloses a couple of factors which might, and
possibly do, come in to qualify the action and account for the observed
effect. One is that though the total amount of heat received is the same, the
manner of its distribution differs in the two hemispheres. In the northern
one the time from vernal to autumnal equinox is 382 days against 305 in the
southern. Consequently, the average daily heat is then five fourths more
intense in the southern hemisphere. Indeed, it is even greater than this and
nearer four thirds, because the melting occurs chiefly in the spring and in
the first two months of summer when the contrast in length of season
between the two hemispheres is at its greatest. Now, a few hotter days
might well work more result than many colder ones. And this would be
particularly true of Mars where the mean temperature is probably none too
much above the freezing-point to start with. Ice consumes so much caloric
in the process of turning into any other state, laying it by in the form of
latent heat before it can turn into water and then so much more before this
water can be converted into steam that a good deal has to be expended on it
before getting any perceptible result. Once obtained, however, the heat is
retained with like tenacity. So that the process works to double effect! If
sufficient heat be received the ice is first melted, then evaporated and
finally formed into a layer of humid air, the humidity of which keeps it
warm. Dry air is unretentive of heat, moist air the opposite. And for the
melting of the ice-cap to proceed most effectively the temperature that laps
it about must be as high as possible and kept so as continuously as may be.
If between days it be allowed to fall too low at night much caloric must
needs be wasted in simply raising the ice again to the melting-point. This a
blanket of warm air tends to prevent, and this again is brought about by a
few hot days rather than by many colder ones. It is not all the heat received
that becomes effective but the surplus heat above a certain point. The gain
in continuity of action thus brought about is somewhat like that exhibited
between the running of an express and an accommodation train. To reach its
destination in a given time the former requires far less power because it
does not have to get up speed again after each arrest. Thus the whole effect
in melting the snow would be greater upon that hemisphere whose summer
happens to be the more intense.

The greater swing in size of the cap most exposed to the effects of the
eccentricity is, then, the necessary result of circumstances when the
precipitation is not too great to be nearly carried off by the subsequent
dissipation. This is the state of things on Mars and the second of the factors
above referred to. On the Earth as we have seen the polar caps are
somewhat larger at their maximum and very much so at their minimum.
Now, this is just what should happen were the precipitation increased.
Suppose, for example, that the amount of precipitation were to increase
while the amount of summer melting remained the same, and this would be
the case if the vapor in the air augmented for one cause or another, and the
result of each fresh deposit was locked up in snow. After a certain point the
cap would grow in depth rather than in extension; the winter deposit would
be thicker but the summer evaporation would remain the same. Now, if this
occurred, it is evident that the minimum size of the cap would increase
relatively much faster than the maximum, and furthermore, that the relative
increase of the minimum in the two caps would be greatest for that which
had seasons of extremes. The result we see in the case of the Earth. In the
arctic cap, where in consequence of the eccentricity of the orbit the winter
is shorter, the maximum is less than in the antarctic and this extra amount of
precipitation cannot be wholly done away with in its intenser summer, so
that the minimum too is greater there.
We reach, then, this interesting conclusion. We find that eccentricity of
orbit by itself not only causes no universal glaciation in the hemisphere
which we should incidentally suppose likely to show it, but actually
produces the opposite result, in more than offsetting by summer proximity
what winter distance brings about. To cause extensive glaciation we must
have, in addition to favorable eccentricity, a large precipitation. With these
two factors combined we get an ice age, but not otherwise. The result has an
important bearing on geologic glacial periods and their explanation.
Once formed, an ice-sheet cools everything about it and chills the climate
of its hemisphere. It is a perpetual storehouse of cold. Mars has no such
general glaciation in either hemisphere, and the absence of it, which is due
to lesser precipitation, together with the clearness of its skies, accounts for
the warmth which the surface exhibits and which has been found so hard
hitherto to interpret. Could our earth but get rid of its oceans, we too might
have temperate regions stretching to the poles.

CHAPTER VI
MARTIAN POLAR EXPEDITIONS

P olar expeditions exert an extreme attraction on certain minds, perhaps
because they combine the maximum of hardship with the minimum of
headway. Inconclusiveness certainly enables them to be constantly renewed,
without loss either of purpose or prestige. The fact that the pole has never
been trod by man constitutes the lodestone to such undertakings; and that it
continues to defy him only whets his endeavor the more. Except for the
demonstration of the polar drift-current conceived of and then verified by
Nansen, very little has been added by them to our knowledge of the globe.
Nor is there specific reason to suppose that what they might add would be
particularly vital. Nothing out of the way is suspected of the pole beyond
the simple fact of being so positioned. Yet for their patent inconclusion they
continue to be sent in sublime superiority to failure.
Martian polar expeditions, as undertaken by the astronomer, are the
antipodes of these pleasingly perilous excursions in three important regards,
which if less appealing to the gallery commend themselves to the
philosopher. They involve comparatively little hardship; they have
accomplished what they set out to do; and the knowledge they have gleaned
has proved fundamental to an understanding of the present physical
condition of the planet.
The antithesis in pole-pursuing between the two planets manifests itself
at the threshold of the inquiry, in the relative feasibility with which the
phenomena on Mars may be scanned. For, curiously enough, instead of
being the pole and its surrounding paleocrystic ice which remains hidden on
Mars, it is rather the extreme extent of its extension and the lowest
latitudinal deposit of frost which lies shrouded in mystery. The difficulty
there is not to see the pole but to see in winter the regions from which our
own expeditions set out. And this because the poles are well displayed to us

at times which are neither few nor very far between; while favorable
occasions for marking the edge of the caps when at their greatest have
neither proved so numerous nor so favorable. The tilt of the planet’s axis
when conveniently placed for human observation has been the cause of the
one drawback; the planet’s meteorological condition in those latitudes at
that season the reason for the other.
What knowledge we have of the size of the caps in degrees upon the
surface of the planet at this their extreme equatorward extension has been
given in the last chapter. Their aspect at the time together with what that
aspect betokens was not there touched upon. With it, therefore, and the
peculiarities it presents to view we shall begin our account of the caps’
annual history.
When first the hemisphere, the
pole of which has for half a
Martian year been turned away
from the sun, begins to emerge
from its long hibernation, the
snow-cap which covers it down
even to temperate regions presents
an undelimited expanse of white,
the edges of which merge
indistinguishably into the
groundwork color of the regions
round about. Of a dull opaque hue
along its border, its contour is not
sharp but fades off in a fleecy
fringe without hard and fast line of
South Polar Cap in winter. demarcation. Such notably was the
aspect of the north temperate zone
in 1896 when, tilted as it then was away from us into a mere northern
horizon of the planet’s limb, it showed prior to the definite recognition of
the north polar cap in August of that year, and such too was the look of the
disk’s southern edge both before and after the first certain detection of the
southern cap in 1903 and 1905. Each was then in the depth of winter. For in
Martian chronology the season corresponded in each at the time to what we
know in our northern hemisphere as the latter part of February and the early
part of March and the appearance of the planet’s surface in both was not

unlike what we know at the same season in latitude 45°. Indeed, there is
reason to suppose bad weather there then and the extreme fringe, from the
pale tint it exhibited, to have been cloud rather than snow.
It is quite in keeping with what we know on earth or can conceive of
elsewhere that such aspect should characterize the cap at or near the
attainment of its greatest development. Whether it were not yet quite arrived
at this turning-point of its career or had but slightly passed it a vagueness of
outline would in either event proclaim the fact. For were the frost still
depositing, the cap’s edge would show indefinite; and on the other hand had
it just begun to melt, evaporation would give it an undefined edge before
the melting water had gathered in sufficient quantities to be itself
noticeable.
Its behavior subsequent to recognition bore out the inference from its
aspect when it first appeared. While for many days prior to its coming
unmistakably into view it was impossible to say whether what was seen of
the southern cap in 1903 and 1905 was cloud or snow; so even after it had
definitely disclosed itself it continued to play at odds with the observer.
Showing sharp at the edges one day it would appear but hazily defined the
next, thus clearly demonstrating itself to be at the then unstable acme of its
spread. Such a state of things we are only too familiar with in our own
March weather when after days of sunshine that have melted off the
winter’s white and fringed it with rivulets and awakening grass, a snow-
storm falling upon it powders the ground again that was beginning to be
bare and at one stroke extends the domain of the snow while mystifying the
actual limits it may be said to occupy. The same condition of things, then, is
not unknown on Mars, and to fix the precise date of so wavering a
phenomenon is not so much matter of difficult observation as of physical
impossibility.
Nor is the southern cap, at this the height of its winter expansion,
confined strictly to its own proper limits. Faint extensions, now so
connected with its main body as to form part and parcel of it, now so
detached and dull of tint as to make the observer doubtful of the exact
relationship, are generally to be seen attendant on it. Hellas in winter is
much given to such questionable garb, and has in consequence been
mistaken by more than one observer for the cap itself, appearing as it does
well upon the southern limb and being often the only region to show white.
Indeed, frost-bound as it then is, to consider it the polar cap, though

possibly geographically incorrect,
may climatologically be
sustainable. Its northern extremity
extends down to latitude 30°, a
pretty low latitude for frost. Still
such equatorward extension is not
without corroborating parallel. In
1903, at what was in Martian dates
April 26, the whole of the region
south of the Solis Lacus and the
Nectar showed white, with a
whiteness which may as well have
been hoarfrost as cloud. Now, the
Nectar runs east and west in
latitude 28°. So that in this
instance, too, it is possible that Hellas in winter.
arctic conditions knocked at the
very doors of the tropics. Encroachment of the sort is equivalent to snow in
Cairo and permanent snow at that; not an occasional snow flurry, but
something to linger on the ground and stay visible sixty millions of miles
away.
Knowledge of either cap in this the midwinter of its year has been a
matter of the most recent oppositions of the planet. Up to within the last few
years our acquaintance with either cap was chiefly confined to the months,
—one might almost say the weeks,—immediately surrounding the summer
solstice of its respective hemisphere. The behavior of the caps during the
rest of their career was largely unknown to us, from the very
disadvantageous positions they occupied at the times the planet was nearest
to the earth. Beginning with 1894, however, our knowledge of both has
been much extended, by a proportionate extension of the period covered by
the observations. It used to be thought impracticable to observe the planet
far on either side of opposition; now it is observed from as much as four
months before that event to the same period after it. The result is a
systematic series of observations which in many ways has given unexpected
insight into Martian conditions. One of the benefits secured has been the
lengthening of the period of study of the cap’s career, a pushing of inquiry
farther back into its spring history and a longer lingering with it in its

autumnal rebuilding. Yet up to the
very last opposition a gap in its
chronology still remained between
February 25 and April 1. The
opposition of 1905 has bridged this
hiatus and brought us down to the
latter date, at which the melting of
the cap begins in earnest.
From this point, April 1 on, we
have abundant evidence of the
cap’s behavior. Its career now for
some time is one long chronicle of
contraction. Like Balzac’s Peau de
Chagrin it simply shrinks, giving
out of its virtue in the process. The
White south of Nectar and Solis cap proceeds to dwindle almost
Lacus. under the observer’s eye till, from
an enormous white counterpane
spread over all the polar and a large part of the temperate zone, its area
contracts to but the veriest nightcap of what it was before. From seventy
degrees across it becomes sixty, then fifty, then forty, till by the middle of
the Martian May it has become not more than thirty degrees in diameter.
During this time, from the moment the melting began in good earnest, the
retreating white is girdled by a dark band, of a blue tint, which keeps pace
with the edge of the cap, shrinking as it shrinks, and diminishing in width as
the volume of the melting decreases.
After the melting has been for some time under way and the cap has
become permanently bordered by its dark blue band a peculiar phenomenon
makes its appearance in the cap itself. This is its fission into one or more
parts. The process begins by the appearance of dark rifts which, starting in
from the cap’s exterior, penetrate into its heart until at last they cleave it in
two. Rifts have been seen by several observers and in both caps; and what is
most suggestive they always appear in the same places, year after year.
Sometimes oppositions elapse between their several detections for they are
not the least difficult of detail; but when they are caught, they prove to lie
just where they did before.

The permanency in place of the rifts, a characteristic true of them all,
shows them to be of local habit. Thus the rift of 1884 and 1897 reappeared
again to another observer in the same position in 1901. They are, therefore,
features of, or directly dependent on, the surface of the planet. But it will
not do from this fact to infer that they are expressive of depressions there.
The evidence is conclusive that great irregularities of surface do not exist
on Mars. As we shall see when we come to consider the orology of the
planet it is certain that elevations there of over two or three thousand feet in
altitude are absent. Differences of temperature, able to explain a melting of
the ice in one locality coincidentally with its retention in an adjacent one,
must in consequence be unknown. And this much more conclusively than at
first appears, for the reason that the smaller the planet’s mass the less
rapidly does its blanket of air thin out in ascent above the surface. This is in
consequence of the greater pull the larger body exerts and the greater
density it imparts to a compressible gas like our atmosphere. Gravity acts
like any force producing pressure and by it the envelope of air is squeezed
into a smaller compass. But as this is done throughout the atmospheric layer
it means a more rapid rarefaction as one leaves the body. The action is such
that the height necessary to reach an analogic density varies inversely as the
gravity of the mass. In consequence of this, to compass a relative
thermometric fall for which a moderate difference of elevation would
suffice on Earth, an immoderate one must be made on Mars. For gravity
there being but three eighths what it is here, eight thirds the rise must be
made to attain a proportionate lowering of temperature. This fact renders
the above argument against elevation and depression being the cause of the
phenomenon three times as cogent as it otherwise would be.
With so gradual a gradient in barometric pressure there and so low a set
of contour lines, altitude must be a negligible factor in Martian surface
meteorologic phenomena. Both density and temperature can be but little
affected by such cause, and we must search elsewhere for explanation of
what surface peculiarities we detect.
Meanwhile the rifts themselves, from being lines which penetrate the cap
from its periphery in toward its centre, end by traversing it in its entirety
and separating portions which, becoming outlying subsidiary patches,
themselves proceed to dwindle and eventually disappear. The rifts usually
take their rise from such broader parts of the cap-encircling blue belt as
make beads upon that cordon and are clearly spots where the product of the

melting of the cap is either specially collected, or produces its most visible
effect.
So far the description might apply with substantial accuracy to either cap.
Yet the conduct of the two is in some ways diverse and begins to accentuate
itself from this point on.
From the time that the north
polar cap reaches a diameter of
about twenty-five degrees, a
singular change steals over it. From
having been up to then of a well-
defined outline it now proceeds to
grow hazy and indistinct all along
its edge. This change in its
character at the same period of its
career has been quite noticeable at
each of the three last oppositions,
so that small doubt remains that the
metamorphosis is a regularly
recurrent one in the history of the
cap. Coincident with the
Northern Cap hooded with vapor. obliteration of its contour, its
dimensions seemingly enlarge. It is
as if a hood had been drawn over the cap of a dull white different from the
dazzling brilliance of the cap itself and covering more ground. Such is
probably what occurs; with vapor for veil. The excessive melting of the cap
produces an extensive evaporation which then in part condenses to be
deposited afresh, in part remains as a covering, shutting off from our view
the outlines of the cap itself. It would seem that at this time the cap melts
faster than the air can carry it off. A sort of steaming appears to be going on,
taking place in situ. For it clearly is not wafted away. The time of its
coming too is significant. For the season is May 15, the height of time for a
spring haze to set in. Then later it dissipates with the same quiet
indefiniteness with which it gathered.
It is some time in Martian June before the spring haze clears away, and
when it does go, only a tiny polar cap stands revealed beneath it, from six to
eight degrees across, or from a tenth to a fifteenth of what it was when it
passed into its curious spring chrysalis. The date of emergence varies. In

1903 it occurred early, the haze not
being marked after June 3, though
recurring again at intervals for a
day or so. In 1905 it was later;
perceptibly thin after June 21 it did
not certainly clear away till June 9
and came back again on July 16
and possibly on the 25th.
These vicissitudes of aspect give
us glimpses into a sweet
unreasonableness in Martian
weather which makes it seem more
akin to our own. And this on two
counts, diurnal and annual. From
day to day atmospheric conditions
shift for purely local cause; while, Northern Cap unmasked.
furthermore, successive Martian
years are not alike. In some the season is early; in others late. So that Mars
is no more exempt than are we from the wantonness of weather.
Clearly disclosed thus reduced to its smallest possible terms it remains
for some months of our days, for six weeks of its own. During that period it
continues practically unchanged, neither increasing nor decreasing
significantly in size, nor altering notably in aspect. Measures of the
drawings of it then make it from five to eight degrees across and it is
possible that it really fluctuates between narrow limits, though its clear-cut
outline at all times renders the variation difficult to explain. We are not so
near it as we could wish; for on these occasions even at their best it is over
two hundred times as distant as the moon and the greatest magnification
possible still leaves it a hundred thousand miles away.
To the south polar cap a somewhat similar history attaches, but with a
difference. In its case no such regularly recurrent spring haze has yet been
noted. The melting of this cap would seem to be of a more orderly nature
than its fellow and not to outdo what can conveniently be carried off.
That an excess of evaporation should not take place is the more peculiar
from the fact that at its maximum it is the larger of the two and therefore
has the greater quantity of matter to get rid of. Its summer, also, is shorter
than the arctic one, so that it has the less time to dispose of its

accumulations. The only other respect in which it seems to be differently
circumstanced from its antipodes is in the character of its surroundings.
About it are large blue-green areas which with intermissions stretch down
in places to within less than ten degrees of the equator; whereas the other
pole is continuously encircled for long distances by practically
uninterrupted ochre. The character of the environment seems thus the only
thing that can account for the difference in behavior and this proves the
more plausible when we come to consider what those two classes of regions
respectively represent.
In other ways as well the southern cap is the more self-contained. The
rifts, indeed, break it up into separate portions and these in part remain as
outlying detachments of the main body, as was notably the case in 1877 and
in 1894, but they hardly have the permanency and importance of those
similarly formed about the arctic pole. Nothing antarctic for instance
compares with the subsidiary patch of the north polar regions lying in
longitude 206°, which both in Schiaparelli’s time, and during the late
oppositions as well was almost as fixed a feature of the arctic zone as the
cap proper. Not quite so constant, however, and not so solid-looking a
landmark is this patch for all its extent, which nearly equals the area of the
more legitimate portion. It bears on its face a more pallid complexion as if it
were thinner, and this is borne out by the fact that it occasionally
disappears, an event which so far at least has never befallen the northern
cap itself.
Less constant the southern one is to its own minimum than the northern.
In some seasons, in most in fact, it reaches like the other a more or less
definite limit of diminution which it does not pass. But this is not always
the case. In 1894 it disappeared entirely at the height of its midsummer. The
season was probably unusually hot then in the southern hemisphere of
Mars.
In position the caps have something to say about physiographic
conditions. Both caps at their minima are then irregular and the centre of
the south one is markedly eccentric to the areographic pole. It lies some six
degrees north along the thirtieth meridian. The northern one is also probably
eccentric, but much less so, with a divergence not much exceeding a degree
and of doubtful orientation. Not only are both caps not upon their respective
poles but they are not opposite each other, the one lying in longitude 30°,
the other in 290°. This speaks, of course, for local action. In some wise this

must depend on the configuration of the surface, yet so far as markings go
there is nothing to show what the dependence is.
The eccentring of the caps is paralleled by the like state of things on
earth. The pole of cold does not coincide in either hemisphere with the
geographic pole. On the earth its position is largely determined by the
distribution of the land-masses. Continents are not such equalizers of heat
as oceans because of their conductivity on the one hand and their
immobility on the other. In winter they part with their heat more quickly
and convection currents cannot supply the loss. This accounting for thermal
pole eccentricity is inapplicable to Mars because of the absence there of
bodies of water. And it is significant that the degree the earthly poles of cold
are out much exceeds what is the case on Mars. Possibly areas of vegetation
there replace to some effect areas of water. It is certainly in favor of this
view that the arctic regions there are more desert than the antarctic and that
the north pole of cold occupies more squarely the geographic pole.
Not till 1903 did the actual starting again of either cap chance to be seen.
Nor was this, indeed, a matter of hazard but of persistent inquiry by
observation prolonged after the planet had got so far away that its scanning
had hitherto been discontinued. Such search beyond the customary limits of
observation was essential to success, because of the relation of the axial tilt
to the position of the planet in its orbit. At an opposition well placed for
nearness, the tilt is such as largely to hide the pole and to present the polar
regions too obliquely to view for effective scanning. This is true both of the
arctic and the antarctic regions in turn. For the Martian axis being inclined
somewhat as our own is to the plane of the planet’s orbit, we at times see
well and at times but poorly the arctic or antarctic zones.
The cap, the starting to form of which was thus caught, was the arctic
one; the date 128 days after the northern summer solstice, or thereabouts,
for as is perhaps natural the advent of the phenomenon partook of the
wavelike advance of such things familiar on earth, an advance succeeded by
a recession and then followed by another advance. So much is proof of
local weather there as here. Hoar-frost was successively deposited and then
melted off.
What is significant, the deposition of the frost took place simultaneously
over large areas. The very first patch of it, in about longitude 320°,
extended at one stroke down to latitude 55°. For it actually crossed the
Pierius somewhat to the south. A second patch stretched to the east of the

cap. Two wings these made to the
kernel of cap itself. Through the
wings could be marked the line of
the canal: the Pierius upon the one
side, the Enipeus upon the other.
Such visibility of the canals
through the white stretches proved
the white not to be due to cloud
suspended between us and them,
but a surface deposit which found
no lodgment upon the canals
themselves. The same avoidance of
dark markings was evidenced by
the showing of the dark rim round
the cap’s kernel. Now, if the
Deposition of frost. deposit were indeed hoarfrost, this
failure to find permanent foothold
on the dark markings is what we should expect to witness. For whether they
were vegetation or water, equally in either case the frost would melt from
them first. Probably they were both vegetal, though some doubt might exist
about the latter, the band around the kernel. It was then August 20 in that
hemisphere.
Such deposition over great stretches of country is perhaps not so
surprising as it appears at first sight when seen from without in its totality.
After all, something not unlike it occurs in our snow-storms when hundreds
of square miles are whitened at once. Furthermore, with an atmosphere as
thin as Mars seems to possess the temperature must be perilously near the
freezing-point in the arctic and subarctic regions at the close of summer.
Steadily, with intermissions, the white sheet increased until even the dark
border to the cap became obliterate, the kernel showing at first through the
veil like the ghost of what it had been, and then ceasing to be visible at all,
its delimitations being buried under deeper and deeper depositions of frost.
The perennial portion of the cap was thus merged in the new-fallen snow.
This marked the on-coming of the arctic winter in full force and happened
even before the polar sun had wholly set. For the pole did not enter into the
shadow till two of our months later, the autumnal equinox occurring 183
days after the summer solstice or 55 days after the first fall of frost. Then

the pole passed into its star-strewn
arctic night, a polar night of twice
the duration of our own and the
circumpolar regions entered upon
their long hibernation of ten of our
months.

First northern snow.

CHAPTER VII
WHITE SPOTS

I
n addition to the polar caps proper and to the subsidiary polar patches that
often in late summer flank them round about, other white spots may from
time to time be seen upon the disk. In appearance these differ in no
respect, so far as observed, from the arctic subsidiary snow-fields. Of the
same pure argent, they sparkle on occasion in like manner with the sheen of
ice. Equally with the polar caps they remain permanent in place during the
period of their visibility and are themselves long-lived. Though by no
means perpetual their duration is reckoned by weeks and even months, and
they recur with more or less persistency at successive Martian years. That,
when seen, they show in particular positions apparently unaffected by
diurnal change precludes their being clouds, and this fact taken in
connection with the character of their habitat is the puzzling point about
them. For they affect chiefly the north tropic belt. They, or at least their
nuclei, are small, about two or three degrees in diameter, and are not
particularly easy of detection as a rule, though certain larger ones are at
times conspicuous. Chromatic, rather than formal, definition is necessary to
their bringing out, as is witnessed by the superb colors the disk presents at
the times when they are best seen. It is then that Mars puts on the look of a
fire-opal.
The first such spot to be noticed was one which Schiaparelli detected in
1879, at the second opposition in which he studied the planet. He called it
the Nix Olympica, showing that he recognized in it a cousinship to the polar
snows. Yet it lay in latitude 20° north, longitude[1] 131°, in the midst of the
ochre stretches of that part of the disk. It was a small roundish white speck
of not more than two thirds the diameter of the polar cap. Reseen by him in
1881, it failed to appear at subsequent oppositions and was not caught again
until 1888. Then once more it vanished, not to be detected anew till many

years after at Flagstaff, coming out rather surprisingly in 1903. It showed,
however, in the same place as before; so that its position but not its
existence is permanent.
A similar but smaller patch was apparent to Schiaparelli at the same
opposition of 1879. This one which he styled the Nix Atlantica lay between
the Thoth and the Syrtis Major. It was about half the size of the Nix
Olympica and has never since been seen, though it should have been had it
continued to be what it then was.
On the other hand, phenomena
of the sort undetected of
Schiaparelli have been remarked at
Flagstaff. On May 18, 1901, I was
suddenly struck by the singular
whiteness of the southeast corner
of Elysium where that region
bordered the Trivium. Elysium has
a way of being bright but not with
such startling intensity as this spot
presented nor in so restricted an
area as was here the case. The spot
was so much whiter than anything I
had ever previously seen outside
the polar caps that it arrested my
attention at once. And this the more White in Elysium.
that I had observed this same part
of the planet the day before and perceived nothing out of the ordinary. Once
detected, however, the spot continued visible. The next day it was there
with equal conspicuousness, and now thrust an arm across the Cerberus,
entirely obliterating the canal for the space of several degrees. In this
salience it remained day after day till the region passed from sight, to
reappear with it six weeks later when the region again rounded into view.
The hour of the Martian day seemed to make no difference in its visibility.
It was seen from early morning till Martian afternoon, as late as the phase
permitted. Clearly there was nothing diurnal about its revealing, and it
lasted for at least three months and a half, until the planet got so far away
that observations were discontinued.

It was to all appearances and intents snow. But now comes the singular
fact about it. It lay within ten degrees of the equator and showed from the
end of June to the latter part of August. To our ideas there could be no more
inopportune place or time for such an exhibition. For it cannot have been
due to a snow-capped peak, as we know for certain that there are no
mountains in this, or in any other, part of the planet. Besides, it had not
appeared in previous Martian years; which it infallibly would have done
had it been a peak. Indeed, it baffles explanation beyond any Martian
phenomenon known to me. It seems directly to contradict every other detail
presented by the disk.
The phenomenon is thus unique in kind; it is not, however, unique as a
specimen of its kind. The eastern coast of Aeria where that region borders
the Syrtis Major is prone to a brilliance of the same sort. It is a narrow belt
of country that shows thus, nothing but the coastline itself, but this for a
considerable distance stretching several hundred miles in length. It has
stood out saliently bright now at every opposition which I have observed,
beginning with 1894. Sometimes it has been described in the notes as bright
simply, sometimes as white, and once, in 1901, as glistening at one point
like ice. Yet when upon the terminator it has never stood forth as a
mountain range should have done to declare its character.
It has been evident regardless apparently of the Martian season. In 1894
it was bright from October 25 to January 16 (Martian chronology); in 1896,
from December 22 to January 7; in 1901, from July 13 to the 15th; in 1903,
at about the same date and so in 1905. It was whitest during the latter
oppositions, showing that the effect is most marked in its midsummer. All
of the above instances of extra-polar white have been located within the
tropics. Examples of the same thing, however, occur in the north temperate
zone. Tempe, a region just to the west of the Mare Acidalium, is
exceedingly given to showing a small white spot close upon the Mare’s
border in latitude 50° north. This spot, too, on occasion glitters as it were
with ice. It is also at times very small. So that whereas much of Tempe is by
nature bright but a small kernel of it is dazzling.
The list might be easily extended from the record book. Thus on March 1
and 2, 1903, the disk showed speckled with minute white spots, one in
Arcadia in latitude 41° north, one in Tharsis near the equator, a third just
north of the Phoenix Lucus in 10° south, and a fourth, the Nix Olympica,
and on April 11, a glittering pin-point starred like a diamond the centre of

the Pons Hectoris. On both these occasions the Martian season was
summer; July 9 for the latter, June 21 for the former date.
As one approaches the north
pole spots of like character become
more numerous. Especially are
such visible north of the Mare
Acidalium in the arctic region
thereabout, from 63° to 75° north.
From so widespread a set of
instances the only explanation
which seems to fit the phenomena
is that the mean temperature of
Mars is low, not very much above
freezing, and that whatever causes
a local fall in the temperature
results in hoar-frost. Such an
explanation accords well with the
White in the Pons Hectoris. distance of the planet from the sun
and the thinness of its atmosphere.
At the same time it shows that the mean temperature over the greater part of
the planet the greater part of the time is above the freezing-point and that
consequently it is no bar to vegetation of a suitable sort.
That the hoar-frost should be found even at the equator may perhaps be
due to the very thinness of the air-covering of Mars, which would tend to
make the actual insolation more of a factor than it is with us, and by the
great length of the Martian seasons. In midsummer the greatest insolation
occurs in the arctic and temperate, not in the tropic regions; on the other
hand, an atmosphere tends to accumulate heat for the tropics. With us the
latter factor is prepotent; it would be less effective on Mars. Then again the
double duration of summer would tend to emphasize insolation as the
important factor in the matter. But it is possible that greater deposition plays
a part in the matter. On earth the rainfall is greatest near the equator and
something of the sort may be true of the zones of moisture on Mars. That
the most striking spots are found to the west of large dark areas may in this
connection have a meaning inasmuch as, such regions being vegetation-
covered, the air over them is probably more moisture-laden.

One point about the position of the spots is of moment: they have all
been found in the northern hemisphere or within ten degrees of it in the
southern equatorial region. This seems at first a question of hemispheres;
but when we consider that the light areas of the surface are chiefly in the
boreal hemisphere and in the south tropic belt, we perceive that it may be
rather the character of the surface there than the particular hemisphere in
the abstract that is decisive in the matter. Nevertheless, the austral
hemisphere is the hemisphere of extremes, possessing a shorter, hotter
summer and a longer, colder winter than its antipodes. This would not favor
sporadic small depositions of frost in summer so much as would a climate
of a more mean temperature.
From the relative lack of atmospheric covering over the planet we should
expect the nights to prove decidedly cool, while the days were fairly warm.
Of this we have perhaps evidence in a singular aspect shown by the Mare
Acidalium in June, 1903. The account of it in the Annals reads thus: “On
May 22 an interesting and curious phenomenon presented itself. On that
day, so soon as the Mare Acidalium had well rounded the terminator on to
the disk, at λ352°, the whole of its central part showed white, the edges of
the marking alone remaining as a shell to this brilliant core. So striking was
the effect that beside appearing in the drawing it found echo in the notes.
The next day no mention is made of it, and a drawing made under λ20°
shows the Mare as usual and the bright spot in Tempe in its customary
place. Neither was anything of the sort noticed on the 24th and 25th. But on
the 26th, the day of the projection (upon the terminator), the effect of the
23d reappeared, the longitude of the centre being 332°. Fortunately on that
day a further drawing was secured which enabled its subsequent behavior to
be followed. Made three hours later than the other, the longitude of the
centre being 13°, this drawing shows the Mare well on the disk, its whole
area as dark as usual and with Tempe bright to the right of it toward the
terminator. The terminator in question was the sunrise one, and we are
offered two suppositions in explanation of the phenomenon: either the white
was due to a morning deposition of hoar-frost which dissipated as the sun
got up, or obliquity rendered some superficial deposit visible which more
vertical vision hid. That the former inference is the more probable seems
hinted at by the simultaneous appearance from the 19th to the 26th of other
areas of white between the Mare and the pole. May 26 was 88 days after the

northern summer solstice, and corresponded to July 31 on the earth.”
Annals, Volume III, §564.
In this connection mention may pertinently be made of Schiaparelli’s
repeated observation of regions that whiten with obliquity, a proclivity to
which he particularly noticed Hellas and certain ‘islands’ in the Mare
Erythraeum to be prone. Here as with the Mare Acidalium we certainly
seem to be envisaging cases of matutinal frost melted by midday under the
sun’s rays.

[1] Martian longitudes are now reckoned from the Fastigium Aryn, the
mythologic cupola of the world, a spot easy of recognition because
making the tongue in the jaws of the Sabaeus Sinus. It further
commends itself because of lying within a degree of the equator. The
longitudes are reckoned thence westward all the way round, or to
360°.

CHAPTER VIII
CLIMATE AND WEATHER

I
n gazing at the successive phases presented by the polar caps as their
annual history unrolls itself to view, beginning with vast white cloaks that
in winter hide so effectively the planet’s shoulders, to little round knobs
that in summer sit like guardsmen’s caps more or less askew upon the poles,
the bodily eye sees only the glisten of far-off snow. The mind’s eye,
however, perceives something more: the conviction they carry of the
presence of an atmosphere surrounding the planet. Elusive as water vapor is
to sight for its transparency and to spectroscopic determination for its
earthly omnipresence, recognition of its existence elsewhere by deduction
raises such reasoning at once to a more conspicuous plane than it might
otherwise assume. Especially is this true where the deduction is itself
conclusive, as is here the case. For it depends on phenomena not its own,
but which are in their turn dependent on it. We are not even beholden to any
knowledge of the substance composing the caps for the fundamental
inference that an atmosphere surrounds them. Whatever that substance
were, the fact that the caps dissipate and reform shows us with absolute
certainty that they pass into the gaseous state, to be later solidified afresh.
This gas constitutes of itself an atmosphere; while another phenomenon, to
wit, their blue girdles as they melt, affirming their substance to be snow and
ice, enables us to precise the fact that this gas is water vapor.
From such premise given us by the polar caps we are able to infer much
more by the help of the kinetic theory of gases. But the speed of parting by
a planet with its gases is conditioned by the mean speed of each gas. Water
vapor will, therefore, go before nitrogen, oxygen or carbonic acid gas. If,
then, we find it present over the surface of a planet we are assured of the
possibility that the other three may be there too, and from the similarity of
matter in space strong reason to suspect that they actually are.

Corroborative evidence of the accuracy of the deduction as to the
presence of a Martian air is shown in several other ways; in the existence of
clouds to begin with. Rare as they are, these certainly float at times over
parts of the planet, although it is doubtful whether they can then be seen.
Fortunately for assurance we have other ways of ascertaining their presence
than that of obscuration. Nor is it of account to the argument that they
should be few and far between, as they unquestionably are. One single
instance of such mediumistic support is enough to support the theory of a
medium; and that instance has been more than once observed.
Direct evidence of atmosphere is further forthcoming in the limb-light.
This phenomenon might be described as a brilliant obscuration. It is a
circlet of illumination that swamps the features as they near the full edge of
the disk, the limb of the planet as it is called. Obliteration of the sort is
evident, more or less markedly, at all times, and is not due to
foreshortening, as the broadest areas are affected. The fading out of the
detail at the limb suggests nothing so much as a veil drawn between us and
it, lighter in tint than what it covers. Such a veil can be none other than air
or the haze and cloud that air supports. From its effect, impartial in place
and partial in character, cloud is inadmissible as a cause and we are left with
air charged with dust or vapor in explanation. Obscuration due to it should
prove most dense at the limb, since there the eye has to penetrate a greater
depth of it; just as on the earth our own air gives azure dimness to the
distance in deepened tinting as the mountains lie remote.
Another bit of evidence lies in the apparent detection of a twilight arc. In
1894 measures made of the polar and equatorial diameters of the planet
showed certain systematic residuals left after all known corrections had
been applied. The only thing which would account for them was the
supposition that a twilight arc had been unconsciously seen and as
unconsciously measured. In delicate quantities of the sort too great reliance
cannot be put, but if the residuals be not referable to other cause they give
us not only further evidence of an atmosphere, but at the same time our only
hint of that atmosphere’s extent. From them it would seem that the air must
be rare, not more than about four inches of barometric pressure, as we
reckon it, and probably less; a thin, high air more rarefied than prevails
upon our highest mountain tops.
Corroborative of this is the aspect of the planet. From the general look of
the disk a scant covering of air is inferable. For one of the striking things

about the planet’s features is their patent exposure to our sight. Except in
the winter time of its hemisphere or in the spring after the greatest melting
of the polar cap, nothing seems to stand in our way of an uninterrupted view
of the surface, whether in the arctic, temperate, or tropic zones. From the
openness of its expression, however, too much case should not be made as
we really know but little of how an atmosphere-enshrouded planet would
look. We find no difficulty in seeing objects a hundred miles away across
the surface of the earth and yet the thickness of the air strata in such
horizontal traversing is many fold what it is when we look directly up. It is
also out of all proportion laden with dust and smoke. In the purer regions of
the earth, a clear air imposes but little bar to sight, and conjures up far
things startlingly distinct.
Nevertheless, every evidence points to a thin air upon Mars: a priori
reasoning, indirect deduction and direct sight. Now, from a thinness of
atmosphere it would follow, other things equal, that the climate was cold.
About this there has been much question, but less of answering reply. From
the distance of the planet from the sun it is certain less heat is received by it
than falls upon the earth in something like the ratio of one to two. But that
the amount effective is as the amount received is far from sure. The
available heat is much affected by the manner of its reception. A blanket of
air acts like the glass of a conservatory, letting the light rays in, but
hindering the heat rays out. The light rays falling on the ground or the air
are transformed into heat rays that, finding the return journey less easy, are
consequently trapped. All substances are thus calorifiers, but water vapor is
many times more potent than ordinary air to heat-ensnaring. A humid air
has a hothouse tang to it most perceptible. Now, what the relative
percentage of water vapor in the Martian atmosphere may be we do not
know.
The thinness of the Martian air has caused it to be likened to that upon
our highest mountain peaks which are in large part covered with perpetual
snow. But the comparison is not well founded. A peak differs materially
from a plateau in the countenance it gives to the heat falling upon it. On a
plateau each warmed acre of ground helps the retention of heat by its
neighbor; while in addition to being destitute of side support the higher
winds generated about an isolated peak blow its own caloric away. Still less
does any analogy hold between the two when the plateau is a world-wide
one.

From these considerations it is evident glosses are possible upon the bald
idea of a much lower temperature prevailing on the Martian surface than on
the earth’s. Doubtless the theoretic cold has been greatly overdone.
Reversely, recent observations tend to lower the apparent temperature
disclosed by the features of the disk, and between the rising of the theoretic
and the falling of the observed we are left with a very reasonable
compromise and reconcilement as the result.
The various look and behavior of the surface of Mars point to a mean
temperature colder than that of the earth, but above the freezing-point of
water; for regions, at least, outside of the polar caps and during all but the
winter months. Except at certain special spots, and possibly even there,
frost is unknown at all times within the tropics and except in winter in
temperate latitudes. These anomalous localities, mentioned in the preceding
chapter, may be said to be the exceptions that prove the rule of general non-
glaciation. For if they be snow, they stand witness to its absence elsewhere
upon the disk, and if they are not, they testify the more emphatically to the
same effect.
As between different parts of the surface, the tilt of the Martian axis and
the greater length of the Martian seasons, the one the same as, the other the
double of, our own, tend to an accentuation of the heat in the temperate and
arctic or antarctic zones. The greatest insolation on earth is not, as we might
suppose, at the equator, but at the parallels of 43.°5 north and south; even
the poles themselves receiving a quarter as much heat again on midsummer
day as ever falls to the lot of the line. This broad physical fact is equally
true of Mars, while in the matter of consecutive exposure Mars in summer
outdoes the earth. For the longer the seasons, the more nearly does the
effective heat approach the received amount. Thus both on the score of heat
received and of heat husbanded these zones must be relatively warm. And
this shows itself in the look of the surface. In summer it is clearly warmer
within the polar regions than is the case on earth, to judge by the effect. In
winter the cold is doubtless proportionately severe.
For the diurnal range of temperature we have less data. There is evidence
pointing to chilly nights, but it is meagre, and we are left to fall back on the
cold of our deserts at night for analogic condition of the state of things over
the Martian desert levels after the sun goes down.
If we are uncertain of the precise character of the Martian climate, we
know on the other hand a good deal about the Martian weather. A pleasing

absence of it over much of the planet distinguishes Martian conditions from
our own. That we can scan the surface as we do without practical
interruption day in and day out proves the weather over it to be permanently
fair. In fact a clear sky, except in winter, and in many places even then, is
not only the rule, but the rule almost without exceptions. In the early days
of Martian study cases of obscuration were recorded from time to time by
observers, in which portions of the disk were changed or hidden as if clouds
were veiling them from view. More modern observations fail to support this
deduction, partly by absence of instances, partly by other explanation of the
facts. Certainly the recorded instances are very rare. Indeed, occasions of
the sort must to any Martians be events, since only one possible example
has presented itself to me during the course of my observations, extending
more or less over eleven years. Even in this case there was no obliteration,
though a certain whiteness overspread an area near the equator temporarily.
Position seemed to point to its identity with a cloud which made its
appearance about that time upon the terminator, and lasted for some thirty-
six hours. The cloud, however, showed evidence of being, not the kind with
which we are familiar, but a dust-storm, in keeping, indeed, with the desert
region (Chryse) in which it originated.
With the exception of sporadic disturbance of the sort the whole surface
of the planet outside the immediate vicinity of the polar caps seems free
from cloud or mist and to lie perpetually unveiled to space. In the
neighborhood of the caps, however, and especially round about their edge, a
very distinct pearly appearance is presented during the months at which the
cap is at its maximum, or in other words, in the depth of its winter. Of a dull
white hue and indefinite contour the phenomenon suggests cloud. Where it
lies spread no markings are visible; an absence explicable by obscuration
due an interposed medium, but equally well by seasonal non-existence of
the markings themselves, which from the general behavior of these
markings we know to be to some extent certainly the fact. Of the regions
where the effect is noticeable, Hellas is the most striking. So conspicuously
white during the winter of the southern hemisphere as to have been often
mistaken for the polar cap, its ghost shows thus almost regularly every
Martian year. What is as suggestive as it is striking, the blanching is
confined to the solid circle constituting Hellas and does not extend into the
dark regions by which it is circumscribed. Hellas is as self-contained when
thus powdered as when, in its normal ochre or abnormal red, it stretches

like a broad buckler across the body of the disk. That the land there lies at a
higher level than its surroundings is pretty certain, but that the difference
can amount to enough to explain its silveriness as ice is improbable. In
latitude Hellas is distinctly temperate, lying between the parallels of 55°
and 30°; but on Mars this is no warrant of a like climate. Again, though
close on the south to what constitutes the polar cap, it does not strictly form
part of that cap, but occupies both in position and in kind a something
intermediary between the frost-bound regions of periodic snow and the
warmer ones of perpetual sunshine. It seems to be afflicted with the winter
weather of the north of Europe, and to owe its pearly look at such times to
the same cloud canopy that then distressingly covers those inclement lands.
Similar in behavior to it is the long chain of so-called islands that,
beginning southwest of Thaumasia, runs thence westward even to the
eastern edge of Hellas. These belt the planet in a west-northwesterly
direction by a strip of territory from ten to fifteen degrees wide, the medial
line of which begins at 55° south and ends in about 40°. They are parted
from the main bright areas by blue-green ‘seas’ of about the same width as
themselves, the Mare Sirenum, the Mare Cimmerium and Mare Tyrrhenum.
These ‘seas’ the white that covers the ‘islands’ never crosses; though the
continent, as we may call it for convenience, descends at the east to 30°
south. Since the ‘seas’ are not seas, the cause which might bound the snow,
were they such, cannot be the cause here. Nevertheless, they have an effect
of some sort on the isothermal lines as is shown not only by latitudinal
comparison with the state of things in Hellas, but with that in Thaumasia as
well. For 30° south is also the limit apparently of the white on Thaumasia,
where ochre desert stretches ten degrees farther south still; the region in its
southern part being white-mantled, in its northern part not. Here again, then,
the ochre areas make exception to what affects the blue-green ones. Clearly
the blue-green regions temper the action of what gives them wintry cloak.
But why they should do this is not easy to explain on any supposition
terrestrial or marine. Bodies of water tend to foster the formation of clouds;
so, less markedly, do areas of vegetation. Neither the old ideas, then, nor the
new lend themselves in explanation. It may be that while we here seem to
be envisaging cloud we are in reality looking at hoar-frost. On the other
hand, light cloud would show less, superposed over a dark background,
than over an ochre one; and this, the simplest of all explanations, may be
the true one. It is facts like these that intrigue us in the study of the Martian

surface by revealing conditions which render offhand analogy with the earth
unsafe. Indeed, we are more sure of some things which appear too strange
to be true than of others so simple on their face as to enlist belief. Among
the most difficult and perplexing are meteorological problems like the
above. Here we can only say provisionally that while cloud best answers to
the appearance, frost best fits the cause. For vegetation might melt frost, yet
not dissipate cloud. By raising our conception of the mean temperature the
facts can, however, be reconciled and this is probably the solution of the
difficulty after all.
As we saw in the annual history of the polar caps a dimness somewhat
different affects the northern cap in May and June. After the melting of the
cap is well under way a haziness sets in along its edge which befuddles its
outline and effectually hides what is going on within it. When at last the
screen clears away the cap is found to be reduced to its least dimensions.
Such obstructing sheet looks to be more of the nature of mist caused by the
excessive melting of the cap. Unfortunately, there are here no patches of
blue-green to test a possible partiality in its behavior over such tracts; nor
has similar action ever yet been remarked in the case of the cap of the
southern hemisphere.
Regular recurrence at the appropriate season of the planet’s year, together
with extensive action at the time, takes this springtide mist to some extent
out of the domain of weather into that of climate. For it prevails all round
the cap and repeats itself in place as each fresh spring comes on. At least it
has done so for the past three oppositions at which it has been possible to
observe well the arctic zones. It is thus both general in its application and
fixed in its behavior. Nevertheless, it betrays something of the fickleness
which characterizes that more inconstant thing: weather. For it comes and
goes, one thinks for good, only to find it there again some days later. Not
less captious is the meteorologic action shown in the making of the new
polar cap. When the northern one starts to form, vast areas of frost are
deposited in a single night. These, however, are not permanent. The ground
thus covered is during the next few days again partially laid bare. Then a
new fall occurs, hiding the surface a little more completely than before, and
the lost domain is more than regained. By such wavelike advance and
recession the tide of frost creeps over and submerges the arctic regions as
the late summer passes into the autumn. In this alternate coming and going
with succeeding days, we have an unsteadfastness of action most fittingly

paralleled by our own weather. It would seem that local causes there as here
are superposed upon the orderly progress of the seasons and though at the
on-coming of the autumn the cold is steadily gathering strength,
nevertheless warm days occur now and then to stay its hand, only to be
succeeded in their turn by frosts more biting than before. Even on Mars
nothing in the way of weather is absolutely predicable but impredicability.

CHAPTER IX
MOUNTAINS AND CLOUD

I
n all ways but one our scrutiny of the planet is confined to such view as
we might get of it from the car of a balloon poised above it in space; from
which disadvantage-point we should see the surface only as a map spread
out below us, a matter of but two dimensions. The exception consists in the
observation of what are called projections; irregularities visible when the
disk is gibbous upon that edge of the planet where the light fades off.
Striking phenomena in themselves they are of particular value for what may
be deduced from them. For by them we are afforded our only opportunity of
gaining knowledge of the surface other than in plan and thus of determining
between peak, plateau, or plain that to a bird’s-eye view alike lie flattened
out to one dead level.
It might at first be thought that our best chance of noting any elevations
or depressions of the Martian surface lay in catching that surface in profile,
by scanning the bright edge of it which stands sharp-cut against the sky and
is called the limb. For this is practically what we do on earth when we mark
a mountain against the horizon and measure its height by triangulation.
Unfortunately the method fails in the case of Mars because of the great
distance we are away. Unless the planet were distinctly more generously
equipped than the earth in the matter of mountains, nothing could be hoped
from so forthright an envisaging. So relatively insignificant to the size of its
globe is the relief of the earth’s surface that an orange skin would seem
grossly rough by comparison. The same proves true for Mars. With the
greatest magnification we can produce, the Martian limb still appears
perfectly smooth.
Luckily, while direct vision is thus impossible, oblique illumination
enables us to get an insight into the character of the surface we had
otherwise been denied. When mountains or valleys chance to lie upon the

boundary of light and darkness, the rim of the disk known as the terminator
in contradistinction to the limb where the surface itself comes to an end,
they make their presence evident through an indirect species of
magnification, the elongate effect of oblique lighting. With a practical
instance of it every one is familiar who has walked by night along a road
imperfectly starred at intervals by electric lights. Startled between posts by
what seemed deep holes and high furrows he has involuntarily imitated a
spavined horse for fear of stubbing his toes, only to encounter when his foot
fell a surface on contact surprisingly smooth. The slant illumination by
lengthening the shadows had painfully deceived him into exaggerated
inference of irregularity. What proves disturbing to a wayfarer misguided
by arc lights is made to do the eye service when it comes to planetary
interpretation. On the boundary of light and shade, those parts of the surface
where it is sunrise or sunset upon the planet, the sun’s rays fall so
athwartwise as to throw enormous shadows from quite small elevations to
an eye so placed as to view the surface with anything approaching
perpendicularity. A mountain mass there will thus proclaim itself by
protracted profile upon the plain in hundredfold magnification. Similarly a
peak there will advertise its height by catching the coming or holding the
lingering light at many times the distance of its own elevation away from
the night side of the planet. Here, if anywhere, then, could mountains be
expected to disclose themselves, and here, when existent, they have as a
matter of fact been found.
Our own moon offers us the first and easiest example of such vicariously
visible relief. When the moon is near the quarter, and for three or four days
on either side of that, a keen eye can usually detect one or more knobs, like
warts, projecting from its terminator, easily distinguished from the limb
both by reason of being less bright and of being bounded by a semi-ellipse
instead of a semicircle. If a telescope or even an opera-glass be substituted
for the eye, it is possible to see what causes them; the knob resolves itself
into the illuminated rim of a crater separated from the main body of the
visible moon by the seemingly black void of space. The peak has caught the
sunlight, while its foot and the country between it and the illuminated
surface still lies shrouded in shadow.
From measurement of the distance the sun-tipped peak seems to stand
aloof from the line where the plain itself is touched by the light, the height
of it above that plain may be calculated. In this way have been found the

heights of the mountains of the moon. Incidentally, brain outstrips brawn.
For pinnacles no Lunarian could scale, both for their precipitous
inaccessibility and their loftiness, man has measured without so much as
setting foot upon their globe. At each lunar sunrise and again at lunar sunset
these old crater walls show their crescent coronets tipped the reverse way;
and peaks higher than the Himalayas make gigantic gnomons of themselves
with hands outstretched to grasp the plains.
In this manner a lunar peak of fifteen thousand feet shows its presence to
the unaided eye. With so much for starting-point we can calculate how low
an elevation could similarly be made out on Mars under a like phase
illumination. Now, in spheres of different diameters the distance out from
the terminator for a given height is as the square root of the diameter. Mars
has about twice the size of the Moon. In consequence, if we saw the planet
at the same distance off as the Moon, the height of a peak upon it sufficient
to cast an equal shadow or be seen at an equal separation from the
terminator need be but two thirds as high. To see it thus equidistant a power
of 250 or 300 is necessary, dependent on the opposition. Twice this power
may at times be used, and by the same reasoning this would reduce the
height sufficient to show by four or to something like 2500 feet. This, then,
would be the theoretic limit of the visible, a limit needing to be somewhat
increased because of the imperfection of our air.
Having found thus what should be visible on Mars we turn now to see
what is. At once we find ourselves confronted with a very unlunar state of
things. Common upon the face of the Moon, excrescences of the terminator
are rare on Mars. The first ever seen was detected by a visitor at the Lick
Observatory in 1888. Since then they have been repeatedly noticed both at
the Lick and elsewhere. But although observers are now on the watch for
them, they are not very frequently chronicled because not of everyday
occurrence. Much depends upon the opposition; some approaches of the
planet proving more prolific of them than others. How rare they are,
however, may be gathered from the fact that the last three oppositions have
disclosed but one apiece.
An account of the great projection of May 25, 1903, will give an idea of
the extent and interest of the phenomenon and will serve to show to what
cause we must attribute all such that have been visible on Mars, for the
behavior of this one was typical of the class.

About half past eight o’clock in
the evening of May 26, 1903, Mr.
V. M. Slipher, astronomer at
Flagstaff, shortly after taking over
the telescope then directed upon
Mars, suddenly noticed a large
projection about halfway up the
terminator of the planet. He at once
sent word of the fact and the
observatory staff turned out to see
it, for a projection has for workers
on Mars the like interest that a new
comet possesses for astronomers
generally. In this case the
phenomenon was specially potent
in that it was the first to be detected Projection on terminator.
that year. Its singularity was amply
seconded by its size. For it was very large, its extent both in length and
height being excessive. When I first saw it, the projection consisted of an
oval patch of light, a little to the north of the centre of the phase ellipse
lying parallel to the terminator but parted from it by darkness to the extent
of half the projection’s own width. It made thus not simply an excrescence
but a detached islet of light. It was easily seen by all those present and was
carefully studied from that time on by Mr. Slipher and me. Both of us made
drawings of it alternately at intervals, as well as micrometer measures of its
position.
Next to its great size, the most striking feature about it was its color. This,
instead of being white or whitish, was ochre orange, a hue closely
assimilated to the tint of the subjacent parts of the disk, which was the
region known as Chryse. This distinctive complexion it kept throughout the
period of its apparition. At the same time Baltia, a region to the north of it
and synchronously visible close upon the terminator, showed whitish. The
seeing was good enough to disclose the Phison and Euphrates double, the
power a magnification of 310 and the aperture the full aperture of the 24-
inch objective.
From the time it was first seen the detached patch of light crept in toward
the disk, the illuminated body of the planet. Four minutes after I noted it the

dark space separating it from the nearest point of the terminator had
sensibly lessened. So it continued, with some fluctuations intrinsic to the
atmospheric difficulties of observations generally and to the smallness of
the object itself, to become gradually less and less salient. It lasted for about
forty minutes from the moment it had first appeared to Mr. Slipher and then
passed from sight to leave the edge of the planet smooth and commonplace
again.
The measures made on it showed that it lay when first seen in longitude
39°.7, latitude 18°.5 north, and that its highest point stood seventeen miles
above the surface of the planet. It was three hundred miles long. These are
my own figures, from which Mr. Slipher’s do not substantially differ.
The return of the part of the planet where it had been seen was eagerly
awaited the night after by both observers, to see if it would bring the
projection with it. For only once a day is the same region of Mars similarly
presented. But in order not to miss the projection, should it be ahead of
time, observations were begun before it was due. Shortly after they were
started, there appeared higher up the terminator and therefore farther north
than had been the case the night before, a small projection. It was with
difficulty made out and its position measured. Without careful watching it
must have been missed altogether. As it was, it differed in every respect
from that of the preceding day. It was not nearly so high, not nearly so
large, and lay in a different place on the planet, being now in longitude
31°.7, latitude 25°.5. Either the two, therefore, were totally different things
or the projection had moved in the elapsed interval of time over seven
degrees of latitude and eight degrees of longitude, a distance of three
hundred and ninety miles in twenty-four hours. Where the previous
projection had been nothing showed. On the following night, May 28, no
trace of anything unusual could be seen anywhere.
We are now concerned to inquire to what this series of appearances could
have been due. The first observers of projections on Mars had
unhesitatingly attributed them to the same cause that produces projections
on the Moon, to wit, mountains. Such they were held to be in France and at
the Lick. This view, however, was in 1892 disputed by W. H. Pickering who
considered them to be not mountains, but cloud. And this view was strongly
supported by A. E. Douglass in a discussion of a large number of them
observed in 1894 at Flagstaff. The mountain theory of their generation was
finally shown to be untenable and their ascription to cloud conclusively

proved to be the correct solution by the observations of a remarkable one
made in December, 1900, and the careful study to which by the writer they
were subjected. We shall now explain how this was done and we will begin
by pointing out that the fact that only a single specimen of the phenomenon
was visible at each of the three oppositions of 1900, 1903, and 1905 was
itself conclusive, rightly viewed, of their non-mountainous character. This
conclusion follows at once from the isolateness of the phenomenon. For a
mountain cannot change its place. Now, the shift in the aspect presented by
the planet’s disk from one night to the next is not sufficient to alter
perceptibly the appearance shown by anything upon its edge on the two
occasions. If, then, a peak stood out upon it one evening, the peak should
again show salient when the region reached the same position upon the
succeeding night. That nothing then was seen where something had
previously been visible proved the phenomenon not that of a mountain
peak, since what produced the projection was clearly not fixed in place and
therefore not attached to the soil. Now the only other thing capable of
catching the light before it reached the surface would be something
suspended in the air, that is, a cloud. Deduction, therefore, from the rarity of
the phenomenon alone showed that the projections must be clouds.
Their behavior in detail entirely corroborates this deduction from their
intermittence. Such was shown by the action of the projection of December
6, 1900, as set forth in a paper before the American Philosophical Society
and such again by that of the one of May 26, 1903, as we shall now note. To
begin with, we notice that the projection seen on May 26 was not found
either in situ or in size on May 27 and had wholly vanished on May 28,
though the seeing was substantially the same if not better on the two nights
succeeding that of its original detection. Hence in its own instance this
projection proved an alibi irreconcilable with the character of a mountain
mass. But it did more. It not only was not on the second evening what and
where it had been on the first, but the remains of it visible on the second
occasion showed clearly that it had moved in the meantime. Furthermore it
was disappearing as it went, for it was very much smaller after the lapse of
twenty-four hours. The something that caused it was not only not attached
to the soil, but was moving and dissipating as it moved. Only one class of
bodies known to us can account for these metamorphoses and that is: cloud.
But what kind of cloud are we to conceive it to be? Our ordinary vapor
clouds are whitish and this would be still more their color could they be

looked at from above. The Martian cloud was not white but tawny, of the
tint exhibited by a cloud of dust. Nor could this color have very well been
lent it by its sunrise position, for other places equally situated to be tinged
by the hues of that time of day, Baltia to wit, showed distinctly white. So
that we must suppose it to be what it looked, a something of the soil, not
beholden to atmospheric tinting for its hue; a vast dust-cloud traveling
slowly over the desert and settling slowly again to the ground.
Precisely the same general course of drifting disappearance was taken by
the projection of December 7 and 8, 1900. And this, too, stood an unique
apparition in the annals of its opposition. Clouds, then, and not mountains
are the explanation of the projections on Mars, differing thus completely
from the lunar ones.

CHAPTER X
THE BLUE-GREEN AREAS

D escending now equatorwards from the polar regions, and their in part
paleocrystic, in part periodic, coating of ice, we come out upon the
general uncovered expanse of the planet which in winter comprises
relatively less surface than on Earth, but in summer relatively more. Forty
degrees and eighty-six degrees may be taken as the mean hiemal and
æstival limits respectively of the snow on Mars; forty-five and seventy-five
as those of the Earth. Whatever ground is thus bared of superficial covering
on Mars lies fully exposed to view, thanks to the absence of obscuring
cloud; and it is at once evident that the terrane is diversified, patches of
blue-green alternating with stretches of reddish ochre. Of the two opaline
tints the reddish ochre predominates, fully five eighths of the disk being
occupied by it.
It was early evident in the study of the surface of Mars that its ochreish
disk was not spotless. Huyghens in 1659 saw the Syrtis Major. From this
first fruit of areography dates, indeed, the initial recognition of the planet’s
rotation; for on noting that the marking changed its place, he inferred a
turning of the planet upon itself in about twenty-four hours. Thirteen years
later he observed and drew it again and this time in company with the polar
cap. Again, after eleven more years, he depicted it for the third time, and
now so changed because of the different tilt of the planet toward the earth
that it may be doubted whether Huyghens himself recognized it for the
same. But that he drew it correctly a globe of Mars will at once show.
From such small beginning did areography progress to the perception of
permanent patches of a sombre hue distributed more or less irregularly over
the disk. Impressing the observers simply as dark at first, they later came to
be recognized as possessing color, a blue-green, which contrasted
beautifully with the reddish ochre of the rest of the surface. Cassini,

Maraldi, Bianchini, Herschel, Schroeter, all saw markings which they
reproduced. Finally, with Beer and Maedler, came the first attempt at a
complete geography. In and out through the ochre was traced the blue;
commonly in long Mediterraneans of shade, but here and there in isolated
Caspians of color. With our modern telescopic means the dark patches are
easily visible, the very smallest glass sufficing to disclose them. When thus
shown they much resemble in contour the dark patches on the face of the
Moon as seen with the naked eye. Now these patches were early taken for
lunar seas and received names in keeping with the conception; as the Sea of
Serenity, the Sea of Vapors, and so forth. Following the recognition of a like
appearance, like appellatives were given to the Martian markings; and the
Mare Sirenum, or Sea of the Sirens, the Mare Cimmerium, and others
sufficiently proclaim what was thought of them at the time they were thus
baptized. Indeed, if a general similarity be any warrant for a generic name
they were not at the time ill-termed. For, common to all three bodies, the
Earth, the Moon, and the planet Mars, is the figuration of their surfaces into
light areas and dark. In the Martian disk, as in the lunar one, we seem to be
looking at a cartographic presentation of some strange geography
suspended in the sky; the first generic difference between the two being that
the chart is done in chiaroscuro for the Moon, in color for Mars. On
mundane maps, we know the dusky washes for oceans; so on the Moon it
was only natural to consider their counterparts as maria; and on Mars as
‘seas.’ Nor did the blue-green hue of the Martian ones detract from the
resemblance.
But in something other than color these markings are alike. In fact, color
could hardly be excuse for considering the lunar maria what their name
implies, for distinctive tint is lacking in them, even to the naked eye. It was
in form that the likeness lay. Their figures were such as our own oceans
show; and allowing for a sisterly contrast amid a sisterly resemblance, the
lunar maria or the Martian seas might well have been of similar origin to
those with which our schoolboy study of atlases had made us familiar. Thus
did similarity in look suggest similarity in origin, and intuitive recognition
clothe its objects with the same specific name.
Considerable assumption, however, underlay the pleasing simplicity of
the correlation on other grounds, consequent not so much upon any lack of
astronomic knowledge as, curiously, upon a dearth of knowledge of
ourselves. We know how other bodies look to us, but we ignore how we

look to them. It is not so easy to see ourselves as others see us; for a far
view may differ from a near one, and a matter of inclination greatly alter the
result. Owing both to distance and to tilt we lack that practical acquaintance
with the aspect of our own oceans viewed from above, necessary to definite
predication of their appearance across interplanetary space. Our usual idea
is that seas show dark, but it is also quite evident that under some
circumstances they appear the contrary. It all depends upon the position of
the observer and upon the position of the Sun. Their usual ultramarine may
become even as molten brass from indirect reflection; while on direct
mirroring, they give back the Sun with such scarce perceptible purloining of
splendor as to present a dazzling sheen not to be gazed upon without regret.
Canopied by a welkin they assume its leaden hue, while at the same time,
their shores, less impressionable to borrowed lighting, show several tints
darker than themselves. Surfaces so sensitive to illumination hardly admit
of more accusable tint than a chameleon. Nevertheless, we are probably
justified in our conviction that perpendicularly visaged, they would on the
whole outdo in sombreness land round about them, and so be evident as
dusky patches against a brighter ground.
One phenomenon we might with some confidence look to see exhibited
by them were they oceans, and that is the reflected image of the Sun visible
as a burnished glare at a calculable point. Specular reflection of the sort was
early suggested in the case of Mars, and physical ephemerides for the planet
registered for many years the precise spot where the starlike image should
be sought. But it was never seen. Yet not till the marine character of the
Martian seas had been otherwise disproved was the futile quest for it
abandoned. Indeed, it was a tacit recognition that our knowledge had
advanced when this column in the ephemeris was allowed to lapse.
On this general marine ascription doubt was first cast in the case of the
Moon. So soon as the telescope came to be pointed at our satellite, it was
evident that the darker washes were not water surfaces at all, but very
palpably plains. Long low ridges of elevation stood out upon them like
prairie swells, which grew in visible relief according to the slanting
character of the illumination. Cracks or rills, too, appeared near their edges
and craters showed in their very midst. Patently solid they betrayed their
constitution not only by diverse topography but by diversified tint. All
manner of shades of neutral tone mottled their surface, from seeming

porphyry to chalk. Belief perforce departed when the telescope thus pricked
the bubble, evaporating as the water itself had done long before.
So much was known before the Mars’ markings were named.
Nevertheless, humanity, true to its instincts, promptly proceeded to commit
again the same mistake, and, cheerfully undeterred by the exposure of its
errors in the case of the Moon, repeated the christening in the case of Mars.
So sure was it of its ground that what it saw was not ground, that though the
particular appellatives of the several seas were constantly altered,
rebaptisms, while changing the personal, kept the generic name. Dawes’
Ocean, for example, later became l’Ocean Newton and later still the Mare
Erythraeum, but remained set down as much a sea as before. About thirteen
years ago, however, what had befallen the seas of the Moon, befell those of
Mars: the loss of their character. It was first recognized through a similar
exposure; but the fact was led up to and might have been realized in
consequence of quite a different line of evidence. The initial thing to cast
doubt upon the seas being what they seemed to be was the detection of
change in their aspect. That the detection was not made much earlier than
actually happened shows how a phenomenon may elude observation if
scrutiny be not persistent, and its results from time to time not carefully
compared. Schiaparelli was the one who first noticed variation in the look
of the seas, and the discovery was as much due to the assiduity with which
he followed the planet opposition after opposition as to the keenness with
which he scanned it. The noting of change in the blue-green areas
constituted, in fact, one of the first fruits of systematic study of the planet.
Change in configuration, that is, alteration of area, preceded in recognition
alteration of tint. Thus the Syrtis Major showed larger to him in 1879 than it
had in 1877. This was natural; difference of degree being a more delicate
matter to perceive than its effect upon extent. From change of area his
perception went on to change of tone. In his own words, what he noticed
was this: Memoria, VI, 1888, “No less certain is it that, from one opposition
to another, one notices in the seas, very remarkable alterations of tone. Thus
the regions called Mare Cimmerium, Mare Sirenum, and Solis Lacus, which
during the years 1877 to 1879 could be numbered among the most sombre
on the planet, during the succeeding oppositions became less and less black,
and in 1888 were of a light gray hardly sufficient to render them visible in
the oblique position in which all three found themselves.... On the other
hand, at the very same moment, the Mare Acidalium and the Lacus

Hyperboreus showed very dark; the latter indeed appeared nearly black,
although seen as tilted as the Syrtis and the equatorial bays. The condition
of the regions called seas is therefore not constant: so much is
unquestionable. Perhaps the change produced in them has to do with the
season of the planet’s year.”
Holding as he did the then prevailing view that the blue-green regions
were bodies of water, he regarded those of intermediate tint as vast marshes
or swamps, and he accounted for change of hue in them as due to
inundations and occasions of drying up. In consequence of losing their
water, the seas, he thought, had in places become so shallow that the bottom
showed through.
Plausible on the surface, this theory breaks down so soon as it is
subjected to quantitative criticism. For the moment we try to track the
water, we detect the inadequacy of the clew. The enormous areas over
which the phenomenon occurs necessitates the establishing an alibi for all
the lost water that has gone. Drying up on such a scale would mean the
removal of many feet of liquid over hundreds of thousands of miles in
extent. To produce any such change in appearance as we witness, even on
the supposition that these seas were none too deep to start with, would
involve lowering the level of the water by from five to twenty feet
throughout two thirds of the whole surface of the southern hemisphere. This
would leave a heap of waters to be accounted for, bewildering in its
immensity. The myriad tons of it must be disposed of; either by drainage
into other regions or by being caught up into the sky.
In this emergency it might seem at first as if the polar cap of the opposite
hemisphere offered itself as a possible reservoir for the momentarily
superfluous fluid. But such hoped-for outlet to the problem is at once closed
by the simple fact that when the lightening of the dark regions of the
southern hemisphere takes place, the opposite polar cap has already attained
its maximum; in fact, has already begun to melt. It, therefore, absolutely
refuses to lend itself to any such service. This was not known to
Schiaparelli’s time, the observations which have established it, by recording
more completely the history of the cap, having since been made. Indeed, it
was not known even at the time when the writer, in 1894, showed the
impossibility of the transfer on other grounds; to wit, on the fact of no
commensurate concomitant darkening of the surface elsewhere and on the
manifest non-complicity, if not impotency, of the Martian atmosphere in the

process. The transference of the water to other dark patches in the northern
hemisphere fails of sufficiency of explanation because of the limited extent
of such areas on that side of the globe; while the air is quite as incapable of
carrying away any such body of liquid, though the whole of it were at the
saturation-point, not to mention that there exists no sign of the attempt. The
reader will find this reasoning set forth in Mars, published eleven years ago.
He will now note, from what has been said above about the northern polar
cap, that continued observations since have resulted in opening up another
line of proof which has only strengthened the conclusion there reached.
The coup de grâce, however, to
the old belief was given when the
surface of the dark areas was found
to be traversed by permanent lines
by Pickering and Douglass.
Continued observation showed
these lines to be unchangeable in
place. Now permanent lines cannot
exist on bodies of water, and in
consequence the idea that what we
looked on there were water
surfaces had to be abandoned.
Thus we now know that the
markings on both the Moon and
Mars which have been called maria
are not in reality seas. Yet we shall Lines in dark area.
do well still to keep the old-
fashioned sonorous names, Mare Erythraeum, Mare Sirenum, and their
fellows, because it is inconvenient to change; while, if we please, we may
see in their consecrated Latin couching the fit embalming in a dead
language of a conception that itself is dead.

CHAPTER XI
VEGETATION

S ince closer acquaintance takes from the maria their character of seas, we are led to inquire
again into their constitution. Now, when we set ourselves to consider to what such
appearances could be due we note something besides sea, which forms a large part of our
earth’s surface, and would have very much what we suppose the latter’s aspect from afar to be,
not only in tone, but in tint. This something is vegetation. Seen from a height and mellowed by
atmospheric distance, great forests lose their green to become themselves ultramarine.
To dispossess a previous conception is difficult, but so soon as we have put the idea of seas
out of our heads a vegetal explanation proves to satisfy the phenomena, even at first glance,
better than water surfaces. In their color, blue-green, the dark areas exactly typify the distant
look of our own forests; whereas we are not at all sure that seas would. From color alone we are
more justified in deeming them vegetal than marine. But the moment we go farther into the
matter the more certain we become of being upon the right road. With increased detection the
markings they reveal and the metamorphoses they undergo, while pointing away from water,
point as directly to vegetation. All the inexplicabilities which the supposition of water involves
find instant solution on the theory of vegetal growth. The non-balancing of the areas of shading
in their shift from one part of the disk to another, no longer becomes a circumstance impossible
to explain, but a necessary consequence of their new-found character, denoting the time
necessary for vegetation to sprout. The change of hue of vast areas from blue-green to ochre no
longer presupposes the bodily transference of thousands of tons of substance, but the quiet
turning of the leaf under autumnal frosts. Even the fact that they occupy those regions most
fitted by figure to contain oceans fits in with the same conception. For that the Martian
equivalents of forest and moorland, tree and grass, should grow now in the lowest parts of the
planet’s surface is what might not unreasonably be expected from the very fact of their being
low, since what remained of the water would tend both on the surface and in the air to drain
into them.

Mare Erythræum
Martian date. December 30

For the change in question to be vegetal it must occur at the proper season of the planet’s
year. This we must now consider. We have said that Schiaparelli detected change in the blue-
green regions and suspected this change of seasonal affiliation. He inferred this from piecing
together the aspects of different seasons of different years as shown in consecutive Martian
oppositions. To mark it actually take place in a single Martian year came later. In 1894, at
Flagstaff, the southern hemisphere was presented during its late spring and early summer; it
was observed, too, for many of our months in succession. During this time the planet was
specially well circumstanced for study of the change in that hemisphere, both by reason of the
appositeness of the season and of the unusual size of the disk. Advantage was taken of the
double event to a recording of the consecutive appearances certain regions underwent, and the
contrasted states thus exhibited were such as clearly to betoken the action of seasonal change.
What Schiaparelli had thus ably inferred from diverse portions of different Martian years was
in this case shown occurring in one and the same semestral cycle.
Usually the change of hue seems essentially one of tone; the blue-green fades out, getting
less and less pronounced, until in extreme cases only ochre is left behind. It acts as if the darker
color were superimposed upon the lighter and could be to a greater or less extent removed. This
is what Schiaparelli noted and what was seen in 1894 at Flagstaff. Three views en suite of the
chain of changes then observed are shown in Mars, the region known as Hesperia being central
in each. Comparison of the three discloses a remarkable metamorphosis in that “promontory,” a
rise into visibility by a paling of its complexion. Nor is the contrast confined to it; changes as
salient will be noticed in the pictures over the other parts of the disk.
There have been instances, however, of a metamorphosis so much more strange as to deserve
exposition in detail; one where not tone simply is involved, but where a quite new tint has
surprisingly appeared.

Mare Erythræum
Martian date. January 16

On April 19, 1903, when, after being hidden for thirty days, owing to the different rotation
periods of the two planets, the Mare Erythraeum, the largest blue-green region of the disk and
lying in the southern hemisphere, rounded again into view, a startling transformation stood
revealed in it. Instead of showing blue-green as usual, and as it had done six weeks before, it
was now of a distinct chocolate-brown. It had been well seen at its previous presentation, so
that no doubt existed of its then tint. At that time the Martian season corresponded to December
30 in our calendar. Eighteen Martian days had since elapsed, and it was now January 16 there.
The metamorphosis had taken place, therefore, shortly after the winter solstice of that part of
the planet. The color change that had supervened proved permanent. For the next night the
region showed the same brown hue, and so it continued to appear throughout the days that it
was visible. Two months passed, and then the chocolate hue had vanished,—gone as it had
come,—and the mare had resumed its usual tint, except for being somewhat pale at the south. It
had come to be February 21 on Mars. Timed and tabulated, the metamorphosis through which
the mare passed stands out thus:—
Mare Erythraeum 1903

After Summer Solstice
Mundane Date (Before = - Martian Date Aspect
After = +)
February 16 -10 December 16 Blue-green
March 20 +22 January 1 Blue-green
April 19 52 January 16 Chocolate
April 22 55 January 18 Chocolate

May 26 89 February 4 Faint chocolate
May 30 93 February 6 Faint chocolate
June 30 123 February 22 Faint blue-green
July 7 130 February 25 Faint blue-green

The culmination of the transformation seems to have taken place about 60 days after the
southern winter solstice, or in the depth of the Martian winter of that hemisphere. This is
certainly just the time at which vegetation should be at its deadest.
The northern and southern portions of the mare did not behave alike in taking on the
chocolate tint. From the notes made about them during the opposition it appears that the latter
was later than the former in undergoing the metamorphosis, as will be seen from the following
depth of the blue green estimated in percentages shown at different dates, calling the deepest
tone ever exhibited by it unity.

December January January February February
Martian Date,
(16) (1) (17) (5) (24)
% % % % %
Northern 50 50 0 25 50
Southern 50 50 0 0 25

From this table we may place the lowest point of the blue-green tint as reached about the 22d
of January for the northern, the 5th of February for the southern, part. This would indicate that
the wave of returning growth came from the north, not the south; an important fact, as we shall
see later in studying the action of the canals.

Mare Erythræum
Martian date. February 1

At the next opposition, in 1905, a recurrence of the transformation was watched for, and not
in vain. It occurred, however, somewhat later in the Martian season. On December 27 of the
planet’s current year the Mare Erythraeum was still as usual, blue-green, nothing out of the
ordinary being remarked in it; and so it was on its January 17, although the southern edge was
darker than the northern. It looked certainly as if the metamorphosis were this year to be
omitted. But such was not the case. When the region again came round, on February 1 of the
Martian calendar, there the strange tint was as unmistakable as it had been on its original
occurrence. Not only was the Mare Erythraeum so colored, but on February 5 (Martian) the
northern portion of the Mare Cimmerium was observed to be similarly affected. In the Mare
Erythraeum the anomalous chocolate hue was confined to a belt between the latitudes of 10°
and 20° south of the equator; in the Mare Cimmerium it stretched a little higher, from 10° at the
west to 25° at the east. It is noteworthy that the southern portion of the latter showed blue at the
time the northern showed brown. Then the metamorphosis proceeded as shown in the following
table:—
Mare Erythraeum 1905

Days after Winter
Mundane Date Solstice of Southern Martian Date Aspect
Hemisphere
January 25 12 December 27 Blue-green
March 6 52 January 16 Blue-green
April 4 81 January 31 Chocolate
April 12 89 February 4 Chocolate

April 30 107 February 13 Faint chocolate
May 8 115 February 17 Faint chocolate
May 12 119 February 19 Faint blue-green
June 11 149 March 6 Faint blue-green
June 15 153 March 8 Faint blue-green
July 16 184 March 23 Pale bluish green

Here, as in 1903, a chromatic rise and fall is evident; the culmination of the change occurring
in Martian early February about ninety days after the winter solstice. That it was not of long
duration is also indicated. If we examine the evidence for the two portions of the mare
separately, the northern and the southern, as in 1903, we find it as follows:—

Martian December January February February March March
Date, (27) (16) (2) (16) (7) (23)
% % % % % %
Northern 50 50 0 10 25 30
Southern 50 50 20 20 25 30

Here again a slight retardation in the advent of the metamorphosis is observable in the
southern portion.
There would seem to be a difference in the time of the change between the two years of
fifteen days, 1905 being by that much the later. But with points of reference themselves thirty
days apart, it is possible the two more nearly coincided than here appears.
Unlike the ochre of the light regions generally, which suggest desert pure and simple, the
chocolate-brown precisely mimicked the complexion of fallow ground. When we consider the
vegetal-like blue-green that it replaced, and remember further the time of year at which it
occurred upon both these Martian years, we can hardly resist the conclusion that it was
something very like fallow field that was there uncovered to our view.

Mare Erythræum
Martian date. February 21

From the recurrence of the phenomenon on two successive years, it is likely that it annually
takes place. That it is seasonal can scarcely be doubted from the timeliness of its occurrence,
and that different portions of its terrane successively underwent their metamorphosis shows
further that it followed a law peculiar to the planet, to which we shall be introduced when we
come to consider the phenomena of the canals.
Instances of relative hue in different dark patches corroboratory of seasonal variation, and
therefore of vegetal constitution, might easily be adduced. Thus, in 1905 during the summer of
the northern hemisphere, the Mare Acidalium was notably darker than the Mare Erythraeum to
the north of it, which is what the law of seasonal variation would require, since it was June in
the one, December in the other at the time. But we need not to add example to example or proof
to proof, for there are no phenomena that contradict it. We conclude, therefore, that the blue-
green areas of Mars are not seas, but areas of vegetation. Just as reasoning to a negative result
drifts us to the first conclusion, so reasoning to a positive one lands us at the second.

CHAPTER XII
TERRAQUEOUSNESS AND TERRESTRIALITY

W ith the vanishing of its seas we get for the first time solid ground on
which to build our Martian physiography. The change in venue from
oceans to land has produced a complete alteration in our judgment of the
present state of the planet. It destroys the analogy which was supposed to
exist between Mars and our earth, and by abolishing the actuality of oceans
there, seems, metaphorically, to put us at first all the more at sea in our
attempt to understand the planet. But looked at more carefully, it turns out
to explain much that was obscure, and in so doing gives us at once a wider
view of the history of planetary evolution.
The trait concerned is cosmic. Study of the several planets of our solar
system, notably the Earth, Moon, and Mars, reveals tolerably legibly an
interesting phase of a planet’s career, which apparently must happen to all
such bodies, and evidently has happened or is happening to these three: the
transition of its surface from a terraqueous to a purely terrestrial condition.
The terraqueous state is well exhibited by our own earth at the moment,
where lands and oceans share the surface between them. The terrestrial is
exemplified by both the Moon and Mars, on whose surfaces no bodies of
water at present exist. That the one state passes by process of development
into the other I shall now give my reasons for believing.
In the first place the appearance of the dark markings both on the Moon
and Mars hints that though seas no longer, they were seas once upon a time.
On the moon, not only does their shape suggest this previous condition, but
the smooth and even look of their surfaces adds to the cogency of the
inference. More important, however, than either of these characteristics, and
confirmatory of both, is the fact that the great tracts in question seem to lie
below the level of the corrugated surface, which is thickly strewn with
volcanic cones. Their level and their levelness fay in explanation into one

another. The first makes possible the former presence of water; the second
speaks of its effect. For their flat character hints that these areas were held
down at the time when the other parts of the surface were being violently
thrown up. That they can themselves be cooled lava flows, their extent and
position seem enough to negative; to say nothing of the fact that they should
in that case lie above, not below, the general level. Something, therefore,
covered them during the moon’s eruptive youth and disappeared later. Such
superincumbence may well have been water, under which the now great
plains lay then as ocean bottoms. Deep-sea soundings in our own oceans
betray an ocean floor of the same extensive sort, diversified as on the moon.
To call the lunar maria seas may not be so complete a misnomer after all;
but only a resurrecting in epitaph what was the truth in its day.
Only doubtfully offered here for the Moon, for Mars the inference seems
more sure. Here again the dark regions not only look as they should had
they had an earlier history, but they, too, seem to lie below the level of the
surface round about. When they pass over the terminator they invariably
show as flattenings upon it, as if a slice of the surface had been pared off.
Such profile in such pass is what ground at a lower level would present.
Undoubtedly a part of the seeming depression is due to relative absence of
irradiation consequent upon a more sombre tint, but loss of light hardly
seems capable of the whole effect. In the case of Mars, then, as with the
Moon, a mistaken inference builded better than it knew, if, indeed, we
should rightly consider an inference to be mistaken which on half data lands
us at the right door.
From the aspects of the dark regions we are led, then, to regard Mars as
having passed through that stage of existence in which the earth finds itself
at the moment, the stage at which oceans and seas form a feature of its
landscape and an impediment to subjugation of its surface in its entirety.
What once were ocean beds have become ocean bottoms devoid of that
which originally filled them.
That the process of parting with a watery envelop is an inevitable
concomitant of the evolution of a planet from chaos to world, we do not
have to go so far afield as Mars and the Moon for testimony. Scrutiny
reveals as much in the history of our own globe. Two signposts of the past,
one geologic, the other paleontologic, point unmistakably in this direction.
The geologic guides us the more directly to the goal.

Study of the earth’s surface reveals the preponderating encroachment of
the land upon the sea since both began to be, and demonstrates that, except
for local losses, the oceans have been contracting in size from archaic
times. So much is evidenced by the successive places upon which marine
beds have been laid down. This suggests itself at once as a theoretic
probability to one considering the matter from a cosmic standpoint, and it is
therefore the more interesting and conclusive that, from an entirely different
departure-point, it should have been one of the pet propositions of the late
Professor Dana, who worked out conclusively the problem for North
America, and published charts detailing the progressive making of that
continent.

Map of North America at the close of Archæan
time, showing approximately the areas of dry
land. (From Dana’s “Manual of Geology.”)

So telling is this reclaiming by nature of land from the sea that it will be
well to follow Dana a little into detail, as the details show effectively the
continuity of the process acting through æons of geologic time. At the

beginning of the Archæan age, or, in other words, at the epoch when
stratified beds were first laid down, the earth reached a turning-point in its
history. Erosion, superficial and sub-aërial, then set in to help restrict the
domain of the sea. At this juncture North America consisted of a sickle of
terrane inclosing Hudson’s Bay and coming down at its apex to a point not
much removed from where Ottawa now stands, in about latitude 45°—a
Labradorian North America only. This, the kernel of the future continent,
curiously symbolized the form that continent was later to take. For its
eastern edge was roughly parallel to the present Atlantic coastline, although
much within and to the north of it, while its western one was similarly
aligned afar off to the now Pacific slope. Besides this continent proper, the
Appalachian, Rocky Mountain, Sierra Nevada, and Sierra Madre chains
stood out of the ocean in long, narrow ridges of detached land, outlining in
skeleton the bones of the continent that was to be. The Black Hills of
Dakota and other highlands made here and there islets in the sea.
Much the same backbone-showing of continents yet to be filled out was
true of Europe, Asia, and South America. In Europe the northern countries
constituted all that could be called continental land. Most of Norway,
Sweden, Finland, Lapland, existed then, while the northern half of Scotland,
the outer Hebrides, portions of Ireland, England, France, and Germany
stood out as detached islands. From this, which is a fair sample of the
proportion of land then to land now over the other continents so far as they
are geologically known, we turn to consider more in detail the history of
North America.
By the time the Upper Silurian period came in, the Appalachian
highlands there had been greatly extended and joined to the Labradorian
mainland by continuous territory; otherwise, no important addition had
occurred, though islands emerged in Ohio, Kentucky, and Missouri.

North America at the opening of the Upper
Silurian. (From Dana’s “Manual of Geology.”)

At the commencement of the Carbonic era what are now the Middle
states had begun to fill up from the north, and Newfoundland, from a small
island in the Upper Silurian, had become a great promontory of Labrador,
while the Eastern states region and Nova Scotia had risen into being. The
movements closing Paleozoic time upheaved from low islands the
Appalachian chain. The earth’s crust here crumpled by contraction upon
itself; and the movement ended, as Dana says, by making dry land of the
whole eastern half of the continent, along substantially its present lines.

Map of North America after the Appalachian
Revolution. (From Dana’s “Manual of Geology.”)

Mesozoic time was the period of the making of the West. It was an era of
deposition and coincident subsidence, when the western land had its nose
just above water at one moment to be submerged the next. Though on the
whole this part of the continent was emerging, the fact was that,
synchronously with the sinking of the sea, much of the land from time to
time sank too. The contraction which raised the Appalachian Mountains at
the beginning of the period and that of the Rockies at its close overdid the
necessities of the case and caused subsidence elsewhere. The southeastern
portion of the continent suffered most, the West on the whole materially
gaining. In the Triassic and Jurassic eras the gain was pronounced; it
occurred in the Cretaceous also, but with much alternation of loss. Finally,
at the close of the Cretaceous, the continent, except for a prolonged Gulf of
Mexico and vast internal lakes, was substantially complete.

North America in the Cretaceous period. (From
Dana’s “Manual of Geology.”)

The filling up of these lakes and the reclaiming of land from the Gulf of
Mexico constituted the land-making work of Tertiary times. The extent of
the lakes in the Eocene era is held to show that the general level of the
mountain plateau was low and rose later. So that the gain by the land at this
time was greater than the map allows to appear. By the beginning of the
Quaternary epoch the continents had assumed their present general area,
and since then their internal features have alone suffered change.

Map of North America, showing the parts under
water in the Tertiary Era; the vertically lined is
the Eocene. (From Dana’s “Manual of Geology.”)

A similar rising from the sea fell to the lot of Europe, though it has not
been detailed with so much care. The skeleton of that continent was at the
beginning of depositary time much what it is to-day, but a great inland sea
occupied the centre of it, which, as time went on, was gradually silted in
and evaporated away, notably during the Upper Silurian period.
From all this it is pretty clear that, side by side with alternating risings
and sinkings of the land, there was a tolerably steady gain in the contest by
which dry ground dispossessed the sea. We may, of course, credit this to a
general deepening of the ocean bottoms due to crumpling of the crust, but
we may also impute it to a loss of water, and that the latter is, at least for a
part, in the explanation the condition of the Moon and Mars makes
probable.
Paleontology has the same story of reclamation to tell as geology, and
with as much certainty, though its evidence is circumstantial instead of
direct and speaks for the growing importance of the land in the globe’s
economy since the beginning of depositary time, and thus inferentially to its
increasing extent. Fossil remains of the plants and creatures that have one
after the other inhabited the earth show that the land has been steadily rising
both in floral and faunal estimation as a habitat from the earliest ages to the

present day. The record lies imprinted in the strata consecutively laid down,
and except for gaps reads as directly on in bettering domicile as in
evolutionary development.
In Archæan times we find no undisputed evidence of life either vegetal or
animal. But beds of graphite and of limestone point to the possible
existence of both. Even anthracite has been found in Archæan rocks in
Norway and also in Rhode Island. Whether Dawson’s Eozoon Canadense
be a rhizopod or a crystal, doctors of science disagree. Dana, while
admitting nothing specific, deems it antecedently probable that algæ and
later microscopic fungi related to bacteria existed then, living in water well
up toward the boiling-point. Indeed, it is practically certain that invertebrate
life existed, because of its already well-developed character in the next era.
The like antedating is inferable for the whole record of the rocks. Relatively
their history is undoubtedly fairly accurate, but absolutely it must be shifted
bodily backward into the next preceding era to correspond with fact not yet
unearthed.
In the Lower Cambrian, when first the existence of life becomes a
certainty, that life, so far as known, was wholly invertebrate and wholly
marine; rhizopods (probably), sponges and corals, echinoderms, worms,
brachiopods, mollusks, and crustaceans grew amid primitive seaweed and
have left their houses in the shape of shells while perishing themselves.
Their tracks too have thus survived. The trilobites, crustaceans somewhat
resembling our horseshoe crab, were the lords of the Cambrian seas and
marked the point to which organic evolution had then attained. Their
aquatic character as well as their simple type is shown by their thoracic legs
having each a natatory appendage.
In the next era, the Lower Silurian, the fauna and flora were still marine,
although of a higher order than before, and in the Trenton period, the upper
part of the era, the earliest vertebrates, fishes, come upon the scene: ganoids
and possibly sharks. Nothing terrestrial of this period has yet with certainty
been unearthed in America. Europe would seem to have either been more
advanced then or better studied since, for there the first plant higher than a
seaweed has been dug up, one of a fresh-water genus betokening the land;
while in keeping with this the first insect, an hemipter, also has been
disinterred. Both the geography and the life of the Eopaleozoic period Dana
styles “thalassic.”

Neopaleozoic time, beginning with the Upper Silurian, marked the
emergence of the continents, and following them the emergence of life from
the water on to this land. In the lower beds of the Upper Silurian in America
we find only the aquatic forms of previous strata, but in a higher one we
come in marshes upon plants related to the equiseta or horsetails. In
England land plants appear for the first time in these latest Silurian beds and
in the schists of Angers have been preserved ferns. In both the old world
and the new fossil fishes are found and the oldest terrestrial species of
scorpions. But the great bulk of forms was still marine; corals, crinoids,
brachiopods, trilobites constituting the principal inhabitants. At this time the
seas were warm, having much the same temperature between 65° and 80°
north as between 30° and 45°; the prevalence of a general temperate
tropicality being shown by the fact that the common tropical chain corals
lived in latitude 82° north.
In the Devonian era, the Old Red Sandstone, fishes grew and multiplied,
increasing in size apparently through the era, and in the last period of it
reaching their culminating point. These pelagic vertebrates much surpassed
in structure the terrestrial population of the time, which was of a low type
and consisted of invertebrates such as myriapods, spiders, scorpions, and
insects; for the land was only making. In the mid-Devonian, forests of a
primitive kind covered such country as there was, an amphibious land,
composed of jungles and widespread marshes. Tree ferns made the bulk of
the vegetation, but among them grew also cycads and yews. Mammoth
may-flies flitted through the gloom of these old forests, but no vertebrate as
yet had left the sea.
Following upon the Old Red Sandstone were laid down the Carbonic
strata, and with the Carbonic entered upon the scene the advance scouts of
an army of progress evolutionarily impelled to spy out the land—the first
amphibians. They made their début in the Subcarboniferous section of the
era, the oldest of the three periods into which the Carbonic is divided,
crawling out of the sea to return again and leaving but footprints at first on
the sands of time. In the second period, the Coal-measures proper, they
ventured so far as to leave their skeletons on terra firma, or rather infirma,
while their tracks there show them to have been now in great numbers. In
this manner the ancestors of the oldest land inhabitants began to struggle
out of the sea. In the Permian, the third and latest period of paleozoic times,
we find their descendants established in their new habitat, for in it we come

upon the first reptiles. Such possession marks a distinct step up in function
as in fact, for while amphibians visited dry land, reptiles made it their
home. The getting out of the water had now, in the case of the more evolved
forms, become an accomplished fact. The reptiles were, indeed, the lowest
and most generalized of their class, Rhynchocephalians, “beak-headed”
species that by their teeth proclaim their marine origin and their relationship
to the great amphibians that still felt undecided where to stay. Meanwhile,
in Europe dragon-flies, two feet across, possessed the air; while amphibians
there, as here, ancestrally preceded reptiles in occupying the land.
Mesozoic times were, par excellence, the age of monsters; for the
Triassic (the New Red Sandstone), Jurassic and Cretaceous eras marked the
reign of the reptiles. Great dinosaurs sleep still in the Triassic strata of the
Atlantic border and in the Jurassic of the Western states, to be unearthed
from time to time and be given mausolea in our museums. Gigantic they
were and very literally possessed the earth. In Europe they were
substantially as in America during these mesozoic eras, and showed their
dominance by long survival in time as well as world-wide distribution in
space; for they lived all the way from Kansas to New Zealand and from the
Trias to the Upper Cretaceous. It is supposed by Professor Osborn that
many of them, like the herbivorous brontosaurus, waded in marshes, not
wholly unlike in habit to the modern hippopotamus. Others were land-
stalking carnivores, like the megalosaurs of a little later date. Of enormous
size, the largest exceeded any animal which has ever lived, the whales alone
excepted; the biggest, the atlantosaurus and the brontosaurus, reaching a
length of sixty feet. For all their bulk they had scant brains, just enough to
enable them to feed and wallow, probably. It is interesting to note that many
of the reptiles, the less adventurous, apparently reverted to the sea. For
though the crocodilians existed already in the Trias, the plesiosaurians did
not come in till the Middle Trias in Europe, and the sea-serpents
(mosasaurus) till the Upper Cretaceous.
Though the dinosaurs dominated life in those days, higher forms, their
descendants, unnoticed were gradually creeping in, eventually to supplant
them. For brain was making its way unobtrusively in the earliest of the
mammals, diminutive creatures at first and of the lowest type. First
appearing in the Trias as something approaching the missing link between
reptiles and mammals, they later developed into monotremes and
marsupials, not rising in differentiation above the latter order to the end of

Mesozoic times. And this both in the old world and the new. In the Jurassic,
too, flying lizards and the first birds appeared, showing their pedigree in
their teeth.
With Cenozoic times we come upon the first true or placental mammals
with their culmination up to date in man. In the Eocene they were of a
primitive type; they were also of a comprehensive one, fitted to eat
anything. From this they specialized, some evolving and some on the whole
devolving; the whale, for instance, taking to the water in the Eocene
through the same degenerate proclivity that had characterized the sea-
saurians ages before. The earth was growing colder, though still fairly
warm, and with the fall in temperature the higher types of life antithetically
rose, evolution gradually fitting them to cope with more advanced
conditions. In this manner did the land supplant the sea as the essential
feature of the earth’s surface, first, in coming into being, and then, by
offering conditions fraught with greater possibilities, as the habitat of the
most advanced forms of life, both plants and animals.
The possibility of advance in evolution was largely due to the fact that
the land did thus supplant the sea. Spontaneous variation, the as yet
unexplained primum mobile in the genesis of species, is probably to be
referred to chemism and is likely later to receive its solution at the hands of
that science. In the meanwhile it is evident that unless the variation obtain
encouragement from the environment no advance in type occurs. Now the
land offers to an organism sufficiently evolved to benefit by it,
opportunities the sea does not possess. First of these, undoubtedly, is the
care it enables to be given to the young. To cast one’s brood upon the waters
is not the best method of insuring its bringing up. There is too much of the
uncertainties of wave and current to make the process a healthy one, and
even when attached to rocks and seaweed, the attachment to a mother is to
be preferred. Without a period of infancy, when the young is unable to do
for itself, no great development is possible. In the only striking exception,
the case of the whales, dolphins, and porpoises, size has probably counted
for much in the matter, while the development of the cetaceans is far behind
that of the majority of land mammals.
Change of place, not in distance, but in variety, is another factor. The sea
is same as a habitat, one square mile of it being much like another, except
for gradually changing temperature. The land, on the other hand, from its
accidented surface, presents all manner of diversity in the conditions. And

the more varied the conditions to which the organism is exposed, the greater
its own complexity must be to enable it to meet them.
That the terrestrial stage of planetary development is subsequent to the
terraqueous one, and must of necessity succeed it if the latter ever exist on a
body, follows from the loss of internal heat on the one hand and from the
kinetic theory of gases on the other. To which of the two to attribute the
lion’s share in the business is matter for doubt; but that both must be
concerned in it we may take for certain.
So long as the internal heat suffices to keep the body fluid, the liquid
itself sees to it that all interstices are filled. As the heat dissipates, the body
begins to solidify, starting with the crust. For cosmic purposes it
undoubtedly still remains plastic, but cracks of relatively small size are both
formed and persist. Into these the surface water seeps. With continued
refrigeration the crust thickens, more cracks are opened and more water
given lodgment within, to the impoverishment of the seas. The process
would continue till the pressure of the crust itself rendered plastic all that
lay below, beyond which, of course, no fissures could be formed. How
competent to swallow all the seas such earth cuticle cracks may be we
ignore; for we cannot be said to know much of the process. We can only
infer that to a certain extent internal absorption of surface seas must mark a
stage of the evolution by which a star becomes a world and then an inert
mass, one of the dark bodies of which space is full.
Of the other means we know more. We are certain that it must take place,
though we are in doubt as to the amount it has already accomplished. This
method of depletion is by the departure of the water in the form of gas, in
consequence of the molecular motions. If we knew the temperature and the
age of Mars and also the amount of atmosphere originally surrounding it,
we could possibly predicate its state. Reversely, we can infer something as
to age and temperature from its present condition.

CHAPTER XIII
THE REDDISH-OCHRE TRACTS

B oth for their evidence and their extent the great ochre stretches of the
disk claim attention first. Largely unchangeable, these show essentially
the same day after day and from the year’s beginning to its end. In hue they
range from sand color to a brick red; some parts of the planet being given to
the one tint, some to the other. It is to the latter that the fiery tint of Mars to
the naked eye is due. The differences in complexion are local and peculiar,
both in place and time. For though saffron best paints the greater part of the
light areas, certain localities present at times a red like that of our red
sandstone. Hellas is one of these ruddy regions and Aeria another. It is only
on occasion that they thus show, and to what to assign their variability is as
yet matter of conjecture. Possibly it is owing to Martian meteorologic
condition; possibly to something else. But whatever its origin, the change is
not so much contradictory of, as supplementary to, the general fact of
unalterableness, which is after all the basic trait about them and the keynote
to their condition.
Land the ochre regions have generally been taken for, and land they still
make good their claim to be considered. For the better they are seen, the
greater the ground for the belief. Indeed, they seem to be nothing but
ground, or, in other words, deserts. Their color first points them out for
such. The pale salmon hue, which best reproduces in drawings the general
tint of their surface, is that which our own deserts wear. The Sahara has this
look; still more it finds its counterpart in the far aspect of the Painted Desert
of northern Arizona. To one standing on the summit of the San Francisco
Peaks and gazing off from that isolated height upon this other isolation of
aridity, the resemblance of its lambent saffron to the telescopic tints of the
Martian globe is strikingly impressive. Far forest and still farther desert are
transmuted by distance into mere washes of color, the one robin’s-egg blue,

the other roseate ochre, and so bathed, both, in the flood of sunshine from
out a cloudless burnished sky that their tints rival those of a fire-opal. None
otherwise do the Martian colors stand out upon the disk at the far end of the
journey down the telescope’s tube. Even in its mottlings the one expanse
recalls the other. To the Painted Desert its predominating tint is given by the
new red sandstone of the Trias, the stratum here exposed; and this shows in
all its pristine nakedness because of the lack of water to clothe it with any
but the sparsest growth. Limestones that crop out beside it are lighter
yellow, whitish and steel-gray, and seen near give the terrane the look of a
painter’s palette. Seen from far they have rather the tint of sand; and the one
effect, like the other, is Martian in look. And as if to assimilate the two
planetary appearances the more, the thread of blue-green that attention
traces athwart the Painted Desert marks the line of cottonwoods along the
banks of the Little Colorado River—deserts both, if look be any guarantee
of character, with verdure banding them.
In other ways these earthly deserts offer a parallel to the Martian. No
desert on the Earth is absolutely devoid of life of some kind, vegetal and
animal. The worst conditioned are not what one is taught in childhood to
believe a desert to be—a vast waste of sand, with a camel and a palm
thrown in to heighten the sterility. In all Saharas outside of the pages of the
school books some vegetation grows, though it is commonly not of a kind
to boast of, being rather a succés d’estime, as sagebrush, cacti, and the like.
But what is of interest here in the connection is its color. For it is commonly
of a more ochreish tint than usual, in keeping with its surroundings, a paling
out of the green to something more tawny, indicating a relative reduction of
the chlorophyll and an increase of the lipochromes in the tissues of the
plant, since the one gives the green tint to the leaves, the other the yellow.
As this vegetation, poor as it is, has its annual history, it must alter the look
of the desert at times and produce precisely those slight variations in tint
observable on Mars in like circumstance.
The Arizona desert dates from no further back than early Tertiary times,
as the limestone of the Cretaceous there present shows. Water then stretched
where desert now is, and the limestone beds were laid down in it. How old
the Martian Saharas are we have no means of knowing. But one thing we
may predicate about both: a desert is not an original, but an acquired,
condition of a planet’s surface, demonstrably so in the case of a planet
which has had a sedimentary epoch in its life-history. In the Arizona desert

the surface is composed of depositary rocks of Mesozoic times, except
where lava streams have flowed down over it since then. The land, then,
was once under water, and cannot but have been fertile for some time after
it emerged.
But we are not left to inference in the matter, however good that
inference may be. A little to the south of the Painted Desert, in the midst of
the barren plateau of northern Arizona, of which the former makes a part,
stand the remains of a petrified forest. Huge chalcedony trunks of trees, so
savingly transmuted into stone that their genus is still decipherable, lie
scattered here over the barren ground in waste profusion, one of them still
spanning a cañon just as it fell in that, to it, destructive day of a far
prehistoric past. The rock stratum on which their remains lie is of Triassic
and Cretaceous times and the petrifications show that in the Cretaceous a
stately forest overspread the land. In those days at least the spot was fertile
where now sparse sagebrush and cacti find a living hard. Not here alone
where the blocks are so conspicuous as to invite their carrying away is a
former flourishing growth of vegetation attested, but over large adjoining
areas of desert search has brought the like past tenancy to light. Fragments
of what once were trees have been picked up in the Little Colorado basin
and in the neighborhood of Ash Fork, on both sides, that is, of the present
forest crown that covers the higher part of the plateau from which rise the
San Francisco Peaks. In the blue distance the mountains look down
verdure-clad upon a now encircling waste, but one which in earlier eras was
as pine-bearing as they. Their lofty oasis is all that is now left of a once
fertile country; the retreat of the trees up the slopes in consequence of a
diminishing rainfall, until a rise of two thousand feet from what once was
timber-land is necessary to reach the tree-line of today, being typical of
desert lands, and testifying to greater aqueous affluence in the past. In the
same manner streams descend from the cedar-clad range of the Lebanon to
lose themselves in the Arabian desert just without the doors of Damascus;
and Palestine has desiccated within history times. Palestine, a land once
flowing with milk and honey, can hardly flow poor water now, and
furnishes another straw to mark the ebbing of the water supply.
This making of deserts is not a sporadic, accidental, or local matter,
although local causes have abetted or hindered it. On the contrary, it is an
inevitable result of planetary evolution, a phase of that evolution which
follows from what has been said in Chapter XII on the abandonment of a

planet by its water. Deserts are simply another sign of the same process.
The very aging which began by depriving a body of its seas takes from it
later its forest and its grass. A growing scarcity of water is bound to
depauperate the one, as it depletes the other. We have positive proof of the
action in our own deserts. For these bear testimony, in places at least, to not
having always been so, but to have gradually become so within relatively
recent times. But we have more general proof of the action from the
position occupied on the earth’s surface by its deserts.
The significant fact about the desert-making so stealthily going on is that
only certain zones of the earth’s surface are affected. Those belting the two
tropics of Cancer and Capricorn, for several degrees on either side of them,
most exhibit the phenomenon. Such positioning of the deserts is not due to
chance. Directly, of course, desertism is due to dearth of rain. This in turn
depends on the character and condition of the winds. If a wind laden with
moisture travel into a colder region of the globe, its moisture is precipitated
in rain and we have a fertile country; if it voyage into a warmer clime it
takes up what little moisture may be there already and a desert is the result.
Now our system of winds is such as to produce a fall of rain for the
different latitudes, as tabulated by Supan, thus:—

Zone I 40°N-27°N Little rain in summer but much in winter.
II 27 N-19 N Little rain at all seasons.
III 19 N- 7 N Little rain in winter but much in summer.
IV 7 N- 1 N Abundant rain at all seasons.
V 1 N-17 S Little rain in winter but much in summer.
VI 17 S-30 S Little rain at all seasons.
VII 30 S-35 S Little rain in summer but much in winter.

Zones II and VI, the zones of minimum rainfall, are also those in which the
deserts occur. The northern one traverses southern California, Arizona, New
Mexico, the Sahara, Arabia, and the Desert of Gobi; the southern, Peru, the
South African veldt, and central Australia. The belts are wavy bands which
by their form betray both a general underlying trend to drought at these
parallels and also the effect of local topography in the matter.
From being distributed thus in belts, it is evident that the deserts are
general globe phenomena, and from their being found only in the zones of

least rainfall, that the earth has itself entered, though not far as yet, upon the
desert stage of its history. Once begun, the desert areas must perforce spread
as water becomes scarce, invading and occupying territory in proportion as
the rainfall there grows small.
Now the axial tilt of Mars is almost exactly the same as that of our Earth,
the latest determinations from the ensemble of measures giving 24° for it.
Here, then, we have initial conditions reproducing those of the earth. But
from the smaller size of the planet that body would age the earlier, since it
would lose its internal heat the more rapidly, just as a small stone cools
sooner than a larger one. On general principles, therefore, it should now be
more advanced in its planetary career. In consequence, desertism should
have overtaken more of its surface than has yet happened on earth, and
instead of narrow belts of sterility we should expect to find there Saharas of
relatively vast extent.
Now, such a state of things is precisely what the telescope reveals. The
ochre tracts occupy nine tenths of the northern hemisphere and a third of the
southern. Three fifths, therefore, of the whole surface of the planet is a
desert.

Desert areas.

Of cosmic as well as of particular import is the correlation thus made
evident between the physical principles that effect the aging of a planet and
the aspect Mars presents. Experimental corroboration of those laws is thus
afforded, while, reversely, confidence in their applicability is increased.
With continued observation the planet appears more desiccate as improved
conditions bring it nearer. Dry land as it was thought to be proves even
drier, something which lacks water for the ordinary necessities of a living
world.

Desert areas.

The picture the planet offers to us is thus arid beyond present analogue
on Earth. Pitiless as our deserts are, they are but faint forecasts of the state
of things existent on Mars at the present time. Only those who as travelers
have had experience of our own Saharas can adequately picture what Mars
is like and what so waterless a condition means. Only such can understand
what is implied in having the local and avoidable thus extended into the
unescapable and the world-wide; and what a terrible significance for
everything Martian lies in that single word: desert.

CHAPTER XIV
SUMMARY

I f, now, we review with the mind’s eye the several features of Mars which
we have surveyed with the bodily one, we shall be surprised to find to
what they commit us. Suggestive as each is considered by itself, the
ensemble into which they combine proves of multiplicate force in its
implication. For each turns out to fit into place in one consistent whole, a
scheme of things in which are present all the conditions necessary to the
existence and continuance of those processes which constitute what we call
life. In short, we are conducted with a cogency, which grows as we consider
it, to the conclusion that Mars is habitable.
Two ways of appreciating this cogency are open to us. We may treat it
with the simple reasoning of common-sense, as we should a dissected map
or a piece of machinery in which we realize we are right when the several
parts at last fit together and the picture stands revealed or the machine
works. Or we may subject the evidence to quantitative estimates for and
against by the doctrine of probabilities, and thus evaluate the chances of its
being correct. Consciously or unconsciously, this is what we are about in
our decisions every day of our lives. At the one end of the line are those
skillful judgments where the balance is so keen-edged that the least
overweight on the one side dips the scales to a conclusion. At the other
extremity stand those deductions which we usually speak of as proved, such
as the law of gravitation. But both assurances rest really upon probability
and differ only in degree. What we mean by proof of anything is that a
supposition advanced to account for it explains all the facts and is not
opposed to any of them, and that the balance of probability in consequence
is very largely in its favor.
Now, if several pieces of evidence, distinct in their origin, concur to a
given conclusion, the probability that that conclusion is correct is far greater

than what results from each alone; and mounts up soon to something much
exceeding what bettors at races call certainty odds. However unversed the
average man may be in calculating the probability, he recognizes the fact in
his dealings with his fellows by the way he attaches weight to concurrent
testimony. It is such concurrent evidence that we have now to consider. To
this end we will marshal the several facts ascertained in a summarized list
for their easier intercomparison.
These facts are:—
(1) Mars turns on its axis in 24 h. 37 m. 22.65 s. with reference to the
stars, and in 24 h. 39 m. 35.0 s. (as a mean) with regard to the Sun. Its day,
therefore, is only about forty minutes longer than ours.
(2) Its axis is tilted to the plane of its orbit by about 23° 59′ (most recent
determination, 1905). This gives the planet seasons almost the counterpart
of our own in character; but in length nearly double ours, for
(3) Its year consists of 687 of our days, 669 of its own.
(4) Polar caps are plainly visible which melt in the Martian summer to
form again in the Martian winter, thus implying the presence of a substance
deposited by cold.
(5) As the polar caps melt, they are bordered by a blue belt, which
retreats with them. This excludes the possibility of their being formed of
carbon dioxide, and shows that of all the substances we know the material
composing them must be water.
(6) In the case of the southern cap, the blue belt has widenings in it in
places. These occur where the blue-green areas bordering upon the polar
cap are largest.
(7) The extensive shrinkage of the polar snows shows their quantity to be
inconsiderable, and points to scanty deposition due to dearth of water.
(8) The melting takes place locally after the same general order and
method, Martian year after year, both in the south cap,
(9) And in the north one. This is evidenced by the recurrence of rifts in
the same places annually in each. The water thus let loose can, therefore, be
locally counted on.
(10) That the south polar cap is given to greater extremes than the north
one, implies again, in view of the eccentricity of the orbit and the tilt of the
axis, that deposition in both caps is light.
(11) The polar seas at the edges of the caps being temporary affairs, the
water from them must be fresh.

(12) The melting of the caps on the one hand and their reforming on the
other affirm the presence of water vapor in the Martian atmosphere, of
whatever else that air consist.
(13) Since water vapor is present, of which the molecular weight is 18, it
follows from the kinetic theory of gases that nitrogen, oxygen, and carbonic
acid, of molecular weights 28, 32, and 38 respectively, are probably there,
too, owing to being heavier.
(14) The limb-light bears testimony to this atmosphere.
(15) The planet’s low albedo points to a density for the atmosphere very
much less than our own.
(16) The apparent evidence of a twilight goes to confirm this.
(17) Permanent markings show upon the disk, proving that the surface
itself is visible.
(18) Outside of the polar cap the disk is divided into red-ochre and blue-
green regions. The red-ochre stretches have the same appearance as our
deserts seen from afar,
(19) And behave as such, being but little affected by change.
(20) The blue-green areas were once thought to be seas. But they cannot
be such, because they change in tint according to the Martian season, and
the area and amount of the lightening is not offset at the time by
corresponding darkening elsewhere;
(21) Nor by any augmentation of the other polar cap or precipitation into
cloud. It cannot, therefore, be due to shift of substance.
(22) Furthermore, they are all seamed by lines and spots darker than
themselves which are permanent in place; so that there can be no bodies of
water on the planet.
(23) On the other hand, their color, blue-green, is that of vegetation; this
regularly fades out, as vegetation would, to ochre for the most part, but in
places changes to a chocolate-brown.
(24) The change that comes over them is seasonal in period, as that of
vegetation would be.
(25) Each hemisphere undergoes this metamorphosis in turn.
(26) That it is recurrent is again proof positive of an atmosphere.
(27) The changes are metabolic, since those in one direction are later
reversed to a restoration of the original status. Anabolic as well as katabolic
processes thus go on there; that is, growth as well as decay takes place. This
proves them of vegetal origin.

(28) The existence of vegetation shows that carbonic acid, oxygen, and
undoubtedly nitrogen, are present in the Martian atmosphere, since plants
give out oxygen and take in carbonic acid.
(29) The changes in the dark areas follow upon the melting of the polar
caps, not occurring until after that melting is under way;
(30) And not immediately then, but only after the lapse of a certain time.
(31) Though not seas now, from their look the dark areas suggest old sea
bottoms, and when on the terminator appear as depressions (whether
because really at a lower level or because of less illumination is not
certain).
(32) That they are now the parts of the planet to support vegetation hints
the same past office, as water would naturally drain into them. That such a
metamorphosis should occur with planetary aging is in keeping with the
kinetic theory of gases.
(33) Terminator observations prove conclusively that there are no
mountains on Mars, but that the surface is surprisingly flat.
(34) But they do reveal clouds which are usually rare and are often, if not
always, dust-storms.
(35) White spots are occasionally visible, lasting unchanged for weeks, in
the tropic and temperate regions, showing that the climate is apparently
cold,
(36) But at the same time proving that most of the surface has a
temperature above the freezing-point.
(37) In winter the temperate zones are more or less covered by a whitish
veil, which may be hoar-frost or may be cloud.
(38) A spring haze surrounds the north polar cap during the weeks that
follow its most extensive melting.
(39) Otherwise the Martian sky is perfectly clear; like that of a dry and
desert land.
The way in which these thirty-nine articles fit into one another to a
mortised whole is striking enough at first sight, but becomes more and more
impressive the more one considers it. For some are due to one kind of
observation, some to another. In the taking they are unrelated; yet in the
result they agree. Equally pregnant is the history of their acquisition. Most
of them were detected as the outcome of observations at the opposition of
1894, and led to the theory which was published in the writer’s first book
on the subject. Others are the result of the five oppositions that have since

occurred. These have proved entirely corroborative of the previous ones and
of the theory then deduced, and that in two distinct ways: first, by the
accumulated evidence they have brought to the matter along the old lines;
and, secondly, by what they have revealed in new directions. Of these
thirty-nine articles of Martian scientific faith in observation or deduction,
(9), (10), (21), (22), (25), (27), (28), (30), (33), (35), (36), and (38) are in
whole or part new. That continued scrutiny is thus corroborative of the
earlier results, both along the old and along new lines of investigation,
warrants additional confidence in the conclusion.
Considering, now, these counts, we see that they make reasonably
evident on Mars the presence of:—
1. Days and seasons substantially like our own;
2. An atmosphere containing water vapor, carbonic acid, and oxygen;
3. Water in great scarcity;
4. A temperature colder than ours, but above the Fahrenheit freezing-
point, except in winter and in the extreme polar regions;
5. Vegetation.
First and foremost of these is air. In order to make it possible for vital
processes of any sort to take place, the body of a planet must be clothed
with an atmosphere, by the modesty of nature, the old astronomers would
have said. Such a covering subserves two purposes: it keeps out the cold of
space, thus permitting the maintenance of a temperature sufficient to
support life, and it affords a medium through which metabolism can go on.
Now the presence of air is attested first and foremost by the fact of
change in the Martian markings, (12), (13), (26), (28), and (35). The
changes observed are conspicuous; are both inorganic (in the case of the
polar caps), (12), (13), and (35), and metabolic or organic, (26) and (28), (in
the case of the blue-green areas); that is, they consist of building up as well
as of pulling down and are planet-wide in occurrence. Such changes could
not occur in the absence of an atmosphere. They show that this atmosphere
consists of water vapor, (5), carbonic acid, and oxygen, (28).
The limb-light, the apparent evidence of a twilight arc and the planet’s
low albedo indicate that this atmosphere is thin. The appearance of the
surface, (35), suggests cold, indicative again of a thin air. Such tenuity is in
accord with what a priori principles would lead us to expect, and tends to
show that reliance on general principles is here not misplaced, a point of
some interest.

Lastly, the occurrence of clouds, (34), visibly floating and traveling over
the surface, and haze at times, (38), proves in another way the existence of
the medium in which alone this could be possible.
Water is the next substance vital to planetary life. As to its actual
presence the polar caps, (4)-(12), have most to say; as to its relative
absence, the rest of the disk, (17)-(22). The forthright conception of the
polar caps as composed of snow and ice is borne out by further
investigation into what could cause the observed phenomenon. Carbonic
acid, the only other substance we know capable in any way of resembling
what we see, turns out not capable of producing one important detail of the
caps’ appearance, the blue band, (5), which accompanies them in their
retreat. Water alone could do this.
The melting of the caps shows that water vapor must be a constituent of
the Martian atmosphere. Moreover, as the molecular weight of water vapor
is less than that of oxygen or nitrogen or carbon dioxide, if the former can
exist in the atmosphere of the planet, a fortiori must these other gases. So
that from this we have knowledge of the possibility of the presence of
oxygen, nitrogen, and carbon dioxide there. From (28) we saw that their
actual existence is demonstrated.
The next step is the ascertainment that the water is in very small amount.
The extensive melting of the caps, (7), shows their quantity to be
inconsiderable, which is the first fact pointing to a dearth of water. The
second comes from the aspect and behavior of the reddish-ochre regions
which proclaim them deserts, (18) and (19); the third from the detection of
the character of the blue-green areas as not seas, (20), (21), and (22). In
several different ways, study of these regions asserts their non-aquatic
constitution, the easiest to appreciate being that they are traversed by
permanent dark lines and other equally sedentary markings, (22). No bodies
of water, therefore, are to be seen outside of the ephemeral polar seas,
immediately surrounding the caps as they melt.
This leads us to the third presence on Mars indicative of a living world:
vegetation. The other two spoke of substances necessary to life, the
premises in the case, this one of organic existence itself, its conclusion. The
evidence consists of static testimony from the look of the blue-green areas,
(23), and of kinematic derived from their behavior, (24), (25), (26), and
(27). Vegetation would present exactly the appearance shown by them, and
nothing that we know of but vegetation could. But suggestive as their

appearance is, it is as nothing compared with the cogent telltale character of
their behavior. The seasonal change that sweeps over them is metabolic,
constructive as well as destructive, that is, and proclaims an organic
constitution for them such as only vegetation could produce. In tint their
metamorphoses are those of the same substance. For the blue-green lapses
into ochre and revives again to blue-green just as vegetation does on our
own Earth at the proper season of the year, taking both the Sun and the
advent of water into the reckoning. Furthermore, certain of the largest dark
areas turn to a chocolate-brown at times, which is the color of fallow
ground and suggestive, at least, as occurring where the blue-green at other
seasons is the most pronounced. Lastly, the change occurs at the epoch at
which, from a knowledge of the melting of the polar caps, theory
demonstrates that it ought to take place if it be due to the action of
vegetation.
That this was the case was evident from much less information than is
forthcoming today; but what is significant, each new fact discovered about
the planet goes to show that it is unquestionably true.

PART II
NON-NATURAL FEATURES

CHAPTER XV
THE CANALS

F rom the detection of the main markings that diversify the surface of
Mars we now pass to a discovery of so unprecedented a character that
the scientific world was at first loath to accept it. Only persistent
corroboration has finally broken down distrust; and, even so, doubt of the
genuineness of the phenomena still lingers in the minds of many who have
not themselves seen the sight because of the inherent difficulty of the
observations. For it is not one where confirmation may be summoned in the
laboratory at will, but one demanding that the watcher should wait upon the
sky, with more than ordinary acumen. This latter-day revelation is the
discovery of the canals.
Quite unlike in look to the main features of the planet’s face is this
second set of markings which traverse its disk, and which the genius of
Schiaparelli disclosed. Unnatural they may well be deemed; for they are not
in the least what one would expect to see. They differ from the first class,
not in degree, but in kind; and the kind is of a wholly unparalleled sort.
While the former bear a family resemblance to those of the earth; the latter
are peculiar to Mars, finding no counterpart upon the earth at all.
Introduction to the mystery came about in this wise, and will be repeated
for him who is successful in his search. When a fairly acute eyed observer
sets himself to scan the telescopic disk of the planet in steady air, he will,
after noting the dazzling contour of the white polar cap and the sharp
outlines of the blue-green seas, of a sudden be made aware of a vision as of
a thread stretched somewhere from the blue-green across the orange areas
of the disk. Gone as quickly as it came, he will instinctively doubt his own
eyesight, and credit to illusion what can so unaccountably disappear. Gaze
as hard as he will, no power of his can recall it, when, with the same
startling abruptness, the thing stands before his eyes again. Convinced, after

three or four such showings, that the vision is real, he will still be left
wondering what and where it was. For so short and sudden are its
apparitions that the locating of it is dubiously hard. It is gone each time
before he has got its bearings.
By persistent watch, however, for the best instants of definition, backed
by the knowledge of what he is to see, he will find its coming more
frequent, more certain and more detailed. At last some particularly
propitious moment will disclose its relation to well-known points and its
position be assured. First one such thread and then another will make its
presence evident; and then he will note that each always appears in place.
Repetition in situ will convince him that these strange visitants are as real as
the main markings, and are as permanent as they.
Such is the experience every observer of them has had; and success
depends upon the acuteness of the observer’s eye and upon the persistence
with which he watches for the best moments in the steadiest air. Certain as
persistence is to be rewarded at last, the difficulty inherent in the
observations is ordinarily great. Not everybody can see these delicate
features at first sight, even when pointed out to them; and to perceive their
more minute details takes a trained as well as an acute eye, observing under
the best conditions. When so viewed, however, the disk of the planet takes
on a most singular appearance. It looks as if it had been cobwebbed all over.
Suggestive of a spider’s web seen against the grass of a spring morning, a
mesh of fine reticulated lines overspreads it, which with attention proves to
compass the globe from one pole to the other. The chief difference between
it and a spider’s work is one of size, supplemented by greater complexity,
but both are joys of geometric beauty. For the lines are of individually
uniform width, of exceeding tenuity, and of great length. These are the
Martian canals.
Two stages in the recognition of the reality confront the persevering
plodder: first, the perception of the canals at all; and, second, the realization
of their very definite character. It is wholly due to lack of suitable
conditions that the true form of the Martian lines is usually missed. Given
the proper prerequisites of location or of eye, and their pencil-mark
peculiarity stands forth unmistakably confessed. It is only where the seeing
or the sight is at fault that the canals either fail to show or appear as diffuse
streaks, the latter being a halfway revelation between the reality and their
not being revealed at all. Much misconception exists on this point. It has

been supposed that improved atmospheric conditions simply amount to
bringing the object nearer by permitting greater magnification without
altering the hazy look of its detail.[2] Not so. They do much more than this.
They steady the object much as if a page of print from being violently
shaken should suddenly be held still. The observer would at once read what
before had escaped him for being a blur. So is it with the canals. In reality,
pencilings of extreme tenuity, the agitations of our own air spread them into
diffuse streaks; an effect of which any one may assure himself by
sufficiently rapid motion of a drawing in which they are depicted sharp and
distinct, when he will see them take on the streaky look. As the writer has
observed them under both aspects, and has seen them pass from the
indefinite to the defined as the seeing improved, he has had practical proof
of the fact, and this not once, but an untold number of times.
Atmospheric conditions far superior to what are good enough for most
astronomic observations are needed for such planetary decipherment, and
the observer experienced in the subject eventually learns how all-important
this is. Under these conditions the testimony of his own eyesight upon the
character of these markings is definite and complete. And the first trait that
then emerges from confusion is that the markings are lines; not simply lines
in the sense that any sufficiently narrow and continuous marking may so be
called, but lines in the far more precise sense in which geometry uses the
term. They are furthermore straight lines. As Schiaparelli said of them: they
look to have been laid down by rule and compass. The very marvel of the
sight has been its own stumbling-block to recognition, joined to the
difficulty of its detection. For not only is the average observatory not
equipped by nature for the task, but what is not good air often masquerades
as such. Trains of air waves exist at times so fine as to confuse this detail, or
even to obliterate it entirely; while at the same time they leave the disk
seemingly sharp-cut, with the result that one not well versed in such
vagaries thinks to see well when in truth he is debarred from seeing at all.
When study of the conditions finally ends in putting him upon the right
road, the sight that rewards him can hardly be too graphically described.
Next to the fact that they are lines, definiteness of direction is the chief of
their characteristics to strike the observer. The lines run straight throughout
their course. This is absolutely true of ninety per cent of them, and
practically so of the remaining ten per cent, since the latter curve in an
equally symmetric manner. Such directness has I know not what of

immediate impressiveness. Quite unlike the aspect of the main markings,
which show a natural irregularity of outline, these lines offer at the first
glance a most unnatural regularity of look. Nothing on Earth of natural
origin on such a scale bears them analogue. Nor does any other planet show
the like. They are, in fact, distinctively Martian phenomena. This is the first
point in which they differ from the markings we have hitherto described.
The others were generic planetary features; these are specific ones, peculiar
to Mars.[3]
Equally striking is the uniform width of each line from its beginning to
its end, as it stands out there upon the disk. The line varies not in size
throughout its course any more than it deviates in direction. It counterfeits a
telegraph wire stretched from point to point. Like the latter seen afar, the
width, too, is telegraphic. For it is not so much width as want of it that is
evident. Breadth is inferable solely from the fact that the line is seen at all,
and relative size by difference of insistency. Indeed, the apparent breadth
has been steadily contracting as the instrumental, atmospheric, and personal
conditions have improved. All three of the factors have conduced to such
emaceration, but the middle one the most. For the air waves spread every
marking, and the effect is relatively greatest upon those which are most
slender. As the currents of condensation and rarefaction pulse along, their
denser and their thinner portions refract the rays on either side of their true
place, and thus at the same time confuse a marking and broaden it. The
consequence is that the better the atmospheric conditions and the more that
has been learned about utilizing them, the finer the lines have shown
themselves to be.
Herein we have a specific intrinsic difference between the fundamental
features and these lines: the main markings have extension in two
dimensions, the latter in one.
Distinctive as they thus are, they have, in keeping with their appearance,
been given a distinctive name, that of canal. Useful as the name is and, as
we shall later see, applicable, it must not be supposed that what we see are
such in any simple sense. No observer of them has ever considered them
canals dug like the Suez Canal or the phœnix-like Panama one. This
supposition is exclusively of critic creation.
Their precise width is not precisable. They show no measurable breadth
and their size, therefore, admits for certain only of an outside limit. They
cannot be wider than a determinable maximum, but they may be much less

than this. The sole method of estimating their width is by comparison of
effect with a wire of known caliber at a known distance. For this purpose a
telegraph wire was stretched against the sky at Flagstaff, and the observers,
going back upon the mesa, observed and recorded its appearance as their
stations grew remote. It proved surprising at what great distances a slender
wire could be made out when thus projected against the sky. The wire in the
experiment was but 0.0726 of an inch in diameter and yet could be seen
with certainty at a distance of 1800 feet, at which point its diameter
subtended only 0.69 of a second of arc. How small this quantity is may be
appreciated from its taking more than ninety such lines laid side by side to
make a width divisible by the eye. Such slenderness at the then distance of
Mars would correspond, under the magnification commonly used, only to
three quarters of a mile. Theoretically, then, a line three quarters of a mile
wide there should be visible to us. Practically, both light and definition is
lost in the telescope, and it would be nearer the mark to consider in such
case two miles as the limit of the perceptible. With the planet nearer than
this, as is often the case, the width which could be seen would be
proportionally lessened. Perhaps we shall not be far astray if we put one
mile as the limiting width which could be perceived on Mars at present,
with distance at its least and definition at its best.
That so minute a quantity should be visible at all is due to the line having
a sensible length and by summation of sensations causing to rise into
consciousness what would otherwise be lost. A stimulus too feeble to
produce an effect upon a single retinal rod becomes recognizable when
many in a row are similarly excited.
The experiment furnished another criterion, of importance as regards the
supposition that the lines on Mars are illusory. It showed that brain-begotten
impressions of wires that did not exist could be told from the real thing
when the wire subtended 0.69 of a second of arc or more; that below this
the outside stimulus was too weak to differ recognizably from optic effects
otherwise produced; while when the real wire was diminished to 0.59′′, it
could not be seen at all. Now, the majority of lines on Mars so far
recognized and mapped lie in strength of impression far above the superior
limit of 0.69′′. To one versed in Martian canal detection there is no
possibility of self-deception in the case, the canals being very much more
salient objects to an expert than those who have not seen them suppose. For
it must not be imagined that, when one knows what to be on the lookout for,

they are the difficult objects they seem to the tyro. Just as the satellites of
Mars were easily seen once they were discovered, so with these lines.
A mile or two we may take, then, with safety as the smallest width for
one of the lines. The greatest was got by comparing what is by far the
largest canal, the Nilosyrtis, with the micrometer thread. From such
determination it appeared that this canal was from 25 to 30 miles wide. But
it is questionable whether the Nilosyrtis can properly be termed a canal, so
much does it exceed the rest. It is certainly far larger than the majority of
them. From comparative estimates between its size and that of the others,
15 to 20 miles for the width of the larger of the Martian canals seems the
most probable value, and 2 or 3 miles only of the more diminutive of those
so far detected.
On the other hand, the length of
the canals is relatively enormous.
With them 2000 miles is common;
while many exceed 2500, and the
Eumenides-Orcus is 3540 miles
from the point where it leaves the
Phœnix Lake to the point where it
enters the Trivium Charontis. This
means much more on Mars than it
would on Earth, owing to the
smaller size of the planet. Such a
length exceeds a third of the whole
circumference of its globe at the
equator. But what is still more
remarkable, throughout the whole
of the long course taken by the Showing the Eumenides-Orcus.
canal, it swerves neither to the right
nor to the left of the great circle joining the two points.
Of these several peculiarities of the individual canal it is difficult to know
to which to allot the palm for oddity,—great circle directness, excessive
length, want of width, or striking uniformity. Each is so anomalously
unnatural as to have received the approving stamp of incredulity. Yet so
much, wonderful as it is, is encountered on the very threshold of the
subject.

[2] M. l’abbé Moreux.
[3] As some misrepresentation has been made on this subject through
misapprehension of the writer’s observations on Venus and Mercury,
it may be well to state that the tenuous markings on both these other
planets entirely lack the unnatural regularity distinguishing the canals
of Mars. The Venusian lines are hazy, ill-defined, and non-uniform;
the Mercurian broken and irregular, suggesting cracks. Neither
resemble the Martian in marvelous precision, and have never been
called canals by the writer nor by Schiaparelli, but solely by those
who have not seen them and have misapprehended their character and
look.

CHAPTER XVI
THEIR SYSTEM

M uch more stands beyond. For, outdoing in suggestiveness the
individual traits of the lines, is the relation shown by them to one
another. It is the communal characteristics of the phenomenon that are most
surprising.
The individual peculiarities of the lines impress themselves at once; the
communal, only as the result of experience, collation, and thought. As the
observer becomes trained, the more lines he is able to make out, until they
fairly seam the whole surface of the light areas of the planet. Their name
collectively is legion; while to name them individually is fast getting, for
the number detected, to be impossible. As with the increasing family of
asteroids, figures alone will prove adequate to the task.
Interdependence, not independence, marks the attitude of the canals.
Each not only proceeds with absolute directness from one point to another,
but at its terminals it meets canals which have come there with like
forthrightness from other far places upon the planet. Nor is it two only that
thus come together at a common junction. Three, four, five,—up to as many
as fourteen,—thus make rendezvous, and it is a poor junction that cannot
show at least six or seven. The result is a network which triangulates the
surface of the planet like a geodetic survey into polygons of all shapes and
sizes, the Arian areolas. The size of the pieces forming this tesselate ground
depends solely upon the fineness of the definition. With every increase in
the power of seeing, each areola is cut into still smaller portions, usually by
connection between its corners. Thus a polygon or rhombus is split into
triangles which may themselves be divided in like manner, the mosaic
breaking into bits, the sides of which, however, always remain clean-cut.
From this arrangement it is at once evident that the canals are not
fortuitously placed. That lines should thus meet exactly and in numbers at

particular points, and only there, shows that their locating is not the
outcome of chance. If very thin rods be thrown haphazard over a surface,
the probability that more than two will cross at the same point is
vanishingly small. Increasingly assured is it that this would not happen
generally. The result we see is therefore not a matter of chance, but of some
law working to that end.
To the detection of what that law is precedes the easier ascertainment of
what it is not. The lines, for example, cannot be rivers, which was the first
explanation offered of them by Proctor many years ago, because of their
peculiar straightness. Nor can they be channels, the name given to them by
Schiaparelli, except in the non-committal sense in which he used the term.
For here again their geometric regularity is bar to any estuary-like
hypothesis. For quite another reason they cannot be cracks, because of their
uniform size throughout. Their unbroken character is another fatal objection
to the same suggestion. For cracks in ground never pursue for any great
distance a continuous course, any more than they keep uniform or straight.
The state of an old ceiling is a case in point. When it breaks, it does so in
fissures that proceed a certain way, then give out to be continued by others
roughly parallel to the first, but parted from them. The same character is
shown by the rills on the moon. The ‘Straight Wall,’ so called, is composed
of three such sections, and the little rill to the right of it, west of Birt, of
four.
Thus were they seen at Flagstaff, and as, to the writer’s knowledge, they
have not been so depicted elsewhere, the fact may serve to give some idea
of the definition there.
That the underlying cause is not explosion or contraction is also
evidenced by the canals collectively as well as individually, their
arrangement into a system, for cracks, however produced, could only
originate from certain centres and could not fit into those starting from
others, as the canals invariably do. For each canal goes as undeviatingly to
one terminal as it left forthrightly from another. If one wishes to see what
explosion or contraction can do, he has only to look at the moon through an
opera-glass, when he will be shown a very different sight from what the
drawings of Mars detail. Thus just as, considered individually, the lines
cannot be watercourses because of their straightness, so they cannot be
cracks because of dovetailing into one another.

The fact that they form a system shows that whatever caused them
operated over the whole planet, linked in cause as in effect throughout each
section. This at once negatives any purely physical cause of which we have
cognizance. For upon a globe still so subject to physical vicissitude as Mars
by its aspect shows itself to be, latitude must tell in the phenomena its zones
exhibit. Polar snows that wax and wane speak of arctic conditions very
diverse from temperate and tropic states, and what would affect the one
could not influence the other. Yet the mesh rises superior to zonal
solicitation as to local barrier. It is not something dependent either on the
temperament or the complexion of the globe’s different parts. It transcends
surface restriction and becomes planet-wide in its working. The importance
of this omnipresence dilates in meaning as one dwells in thought upon it.
Ubiquitous as it is, the mesh which thus covers the Martian surface like a
veil spread completely over it, is unlike a veil in being of irregular texture.
Not only are the interstices of various shape and pattern, but the mesh itself
is of locally differing size. Though the threads are straight and uniform
throughout, they are not all alike, besides being unsymmetrically
interwoven. Some are at least of ten times the coarseness of others, and
from this fact and the bo-peep effect of our air waves all are not visible at
once. In consequence the network is not so impressive at first glance as it
becomes upon a synthesis of the observations. When this is done, the
surface proves to be fairly evenly cut up, as recourse to the maps printed in
this volume will amply demonstrate. These maps, as on page 31, are made
from the results of but one opposition, and as at each opposition some zone
is in a more canal-showing state than others, owing to the Martian season at
the time, a still greater uniformity in canal distribution results from a
blending of many.
From the completeness of the mesh, it follows that in the course taken
severally by the canals no one direction preponderates over another.
Considered by and large, the canals seem to be equally distributed round the
compass points; and this at all longitudes and nearly all latitudes. Tropic,
temperate, and even arctic canals show a pleasing impartiality in the matter
of the course pursued. The only exceptions occur in the neighborhood of the
pole. There a slight tendency may be seen to a north and south setting.
Though so much is visible in a general way from the map, it is of interest
to go into the subject with more particularity and to that end to show it
statistically. The several canals traversing each zone were therefore

counted, and the area of the zone computed. The manner of canal
distribution thus found is given in the following table, in the second column
of which stand the areas of the several zones upon the planet, each ten
degrees wide, except the one next the snow, and in the third the number of
canals found traversing them, reduced to percentages of the 0°-10° zone. A
fourth column shows the total length of the canals in each zone, those from
0° to 20° being taken from the 1896 globe, those from 20° to 90° from the
1903. This is in order to annul the effect of the seasons upon the showing of
the canals as much as possible.

Zone Area No. of Canals Wtd. Actual Length
0°-10° 1.00 1.00 1.00
10°-20° .97 .89 .91
20°-30° .91 .93 .72
30°-40° .82 .90 .71
40°-50° .71 .78 .66
50°-60° .58 .64 .59
60°-70° .42 .43 .42
70°-80° .26 .30 .34
80°-85° .07 .12 .11

The numbers continue fairly non-committal until we begin to approach
the pole, when they commence to increase. Much the same result is got if
we take the actual canal-lengths in each zone, as the fourth column shows.
The crowding of the canals poleward is marked. The canals, therefore, are
phenomena that stand in peculiar relationship to the polar cap. This
corroborates the inference about them due to their running out of the edge
of the snow. They not only emanate from it, but they do so in numbers
surpassing what is elsewhere observable over the disk.
Otherwise is it with their departure-points. These are not scattered
haphazard over the surface, but bear to its general features definite
relations. If we consider the map, obliterating the lines, and then seek to
connect the most salient points of the planet’s topography by direct avenues
of communication, we shall find that our putative lines fall exactly where
the real ones occur. For the most part, the real lines emanate from well-

marked indentations in the dark regions, fitted by natural position for
departure-points, what, if these were seas, we should call their most
conspicuous bays. They thus leave in the southern hemisphere the deeper
folds of the great diaphragm, for the most part; though on occasion they run
out of them where they will. From equally conspicuous points in the dark
northern areas other lines proceed; while in the centre of the continents, the
canals make for more or less salient spots, small patches of shading like the
Trivium or the Wedge of Casius, or simply round black radiants, like the
Luci Ismenii.
From this it appears that the lines are locally dependent upon the general
topography of the fundamental features of the surface. For some reason
they connect the very points most suggestive of intercommunication. As
from their characteristics it is perfectly evident that the lines are neither
rivers nor cracks, it follows that such a communicating habit is of the most
telltale character. To be so dissimilar in kind from the main markings and
yet so dependent upon them, hints that their positioning occurred after the
formation of the main features themselves. We reach thus from the look of
the lines and their location a most striking deduction, that the lines are not
coeval with the main markings, but have come into being later and with
reference to the general topography of the planet. The network is not only a
mesh de facto, then, but one de jure, which, subsequent to the fashioning of
the seas and continents and what these have now become, has been
superposed upon them.

CHAPTER XVII
GEMINATION OF THE CANALS

F raught with more difficulty than the detection of the lines alone is the
next discovery made upon the disk: the recognition of pairs of lines
traversing it.
In 1879, while Schiaparelli was engaged in scrutinizing the strange
canali he had discovered on the planet the opposition before, he was
suddenly surprised to mark one of them double. Two closely parallel lines
confronted him where but a single one had previously stood. So
unaccountable did the sight seem, that he hesitated to credit what he saw,
being minded to attribute the vision to illusion of some sort and the more so
that it was not renewed. While he was still wondering what it meant, the
planet parted company with the Earth, carrying its enigma with it.
When the two bodies again drew near to one another in 1882,
Schiaparelli set himself to watch for a recurrence of the strange
phenomenon. Before long it came, and more bewilderingly than at first; for
not one canal alone, but a score of them now showed in duplicate, each
presenting to his astonished gaze twin lines perfectly matched and
preserving throughout their distance apart. Suspecting diplopia or some
other optical trick, he tried various eyepieces to a test of the cause but to no
change in the effect. The twin lines continued visible, do what he would,
insisting on their own reality in spite of all solicitation to merge. How
cautious he was in the matter, and how unwilling at first to believe the
evidence of his eyes, is shown by the care he took to guard against
deception. It was not until he had assured himself of the reality of the
phenomena that he believed what he had seen.
It so chanced that my first experience of the thing was almost equally
startling, so unexpected was it and so exceedingly sharp was the definition
at the time. It was in an autumn early twilight, through air almost perfectly

still, as the light went out of the sky and the markings on the planet began to
come forth that the Phison of a sudden showed in duplicate to me, clear-cut
upon the disk, its twin lines like the rails of a railway track traversing Aeria.
Not more vivid do those of our transcontinental tracks appear as one sees
them stretching off into the distance upon our Western plains. More
impressive was the sight from the fact that I was not looking for it. It simply
suddenly stood forth, this strange parallelism of pencil lines. My surprise
matched the wonder of the sight.
Since then I have witnessed it several hundred times, but never with more
absolute certainty than at that first fortunate revelation. To this distinctness
is due the amazement it then aroused. Not simply because of its surpassing
novelty, but for the insistence with which it proclaimed itself was the effect
to be ascribed. Less well seen, doubt had robbed it of its full surprise. It
requires as a rule steady definition for its initial unmistakable showing, if
one would be instantly convinced. Except for such it is not usually easy to
the unpracticed, though often discernible to the expert after it has once been
seen. But that it is real no one who had had a good view of the sight could
doubt; still less after the experience had been repeated over and over again.
What appears to take place is this: where previously a single pencil-like
line joined two well-known points upon the disk, twin lines, the one the
replica of the other, stand forth in its stead. The two lines of the pair are but
a short distance apart, are of the same size, of the same length, and
absolutely equidistant throughout their course. It is as if a second line had in
some way been mysteriously added to the first since the latter was last seen
some weeks before. This in a word is the phenomenon, technically called
the gemination of the canals, which has since its discovery called forth so
much comment. It is not in reality quite as simple or as sudden as it seems,
but this was the way in which the phenomenon was first seen and in which
it still continues to be criticised.
Self-assertive of reality, the double lines are patently objective to him
who is fortunate enough to see them well. Nevertheless the great difficulty
of detecting them, and the still greater difficulty of conceiving how such
things can be, has led many not versed in the subject to disbelieve and from
that to attempt to explain the sight as illusory. Scepticism seeks self-
justification; what is hard of acceptance for its strangeness begetting
hypotheses of committed error which find easy credence for their
comforting conservatism. Several such have in consequence been

propounded to account for the double canals. There is the diplopic theory
which credits them to non-focusing; the interferential theory which would
make them optical products of the telescope; and the illusion theory which
would have them quite simply imaginary.
Inasmuch as in any research the assurance that a phenomenon is real is
the first point about it to be established, it is a scientist’s duty, not only to
scan the phenomena with jealous care to that end, but to scrutinize every
theory which would seek otherwise to account for them—the testing such
being only second in importance to observing the things themselves.
Accordingly I have examined each of the optical theories that have been
advanced and critically compared what they assert and require with the
results of observation. The outcome of this research has proved as
negativing to any other origin for the double canals than reality as direct
observations at the telescope are positive on the point. To show this I shall
review each in its consequences, confronting it with what the telescope has
to say on the subject; for it is of the pith of the matter that the reality should
be as demonstrable on demand as on sight. Furthermore, I shall do this
before embarking on the general account of these strange things, because it
is vital to any interest that one should be assured from the start of the truth
of what he is to read. The preface may seem to him abstruse and prosy, but
it will introduce him to some curious optical properties and will eventually
enhance his concern by proving to him that what reads like fiction is all the
more wonderful for being fact.

I. The Diplopic Theory

Diplopia is the property of seeing double with one eye. Surprising as it
sounds it is an effect not unknown to students of optics, though it usually
requires training to produce. It is possible only when the eye is not focused
on the object, and is not always possible then. From my experiments its
feasibility seems to depend upon whether the focus be beyond or before
what it should be. If the eye be focused for a point beyond the object, the
object is doubled, if for a point this side of it, the latter is simply blurred.
When the double is formed, the amount of the separation of the two images
is a function of the distance the focus is out. The greater the discrepancy,
the wider apart is the ensuing double. Nor does the image, of a line, for
example, stop at doubling. After a certain breadth of separation is reached a
third line appears, bisecting the interval between the other two. With yet
greater widening the third line itself splits into a pair and so the resolution
goes on. In my own experiments I have gone so far as to suspect a fifth line.
Far from being unconscious, the process of producing the phenomenon is,
with some people, of difficult accomplishment. Mr. Lampland, for instance,
of the Flagstaff Observatory, to whom we owe the first photographing of
the canals, and who sees the doubles of Mars without difficulty, has hitherto
found diplopic vision an impossible feat. Even with the most practiced
diplopia is never unconscious except when the object viewed, as a
micrometer wire, has nothing to locate it in space. Now, the diplopic theory
of the double canals supposes that in all cases the eye of the observer is thus
unconsciously out of focus.
To this method of their manufacture the telescopic phenomena prove
unamenable on five counts.
1. Focusing the eye on an object is now a reflex action, so automatic has
it become; in consequence one is commonly directly conscious when an
object is not in focus, always so when the object presents detail. Were such
not the case we should never, except by chance, see anything defined.
Observing through a telescope, after a modicum of practice, differs in no
respect from observing in everyday life. Consequently, that an experienced
observer should not know his business in so primary a matter is

preposterous. One may or may not believe that “the undevout astronomer is
mad,” but that the perpetually unfocused one would be is beyond debate.
2. Generically unlikely, the failure to focus is here specifically out of the
question. For the observer does not use the canals to focus on for the simple
reason that he cannot. Like all delicate detail, the doubles appear not
continuously but by flashes of revelation, according as the atmospheric
waves permit of passage undisturbed. To focus on them would be next to
impossible even were it resorted to—which it never is. By the exponents of
the theory this important fact is overlooked: the unforeseen showing of the
canals and therefore the absolute lack of complicity of the eye in the matter.
What one focuses on is the look of the main markings of the disk. Now, to
suppose an observer systematically out in his perceptions of so featureful a
planet as that of Mars, so that he does not know when he sees its image
sharp, implies a lack of knowledge of astronomic observation in the
supposer.
3. Study by the writer shows the width of a given double canal to be
constant for a given date. Within the errors of perception or recording the
twin lines are always at the same epoch the same distance apart. The greater
the number of determinations made, the nearer the result approaches to this
mean; and the greater the care used in delineation, the less each value
departs from it.
Now, if the thing were a matter of mistaken focusing, an eye could not be
thus true to its own mistakes. If it were out in its focus by a certain amount
at one time, it would be likely to be out by a different amount at another. So
that by the very terms of its making a diplopic double would be sure to
vary. Indeed, in laboratory experiments it is impossible to prevent it. For the
eye rests itself automatically by change of focus, and if it be not
consciously kept awry it reverts as near to the true focus as it can of its own
accord.
4. Diplopia might be a respecter of persons, but it certainly could not be
one of canals. For a given observer it must be objectively general in its
application to the same class of objects. Consequently, if the doubling were
diplopic, all canals inclined at the same angle to the vertical—for the tilt
might affect the result were the eye astigmatic—should be similarly
affected. Parallel canals should parallel each other’s action. With the
Martian doubles this is not the case. Of two canals similarly inclined the
one will be double, the other not, at the same instant and under conditions

that are alike. And this persistently. For gemination is an attribute of certain
canals and never of others. At a given season of the Martian year, some
canals are regularly double, some invariably single. Night after night and
presentation after presentation these idiosyncrasies are preserved: the
doubles, always pairs, the single, always alone. Nor does the strength of the
line affect the action. The single canals are some of them stronger, some of
them weaker, than the doubles seen at the same time.
5. If of diplopic origin the mean width of all the doubles should be the
same. For though the diplopic width would vary for a given canal according
to the moment, a sufficient number of views would yield a mean width
which would be the same for all. Tilt apart, the mean width of one canal
would be that of another. Among Martian doubles, on the contrary, I have
found the width to be a specific property of the particular canal. Each has its
own mean width regardless of inclination, and this individual width differs
as between one and another by as much as five to two, or, if we consider
such canals as the Nilokeras I and II, by more than ten to two.
Any one of these five points is fatal to the theory; a fortiori all.

II. The Interference Theory

From the wave propagation of light it follows that the image of a bright
line made by a lens is not itself a simple bright line but a bright band
flanked by alternate dark and bright ones. It has, therefore, been suggested
that a bright medial line is here concerned and that the double canal is the
first of its dark pair of outriders. But the suggestion does not bear scrutiny.
1. It presupposes a central streak brighter than the rest of the disk to give
birth to the twin dark lines. This should itself be visible in the image; but no
such bright backbone is seen.
2. It demands a perfectly definite width of separation for a given aperture
—which is not that observed.
3. It makes the width a function of the aperture, decreasing as this
increases—which is not sustained by observation. Different apertures
produce no effect on the widths of the Martian doubles, as the writer has
shown (Lowell Observatory Bulletin, No. 5) by a change of aperture from
twenty-four to six inches.
4. Under like optical conditions the optically produced doubles would be
all of a width; while the Martian ones show idiosyncratic widths, each
peculiar to itself.

III. The Illusion Theory
Known also as the Small Boy Theory from the ingenuous simplicity on
which it rests, this theory attacks the reality of the doubles by questioning
that of the canals en bloc. Because some boys from the Greenwich (Reform
or) Charity School, set to copy a canal-expurgated picture of the planet,
themselves supplied the lines which had preceptorily been left out, the
Martian canals have been denied existence; which is like saying that
because a man may see stars without scanning the heavens, therefore those
in the sky do not exist. As to the instructions the boys received we are left in
the dark. It looks as if some leading questions had unconsciously been put
to them. At all events, English charity boys would seem to be particularly
pliant to such imagination, for when Flammarion retried the experiment
with French schoolboys, and even inserted spaced dots for the canals in the
copy, not a boy of them drew an illusory line.
The fact is, this is one of those deceptive half-truths which is so much
more deleterious than an unmitigated mistake. Under certain circumstances
it is quite possible to perceive illusory lines, due either to shadings
otherwise unmarked and thus synthesized or to immediately precedent
retinal impressions transferred to places where they do not belong by rapid
motion of the eye, as I had myself discovered before the English experiment
had been tried. But, as I have also found out, these effects are produced
only at the limit of vision, and in that limbo of uncertainty the whole art of
the observer consists in learning to distinguish the true from the false.
Strength of impression, renewed effect in situ, and a peculiar sense of
reality or the reverse enable him to adjudge the two. More experience than
the boys possessed would have helped them to part the sheep from the
goats. But, furthermore, and fatally to the theory here in question, the
Martian canals when well seen are not at the limit of vision as its framers
supposed, but well within that boundary of doubt; so that the premise upon
which the whole theory rests gives way. Under good atmospheric conditions
the canals are comparable for conspicuousness to many of the well-
recognized Fraunhofer lines and are just as certainly there.
Thus each attempt to prove the doubles non-objective turns out when
specifically examined to be inconsistent with the facts. With the assurance

of their reality thus made doubly sure, we pass to consideration of the
things themselves.

CHAPTER XVIII
THE DOUBLE CANALS

I

R ightly viewed, no more subtle tribute could be paid to the remarkable character of
the phenomenon of gemination than the scepticism with which it was immediately
received and which it still continues to elicit. That the sight should be regarded as
illusory speaks for its surpassing strangeness; and so far as oddity goes the encomium
is certainly deserved. Of the bizarre features of this curiously marked disk, the double
canals were at the time of their discovery the culmination, and though things stranger
still if possible have since been seen there, it is not wonderful that doubt should still
incredulously stare. If the mere account of them reads like romance, to see them is an
experience.
Nothing astronomical that I have ever seen has been so startlingly impressive as my
first view of a double canal. Even in narration the thing justifies its effect. For a double
canal consists of a pair of twin dark filaments, perfectly parallel throughout their course
and inclosing between them ground of the same ochreish cast as that which lies
without. Only on occasion is this tint of their midway departed from, and then only
toward a darkening, never toward a lightening of it. Except for appearing paired, the
lines resemble precisely the usual single canals. In length they vary from a few hundred
to a few thousand miles, while in width each component, for narrowness, hardly
permits of definite ascription.
Compared for strength with the usual canal the lines of a double seem to hold on the
average an intermediate position between the larger and the smaller of the single canals
so far detected. Owing, however, to the massed effect of the pair by reason of their
closeness, they have an advantage in showing over the singles of two to one. And this
renders them among the most conspicuous and important meshes of the canal network.
Like the single canals, they vary in strength with the Martian time of year; at certain
seasons developing into heavy pencil lines and at others fading away to the merest
gossamers, only just discernible like cobwebs stretched across the face of the planet.
Although the individual constituent lines vary in aspect and never rise at their most
to cognizable breadth, the distance parting their centres, or the width of the double, is
quite measurable. The only difficulty in the way of its determination lies in the absence
of a procurable unit small enough to mete it. The usual spider-threads of the

micrometer are colossal in comparison with these filaments and present a standard only
analogic at best. Nevertheless, by means of the finest threads that could be got,
estimates of the distance between the pairs were made at Flagstaff in 1905, and the
results agree as closely as the means permit with those got by measurement of the
doubles as depicted in the drawings.
Of what they look like, the following
illustrations give a fair idea, only that instead
of being more geometrically regular in the
drawing than in reality the fact is the other
way. Freehand draftsmanship at the telescope
is incapable of rendering their ruled effect. No
railway metals could be laid down with more
precision. As to their size, the following
figures derived from a typical double canal,
the Phison, give some conception. This great
artery of intercommunication between the
Sabaeus Sinus and the Nilosyrtis is, roughly
speaking, 2250 miles long; the distance
between the centres of the two constituents is
about 130 miles, and each line is perhaps 20
Martian doubles. miles in breadth, when at its maximum
strength. The pair follow, apparently, the arc
of a great circle from the Portus Sigaeus on
the Mare Icarium to the Pseboas Lucus in latitude 40° north. The Portus Sigaeus
consists of two little nicks in the coastline, looking like the carets one makes in
checking off items down a list, if the space between the down and up strokes were then
filled in; the Pseboas Lucus, on the other hand, is a large round dot like a small ink
spot. To these two differently appearing spots, the twin lines of the Phison behave
differently. While each line leaves centrally its own caret of the Portus Sigaeus at the
south, at the north each touches peripherally the Pseboas Lucus, on the east and west
sides respectively, the two thus just holding the Lucus between them. In position the
lines are invariable, though in visibility not. Sometimes only one is seen, sometimes
both show faintly, and sometimes both are conspicuously strong. The delicacy of the
observations by which this detail was established is second only to its importance. It
destroys at a stroke all possibility of diplopic unreality, since were that the fact the
Pseboas Lucus should be doubled, which it is not. At the same time it opens vistas into
the true construction of the things themselves, at present more suggestive than
satisfactory.
In the great circle character of its course the Phison is quite normal. The majority of
the double canals pursue the like method, running straight over the surface from one
point to another, the constituents remaining equidistant throughout. But such
forthrightness of direction, though the rule, is not without exceptions. The Thoth-
Nepenthes, for example, sweeps round in a seemingly continuous curve to the west-

southwest from the Aquae Calidae to the
Lucus Moeris like some mighty bow
perpetually bent. Nevertheless its lines are no
less careful for all their curving to keep their
distance from one end to the other of their
course. The quality of being paired rises
superior to change of direction.

II

Now, the first point to be noticed about the
doubles is that bilateralism, or the quality of
being double, is not a universal trait of the
canals, either actually or potentially; it is not
even a general one. Out of the four hundred Martian doubles (corroborating the
canals seen at Flagstaff, only fifty-one have at above).
any time displayed the quality; that is, one
eighth roughly of the whole number observed.
This point is most important; for the fact is of itself enough to disprove any optical
origin for the phenomenon. The characteristic of doubling so confidently ascribed by
those who have not seen it to general optical or ocular principles proves thus the
exception, not the rule, with the canals, and by so doing disowns the applicability of
any merely optical solution. We shall encounter many more equally prohibitive bars to
illusory explanation before we have done with the doubles, but it is interesting to meet
one in this manner at the very threshold of the subject.
On the other hand, the characteristic when possessed is persistent in the particular
canal, in posse if not in esse. Once shown by a canal, that canal may confidently be
looked to at a proper time to disclose it again. In short, bilateralism, or the state of
being dual, is an inherent attribute of the individual canal, as idiosyncratic to it as
position and size.
The catalogue of canals possessing this property, so far as they have been detected at
Flagstaff to date, number fifty-one if we include in the list wide parallels like the
Nilokeras I and II. Eight of these were observed in 1894; nineteen more were added in
1896, making twenty-seven; in 1901 the total was raised to thirty; in 1903 to forty-
eight; and in 1905 to fifty-one. Arranged by years they are tabulated below, where the
numeral to the left registers for each its first recording and the position held by it in the
list. The starred canals much exceed the others in width, and possibly denote a different
phenomenon.
Date Confused
1894
1. Ganges

2. Nectar
3. Euphrates
4. *Nilokeras I and II
5. Phison
6. Asopus
7. Jamuna
8. Typhon
1896-7
Ganges Typhon
Euphrates Avernus S.
Phison
9. Lethes
Jamuna
10. Dis S.
11. Titan
12. Laestrygon
13. Tartarus
14. Cocytus
15. Sitacus
16. Amenthes
17. Adamas
18. Cerberus N.
19. Cerberus S.
20. Cyclops
21. Gelbes
22. Erebus
23. Avernus N.
24. Gigas
25. Alander
26. Gihon
27. Hiddekel
1900-1
Phison Dis S.
Euphrates Boreas
Hiddekel Cerberus S.
Amenthes Jamuna

Cerberus N. Pyramus
Cyclops Laestrygon
Ganges
28. Deuteronilus
Sitacus
Adamas
29. Djihoun
Gihon
30. Is
1903
Djihoun Typhon
Hiddekel Orontes
Phison
Euphrates
31. Protonilus
Gihon
32. Marsias
Amenthes
Laestrygon
Cyclops
Gigas
*Nilokeras I and II
Ganges
Deuteronilus
33. Pierius
34. Callirrhoe
Jamuna
Sitacus
35. Astaboras S.
36. Nar
37. Chaos
38. Aethiops
39. Hyblaeus
40. Eunostos
41. Thoth
42. Nepenthes

43. Triton
44. Pyramus
45. Fretum Anian
46. Vexillum
Lethes
Cerberus S.
47. Nilokeras I
Cerberus N.
48. Tithonius
1905
Nilokeras Ganges
Hiddekel Chrysorrhoas
Djihoun
Sitacus
Phison
Euphrates
Amenthes
Vexillum
Astaboras S.
Adamas
Cyclops
Cerberus S.
Cerberus N.
Tartarus
49. *Propontis
Gigas
Gihon
Nepenthes
Thoth
Laestrygon
50. Polyphemus
Deuteronilus
Triton
Eunostos
Tithonius
Callirrhoe

Pyramus
Nar
Protonilus
51. Naarmalcha

In spite of possessing the property of pairing, a canal may not always exhibit it. To
the production of the phenomenon the proper time is as essential as the property itself.
So far as a primary scanning or first approximation is capable of revealing, a canal will
be single at one Martian season and double at another. Thus these canals alternated in
their state to Schiaparelli and for the earlier of his own observed oppositions to the
writer. In consequence Schiaparelli deemed gemination a process which the canal
periodically underwent. Three stages in the development were to him distinguishable:
the single aspect, a short confused aspect, and the clearly dual one.
In the single state the canal remained most of the time. It then underwent a chrysalid
stage of confusion to emerge of a sudden into a perfect pair. Furthermore, he noted the
times at which the pairing took place, to the formulating of a law in the case—derived
from the observations of more than one opposition. His law was that the gemination
occurred, on the average, three months (ours) after the summer solstice of the northern
hemisphere, lasted four to five months, then faded out to begin afresh one month after
the vernal equinox of the same hemisphere and continue for four months more.
Expressed in Martian seasonal chronology, the periods would be about half as long. At
certain times then the most pronounced specimens of doubles showed obstinately
single, while the periodic metamorphosis that transformed them into duplicates was
timed to the changes of the planet’s year. Gemination, then, was a seasonal
phenomenon.
Advance in our knowledge of the phenomenon since Schiaparelli’s time, while still
showing the thing to be of seasonal habit, has changed our conception of it. It now
appears that in some cases certainly, and possibly in all, the dual aspect is not a
temporary condition, but the differing pronouncement of a permanent state, the fact of
gemination so called being confined to a filling out of what is always skeletonly there.
As the canals have come to be better seen, the three stages of existence have in some
cases become recognizable as only different degrees in discernment of an essential
double condition; the single appearance being due to the relative feebleness of one of
the constituents and the confused showing to the weakness of both, which are then the
more easily blurred by the air waves. In certain canals the last few oppositions, 1901,
1903, and 1905, have disclosed this unmistakably to be the case, as with the Phison and
Euphrates, for example. With them the double character has been continuously visible,
appearing not only when by Schiaparelli’s law it should, but at the times when it should
not; only on these latter occasions it was harder to see, whence the reason it was
previously missed. So that further scrutiny, while in no sense discrediting the earlier
observations, has extended to them some modification, and disclosed the underlying
truth to be the varying visibility, the thing itself, except for strength in part or whole,

persisting the same. Improvement in definition has lowered the see-level to revelation
of continuous presence of the dual state. It is only on occasion that the improvement is
sufficient for the thing when at its feeblest to loom thus above the horizon of certainty;
yet at such moments of a rise in the seeing it is enough to allow it to be glimpsed. Thus
it fared with the Adamas at the opposition of 1903, with the Gigas, and with many
another in years gone by. Separation has come with training and generally in the case
of the wider doubles, which leads one to infer that ease of resolution is largely
responsible for assurance of the permanency of the dual state. Perplexing exceptions,
however, remain, so that it is possible at present only to predicate the principal of most
of the double canals but not of all. Leaving the exceptions out of account for the
moment, we pass to those general characteristics which are intimately linked with what
has just been said.
Inasmuch as the act of getting into a state antedates the fact of being there, it is
logical to let the description of the first precede. An account of the process of
gemination may thus suitably come before that of its result.
Flux, affecting the double canals in whole or part, is the cause of the apparent
gemination. According as the flux is partitive or total is a single or a dual state
produced. At the depth of its inconspicuousness the canal may cease to be visible at all;
this occurs when both lines fade out. On the other hand, the one line may outfade the
other, and we are presented with a seemingly single canal, at this its minimum
showing. In such seasons of debility the one line may appear and the other not, or
occasionally the other show and the one not, according to the air waves of the moment.
It is at these times that the double simulates a single canal, and unless well seen and
carefully watched might easily masquerade successfully as such. The Hiddekel in the
depth of its dead season is peculiarly given to this alternately partitive presentation. As
the flux comes on, one or both lines feel it. If one only we are likely to have a confused
canal; if both, a difficult double. The strength of the lines increases until at last both
attain their maximum, and the canal stands revealed an unmistakable pair, the two lines
paralleling one another in appearance as in position.
At the canal’s maximum and minimum the equality of its two constituents is chiefly
to be remarked, though it occurs on other occasions as well. But, what is significant,
when the two differ it is always the same one that outdoes its fellow. It may be the
right-hand twin in one pair, the left-hand one in another; but whichever it be, for the
particular canal its preëminence is invariable. It is this canal which, except for
adventitious help or hindrance from the air-waves, alone shows when the double
assumes the seemingly single state. We may therefore call it the original canal, the
other being dubbed the duplicate. In some cases it has been possible to decide which is
which. It might seem at first sight as if this point should always be ascertainable. But
the determination is more dilemmic than appears, not from any difficulty in seeing the
canal, but from the absence of distinguishing earmark at its end. In a long stretch of
commonplace coast, the precise point of embouchure of a solitary canal cannot be so
certainly fixed as to be decisive later between two which show close together in the
same locality. It is only where some landmark points the canal’s terminal that the

problem admits of definite solution. This telltale tag may be a bay like the Margaritifer
Sinus, or double gulfs like the Sabaeus Sinus, or portions of a marking not too large to
permit of partitive location like the Mare Acidalium, or a canal connection like the
Tacazze which prolongs the one line and not the other. In these and similar instances
the two lines become capable of identification, and in such manner have been found
those comprised in the following list:—

Double Canal Original Line Date of Ascertainment
Phison The Eastern 1894
Euphrates The Western 1894
Titan The Western 1896
Hiddekel The Eastern 1896
Gihon The Western 1896
Gigas The Northwestern 1896
Djihoun The Western 1901
Laestrygon The Eastern 1903
Nilokeras I and II The Northern 1903
Astaboras The Southern 1903
Jamuna The Eastern 1905
Ganges The Western 1905

In this list of originals the canals stand chronologically marshaled according to date
of detection. The Phison and Euphrates were the first to permit of intertwin
identification in 1894, while the Jamuna and Ganges were the last to be added to the
column in 1905. The list is not long, though the time taken to compile it was. In the
case of the Ganges and the Jamuna, for example, although suspected for some time on
theoretic grounds, it was only at the opposition just passed that the fact was
observationally established. In his Memoria V, Schiaparelli has a list of similar
detection, and if the present list be compared with his, the two having been
independently made, the concordance of the result will prove striking, corroborative as
it is of both. For the necessary observations are very difficult.
Having thus realized the original by means of its superior showing, and then
identified it by its position, it is suggestive to discover that the duplicate betrays its
subordinate character, not only by its relative insignificance, but by its secondary
position as well. The original always takes its departure from some well-marked bay,
seemingly designated by nature as a departure-point, or from a caret belonging clearly
to itself; the adjunct, on the other hand, leaves from some neighboring undistinguished
spot, as in the case of the additional Djihoun, or makes use of a neighbor’s caret, as in
the case of the second Phison and the supplementary Euphrates. In either case it plays
something of the part of an afterthought; and yet the postscript when finished reads as

an integral part of the letter. An example will serve to make the connection evident
while leaving the character of the connection as cryptic as ever.
In the long stretch of Aerial coastline bounding the Mare Icarium, which sweeps
with the curve of a foretime beach from the Hammonis Cornu to the tip of the Edom
Promontory, there stand halfway down its far-away seeming sea-front two little nicks
or indentations. Even in poor seeing they serve to darken this part of the coast while in
good definition they come out as miniature caret-like bays. They are the Portus Sigaei,
and mark the spots where the Phison and the Euphrates respectively leave the coast.
About four degrees apart, the eastern makes embouchure to the original Phison, the
western to the original Euphrates, and each in some mysterious manner is associated
not only in position but in action with the canal itself. In the single state each canal
leaves the Mare from this its own caret, the Phison proceeding thence northeast down
the disk, the Euphrates nearly due north, so that starting four degrees apart at the south
they are forty degrees asunder at their northern termini. Clearly at these latter points
they are not even neighbors, and except for the accident of close approach at their other
ends have nothing in common anywhere. And yet when gemination takes place a
curious thing occurs: each borrows its neighbor’s terminal as departure-point for its
own duplicate canal. Having thus got its base the replica proceeds to parallel its own
original canal without the least reference to the other canal whose own caret it has so
cuckoo-wise appropriated. What the Phison thus does to the Euphrates, the Euphrates
returns the compliment by doing to the Phison. In this manner is produced an
interrelation which suggests, without necessarily being, an original community of
interest; suggests it on its face and yet appears to be rather of the nature of an
adaptation to subsequent purposes of a something aboriginally there.
That such latter-day appropriation is the
fact is clearly hinted by the behavior of
another understudy of an original canal, in this
case the duplicate of the Djihoun, which in
consequence of the position of its original
finds no neighboring embouchure already
convenient to its use. The single or original
Djihoun leaves the tip of the needle-pointed
Margaritifer Sinus, which serves a like end to
the Oxus and the Indus, both single canals.
The Sinus is itself a single bay, and so large Mouths of Euphrates and Phison.
that for many degrees its shores on both sides
converge smoothly to their sharp apex. June. 1903.
Because of this probably, the coast in the
immediate neighborhood is without canal
connection, no canal being known along either side till one reaches the Hydraotes at the
Aromaticum Promontorium, which marks the western limit of the gulf. The
consequence is that when the Djihoun doubles, the duplicate canal, not having any
terminus ready to its hand, has to make one for itself by simply running into the

Margaritifer Sinus, some distance up its eastern side. It thus advertises its adjunctival
character, and at the same time the general fact that a neighbor’s terminus, though used
from preference, when convenient, is not an essential in the process. Gemination occurs
of its own initiative, but is conditioned by convenience.
Whether one canal shows thus to the exclusion of the other, or whether both stand so
confused as not to be told apart, the fact remains that the double is not always
recognizable as such. If we turn to the list of the doubles on page 222, we shall note
that the same canals were not always seen in the dual condition at successive
oppositions. Some, indeed, are so emphatically of the habit as to appear year after year
in a paired state, but others are not so constant to their possibilities. Now, when it is
remembered that at different oppositions we view Mars at diverse seasons of its
tropical year, we see that this means that the phenomenon is seasonal; and furthermore
that its exhibition depends upon the canal’s position. Gemination, like the showing or
non-showing of the single canal, is conditioned by the place of the canal upon the
planet.

III

Turning from such generic characteristics to more specific traits, the first thing to
strike an attentive observer is that the doubles differ in width; that they are not
mensurably alike in the property they hold in common of being paired. In some the
twin lines are obviously farther apart than in others, and the relation persists however
repeated the observations. Of two doubles the one will always surpass its fellow. This
contrasted individuality first struck me in the Phison and the Euphrates; and from the
first moment at which these doubles showed as such. The Phison pair seemed
perceptibly the narrower of the two. A like distinction was evident at the next
opposition and the next; in fact, at every succeeding one to the present day. Nor was the
recognition of the fact confined to me. If we turn to Schiaparelli’s Memoriae we shall
find that that master had registered the same idiomatic width for the two canals from
first to last throughout his long series of records. The observation thus made proved to
apply to each and all of these curious twins.
Diversity in width for different doubles appears plainly in drawings where more than
one double is depicted. As an example, two drawings are here given in the text, made,
the one on July 13, 1905, λ15°, and the other on July 20, λ313°. In them the Phison,
Euphrates, Djihoun, and Thoth appear contrasted as unmistakably as either of them
does with the single canals apparent at the same time. That this drawing is typical is
borne out by all the best measures of the several doubles as seen at successive
oppositions, and marshaled in the subjoined list. How truly individual the quality is
stands proved by the relative values in different years which are even more accordant
than the absolute ones.
The canals were:—

Width
1903 1905 Mean
1. Phison 3.5 3.4 3.4
2. Euphrates 4.0 4.2 4.1
3. *Protonilus 2.8 2.0 2.4
4. Deuteronilus 2.2 2.4 2.3
5. Pierius 2.5 — 2.5
6. Callirrhoe 2.5 *2.1 2.3
7. *Hiddekel 3.8 4.9 4.3
8. *Gihon 3.9 4.9 4.4
9. Djihoun 2.0 1.9 1.9
10. Sitacus 3.8 *3.3 3.6
11. Jamuna 4.5 — 4.5
12. Ganges 5.0 5.2 5.1
13. Nilokeras I and II 11.0 11.7 11.3
14. Nilokeras I 2.3 — 2.3
15. Gigas 3.5 — 3.5
16. Laestrygon 2.2 — 2.2
17. Cerberus N. 4.0 — 4.0
18. Cerberus S. 4.0 — 4.0
19. Cyclops 2.9 *2.2 2.6
20. Nar 2.6 2.0 2.3
21. Fretum Anian 2.8 — 2.8
22. Aethiops 3.3 — 3.3
23. Eunostos 2.8 — 2.8
24. Lethes 2.9 — 2.9
25. Marsias 3.2 — 3.2
26. Hyblaeus 3.0 — 3.0
27. Amenthes 3.2 3.5 3.3
28. Thoth 2.8 2.3 2.5
29. Nepenthes 2.8 2.3 2.5
30. Triton 2.7 *2.3 2.5
31. Pyramus 2.9 *2.0 2.5
32. Astaboras S. 3.2 3.1 3.1
33. Tithonius 2.6 2.2 2.4
34. Vexillum 3.5 2.9 3.2
35. Tartarus — 2.7 2.7

* Poor.
Here we have widths ranging from eleven degrees to two. The widths given are those
when the canal was at or sufficiently near its full strength, and are measured from the
centres of the constituents. We notice two points: the agreement of the same canal with
itself and its systematic disagreement with others. But what is especially to the point, if
we compare the values found at successive oppositions, we find that for different
canals the values agree in their difference. This shows that each of these values is, in
most cases if not in all, a norm for that particular canal; a value distinctive of it and to
which it either absolutely or relatively conforms. In other words, the width of the
gemination is a personal peculiarity of the particular canal, as much an idiosyncrasy of
it as its position on the planet.
Two general classes may be distinguished; those up to about five degrees in width
apart and those above this figure. Whether such very widely separated lines as go to
make up the second class, such as the Nilokeras I and II, constitutes a double is a
debatable point. Schiaparelli thought they did, and so classed them. To me it did not at
first occur so to consider them, and in some instances, such as the Helicon I and II,
later observations seem to justify the omission. With the Nilokeras I and II the outcome
seems the other way. The reasons for distrust of a physical relation between the
constituents is not so much the distance separating them, nor any lack of parallelism, as
the self-sufficient manner in which they show alone. Even this, however, tends to be
recognized in the narrower pairs as they come to be better seen. It may be that width
alone is wholly competent to selective showing. For the farther apart two lines are on
the planet, the more opportunity is afforded the air waves to disclose the one without
the other, a relative revelation which is constantly happening to detail in different parts
of the disk. As long as any doubt exists of a physical community of interest, it seems
best to distinguish such possibly merely parallel canals by suffixed numerals.
Of this class of doubles is the Nilokeras I and II. So wide is it that Mr. Lampland
succeeded in photographing it as such, the two constituents showing well separated,
and if it prove a true double it will be the first Martian double to leave its impress on a
sensitive plate. Although separated by four hundred miles of territory, the two lines are
parallel so far as observation can detect, which, of course, is not so very easy with the
lines so far apart. In the country between one crosswise canal certainly lies, the
Phryxus, and much shading thus far unaccounted for. Recent discoveries, however,
point to the cause of such shading as lines imperfectly seen. For in some cases the lines
have actually disclosed themselves, and warrant us in believing that it is only imperfect
seeing that keeps the others hid. Of the pair the Nilokeras I is itself double, curiously
reproducing what sometimes is seen in the case of double stars, one of whose
components turns out to be itself a binary. The second line of the Nilokeras I lies close
to its primary on the north, and was on the only occasion of its detection the merest of
gossamers, while the Nilokeras I itself stood out strong and dark. Thus do these
Martian details increase and multiply in intricacy the better the seeing brings them out.
In the case of the other doubles, the doubles proper so to speak, there is every
indication of a physical bond between the pair. What that bond may be is another

matter and seems to be of different divulging, according to the particular instance. At
one end of the subject, both as the widest of these doubles and one of the most
important, stands the Ganges. The components of the canal are 5°.1 apart. This great
width, joined to the fact of scant extension, gives the canal a stocky aspect, its breadth
being but one sixth of its length. Its width draws attention to it while the phenomena it
exhibits intrigue curiosity.
As early as the first opposition of my observations in 1894, the canal, as it underwent
the process of doubling, showed phases of peculiarity. It was first caught by me as a
double over toward the terminator, or fading edge of the disk; then as it was brought
nearer the centre by the gaining upon the longitudes, showed as a broad swath of
shading of a width apparently equal to any it later exhibited. In this appearance it
continued for some months, and then in October began to show a clarification toward
the centre. Once started, the lightening of its midway advanced till at last, on
November 13, it stood out an unmistakable double, the two lines standing where the
edges of the swath had previously been. Had the observations here been all that one
could wish, the method of gemination would have been certain and of great interest.
Unfortunately, the observations left much to be desired, and those repeated in 1896-
1897 and 1901 were of like doubtfulness. A period of swarthy confusion preceded the
plainly dual state, but whether the double simply clarified or widened as well it was not
possible to assure one’s self. That the canal exhibited plainly the effects of seasonal
development was as unmistakable as the steps themselves were open to ambiguity. In
1903 the canal was at its minimum and hardly to be made out. It seemed then to show
an actual change in width coincident with alteration of visibility. But this, too, could
not be predicated with certainty. It was also surmisable that the westernmost line was
the one from which the development proceeded.
In 1905 much more was made out about it, training in the subject and increased
proximity of the planet contributing to the result. It now became clear to me that the
canal did develop from the western side; for the western edge made a dark line of
definite boundary from which shading proceeded to the eastern side, where it faded
almost imperceptibly off with no defined line to mark its limit. That this shading
gradually darkened was evident, but that when it could be seen at all it extended to the
extreme limit of the eventual double, restricted the character if not the fact of an actual
widening. At this opposition, too, the canal passed through its period of minimum
visibility and was then seen, whenever it could be caught, as a confused swath of full
width. In the case of this canal, then, a widening in the sense of a bodily separation of
two lines seems inadmissible. On the other hand, the gradual darkening of the swath,
and especially the advance of the darkening from the western side, points to an
interesting process there taking place.
At the opposite end of the series stands the Djihoun. As the Ganges is the widest of
the instantly impressive doubles, so the Djihoun is the narrowest the eye has so far
been able to make out. Only two fifths of the width of the Ganges pair, this slender
double is very nearly at the limit of resolvability. So well proportioned are its lines to
the space between them, however, that in ease of recognition it surpasses many wider

pairs. In form, too, it is distinctive, turning by
a graceful curve the trend of the Margaritifer
Sinus into the Lucus Ismenius. With its
fundamental branch—the northern of the two
—it joins what is evidently the main line of
the Protonilus—also the northern one—to the
Margaritifer Sinus’s tip.
It
differ
s
from
the
Gang
es in
some
Peculiar development of the Ganges. other
impo
rtant particulars besides width. In its case no
band of shading distinguishes it at any time. It
has always been two lines whenever it has
been seen other than as a single penciling; the
only confusion about it being evidently our
own atmosphere’s affair. These two lines, Djihoun, the narrowest double.
furthermore, have showed, within the errors of
observation, always the same distance apart.
So that not only no change of intercommunication between the lines but no change in
their places apparently occurs.
Between these extremes in width, two hundred miles more or less for the Ganges and
seventy-five miles for the Djihoun, the distance parting the pairs of most of the double
canals lies. From 3° to 3°.2 on the planet may be taken as that of the average; the
degrees denoting latitudinal ones on the surface of Mars, the length of which is equal to
thirty-seven of our English statute miles.
Most of the canals conform apparently to the type of the Djihoun rather than to that
of the Ganges. Careful consideration of them fails to find any increase or decrease of
distance, between the pairs of the same canal at different times, which cannot be
referred to errors inevitable to observation of such minute detail. In short, the double is
made by the addition of a second line in a particular position and not by a growth out to
it of a line coincident to begin with with the first.
I have said that the average width between the two lines of the doubles was about 3°.
It must not be supposed that this average width denotes anything more than an average;
or, in other words, that it denotes anything in the nature of a norm. The remark is
important in view of a suggestion which I have heard made that we have here a system
based on fundamental Martian units, in which, or in multiples of which, the dimensions

of the canals are implicitly expressed. Such, however, does not seem to be the case. In
some instances, indeed, we have certain evidence to the contrary and that the width of
the double is conditioned solely by antecedent place. The Phison and Euphrates offer a
case in point. These two important arteries in duplicate leave, as we saw, from two
carets in the Mare Icarium, the Portus Sigaei, held in common tenancy by both. Each
pair then proceeds down the disk inclined at its own particular angle to the meridian in
order to reach by a great circle course a certain spot; the Pseboas Lucus in one case, the
Luci Ismenii in the other. As one of these angles is thirty-five degrees while the other is
only three, they must, from the circumstances of their setting out, have not only
different widths, but widths determinately different in advance, since each is, roughly
speaking, foreshortened by the degree of divergence from the meridian. The one,
therefore, must be about four degrees to the other’s something less than three and a
half. This is what they actually are as determined by measurement from observation.
That the calculated value agrees with that found from observation helps certify to a
community of starting-points, but it completely does away with comprehensive design
in the question of their widths. For if the one were so settled, the other could not be.
Indeed, the next example seems to deny it to both. This example occurs, too, not far
away from the scene of the first, in the twin bays of the Sabaeus Sinus, from which
depart, mutatis mutandis, the double Hiddekel and the two Gihon. These twin gulfs
bear so little imprint of being other than natural formations, that they have been
universally and very likely quite rightly taken for such ever since Dawes discovered
them in 1859, long before things like canals were dreamed of. It is strange that when
the Hiddekel and the Gihon were found by me to be double in 1897, with a branch of
both leading from each bay, the connection between the sceptically scouted doubles
and the thoroughly believed-in bays should have been apparent. For to link a ghost to
materiality, if it does not discredit the materiality, serves to substantialize the ghost.
Furthermore, it shows that in this case neither the one double nor the other can have
had its width engineered on any preconceived scale, unless the twin bays be themselves
so accounted for. So that it seems useless to seek for cryptic standards in the canals or
to think to find them a measure of value from the fact of their being a medium of
exchange.
A third instance of the same thing in the case of the Ganges and the Jamuna was
proved at the last opposition after having long been suspected without my being able to
make sure of it. These instances, taken in connection with the wide range of values in
the widths presented by different canals, serve to show that the distance between the
twin lines is an individual characteristic of the particular canal, and further to point to
its cause, in some cases certainly and possibly in all, as topographical. The duplicate
line makes a convenience of a neighbor, and suits its distance from its fellow to
friendly feasibility. To cut a ‘canal’ to conform to the country seems logical if not
obligatory, and quite in keeping with the nomenclature of the subject; but here the
starting-point appears to be the only thing considered—the canal once safely launched
being left to shift, or rather not shift, for itself.

IV

Topography thus introduced to our notice
for its effect on the breadth of the doubles
proves upon inspection to be of extended
application to the whole subject. Examined for
position these canals turn out to have
something to say for themselves bearing on
the question of their origin and office.
With regard to position, probably the first
query to suggest itself to an investigator to ask
is of the direction in which they run. Is there a
preponderance manifest in them for one
direction over another? Do they show an
inclination to the vertical, to the horizontal, or
The Sabaeus Sinus, embouchure for to some tilt between? To answer this we may
the double Hiddekel and Gihon. box the compass, and taking the four cardinal
points with the twelve next most important
points between for sectional division segregate the doubles according to their
individual trend. As we have no means of determining in which sense any direction is
to be taken,—if indeed it is not to be taken alternately in each,—we get eight
compartments into one or the other of which all the doubles must fall. This they do in
the following manner:—

S. & N., Laestrygon, †Fretum Anian, Aethiops, Amenthes, Titan, †Dis, †Is 7
S. S. E. & N. N. W., †Gihon, Ganges, ‡Tithonius, Euphrates, Adamas 5
S. E. & N. W., †Eunostos, Triton, Tartarus, Naarmalcha 4
E. S. E. & W. N. W., †Astaboras, Typhon, †Pierius 3
E. & W., †Nar, †Protonilus, *Propontis, ‡Nectar, †Cocytus, †Chaos 6
E. N. E. & W. S. W. †Deuteronilus, †Callirrhoe, †Cerberus N., Cerberus S.,
6
†Sitacus, †Erebus
N. E. & S. W., †Djihoun, *Nilokeras I & II, †Avernus, †Nepenthes, Gigas,
12
†Alander, Polyphemus, †Gelbes, †Marsias, †Pyramus, †Nilokeras I, Asopus
N. N. E. & S. S. W., Jamuna, Phison, †Hyblaeus, Cyclops, Lethes, †Thoth,
8
†Vexillum, †Hiddekel
51

* Wide canals.
† Northern hemisphere exclusively.
‡ Southern hemisphere exclusively.

No conclusively marked preponderance for one direction over another manifests
itself by this partitionment. Nevertheless, a certain trend to the east of north, as against
the west of north, is discernible. More than twice as many doubles run northeast and
southwest or within forty-five degrees of this as do similarly northwest and southeast,
there being twelve of the latter and twenty-six of the former. That this seems to mean
something the nearly equal pairing of quadrantal points goes to show. Thus:—

N. & S. and E. & W. inclined canals number 7 + 6 = 13
N. N. E. & S. S. W. and E. S. E. & W. N. W. inclined canals number 8 + 3 = 11
N. E. & S. W. and S. E. & N. W. inclined canals number 12 + 4 = 16
E. N. E. & W. S. W. and N. N. W. & S. S. E. inclined canals number 6 + 5 = 11
33 18 51

a fairly equable division in direction. A trend to the westward would be given a particle
descending from the north to the equator by the planet’s rotation, thus turning it
southwesterly; and one to the west to a particle travelling equatorwards from the south,
turning it northwesterly. As the doubles lie in the northern hemisphere, either in whole
or part, to the extent of 93%, this might account for the preponderating tilt to the east of
north and west of south exhibited by them. It would correspond with the lines of flow.
To see whether this be so we will take only those double canals that lie exclusively
in the northern and southern hemispheres respectively, and note those in the former that
trend to the west of south as against those that run to the east of it, and vice versa in the
southern. In the northern the proportion of the westerly to the easterly ones is 17 to 4;
in the southern, 1 to 0 the other way.
Of those whose course is common to both hemispheres we find for the ratio of the
southwesterly to the southeasterly 8 to 7. But the proportion of the course of these
canals in the two hemispheres is on the side of this same ratio.
From their direction we now pass to consideration of their distribution in longitude.
It appears that some meridians are more favored than others. The hemisphere which
has the Syrtis Major for centre is more prolific in them than its antipodes. From
longitude 80° to 200° there are ten doubles, from 200° to 320° twenty-four, and from
320° to 80° seventeen; or, roughly, in the proportion of 2, 5, and 3. That this
distribution means anything by itself is doubtful; it is much more likely to be a general
topographical consequence of their distribution in another direction, which proves to be
highly significant and which we shall now expose—that of latitude.
If we separate the surface into zones, each ten degrees wide, and count the doubles
found traversing in whole or part the several zones, we find the following arrangement:
—

Double Canals of Mars arranged according to At At All
Latitude Opposition Oppositions

of 1903 so far
Alone observed
at
Flagstaff
Tithonius, Nectar,
Between 30° S. and 20° S. 2 3
Laestrygon
Jamuna, Ganges,
Gigas,
Laestrygon,
Between 20° S. and 10° S. Cyclops, Titan, 7 9
Tartarus,
Polyphemus,
Tithonius
Jamuna, Ganges,
Gigas,
Laestrygon,
Cyclops,Cerberus
S, Aethiops,
Lethes,
Amenthes,
Between 10° S. and 0° Triton, Phison, 15 20
Euphrates, Titan,
Tartarus,
Adamas, Typhon,
Vexillum,
Asopus,
Naarmalcha,
Polyphemus
Between 0° and 10° N. Gihon, Djihoun, 21 29
Jamuna, Ganges,
Gigas,
Laestrygon,
Cerberus N,
Cyclops,
Cerberus S,
Eunostos,
Aethiops, Lethes,
Amenthes,
Triton,
Nepenthes,
Phison,
Euphrates,

Sitacus,
Hiddekel,
Tartarus,
Adamas, Asopus,
Typhon,
Vexillum,
Cocytus, Is,
Avernus N,
Naarmalcha,
Polyphemus
Gihon, Djihoun,
Jamuna,
Nilokeras I and
II[4], Nilokeras I,
Ganges, Gigas,
Eunostos,
Aethiops, Lethes,
Amenthes,
Between 10° N. and 20° N. Thoth, Astaboras, 18 26
Phison, Sitacus,
Euphrates,
Hiddekel,
Adamas, Asopus,
Gelbes, Avernus
N, Erebus,
Naarmalcha,
Vexillum, Is, Dis
Between 20° N. and 30° N. Gihon, Djihoun, 17 23
Jamuna,
Nilokeras I & II,
[4]
Nilokeras I,
Alander,
Hyblaeus,
Lethes,
Amenthes,
Thoth, Sitacus,
Astaboras,
Vexillum,
Phison,
Euphrates,
Hiddekel,
Adamas,

Eunostos,
Aethiops, Gelbes,
Avernus N,
Naarmalcha, Is
Deuteronilus,
Alander, Nar,
Marsias, Fretum
Anian,
Amenthes,
Thoth, Vexillum,
Phison,
Euphrates,
Between 30° N. and 40° N. 12 20
Hiddekel,
Adamas,
Eunostos,
Djihoun, Gihon,
Nilokeras I,
Chaos, Gelbes,
Aethiops,
Naarmalcha
Fretum Anian,
Pyramus,
Between 40° N. and 50° N. 3 4
Protonilus,
Propontis[4]
Between Callirrhoe, Fretum
3 3
50° N. and 60°&nbpp;N. Anian, Pierius
Between 60° N. and 63° N. Pierius, Callirrhoe 2 2

From this tabulating of them it is apparent that the doubles are practically confined
to the zones within forty degrees of the equator. Only 7% of them straggle farther north
than this, while above 63° north latitude and 35° south latitude there are none. Such a
distribution is not in proportion to the areas of the zones, which though diminishing
toward the poles do so at no such rate. The surface included between the equator and
40° of latitude is 65% of the hemisphere, whereas the fraction of the number of doubles
found there is 93%. The doubles are, then, an equatorial feature of the planet, confined
to the tropic and temperate belts.
To perceive the tropical character of the doubles in another way we have but to
consider the zonal distribution of the single canals. Unlike the former the latter do not
thin out as one advances toward the poles; since in the arctic regions single canals
bemesh the surface as meticulously as elsewhere. It is only that they there replace the
doubles; or, not to put the cart before the horse, it is the doubles that in part replace the
singles in the tropics. And that this arrangement has something physical behind it by

way of cause is curiously shown by two canals, the Arnon and the Kison, which are
neither of the one kind nor yet the other, but a cross between the two. For the Arnon
and the Kison are convergent doubles; the two lines of the Kison leaving a common
point at the edge of the polar cap and separating as they travel south, while the two
Arnon take up and continue the divergence, connecting at last with the parallel pair of
the Euphrates. These canals thus make transition between the true doubles and the true
singles, and may be looked upon as endowed with the potentialities of both. From their
association with the double Euphrates, it is clear that the transition between the two
forms is not only formal but physical, and that the stopping of the dual condition at the
fortieth parallel is not the outcome of chance.
It may occur to the thoughtful that the doubles appear confined to the more tropical
portions of the planet because of a better presentation of those zones, the reader
supposing the planet to be seen axised perpendicularly to the plane of sight, as
geographies represent the earth’s globe. The supposition, however, is erroneous. We
sometimes see the planet so, but more often not. Such is the tilt of the Martian axis to
the plane of the Martian ecliptic that the different zones are rarely seen on an even keel,
so to speak, their aspects shifting totally from one opposition to another. What shows in
mid-disk on one occasion may be forty-eight degrees removed from it at another, a
distance amounting to three-quarters of the way from apparent equator to apparent
pole.
Thus the double canals are for some intrinsic reason equatorial features of the planet
as opposed to polar ones. And this not simply because of greater space there. Duality is
a result of conditions intrinsic to the several localities. What the cause may be is related
to the character of the things themselves, which we shall later consider. For the moment
we may note that the fact disposes quietly of the diplopic theory of their manufacture.
For, for diplopic doubles to show such respect for the equator would betoken a courtesy
in them to be commended of Sydney Smith.
But this is not their only geographic bias. In addition to not being partial to the poles,
the double canals show a certain exclusiveness toward the dark areas generally. Not
only do they avoid the arctic and antarctic zones entirely, but they largely shun the
blue-green regions. In these but two suspicions of doubles occur, in the Aonium Sinus,
although single canals there are as numerous as anywhere else on the planet.
Nevertheless, although they avoid running through them, they run from them in a
manner that is marked. Proceeding from the great diaphragm are no less than 28 out of
the 53 doubles. Connecting directly with these are 17 more; while the remaining 8 are
also associated through the intermediarism of dark areas, the Solis Lacus and the
Trivium.
In like relation to dark regions, they are limited on the north by the Mare Acidalium,
the Propontis, the Wedge of Casius and their interconnecting bands, the Pierius,
Callirrhoe, Helicon. In this manner do they form a broad girdle round the planet’s
waist, leaving the polar extremities bare.

[4] Very wide and possibly not of the same class.

CHAPTER XIX
CANALS IN THE DARK REGIONS

S eventeen years after the recognition of the canals in the light regions
occurred another important event, the discovery of a similar set in the
dark ones. The detection of these markings in the dark areas was a more
difficult feat than the perceiving of those in the light, and in consequence
was later accomplished. Also was it one where recognition came by
degrees.
I have previously pointed out what this discovery did for the seas—
nothing less than the taking away of their character in a generally
convincing manner. To one who had carefully considered the matter, the
seas had indeed already lost it, as was shown in Chapter X, but to those who
had not these canals presented a very instant proof of the fact.
From such not wholly supererogatory service they went on to furnish
unlooked-for help in other directions. Their discovery showed in the first
place that no part of the planet’s surface was free from canal triangulation.
But it did more than this. For these canals in the dark regions left the
edge of the ‘continents’ at the very points where the canals of the light
regions entered them, which fact proved for them a community of interest
with the latter. Such continuation was highly significant, since it linked the
two together into a single system, compassing the whole surface of the
planet. Starting from the places where the light-region canals come out
upon the great girdle of seas that stretches all round the planet, most of the
new canals headed toward the passes between the islands south, as nearly
polewards as circumstances of local topography would permit. In the
broader expanses of the Syrtis Major and the Mare Erythraeum, besides
main arteries others went to spots in their midst after the same fashion as
those of the light regions. These spots differed in no way apparently from
their fellow oases elsewhere. From a spot in the centre of the Syrtis three

great lines thus traveled south: the Dosaron, heading straight up the Syrtis
on the meridian till it struck the northernmost point of Hellas; the Orosines,
inclined more to the right, passing through the dark channel to the west of
that land and so proceeding south; and lastly the Erymanthus turning
eastward till it brought up finally at the Hesperidum Lucus. Where, on the
other hand, the long chain of lighter land, called by Schiaparelli islands, and
stretching from the Solis Lacus region westward to Hellas, offered only
here and there an exit, the canals made for these exits. The canals in the
Mare Sirenum, the Mare Cimmerium, and the Mare Tyrrhenum struck more
or less diagonally across those seas from their northern termini to the
entrances of the straits between the islands, thus lacing the seas in the way a
sail is rolled to its spar. From the exact manner in which they connected
with the light-region canals they proved the two to be part and parcel of one
system, which in its extension was planet-wide and therefore
proportionately important. Whatever of strange interest the curious
characteristics of the canals themselves suggested was now greatly
increased by this addition; for the solidarity of the phenomenon affected the
cogency of any argument derived from it.
In 1894 only the dark areas of the southern hemisphere were found to be
thus laced with lines. For then so great was the tilt of the planet’s south pole
toward the earth, that while those zones were well displayed the dark
patches of the northern hemisphere were more or less hull-down over the
disk’s northern horizon.
Contrast was the open sesame to their detection. When the maria show
dark, the lines are lost in the sombreness of the background. As the maria
lighten the lines come out. Such was amply witnessed by the effect in 1894
and 1896. In 1894 I found it impossible to perceive them, except where the
Padargus crossed Atlantis, for the hue of the maria themselves was then
very dark. In 1896, on the other hand, I saw them without difficulty. What is
also of interest: so soon as seen they appeared small, without haziness or
distention.
As the oppositions succeeded one another the northern regions rose into
view, and with their appearance came the detection in them of the same
phenomena. No large dark areas like the diaphragm exist there, but the
smaller patches of blue-green which bestrew them proved to be similarly
meshed. At first canals were evident upon their peripheries, contouring

them about; then the bodies themselves of the patches showed grid-ironed
by lines.
The Mare Acidalium with its adjuncts, the Lucus Niliacus on the south
and the Lacus Hyperboreus on the north, thus stood out in 1901. On a
particularly good evening of definition at the end of May, the Mare
suddenly made background for a sunburst of dark rays, six of them in all
radiating from a point between it and the Lacus Hyperboreus. Considering
how sombre the Mare was at the time, this was as remarkable a vision as it
was striking to see. Although at the moment the sight was of the nature of a
revelation, these lines have been amply verified since, as the Martian season
has proved more propitious.
Similar decipherment has befallen all the other patches of blue-green in
the northern hemisphere; these having shown themselves first
circumscribed and then traversed by canals. Interesting instances were the
Wedge of Casius and the Propontis. These markings, first perceived years
ago as mere patches of shading, then partially resolved by Schiaparelli, now
stood revealed as a perfect network of lines and spots. So many of both
kinds of their detail occupied the ground that to identify them all was matter
of exceeding difficulty. The outcome is shown in the diagrammatic
representations opposite and on page 256. These drawings disclose better
than any description the mass of detail of which the patches are in reality
composed, and serve to convey an idea of the complexity involved. If the
general canal system seems intricate, here is something which exceeds that
as much again.
The extension in this manner of the curious triangulation of the light
areas into and through all the dark areas as well, by thus spreading the field
of its operations over both terranes complexioned so unlike, greatly
increases the cogency of the deduction that this detail is of later origin than
the background upon which it rests. That the mesh of lines covers not only
the ochre stretches of the disk, but the blue-green parts as well, makes it
still more certain that it is not a simple physical outcome of the fundamental
forces that featured the planet’s face. For in that case it could not with such
absolute impartiality involve both alike. Thus here, again, we find
corroboration by later observations of what earlier ones established.
A last link in the chain of canal sequences remains to be recorded. Just as
the lines in the dark regions continued those in the light, so they themselves
turned out to be similarly prolonged and in no less suggestive a manner. For

when the north polar zone came to
be displayed, canals were evident
there, continuing those in the other
zones and running at their northern
ends into dark spots at the edge of
the polar cap. Here, then, we have
the end of the whole system, or
more properly its origin, in the
polar snows. The significance of
this will be seen from other
phenomena, to a consideration of
which we now proceed.
The Propontis, 1905..

CHAPTER XX
OASES

N ext to be caught of the details of this most curious network that meshes
the surface of Mars was a set of phenomena stranger even than the
lines; to wit, dark round dots standing at their intersections. More difficult
to make out than the lines, they were in consequence detected thus later by
fifteen years. Once discovered, however, it became possible to trace their
unconscious recognition back in time. Thus Schiaparelli told the writer in
1895, apropos of those found at Flagstaff, that he had himself suspected
them but could not make sure. Some of them stand figured in his Memoria
Sesta dealing with the opposition of 1888, but not published till 1899. In
such posthumous recognition, as one may call it, the spots repeated the
history of the canals. For Schiaparelli had himself pointed out a similar
preconscious visioning of the canals in the delicate pencilings of Dawes and
the streaks of Lockyer, Kaiser, and Secchi, now translatable as representing
the Phison, the Euphrates, and half a dozen other canals imperfectly seen.
That both the canals and the oases were thus sketched before they were seen
well enough to be definitely discovered is to an unprejudiced mind among
their strongest credentials to credit.
Nor was Schiaparelli the sole person thus to get proof before letter. One
of their very earliest portrayals appears in a drawing by Otto Boeddicker,
made on December 26, 1881, where the Pseboas Lucus is clearly
represented. In a still more imperfect manner some of the spots had been
adumbrated and their shadows drawn long before that. Thus they may be
deciphered as the cause of patches drawn by Dawes in 1864, though none
of them were in any definite sense detected till 1879, and only then so ill
defined that their true character was not apparent. As patches they are still
commonly seen at observatories where the observational conditions are not

of the best and the study of the planet not systematically enough pursued to
have them disclose their true shape and size.
The history of their detection is resumed in the experience of the
individual observer. During the course of my own observations I have had
occasion to notice the several stages in recognition of the spots which have
marked their chronologic career. As with the lines, three stages in the
appearance of the spots may be remarked: first, where the scattering of the
rays is so wide that dilution prevents anything from being seen; second,
where the commotion being less the object appears as a gray patch; and
third, where in comparative quiet it condenses into a black dot. For the two
former our own air waves are to blame. In coursing waves of condensation
and rarefaction they spread the image of the spot as they do that of the
canal. Then as the currents calm the spot shrinks to its normal proportions,
and in so doing darkens in consequence of being less widely diffused. Thus
the evolution in perception which may take place in the course of an hour
for a particular observer represents exactly what has occurred in the person
of the race by the improvement in observational methods and sites.
That the spots, although wider than the canals, remained longer hidden
from human sight, is due to the optico-physic fact that a tenuous line may
be perceived owing to its length when a dot of the same diameter would be
invisible. Summation of impressions is undoubtedly the cause of this. The
mere fact that a row of retinal cones is struck, although each be but feebly
affected, is sufficient to raise the sum total into the sphere of consciousness.
In the second stage of their visibility, the spots are in danger of mistake
with the smaller true patches of sombre hue which fleck the northern
hemisphere of the planet and from which they differ totally in kind, totally
so far as our present perception goes. Such true patches consist of a
groundwork of shading, upon which, indeed, are superposed the usual
network of lines and spots. Prominent as instances of them are the Trivium
Charontis, the Wedge of Casius, and the Mare Acidalium. With patches of
the sort the spots proper must not be confounded.
Close treading on the heels of the detection of lines athwart the seas came
the recognition of spots there likewise. At the opposition of 1896-1897 the
number was added to; and so the tale has been steadily increased. Their
number as found at Flagstaff up to the present time, that is, to the close of
the opposition of 1905, is 186; of which 121 lie in the light regions, 42 in

the dark areas of the southern hemisphere, and 23 in the smaller sombre
patches of the northern zones.
From their relationships and behavior it became apparent that the spots
were not lakes but something which answered much more nearly to oases.
Of the spots three kinds may be distinguished: the large, the little, and the
less, if by the latter term it may be permitted to denote what has but
collateral claim to be included and yet demands a certain recognition. For
though not spots like the others, the members of the third class have certain
traits in common with them while differing radically in others.
To the kind called large belong the greater number of spots so far found
upon the disk. They are large only by comparison with the little. For they
measure according to my latest determinations but seventy-five or one
hundred miles in diameter; on the planet some two degrees across. Sizable
black pin-heads, it is their tone that chiefly catches the eye, for they are
commonly the darkest markings on the disk. Against the ochre stretches
they appear black, and even in the midst of the dark areas they stand out
almost as much contrasted with their surroundings as these do with the light
regions themselves. About a hundred and forty are now known. Those in the
light areas were discovered first; those in the dark regions being harder to
see.
Of this first kind are such spots as the Pseboas Lucus, the Aquae Calidae,
the Lacus Phoenicis, and the Novem Viae; or, in English, the Grove of
Pseboas, the Hot Springs, the Phœnix Lake, and the Nine Ways, to mention
no more. That they bear dissimilar names implies no dissimilarity in
structure. The phenomena are all remarkably alike, and clearly betoken one
and the same class of objects; differing between themselves at most in size
and importance.
In form they all seem to be round. They certainly appear so, and were it
not that retinal images of small areas tend to assume this shape might
implicitly be credited with being what they seem. The reason for optical
circularity probably resides in the shape of the retinal cones and in their
patterning into a mosaic floor. So that unless a sufficient number of cones
be struck the image takes on to consciousness a roughly circular figure—
whether it be so in fact or not. In the present case, however, they seem to be
too well seen for self-deception of the sort.
The little are distinguished from the large by being pin-points instead of
pin-heads. They are most minute; from fifteen to twenty-five miles in

diameter only. That anything except size distinguishes the two apart is from
their look improbable. In color or rather tone,—for distinctive color is of
such minute objects unpredicable,—they would seem to be alike. Such is
also the case with their distribution and detail association.
To the second class belong the
Fons Juventae,—Schiaparelli’s
Fountain of Youth,—the Fons
Immortalis in Elysium in 1905, and
the Gygaea Palus, besides many
more. These are all pin-points, just
upon the limit of vision, and
noteworthy chiefly for being
visible at all. All those detected so
far lie not very distant from the
equator, which may or may not be
a matter of accident. It is not one of
perception, since this part of the
planet was not the best place for
observation at the time they were
Fons Immortalis, June 19. discovered. To make out one of
these little dots is a peculiarly
pleasing bit of observation, as it requires particularly good definition. One
might almost take them for fly-specks upon the image did they not move
with the disk. They have no perceptible size and yet are clearly larger in
diameter than the canals which run into them; which proves how very
slender the latter must be.
Very early in the detection of the spots it became evident that they were
not scattered haphazard over the surface, but that on the contrary they were
never found except at the meeting-points of the lines. From this it must not
be supposed, as has been done, that the spots are merely optical
reinforcements of the lines at their crossings due to the more crowded
character there of the lines themselves. That they are not such is
demonstrated by the existence of crossings where, either temporarily or
permanently, none appear; which shows that they are far too well seen for
any such illusion about them to be possible. At these crossings the lines
traverse one another without thickening, whether they be single or double
lines. The spots, on the other hand, are much wider than the lines, giving a

beaded look to the threads. In short, they are the knots to the canal network.
All the more important junctions are characterized by their presence. Such
starred junctions are not confined to the ochre regions; they dot the light
and the dark areas with equal impartiality, thus showing themselves to be
independent of the nature of the ground where large stretches of country are
concerned. On the other hand, they appear to be unusually numerous in the
smaller, isolated, dark areas of the northern hemisphere, such as the
Trivium, the Mare Acidalium, the Propontis, and the Wedge of Casius. Here
they crowd; and one cannot avoid the inference that their plentifulness in
these regions is not due to chance.

Utopia regio—1903.

To the large spots, those of the first class, fall the places of intersection of
the largest and most numerous canals, while the little spots make termini to
fainter lines, ones that bear to them a like ratio of unimportance. Spots and
lines are thus connected not simply in position but in size. The one is
clearly dependent on the other, the importance of the centre being gauged
by the magnitude of its communications.
From the fact of association we now pass to the manner of it, which is
quite as remarkable. The position of the spot relative to its tributary canals
depends upon the character of the connecting lines. If the canal be single it
runs, so far as may be judged, straight into the middle of the oasis, or, in
other words, the oasis is symmetrically disposed about its end. This is true

of the greater number of the large spots and of all the little ones, since the
latter have as connections only single canals.
In the case of a double canal arriving at a spot, a different and most
curious dependence is observable. This fact I first noticed in a general way
at the opposition of 1896-1897, the initial appearance of it being presented
on September 30, 1896, by the Coloe Palus and the Phison. It was again
visible in the case of the spots in the Trivium at the time the canals leading
to that place doubled in March, 1897. But the exact nature of the
phenomenon was not fully appreciated till 1903, when the thing was seen so
well as to appear cut on copper plate. It was this: the spot is exactly
embraced between the two arms of the double canal. It is, moreover,
seemingly perfectly round and just fits in between the parallel lines. The
Ascraeus Lucus was the first spot that showed thus in association with the
double Gigas. Others followed suit in so showing, several specimens
presenting themselves so well as to leave no doubt of the precise
connection. The sight presented by such a spot and its incasing double is a
beautiful bit of detail, perhaps the most beautiful so far to be seen upon the
Martian disk. The distinctness with which it stands out on occasion suggests
a steel engraving, and shows how clear-cut the Martian features really are
when our own air ceases from troubling and allows them to be at rest.
Incidentally, we may note that this phenomenon alone serves to disprove
the diplopic theory of the production of the double canals. For if a double
were a single line seen out of focus, any spot upon it should be doubled too.
It may seem to the reader as if
what was seen in 1903 was but an
unimportant advance over the
observed phenomena of 1896-
1897. Not so, however. For with
the earlier instances it was not
possible to be sure of the precise
limits of the spot with regard to the
double. The Coloe Palus, on the
one hand, did not fill all the space
Ascraeus Lucus and Gigas.—March. apparently between the double
2. 1903. Phison; while the Lucus Ismenius
more than did so with the double
Euphrates. To have set down the

different appearances to insufficient definition would have been a great
mistake, as subsequent observation has served to show. The Lucus Ismenius
instances this. In 1896-1897 it was seen terminating the Euphrates, blocking
all the space between the two lines and extending a little upon either side of
them. Now, from its appearance in 1901 it was evident that the effect had
been produced by twin spots lying along the Deuteronilus, the axis joining
them being perpendicular to the Euphrates. In 1903 the relation was still
better explained by what appeared then, when not only did the two spots
stand out, but the Euphrates showed with a line running centrally into each.
Although originally seen by Schiaparelli as a single spot and so at first
seen by me, better acquaintance with the disk disclosed to both observers its
really dual character. As this pair has persisted through all three of the most
recent oppositions, it seems fairly certain that it is always of this character,
and more fitting, therefore, to give it the plural appellative. This is the
single instance of a double oasis. There are many that lie close together and
might be taken as such; but this is the only one where the connection is
intrinsic. According to measures of the drawings of 1905 extending through
six presentations, the distance between the twin oases is 4°.2.
Their relation to the canals which run into them is of the most
complicated description and of the most suggestive character. For to the
twin spots converge no less than seven double canals, one wedge-shaped
pair and three single canals, a most goodly number of communication lines.
Four of the double canals run into the oases with one line to each; these
canals are the Astaboras, the Naarmalcha, the Euphrates, and the Hiddekel.
Three doubles, the Protonilus, the Djihoun, and the Deuteronilus, embrace
the oases between their two lines, while, in the singles, the canal connects
with one or other of the twins, as the case may be.
Now, there is method as to which of the doubles shall straddle, which
embrace, the two Ismenii. Those which leave the place parallel or nearly so
to the direction joining the Luci, inclose them both; those of which the
setting forth is at an angle to this direction depart, each line of the pair, from
the eastern and the western spot respectively.
Consider, now, the disposition of these seven pairs of lines. All of them
lie in one semicircle about the Luci, beginning with the Protonilus on the
east and ending with the Deuteronilus on the west. Furthermore, all follow
approximately arcs of great circles, except the Djihoun, and all send one of
their twin lines to one Lucus, one to the other. The data are enough to make

this statement possible. Although
the west line of the Naarmalcha has
not been caught entering its oasis,
the east one has been seen to enter
the other, and the width of the
double shows that the west one
must enter the corresponding spot.
In the case of the Astaboras the
double has only been observed as
far as the Vexillum, but the south
line has continued on to the west
Ismenius, and here again the width
makes it certain that were the canal
double throughout, the other line
must enter the east Ismenius. From
Peculiar association of the Luci the base line of the Proto-
Ismenii with double canals. Deuteronilus the inclinations of the
seven pairs are as follows:—
Protonilus 0° Due East
Astaboras 40° North of East
Naarmalcha 70° North of East
Euphrates 80° North of West
Hiddekel 55° North of West
Djihoun 0° North of West
Deuteronilus 0° Due West
Now, the width between the two lines of the four canals to the east increases
regularly from the Protonilus round; the Protonilus being the narrowest
double, the Astaboras the next, the Naarmalcha the next, and the Euphrates
the widest. And from the width between the twin oases, it would seem that
they severally enter the centres of them. What takes place in the case of the
Hiddekel, which is wider than its tilt would imply, and in the Djihoun,
which is narrower, is not so clear. But that they enter the oases in some
place is certain.
The spots make common termini for all the canals of a given
neighborhood. In other words, canals converge to the places occupied by
the spots and do not cross haphazard according to the laws of chance. Only

one instance exists where a spot
fails to gather to itself the whole
sheaf of canals and even there it
collects all but two. This anomaly
is the Pseboas Lucus. The
peculiarity of this oasis is that it
lies not on, but just off, the
Protonilus. That it does so is
exceeding curious, considering that
it is the sole example of such extra-
Lucus Ismenius. March 1903. canaline position. Strictly speaking,
it is not the Protonilus but the point
where the Protonilus turns into the
Nilosyrtis to which it stands thus neighboringly aloof. And this may explain
the anomaly. For the Nilosyrtis has not the full geometric regularity of the
normal canal, and seems to have been a more or less fundamental feature of
the region.
For the rest, the Lucus has the form and possesses the canal connections
appropriate to its state. It is apparently round, and lies between the twin
lines of the Phison and also between those of the Vexillum.
Not far from the Pseboas Lucus are to be found all the examples of the
third class of spots; for so far they have not been observed outside of Aeria,
a region peculiarly peopled by double canals. With double canals they are
necessarily associated, inasmuch as they consist of shading in the form of a
square or parallelogram, filling the deltas between two pairs that cross.
Thus have shown the Coloe Palus at the crossing of the double Phison with
the double Astaboras, and the Juturna Fons where the double Sitacus
traverses the double Euphrates.
At these same places a fourth kind is sometimes noticeable: a four-square
set of pin-points or a two-square set of the same at the corners of the line-
made parallelogram. This kind may well be synchronous with the third,
though it has only been noticed at consecutive presentations. The third,
however, has no observed dependence upon the first or second classes. And
this serves to make more probable the true objectivity of the circular and the
square figures respectively shown by each.
The spots apparent in the dark regions do not appreciably differ in either
size or shape from the bulk of those visible in the light. Equally with them

they seem to be round, small, and nearly black. They would seem, too, in
the great diaphragm—or larger contiguous sombre region—to be equally
plentifully distributed.

CHAPTER XXI
CARETS ON THE BORDERS OF THE GREAT DIAPHRAGM

F unctionally related to the canal system, and yet in look and location
contrasted with its other details, is a further set of markings, detected by
me in 1894, and reseen at subsequent oppositions since, along the north
border of the southern seas. They lie upon what used to be thought the
continental coastline, the fringing edge of that almost continuous band of
shading that belts the Martian globe throughout the southern subtropic zone
and called by Schiaparelli the great diaphragm. The terrane lends itself to
the appellative, forming, as it does, a dark dividing strip of country between
the brilliant reddish-ochre hemisphere on the north and the half-toned
islands to the south of it. By Schiaparelli it was thought to be one long
Mediterranean, and though its marine character is now disproved, that it lies
lower than the bright ochre regions is likely. To this difference of level is
probably due the peculiar phenomenon which there manifested itself to
careful scrutiny in 1894. For it was there only that it occurred.
The phenomenon in question consisted of nicks in the coastline, of
triangular shape and filled with shading. They occurred at intervals along it
and were of the general form of carets, such marks as one makes in
checking items down a list. Their position was always where a canal
debouched from the diaphragm upon its career across the open continent.
The canal itself was by no means necessarily visible. On the contrary, at
first it was usually absent. Such was the case with those marking the
departure-points of the Phison and Euphrates and of the Amenthes and
Lethes, which appeared, without being well defined, from the moment the
planet came to be scanned.
One by one these carets stood out to view, punctuating the points where
canals later were to show or terminating those that already existed. Strung
thus with them at intervals was the whole coastline of the diaphragm,

beginning with the Mare Icarium and stretching round through the Mare
Tyrrhenum, Mare Cimmerium, Mare Sirenum, and Mare Erythraeum to the
Mare Icarium again. As the planet got nearer to the earth their peculiar
shape began to define itself, and it was again in the case of those giving
origin to the Phison and Euphrates that the recognition came first. What had
appeared earlier simply as a spot now stood out as two triangular notches,
indenting the coast and giving exit at their apices, the eastern one to the
Phison, the western to the Euphrates. These were the things, then, that had
constituted the Portus Sigaeus of Schiaparelli.
Commonly the carets lie at the bottom of well-marked bays, as, for
example, those terminating the Syrtis Minor and the Sinus Titanum. But
frequently they are placed in the very midst of a long and otherwise
unaccented coast, as is the case in mid-course of the Mare Cimmerium and
the Mare Sirenum. Yet in no instance is the thing unassociated with a canal.
In every case one or more canals leave the caret for their long traverse
down the disk.
This is not their only canal connection. When the canals in the dark
regions came to be discovered, each of them was found by me, as nearly as
difficult observations would permit, to be associated with the caret upon its
other side. Thus the lacing of the Mare Cimmerium and Sirenum used them
as its reeving-points. Similarly those at the mouths of the Phison and
Euphrates did duty likewise to the Maesolus and the Ion. In such manner
the carets stood in dual relation to canals; subserving a purpose to the light-
region canals on the one hand and to the dark-region ones on the other. In a
way the caret, then, holds the same position toward the canals that do the
spots in the light or dark regions. Like them it is a canal-distribution point.
Unlike them, however, in shape it is triangular instead of round, and we are
piqued to inquire to what cause it can owe its different contour. The answer
seems to lie in the character of the locality, not simply in its complexion.
For the spots in both the northern and the southern dark patches are as
circular as those standing in the light, whether they lie in the centre or upon
the edges of them. The edges of the northern patches, however, and the
other sides of the southern ones do not present the clear-cut character of the
northern coast of the diaphragm. Where they seem to be definitely bounded
they are so by darker canals. This hints that their contours are not defined
by antithesis of level, while that of the northern coast of the great
diaphragm is. Difference of altitude is then concerned in their constitution;

the canal system here falls to a lower level, and these triangular spots
instead of round ones are the result. Topographic only, such explanation
leads the way to a more teleologic one, and serves even on first
acquaintance to stir curiosity to some satisfying cause.
Suggestive in several ways for its resemblance to the carets is another
detail not far distant from the Portus Sigaei, the twin-forked Sabaeus Sinus.
Curiously enough, this feature of Mars, which has been well known and
recognized ever since the eagle-eyed Dawes detected it more than forty
years ago, proves to be a sort of connecting link between the main markings
and the details of more modern detection. The twin-forked Sabaeus Sinus,
as its name implies, is of the form of a double bay; was considered to be
one in fact so long as the maria were held to be seas. It straddles the point
of land which, called the Fastigium Aryn, has been taken for the Greenwich
of Martian longitudes. Each ‘bay’—not in truth a bay at all—indents the
ochre in an acute triangle, from the tip of which many canals proceed like
the rays of a fan from a holding hand. Both tips are darker than the main
body of the dark mare from which they proceed. They thus recall in general
character the carets. They further reproduce specifically the Portus Sigaei,
for they give origin to two doubles, the Gihon and the Hiddekel, in exactly
the same manner that the two nicks of the Portus Sigaei do to the Phison
and Euphrates. Nor are their tips much farther apart than those of the
Portus, five degrees measuring the spread of the one and four degrees that
of the other respectively; the reason for their earlier discovery lying in their
greater size. They thus perform the same office as the Portus Sigaeus, are
quite comparable to it in width, and differ in shape only as a larger and
more acute triangle differs from a smaller and blunter one. Undreamt of by
Dawes and unheeded since, they were the first hint to the world of the
duality which forms so strangely pervasive a feature of the canal system of
the planet.
Thus the carets stand connected with the canals quite as intimately as the
oases but in a significantly different manner. For, in addition to their
intermediary standing between the light regions and the dark, their relation
to the doubles is peculiar. An instance is offered by the double Euphrates
and another by the Ganges. The Euphrates, as we saw in Chapter XVIII,
leaves the Portus Sigaei at the south, one line leaving each caret centrally,
so that each caret is concerned only with its own line and has no connection
with its fellow. At their northern ends both lines have similarly each its own

Lucus Ismenius. The like seems to be true of the Ganges. Similarly the twin
Titan, have each its own. Such twin duty in the matter of doubles seems to
be the rule with the carets, even more so than with the oases; and this is
probably from the fact that the coastline is of more limited extent than the
interior.
Altogether the carets offer to our inspection glosses in finer print upon
the general text of the canals. Thought upon what they show takes us a step
farther toward the solution of the strange riddle of this other world, a riddle
which he who runs may not read, still less scout, and which only reasoning,
without prejudice or partiality, can unravel.

CHAPTER XXII
THE CANALS PHOTOGRAPHED

P hotography holds to-day a place of publicity in the exposition of the
stars. Directed by Draper to the heavens thirty-four years ago, the
camera recorded then the first picture ever taken of the moon. From this
initial peering into celestial matters, practice has progressed until now the
dry plate constitutes one of the most formidable engines in astronomic
research. Not most effectively, however, in the field which might have been
predicted. Beautiful as the lunar presentment was, as a presentiment of what
was coming, it pointed astray. For it is not in lunar portrayal, superbly as its
crater walls in crescent chiaroscuro or its crags that cast their tapering
shadows athwart the dial of its plains stand out in the latest photographs of
our satellite, that the camera’s greatest service has since been done.
Impressive as they are, these pictorial triumphs are chiefly popular, and
appeal on their face to layman and scientist alike. Not in the nearest to us of
the orbs of heaven, but in the most remote has celestial photography’s most
prolific field been found to lie. Its province has proved preëminently the
stars, especially the farthest off, and that star-dust, the nebulæ, from out of
which the stars are made. Reason for this explains at once its efficiency and
its limitations.
Its rival, of course, is the eye. It is as regards the eye that its comparative
merits or demerits stand to be judged. Now, thus viewed, its superiority in
one respect is unquestionable; it simply states facts. But though it cannot
misinform, it can color its facts by giving undue prominence to the effect of
some rays and suppressing the evidence of others, so that its testimony is
not, it must be remembered, always in accord with that of human vision.
Speaking broadly, however, it is so little complicated a machine as to
register its results with more precision than the retina. The evidence of the
camera has thus one important advantage over other astronomic documents:

it is impersonally trustworthy in what it states. Bias it has none, and its
mistakes are few. Imperfections, indeed, affect it, but they are of purely
physical occasion and may be eliminated or accounted for as well by
another as by the photographer himself.
In trustworthiness, then, so far as it goes, it stands commended; not so
much may be said of its ability. This depends upon the work to which it is
put. In certain lines it asserts preëminence; in certain others it is so far
behind as to be out of the race. The reason for both is one and the same, for,
as the French would say: It has the faults of its quality. The very trait that
fits it for one function, bars it from the other. This excellence is that by
which the tortoise outstripped the hare,—a plodding perseverance. Far less
sensitive than the retina the dry plate has one advantage over its rival,—its
action is cumulative. The eye sees all it can in the twentieth of a second;
after that its perception, instead of increasing, is dulled, and no amount of
application will result in adding more. With the dry plate it is the reverse.
Time works for, not against it. Within limits, themselves long, light affects
it throughout the period it stands exposed and, roughly speaking, in direct
ratio to the time elapsed. Thus the camera is able to record stars no human
eye has ever caught and to register the structure of nebulæ the eye tries to
resolve in vain.
Where illumination alone is concerned the camera reigns supreme; not so
when it comes to a question of definition. Then by its speed and agility the
eye steps into its place, for the atmosphere is not the void it could be
wished, through which the light-waves shoot at will. Pulsing athwart it are
air-waves of condensation and rarefaction that now obstruct, now further,
the passage of the ray. By the nimbleness of its action the eye cunningly
contrives to catch the good moments among the poor and carry their
message to the brain. The dry plate by its slowness is impotent to follow. To
register anything, it must take the bad with the better to a complete
confusion of detail. For the air-waves throw the image first to one place and
then to another, to a blotting of both.
All of which renders the stars, where lighting counts for so much and
form for so little, the peculiar province of celestial photography. With the
study of the surfaces of the planets the exact contrary is the case. With most
of them illumination is already to be had in abundance; definition it is that
is desired. What succeeds so excellently with the stars is here put to it to do
anything at all. At its best, the camera is hopelessly behind the eye when it

comes to the decipherment of planetary detail. To say that the eye is ten
times the more perceptive is not to overstep the mark. To try, therefore, here
to supplant the eye by the camera is time thrown away.
Of scant importance to the expert in such matters as Mars, there is a side
of the subject in which service might be hoped of it: that of elementary
exposition. Congenitally incapable of competing with the eye in discovery,
the most that, by any possibility, could be looked for would be a recording
of the coarser details after the fact. For this reason it had long been a
purpose at Flagstaff to photograph some at least of the canals. But the
project seemed chimerical. To get an image suitable at all some seconds of
exposure would be required, and during such time the shifting air-waves
would blur the very detail desired to be got. It was a problem of essential
premises mutually annihilative. The more the would-be photographer
should avoid the one; the more he would fall into the other.
Nevertheless the thing was tried in 1901. In 1903 the subject was taken
up by Mr. Lampland, then new at the observatory. The results were better
than those of two years before, the images more clear-cut but still
incommunicable of canals. Still they were satisfactory enough to spur to
increased endeavor, and during the following interopposition preparations
were made to grapple with the planet as successfully as could be devised at
its next return. This happened in May, 1905. It then showed a disk only 17′′
in diameter, or 1/120 that of the moon,—and this disk Mr. Lampland
attacked with the 24-inch and a negative amplificator that increased the
focal length of the former to 143 feet. At such focus the planet’s image was
received upon the plate. Everything that could conduce to success had been
put in requisition. To this end of better definition the color curve of the
objective was first got, and for it a special color screen constructed by
Wallace. In spite of its name no achromatic is so in fact, but brings rays of
different tint to different focus. The color curve shows where these
severally lie, and the color screen, a chemically tinted piece of glass, is to
absorb all those which would blur the image by having a different focus
from the ones retained. Next, all manner of plates were tried. For in these
again it was necessary to reconcile two contradictory characters, a rapid
plate and a well-defining one. For the coarser the grain the speedier the
plate; and coarse grain disfigures the detail. Both qualities on so small an
image were obligatory and yet both could not be got. Then the clock had to
be as smooth-running as possible. So by a suggestion of Mr. Cogshall’s one

was obtained that filled this requisite, a new form of conical pendulum.
Upon this a further refinement was practiced. Ordinarily clockwork is timed
to follow the stars; this was altered to follow the planet, and so keep it more
nearly motionless while its picture was being taken. Then the device of
capping down the telescope to suit the air-waves, which had been found so
effective to the bringing out of fine detail, was put in practice. Lastly, all
developers were tried, and those found suited to the finest work were used.
Many pictures were taken on each plate one after the other, both to vary
the exposure and to catch such good moments as might chance. Seven
hundred images were thus got in all; the days of best definition alone being
utilized. The eagerness with which the first plate was scanned as it emerged
from its last bath may be imagined, and the joy when on it some of the
canals could certainly be seen. There were the old configurations of
patches, the light areas and the dark, just as they looked through the
telescope, and never till then otherwise seen of human eye, and there more
marvelous yet were the grosser of those lines that had so piqued human
curiosity, the canals of Mars. He who ran might now read, so that he had
some acquaintance with photography. By Mr. Lampland’s thought,
assiduity, and skill, the seemingly impossible had been done.
After the initial success was thus assured, plates were taken at other
points around the planet and other well-known features came out;
“continents” and “seas,” “canals” and “oases,” the curious geography of the
planet printed for the first time by itself in black and white. By chance on
one of the plates a temporal event was found registered too, the first
snowfall of the season, the beginning of the new polar cap, seen visually
just before the plate happened to be put in and reproduced by it
unmistakably. Upon the many images thirty-eight canals were counted in
all, and one of them, the Nilokeras, double. Thus did the canals at last speak
for their own reality themselves.

PART III
THE CANALS IN ACTION

CHAPTER XXIII
CANALS: KINEMATIC

S o far in our account of the phenomena we have regarded the lines, the
spots, and everything that is theirs solely from the point of view of their
appearance at any one time. In other words, we have viewed them only
from a static standpoint. In this we have followed the course of the facts,
since in this way were the canals first observed. We now come to a different
phase of the matter,—the important disclosure, with continued looking, that
these strange things show themselves to be subject to change. That is, they
take on a kinematic character. This at once opens a fresh field of inquiry
concerning them and widens the horizon of research. It increases the
complexity of the problem, but at the same time makes it more determinate.
For while it greatly augments the number of facts which must be collected
toward an explanation of what the things are, these once acquired, it
narrows the solution which can apply to them.
The fact of change in the Martian markings forces itself upon any one
who will diligently study the planet. He will be inclined at first to attribute
it to observational mistakes of his own or his predecessor’s making,
preferably the latter. But eventually his own delineations will prove
irreconcilable with one another, and he will then realize the injustice of his
inference and will put the cause, where indeed it rightly belongs, on the
things themselves. Confronted by this fact he will the more fully appreciate
how long and systematic must be the study of him who would penetrate the
planet’s peculiarity. Just as the recognition of something akin to seasonal
change came to Schiaparelli, because of his attending to the planet with an
assiduity unknown to his predecessors; so it became evident that to learn
the laws of these changes and from them the meaning of the markings, there
was necessary as full and as continuous a record of them as it was possible
to obtain. For this end it was not enough to get observations from time to

time, however good these might be, but to secure as nearly as might be a
complete succession of such, day after day, month after month, and
opposition after opposition. The outcome justified the deduction. And it is
specially gratifying to realize that to no one have the method and the results
thus obtained appealed with more force than to Schiaparelli himself.
Perseverance in scanning the disk long after the casual observer had
considered it too far away for observational purposes, resulted in
Schiaparelli’s detection of the canals, and this through a characteristic of
theirs destined to play a great part in their history, their susceptibility to
change. He tells us in his Memoria I how Aeria and the adjoining regions
showed blank of any markings while the planet was near in 1877 and the
disk large and well shown, and then how, to his surprise, as the planet got
farther away and the disk shrank, lines began to come out in the region with
unmistakable certainty. Thus to the very variability which had hidden them
to others was due in Schiaparelli’s hands their initial recognition.
Flux affecting the canals was apparent from the outset of my own
observations. No less the subject of transformation than the large dark
regions was the network of tenuous lines that overspread them. At times
they were very hard to make out, and then again they were comparatively
easy. Distance, instead of rendering them more difficult, frequently did the
reverse. Nor was the matter one of veiling. Neither our own atmosphere nor
that of Mars showed itself in any way responsible for their temporary
disappearance. It was not always when our atmospheric conditions were
best that the lines stood out most clearly, and as to Martian meteorology
there was no sign that it had anything whatever to do with the obliteration.
Long before the canals were dreamt of, veiling by Martian clouds or mist
had been considered the cause of those changes in the planet’s general
features, which are too extensive and deep-toned wholly to escape
observation even though none too clearly seen. It was early evident to me
that they were not the cause of general topographic change, and equally
clearly as inoperative in those that affected the canals. In short, nothing
extrinsic to the canal caused its disappearance; whatever the change was, its
action lay intrinsic to the canal itself.
On occasion canals in whole regions appeared to be blotted out. The most
careful scrutiny would fail to disclose them, where some time before they
had been perfectly clear. And this though distance was at its minimum and
definition at its best. Even the strongest marked of the strange pencil lines

would show at times only as ghosts of their former selves, while for their
more delicate companions it taxed one’s faith to believe that they could ever
really have existed. Illumination was invoked to account for this, and plays
a part in the effect undoubtedly. For at plumb opposition the centre of the
disk for two or three years has shown less detail than before and after that
event. This is probably due not, as with the moon, to the withdrawal of
shadows, but to the greater glare to which the disk is then subjected. But
this is not the chief cause of the change.
Still more striking and unaccountable was the fact that each canal had its
own times and seasons for showing or remaining hid. Each had its entrances
upon the scene and its exits from it. What dated the one left another
unaffected. The Nilokeras was to be seen when the Chrysorrhoas was
invisible, and the Jamuna perfectly evident when the Indus could scarcely
be made out.
So much shows in the two
drawings here reproduced. The
increase of the Ganges and the
advent of the Chrysorrhoas are
noticeable in the second over the
first.
Seasonal changes seemed the
only thing to account for the
phenomena. And in a general sense
this was undoubtedly the
explanation. To learn more about
the matter, to verify it if it existed,
and to particularize it if possible, I
determined to undertake an
investigation permitting of
quantitative precision in the case. A Showing seasonal change.
method of doing this occurred to I.
me which would yield results
deserving of consideration from the amount of data upon which each was
based and capable of being compared with one another upon an equal
footing from which relative information could be derived. It seemed wise to
determine from the drawings the degree of visibility of a given canal at
different seasons of the Martian year, and then to do this for every

important canal during the same
period of time. The great number
of the drawings suggested this use
to which they might be put. For
from a great accumulation of data a
set of statistics on the subject could
be secured in which accident or
bias would be largely eliminated
and the telling effect of averages
make itself felt.
To render this possible it was
necessary that the drawings should
be alike numerous, consecutive,
and extended in time. These
conditions were fulfilled by the
Showing seasonal change. drawings made by me at the
II. opposition of 1903. Three hundred
and seventy-two drawings had then
been secured, and they covered between them a period of six months and a
half. They were also as consecutive as it was possible to secure. During a
part of the period the planet was seen and drawn at every twenty-four hours,
from April 5, namely, to May 26, or for forty-six consecutive days. Though
the rest of the time did not equal this perfection, no great gap occurred, and
one hundred and forty-three nights were utilized in all. Furthermore, as
these drawings were all made by one man, the personal equation of the
observer—a very important source of deviation where drawings are to be
compared—was eliminated.
But even this does not give an idea of the mass of the data. For by the
method employed about 100 drawings were used in the case of each canal,
and as 109 canals were examined this gave 10,900 separate determinations
upon which the ultimate result depended. That each of these determinations
was independent of the others will appear from a description of the method
itself on which the investigation was conducted. To understand that method
one must begin a little way back.
As the two planets, Mars and the Earth, turn on their axes the parts of
their surfaces they present to each other are constantly changing. For a
feature on Mars to be visible from a given post on earth, observer and

observed must confront each other, and, furthermore, it must be day there
when it is night here. But, as Mars takes about forty minutes longer to turn
than the Earth, such confronting occurs later and later each night by about
forty minutes, until finally it does not occur at all while Mars is suitably
above the horizon; then the feature passes from sight to remain hidden till
the difference of the rotations brings it round into view again. There are
thus times when a given region is visible, times when it is not, and these
succeed each other in from five to six weeks, and are called presentations.
For about a fortnight at each presentation a region is centrally enough
placed to be well seen; for the rest of the period either ill-placed or on the
other side of the planet.
If a marking were always salient enough it would appear in every
drawing made of the disk during the recurrent fortnights of its display. If it
were weaker than this, it might appear on some drawings and not on others,
dependent upon its own strength and upon the definition at the moment, and
we should have a certain percentage of visibility for it at that presentation.
While if it changed in strength between one presentation and the next, the
percentage of its recording would change likewise. Definition of course is
always varying, but if its value be noted at the time of each drawing this
factor may be allowed for more or less successfully. Making such
allowance, together with other corrections to produce extrinsic equality,
such as the planet’s distance, which we need not enter upon here, we are left
with only the marking’s intrinsic visibility to affect the percentages; that is,
the percentages tell of the changes it has successively undergone and give
us a history of its wax and wane.
From drawings accurately made it is possible to add to the accuracy of
the percentage by noting in each, not only the presence or absence of the
marking, but the degree of strength with which it is represented. This was
done on the final investigation in the present case, and it was interesting to
note how little difference it made in the result.
The longitude of each canal was known, and the longitude of the central
meridian of each drawing was always calculated and tabulated with the
drawing, so that it was possible to tell which drawings might have shown
the canal. Only when the position of the canal was within a certain number
of degrees of the centre of the drawing (60°) was the drawing used in the
result, allowance being duly made for the loss upon the phase side. Each
drawing, it should be remembered, was as nearly an instantaneous picture

of the disk as possible. It covered only a few minutes of observation, and
was made practically as if the observer had never seen the planet before. In
other words, the man was sunk in the manner. Such mental effacement is as
vital to good observation as mental assertion is afterward to pregnant
reasoning. For a man should be a machine in collecting his data, a mind in
coördinating them. To reverse the process, as is sometimes done, is not
conducive to science.
When the successive true percentages of visibility of a given canal had
thus been found, they were plotted vertically at points along a horizontal
line corresponding in distance from the origin to the number of days after
(or before) the summer solstice of the Martian northern hemisphere. The
horizontal distance thus measured the time while the vertical height gave
the relative visibility. The points so plotted were then joined by a smooth
curve. This curve reproduced the continuous change in visibility undergone
by the canal during the period under observation. It gave a graphic picture
of the canal’s change of state. It seemed, therefore, proper to call it the
canal’s cartouche or sign manual.
In this manner were obtained the cartouches of 109 canals. Now, as the
presence or absence of any canal in any drawing was entirely irrespective of
the presence or absence of another, each such datum spoke only for itself,
and was an entirely independent observation. The whole investigation thus
rested on 10,900 completely separate determinations, each as unconditioned
by the others as if it existed alone.
As every factor outside of the canal itself which could affect the latter’s
visibility was taken account of, and the correction due to it as nearly as
possible applied before the cartouches were deduced, the latter represent the
visibility of the canal due to intrinsic change alone. In other words, they
give not the apparent only but the real history of the canal for the period
concerned.
Important disclosures result from inspection of the cartouches. This we
shall perceive by considering what different curves mean in the case. If the
canal were an unchangeable phenomenon, for any reason whatever, its
cartouche would be a straight line parallel to the horizon of the diagram.
This is evident from the fact that the visibility would then never vary. If, on
the other hand, it were waxing and waning, and the wax or wane were
uniform, the cartouche would be a straight line inclined to the horizontal;
rising if the canal were increasing, falling when it decreased. Lastly, if the

rate of change itself varied, the cartouche would be a curve concave or
convex to the line denoting the time, according as the rate of change of the
growth or decay grew greater or less.
To see this the more clearly, we may set over against the cartouche the
canal character it signalizes:—

Cartouche. Character.
A horizontal straight line. Canal invariable.
A straight line tilted up on the
Canal increasing steadily.
right.
A straight line tilted up on the left. Canal decreasing steadily.
A curved line descending, concave Canal decreasing, but more and more
from above. slowly.
A curved line ascending, concave Canal increasing, but more and more
from above. rapidly.
A curved line descending, convex Canal decreasing more and more
from above. rapidly.
A curved line ascending, convex Canal increasing more and more
from above. slowly.
A curved line first descending, Canal decreasing more and more
then ascending, concave from slowly to a minimum, thence
above throughout. increasing more and more rapidly.
A curved line first descending, Canal increasing more and more slowly
then ascending, convex from to a maximum, thence decreasing
above throughout. more and more rapidly.

If the cartouche first falls and then rises, this shows the canal to have
passed through a minimum state at the time denoted by the point of
inflection; if it rises first and falls afterward, this betokens in the same way
a maximum. Thus the cartouches reveal to us the complete history of the
canals,—what changes they underwent and the times at which these
occurred. The cartouche, then, is the graphic portrayal of the canal’s
behavior. It not only distinguishes at once between the dead and the living,
as we may call the effect of intrinsic change, but it tells the exact character
of this change,—the way it varied from time to time, the epoch at which the
development was at its minimum or its maximum for any given canal, and

lastly, its actual strength at any time, thus giving its relative importance in
the canal system. For the height of the curve above the diagrammatic
horizon marks the absolute as well as the relative visibility and enables us
to rank the canals between themselves.
Now, the first point it furnishes a criterion for is the real or illusory
character of the canals. If a line be due to illusion, whether optical or
physical, it can vary only from extrinsic cause, since it has no intrinsic
existence. If, therefore, all extrinsic cause be allowed for, the cartouche of
this ghost must needs be a horizontal straight line. Even if the extrinsic
factors to its production be imperfectly accounted for, their retention could
only cause systematic variations from the straight line in all the lines, which
would themselves vary systematically, and these factors could therefore be
detected.
This criterion is absolute. Unless all the cartouches were approximately
straight lines, no illusion theory of any kind whatever could explain the
facts. Even then the lines might all be real; for unchangeable reality would
produce the same effect on the cartouches as illusion. In the case therefore
of horizontal straight line cartouches, we should have no guarantee on that
score of reality or illusion; but, on the other hand, curves or inclined straight
lines in them would be instantly fatal to all illusion theories.
Turning now to the 109 cartouches obtained in 1903, the first point to
strike one’s notice is that all but three of them are curves and that even these
three must be accepted with a caveat. Here, then, the cartouches dispose
once and for all of any and every illusion theory. They show conclusively
that the canals are real objects which wax and wane from some intrinsic
cause.
The second result afforded by the cartouches is not of a destructive,
negative character,—however valuable the destruction of bars to knowledge
may be,—but of a constructive, positive one. It does not, like the first,
follow from mere inspection, but is brought to light only by comparison of
all the cartouches. In a positive way, therefore, its testimony is as
conclusive as it was in a negative direction. For that 10,900 separate and
independent data should result in a general law of development through
either conscious or unconscious bias, when those data would have to be
combined in so complicated a manner for the result to emerge as is here the
case, is impossible. Chance could not do it and consciousness would require

a coördinate memory, to which Murphy’s nine games of chess at once
would be child’s play.
Of the 109 canals examined 106 showed by their cartouches that they had
been during the whole or a part of the period in a state of change. But the
change was not the same for all. In some the minimum came early; in
others, late. Some decreased to nothing and stayed there; others increased
from zero and were increasing still at the time observations closed.
Latitude proved the means of bringing comparative order out of the
chaos. When the canals were ranged according to their latitude on the
planet, a law in their development came to light. To understand it, the
circumstances under which the canals were presented must be considered as
regards the then season of the planet’s year. In 1903 the planet passed on
February 28 through the point of its orbit where the summer solstice of the
northern hemisphere occurs. One hundred and twenty-six days later took
place the first snowfall in the arctic and subarctic regions, an event that
denoted the beginning of the new polar cap; from which date the snow there
gradually increased. Its autumnal equinox the planet did not reach till
August 29. Now, the canals were observed from thirty-six days before the
summer solstice of the northern hemisphere to one hundred and forty-seven
days after that event. We may tabulate the dates as follows:—

Day from Summer Vernal Corresponding Date on
Solstice Longitude Earth
-30 77° June 9
0 90° June 22
+30 103° July 6
+60 117° July 20
+90 131° August 4
+120 146° August 20
+150 162° September 5

The vernal longitude is the longitude of the planet in its orbit reckoned
from the vernal equinox. From the table it appears that the cartouches cover
the development of the canals from about June 6 to September 1 of the

Martian northern hemisphere for the current but to us undated year, ab
Marte condita.
The 109 canals included all the more conspicuous canals on the planet at
that opposition, all those that lent themselves by the sufficient frequency
with which they were seen to a statistical result. They lay spread all the way
between the edge of the polar cap in latitude 87° north to the extreme limit
south, at which the then tilt of the north pole toward the earth permitted of
canal recognition. This southern limit was in about latitude 35° south.
Farther south than this vision became too oblique, amounting as it did, with
an adverse tilt of twenty-five degrees to start with, to something over sixty
degrees, for detection of such fine markings to be possible. Between the
two limits thus imposed, by the perpetual snow on the one side and the
observational tilt on the other, the 109 canals were distributed by zones as
follows:—

Zone Latitude Number of Canals
North Polar 87° N.-78° N. 1
Arctic 78° N.-66° N. 9
Sub-Arctic 66° N.-51° N. 9
North Temperate 51° N.-37° N. 11
North Sub-Tropic 37° N.-24° N. 18
North Tropic 24° N.-12° N. 21
North Equatorial 12° N.- 0° N. 14
South Equatorial 0° N.-12° S. 17
South Tropic 12° S.-24° S. 7
South Sub-Tropic 24° S.-37° S. 2

As the latitude of a canal in the investigation was taken as that of its mid-
point, such being the mean value of its successive parts, the latitudes about
which information was obtained lay within the limits given above, the most
northern canal, the Jaxartes N having for its mid-latitude 78° north, and the
most southern, the Nectar, that of 27° south.
The zones comprised each a belt of territory about thirteen degrees wide,
the first being less solely because in part occupied by the permanent polar
cap.

The curves of all the canals in a given zone have been combined into a
mean curve or cartouche for that zone; and then the cartouches for the
several zones have been represented and ranged according to latitude on the
accompanying plate. Consideration of these mean canal cartouches is very
instructive. In the first place not one of them is a straight line, either
horizontal or inclined. All are curves and, with the exception of the top one,
all show a minimum or lowest point during the period under observation.
From this point they rise with the time, or to the right on the plate. A black
star marks this minimum, and is found farther and farther to the right as one
goes down the plate; that is, as one travels from the neighborhood of the
arctic regions down to the equator and then over into the planet’s southern
hemisphere. Drawing now a line approximately through the stars and
remembering that the minimum means the date at which the canal started to
develop, we see that the canal development began at the border of the north
polar cap and thence continued down the disk over the planet’s surface, as
far as observation permitted the surface to be seen, which was some thirty-
five degrees into the other hemisphere. This is the first broad fact disclosed
by the cartouches.

MEAN CANAL CARTOUCHES
P.L.

Furthermore, the development took place at an approximately uniform
rate. This is shown by the fact that the line passing through the black stars is
approximately straight; for such straightness means that progression down
the disk as measured by the latitude bore throughout the same ratio to the
time elapsed.
Looking at them again we notice that the three topmost cartouches, those
of the north polar, arctic, and sub-arctic canals respectively, dip at the right
before the end of the observations, while the other seven were still rising
when those observations were brought to a close. A reason for this, or at
least a significant coincidence, is to be found in the dotted line pendent
from the top of the table and labelled “First Frosts.” This dotted line denotes
the date at which the first extensive frost occurred in the polar regions; for
even before this time patches of white had appeared north of the Mare
Acidalium, denoting the on-coming of the cold. The frost did not last but
came and went and came again just as it does on earth, growing more

insistent and long-lived at each fresh fall. Its sphere of operation was
confined to the three zones in question. Even these zones it by no means
covered, merely blotching them in places with fungi-like patches of frost.
Beyond them south it never extended during the period of the observations;
indeed, it hardly entered the sub-arctic zone at all at this very beginning of
the polar winter. For it was only August 20 then. The coincidence of the
isotherm as betrayed by the deposition of frost with the dividing line
between the canal-development curves that dip down at this season and
those that still continue to rise is suggestive.
It becomes all the more so when the three cartouches are considered
seriatim. The most polewards, the north polar one, had sunk to zero
sometime before the first extensive frost occurred; the second, the arctic,
did so later than its northern neighbor, probably just before the epoch in
question; while the third, practically outside the zone of deposition, was
behind both the others in its descent. Inspection of the drawings upon which
the cartouches are based confirms an inference deduced from this: that it
was cold that killed, not frost that covered, them, which was responsible for
their obliteration. The drawings show that the canals ceased to be seen
before the white patches were evident. Now this would be the exact
behavior of vegetation. It would be killed, turned brown by freezing, and so
rendered invisible to us against its ochre desert background, before the cold
had grown intense enough to cover that ground with a solid white carpet of
frost. At the opposition of 1905, however, the extreme northern canals were
visible after the snow had covered all the country about them, being evident
as lines threading the new cap.
These three cartouches furthermore show each a maximum, and what is
significant the maximum occurs later in time for each, according as the
zone lies remote from the pole. A red star marks this maximum and shows
that the time of greatest development for the three zones was respectively:
—

41 days after the summer solstice for the North Polar.
61 days after the summer solstice for the Arctic.
95 days after the summer solstice for the Sub-Arctic.

We now pass to the other curves, those that were unaffected by cold.
Though in these the minima themselves show the law of latitudinal

progression, the wavelike character of the advance is even better disclosed
by the curves. As the eye follows them down the page, the advance of the
wave to the right is plainly apparent. The slope of the wave is much the
same for all, implying that a like force was at work successively down the
latitudes.
It will be noticed next that in all the mean cartouches the gradient is
greater after the minimum than before it. The curves fall gently to their
lowest points and rise more steeply from them. Such profile indicates that
the effects of a previous force were slowly dying out down to the minimum
and that then an impulse started in to act afresh. This explains the attitude of
the canals that died out. In them the effect of the old force shows as in the
others, but no impulse came in their case to resuscitation.
It seems possible to trace this force to an origin at the south. For
beginning with the north sub-tropic zone the gradient on the left shows less
and less steep southward to the south sub-tropic zone. Such a dying-down
swell is what should be looked for in an impulse which had travelled from
the south northward, since the wave would affect the more northern zones
last, and less of a calm period would intervene between the two impulses
from opposite poles.
The cartouches, then, state that the canals began to develop after the
greatest melting of the polar cap had occurred; that this development
proceeded down the latitudes to the equator, and then not stopping there
advanced up the latitudes of the other hemisphere. In the next place they
show that in the arctic region the development was arrested and devolution
or decay set in as it began to get cold there, the most northern canals being
affected first. Finally, that a similar wave of evolution had occurred from
the opposite pole some time before and had then passed away. And this
evidence of the cartouches is direct, and independent of any theory.

CHAPTER XXIV
CANAL DEVELOPMENT

Individually Instanced

A s an interesting instance of the law of development we may take the career
of the Brontes during this same Martian year; the Brontes witnessing
individually to the same evolutionary process that the canals collectively
exhibit.
The Brontes is one of the most imposing canals upon the planet. It is not
so much its length which renders it a striking object, though this length is
enough to entitle it to consideration, being no less than 2440 miles. Its
direction is what singles it out to notice, for it runs almost north and south.
For this reason it swings into a position to hold the centre of the stage for a
time with the precision of a meridian, as the planet’s rotation turns its
longitude into view. The points which it connects help also to add to its
distinction. For the Sinus Titanum at its southern end and the Propontis at
its northern are both among the conspicuous points of the disk. The latter is
but twelve degrees farther east than the former, while it is sixty-six degrees
farther north. This long distance,—from nearly the line of the tropics in the
southern hemisphere to mid-temperate regions of the northern,—the canal
runs in an absolutely straight course.
Its north and south character commends it for any investigation of canal
development, since it runs in the general direction that development takes.
Its great latitudinal stretch further fits it for a recorder of changes sweeping
down the disk; so that both in direction and length it stands well
circumstanced for a measure of latitudinal variations. The fact that it is
usually a fairly conspicuous canal does not detract from its virtue in this
respect. It was first recognized at Flagstaff in 1894. But once realized, so to

speak, it was possible to identify it with a canal seen by Schiaparelli and
supposed by him to be the Titan; indeed, it played hide and seek with that
canal throughout his drawings. In 1894 both it and the Titan were so well
seen that its separate existence was unmistakable, causing it to be both
recognized and named. It is, like the Titan, one of the sheaf of canals
descending the disk from the Sinus Titanum, and lies just to the east of the
Titan in the bunch. In 1896 it was also prominent; and at both these
oppositions most so from its southern end, its northern one being more or
less indefinite, especially in 1894.
In 1901 it was not the same. Instead of being the conspicuous canal it had
been in earlier years, it was now so faint as with difficulty to be made out. It
remained so to the close of observations. It was now under suspicion. Its
behavior in 1896-1897 had led to the supposition that not only were
seasonal changes taking place in it, but that those changes were such as to
point to a law in the case with which its conduct in 1901 fayed in. The
suspicion did not, however, become a certainty till the opposition of 1903.
The length of time during which the disk was then kept under scrutiny
resulted in the method of its metamorphosis being discovered.
At the very start of observations
its longitude chanced to be nearly
central and it was made out; but so
far off was the planet that only its
northern part could be detected,
because, as afterward appeared,
this part was the stronger, the canal
being decidedly inconspicuous,
whereas other canals, the northern
and even the Pallene and the Dis,
were strongly marked. At the next
presentation the planet was nearer,
and details previously hidden for
the distance now came out. Among
them was the Brontes, which,
I. February 25. showing better than in January,
could be traced all the way to the
Sinus Titanum. A drawing (I) made on February 25 and reproduced in the
text shows its appearance at the time. Its emergence under neared

conditions only served to accentuate its relative inconspicuousness, for it
showed now notably inferior to the northern canals, and this not only in the
matter of general visibility, but in the character it displayed. It was a line of
hazy definition, contrasting thus with the sharp dark forms of its northern
neighbors.
As the planet steadily
approached the earth, and the
canals to the north became better
and better seen, the Brontes instead
of sharing in the general
improvement did exactly the
opposite. It grew less visible when
it should have grown more so, if
distance had been the cause of its
appearance. It was now only to be
seen at the north, even when it was
seen at all; a state of things
exemplified in Drawings II and III.
As the planet now went away
and detail should have dimmed, the
Brontes proceeded to do the II. March 30.
opposite. One had almost said it
was actuated by a spirit of contrariety. For now when it had reason to grow
faint it grew in conspicuousness; just as, before, when it should have
become evident, it had declined. Distinctly farther off and smaller as the
planet was at the next presentation, the Brontes had clearly developed both
in tone and in the amount of it visible. This was in May (Drawings IV and
V). In June bad seeing prevented good observations, but in July, Drawing
VI, when the region again came round, the Brontes, in spite of the then
greatly increased distance, asserted itself so strongly that even in not very
good seeing its presence could not be passed by.
This contrariety of behavior had about it one very telling feature. That the
canal waxed or waned in exact opposition to distance and even toward the
last to seeing too, showed conclusively that neither distance nor definition
could in any way be held responsible for its metamorphoses. A very
fortunate circumstance, this of the observations, for it directly eliminated
size of disk, phase, and seeing, for which correction are none too easy to

make, and which in the minds of
the sceptical could always remain
as unexplained possibilities of
error.
The mean-canal cartouches show
synthetically, and all the more
conclusively for being composite,
the laws of the flux of the canals.
Something more of vividness,
however, is imparted by the actual
look of one of the constituents
during the process. It is the
difference between seeing a
composite picture made from a
given group of men and the gazing
III. April 3. on the actual features of any one of

them. So much is gained by the
drawings across the page of the
Brontes at different stages of its
evolution during the period here
concerned. But in another way, too,
the one canal may be made to yield
a more lifelike representation of the
process than a number taken
together are capable of affording.
In the mean-canal cartouches each
canal is treated as an entity; but it
is possible to consider a canal by
parts, and by so doing to see it in
action, as it were. It occurred to me
to treat the Brontes in this way. For
IV. May 4.
this purpose I divided the canal
into sections, five of them in all,
between the point where it left the Propontis, at a spot called the
Propropontis, to where it ended in the Sinus Titanum. The first, the most
northern, extended as far as Semnon Lucus, the southernmost outpost of the

Propontis congeries of spots. The
second continued on from these to
Eleon, the junction where the
Erebus crossed. The third thence to
Utopia, where the canal met the
Orcus; the fourth to an arbitrary
point in latitude 8° south, and the
fifth and last to the Sinus Titanum.
The lengths of these sections were
respectively: 12°, 16°, 15°, 12°,
and 13°. Each of the sections was
then treated as if it were a separate
canal and its cartouche found. To
the cartouches’ determination there
were available drawings:
V. May 7.

January 21- 12
25 drawings.
February 23- 15
March 2 drawings.
March 28- 14
April 5 drawings.
April 26- 27
May 8 drawings.
June 3-16 6 drawings.
16
July 11-21
drawings.
90 drawings
in all.

The cartouches are given in the VI. July 18.
plate opposite, which is constructed
precisely like the one for the mean
canal cartouches presented on page 298. The mid-latitude of the section and
its mid-longitude are given in the margin with its description.

BRONTES
Showing Successive Development
South
January to July, 1903
P.L.

Examining them now we note a family resemblance between the
successive cartouches. All sink slowly on the left to rise sharply from their
lowest point to the right. Such resemblance betokens the action of one and
the same cause.
Next, although the curves are resemblant, each has been, as it were,
sheered to the right as one reads down; that is, the action took place later
and later as the latitude was north.
Lastly, the dying out of a previous impulse can be traced in the
cartouches, which shows that the canals were quickened six months
previously from the south polar cap, as they were now being quickened
from the north polar one.

CHAPTER XXV
HIBERNATION OF THE CANALS

C onnected with the conduct of the canals is a phenomenon, examples of
which were early noted in a general way by Schiaparelli and later, but
of which the full import and exhibition only came to light during the
opposition of 1903 by a very striking metamorphosis: what may be called
the hibernation of a canal for a longer or shorter term of years. What
observation discloses is certainly curious. For several successive
oppositions a canal will be seen in a definite locality, as regular in seasonal
recurrence as it is permanent in place, a well-recognized feature of the disk.
Then to one’s surprise, with the next return of the planet, it will fail to
appear, and will proceed to remain obliterate without assignable cause for
many Martian years, until as unexpectedly it will be found what and where
it was before. Neither to deposition of hoar-frost, such as frequently whitens
whole regions of Mars, nor to other circumstances can be attributed its
disappearance. Without apparent reason it simply ceases to be and then as
simply comes back again.
Such bopeep behavior is quite beyond and apart from the seasonal
change in visibility, to which all the canals are by their nature subject. For
being creatures of the semi-annual unlocking of the water congealed about
the polar caps, they quicken into growth and visibility, each in its season,
and as regularly die out again. Different, however, is the phenomenon to
which I now refer. In it not a seasonal but a secular change is concerned.
The season proper to the canal’s increase will recur in due course, and the
canals round about it will start to life, yet the canal remains unquickened.
Nothing responds where in years the response was immediate and
invariable. The canal lies dormant spite of seasonal solicitation to stir.
Such curious hibernation was early hinted to the keenness of Schiaparelli,
and most incomprehensible as well as difficult of verification at that stage

the phenomenon was. That the absence was a fact, however, he assured
himself, although he was not able to prove an alibi. But at the last
opposition an event of the sort occurred which, from the length of time the
planet was kept under observation, combined with continued suitableness of
the seeing, unmasked the process. In the light of what then happened, taken
in connection with the side-lights thrown upon it by the canal’s past and by
the knowledge we have meanwhile gained of the planet’s physical
condition, the riddle of the phenomenon may in part at least be read, and
most interesting and instructive the reading proves to be.
Among the initial canals detected by Schiaparelli, in 1877, was a tricrural
set of lines recalling the heraldic design of three flexed legs joined
equiangularly above the knees. It lay to the east of the Syrtis Major, and he
called its three members the Thoth, the Triton, and the Nepenthes. Starting
from the head of his gulf of Alcyonius, at a point now known to be
occupied by the oasis called Aquae Calidae, the Thoth started south
inclining westward as it went, till in longitude 267° and latitude 15° north,
it met the Triton, which had come from the Syrtis Minor with similar
westward inclination. To the same point in the same manner came the
Nepenthes. Part way along the course of the latter was to be seen a small
dark spot, the Lucus Moeris, which he estimated at four degrees in
diameter. Some of the markings were easier than others, the easiest of all
being the Lucus Tritonis, a largish dark spot at the common intersection of
all three canals; but that none of the markings were remarkably difficult is
sufficiently shown by their detection at this early stage of Schiaparelli’s
observations. It is worth noting also that he discovered the southern ones
first; the Thoth not being seen till March, 1878. As his then recognition of
these canals witnesses, they must have been among the most evident on the
disk. And the point is emphasized by the fact that he failed at this
opposition to detect the Phison and the Euphrates as separate markings.
Much the same the three canals appeared to him at the next opposition of
1879, the Thoth being seen at its several presentations from October 5,
1879, to January 11, 1880.
At the next opposition a noteworthy alteration occurred, the full
significance of which escaped recognition. Schiaparelli saw, at the place
where the Thoth had been, two lines which he took for a gemination of that
canal, one of which followed the course of the old Thoth, while the other
went straight from the Sinus Alcyonius to the Little Syrtis, or, more

precisely, to the junction of the Triton and the Lethes. It was not the Thoth,
however, but something unsuspected, of more importance.
In 1884 the Thoth showed really double, the western line being much the
stronger, “una delle piu grosse linee que si vedessero sul disco.” That
neither branch went farther than the meeting-place with the Nepenthes
argues that it was indeed the Thoth that was seen. Schiaparelli himself had
no doubt on the subject, although he drew the double canal he saw due
north and south from the tip of the Sinus Alcyonius to the junction, but
nevertheless along the 263° meridian.
In 1886 and 1888 the system was in all essentials, what it had been in
1877 and 1879, except that the Thoth and Nepenthes were double and were
more minutely seen.
Here, then, was a system of canals and spots which for six Martian years
had been a persistent and substantially invariable feature of the Martian
surface. Any changes in it had been of a secondary order of importance,
while its general visibility was of the first. It is possible, then, to judge of
my perplexity when in beginning my observations in 1894 no sign of the
system could I detect. Of neither the Thoth, the Triton, the Nepenthes, nor
the Lucus Moeris was there trace. And yet, from the other canals visible, it
was evident that the disk was quite as well seen as it had been by
Schiaparelli. Not only were practically all his canals there, but many much
smaller ones were to be made out. And the same was true of the spots, a
host of such not figured by him appearing here and there over the planet’s
surface.
Nor was this all. Instead of the Thoth, another canal showed straight
down the disk from the Syrtis Minor to the Aquae Calidae. This canal was
as unmistakable as the Thoth had been before to Schiaparelli. It was among
the first to be detected, and continued no less conspicuous to the end, the
dates at which it was seen being July 10, August 14, and October 21. I
called it the Amenthes, identifying it with the canal so named in
Schiaparelli’s chart published in Himmel und Erde, of the ensemble of his
observations from 1877 to 1888. But in his Memoirs he never called it so,
seeing it, indeed, only in 1881-1882, and deeming it then the Thoth.
Nevertheless, in 1894, it was the conspicuous canal of the region, and, what
is more, had come, as it proved, to stay.
The invisibility of the Thoth continued for me the same during the
succeeding oppositions of 1896-1897 and 1901. At the former opposition I

drew it in 1896 on July 28, August 26, September 2, October 5-9, seeing it
single; and in 1897 on January 12-19, February 21, and March 1. It was
single but with suspicions of doubling in January, and was indubitably
double in February. As for the Thoth, I had come to consider it and the
Amenthes one, attributing their diversity of depiction to errors in drawing.
For while the Thoth remained obstinately invisible, the Amenthes presented
itself as substitute so insistently as to make one of the most obvious canals
upon the disk.
One exception only was there to this state of things. On June 16, 1901,
my notes contain this adumbration of a something else: “Amenthes
sometimes appeared with a turn to it two-thirds way up; two canals concave
to the Syrtis Major.”
So matters opened at the
opposition of 1903. With the
advent of the planet and the
presentation in due course of Libya
in February, the Amenthes duly
appeared, much as it had showed at
the opposition before, only less
salient. It was a confused and
seemingly narrower double.
Suspected on the 16th of that
month, it was definitely seen from
the 18th to the 23d. Of the Thoth
no mention is made either in the
notes or in the drawings. When the
region came round again, in March,
the Amenthes was still there, Amenthes alone in February.
showing more feebly, however,
than it had in February, in spite of better seeing and the fact that the planet
had considerably neared. Clearly the canal was fading out; a fact further
witnessed to by the following note made on March 25: “Throughout this
opposition thus far the dark triangle tipped by Aquae Calidae has been
sharply divided in intensity from the Amenthes, which is very narrow and
exceedingly faint.” Still was there no trace of the Thoth.
With the April presentation entered a new order of things. When the
region first became visible, on the 16th, the Amenthes could still be seen

and alone; but on the 19th, as the
relative falling back of the Martian
longitudes swung the region nearer
the centre of the disk, the Thoth
appeared alongside of it. On the
20th the Thoth showed alone.
Unmistakable it was and just as
Schiaparelli had drawn it,
accompanied by the Triton and the
curved Nepenthes. The thing was a
revelation. What before I had seen
only in the spirit of another’s
drawings stood there patent to me
in the body of my own; while the
Amenthes, to which I had so long
been accustomed, had vanished Amenthes feebler and still alone in
into thin air. Only a trace of it was March.
now and then to be made out. So
startlingly strange was the metamorphosis that I could not at first trust my
eyes, and questioned the broken line, which had replaced the straight, for
some ocular deception. But nothing I could do would rectify it. The
Amenthes was gone and the Thoth stood in its stead.
At the next presentation, May 26 to June 8, the phenomena were
repeated, and with increasing clarity. And then of a sudden, on May 29, I
saw the long-given-up Lucus Moeris. There it was indubitably. And its
definiteness was the most astonishing part of the affair. It was no question
of difficult detection. Indeed, I had not been on the lookout for it, having
searched the region too often fruitlessly before to have left incentive to
search again. And so, when I was not searching, the thing of its own accord
stepped forth to sight. It was a small round dot, like to any other oasis, and
showed, as it were, a black pearl pendent by the Nepenthes from the Syrtis’s
ear. For the Libyan bay made a dark projection of the sort high up on the
Syrtis’s eastern side, from which the Nepenthes, precisely as Schiaparelli
had drawn it, curved down to the point where the Thoth and Triton met. All
three canals were geminated, the gemination being about three degrees
wide.

And now occurred the last act in
the drama. In July the Amenthes
reappeared, showing alongside of
the Thoth-Nepenthes, and thus
removing any possible doubt as to
their separate identity. It had,
indeed, become the stronger of the
two, having gained in strength in
the interval between June and July
and the Thoth-Nepenthes having
lost. The lines were in process of
relapsing into the status quo ante.
Had these three presentations not
been watched, the brief apparition
of the Thoth-Nepenthes had been
Appearance of Thoth with Triton and missed and with it the revealing of
curved Nepenthes. Amenthes its curious character, and of certain
vanished. April 20. deductions thereupon.

First among these is a truth of
which I have long been convinced;
to wit, that when a seeming
discordance arises between the
portrayals of a canal, it is
commonly not a case of mistake
nor of change, but one of separate
identity. The canal has not shifted
its place, nor has an error been
committed; the fact is that one
canal has been observed at one
time, another at another.
So it was here, and thus were the
old and the new observations
reconciled. There had been no
mistake in either. Two separate Advent of the Lucus Moeris. May
canals accounted for the 29.
discrepancy, and only an

unfounded distrust of the accuracy
possible in such observations was
to blame for any failure to
recognize the fact.
Now, scrutiny of the notes upon
the appearance of the two canals,
together with their labeling by the
seasonal longitudes of the planet at
the dates they were made, discloses
a curious relation between the two.
The seasonal longitudes are
important, as they date the
phenomena according to the
Martian calendar. Ordered thus, the
successive aspects reveal first a
Amenthes with Thoth-Nepenthes. seasonal change in each canal and
July. then over and above this a secular
one. And this secular change was
such as to cause the two canals to alternate in visibility. When the one was
present the other was not, and vice versa.

Cartouches
or
Curves of Visibility
of
Amenthes, Thoth and Their
Combination.

We shall see this more clearly and at the same time bring out a curious
relation between the two systems, the broken bow of the Thoth-Nepenthes-
Triton and the straight arrow of the Amenthes, while looking at the
cartouches of the Thoth, the Amenthes, and a combination of both given in
the plate on previous page.
The antithetical character of the two canals is apparent. But what is
further interesting, the combination cartouche of both bears a singular
resemblance to that of the mean canal of the north tropic zone, the zone to
which both canals belong. Here, then, is a combination which is perfectly
regular while each of its constituents is anomalous.
And now we come to something as important: at the opposition of 1905
the curious alternation metamorphosis was enacted anew. The Amenthes
appeared, disappeared to be replaced by the Thoth, and then reappeared
again beside the other. This corroboration of behavior showed the previous
observations to have been due to no mistake, and only served to deepen the
interest in this last and more singular phase of canal conduct.

CHAPTER XXVI
ARCTIC CANALS AND POLAR RIFTS

L
ast in time but not least in importance of the details of canal development
to be detected is one that connects these strange features directly with
the melting of the polar caps. The cartouches showed that such
connection was to be inferred; the facts now to be recorded depict it by an
identity of place between certain phenomena of the two subjects following
one another in order of time.
On January 8, 1897, while scanning the planet, I was suddenly ware of a
rift in the north polar cap. It ran a little to the west of south from where it
started in at the cap’s edge and went clean through to the limb, the pole
being then slightly tilted away from us. At the time it seemed to be the first
rift ever seen in that cap; but on opening a little later Schiaparelli’s
Memoria Quarta, which had just arrived, the first thing my eye fell on was
a drawing of a rift in the north polar cap observed by him when the planet
had held the like attitude toward the Earth thirteen years before. Reference
to its longitude showed it to be the identical rift, seen again after all these
years and the only one so far seen in the northern cap.
At the next opposition more rifts were detected, one in especial on
December 27, running from Arethusa Lucus, then upon the edge of the cap,
athwart the snow in a northwesterly direction.
In the forepart of the opposition of 1901, which in its Martian season
corresponded to that in 1897, when the rift had been observed, many rifts
were detected in the cap, and among them one traversing the cap north-
northeasterly in longitude 136°.
So far the season when the cap had been observed was that when the rifts
were in process of forming. The ground they and the snow-cap covered had
not yet at any opposition been uncovered.

It was only when my observations began in the latter half of the
opposition of 1901 that, the season on Mars having so far advanced, all
snow in those latitudes had melted. Then appeared, however, the canal
Hippalus, an arctic canal of some importance, lying on that part of the
planet previously occupied by the polar cap. When later studying the
observations on the rifts I remembered this canal, and turning to the
drawing made some months before to compare the two critically,
discovered that the canal occupied the precise position held earlier by the
rift. One had said the rift had never vanished, but that the white surrounding
it had simply turned to ochre. Here, then, was a striking coincidence of
place, too exact to be the result of chance.
Impressed by the identity, I examined all the other rifts seen early in
1901, comparing them with the arctic canals seen later, to the finding of no
less than five cases of the same coinciding positions.
The importance of the identification here made of an arctic canal with a
previous rift in the polar cap has led me to make a list of the canals thus
identified at this opposition.

Visible as a Rift Visible as a Canal
January 1 and April 18 (?), May 20, 22, 27,
Hypanis
February 4 June 4, 5, 6, 7, 8, 25
January 19 and
Hippalus April 18, May 27
February 4
Rhombites February 4 May 27
Python February 20 March 31
Zygatis January 18, 19 May 7, June 3 to 8

If it be asked why these canals do not appear recorded at the March
presentation as either the one phenomenon or the other, the answer is
twofold. First, because they showed as shadings lost amidst a shaded mass;
and, secondly, the observations at several oppositions indicate a great
amount of haze over the region at that season of the Martian year.
We may now go back to the very first rift, that of 1897. The Martian
season grew later with each succeeding opposition, and it so chanced,
abetted by this fact, that the delaying snow was never seen covering that
part of the planet again and so, of course, not the rift. The Martian summer

in those high latitudes came on, and with it brought the great arctic canal,
the Jaxartes, into conspicuousness. The canal in consequence had been
observed for some time before it proclaimed itself the apotheosis of a rift
and that of the first and most important rift of all. Comparison of position,
however, entirely confirmed the conjecture and added another and the most
striking of all to the list.
These six canals, on the whole the largest which run into the northern
cap, have thus a dual character. Starting originally as rifts, they later come
out unmistakably as canals. So that we may say in general that the two
phenomena are different seasonal states of the same thing. This instantly
explains the rifts, the origin of which we found of so difficult, not to say
impossible, interpretation before in these pages, and incidentally it confirms
what we deduced on other grounds as the character of the canals; to wit,
strips of vegetation. For if the cap covered desert and fertility alike, it is
precisely over the latter that it would first melt.
Vegetation has the property of melting snow. The metabolism of the
plant, like that of the animal, though in a less degree, generates caloric. A
living animal is warm, even the so-called cold-blooded ones, in some sort,
and a growing plant is too. The chemic processes concerned give off heat,
though in such small quantities that we are often not aware of it. While the
plant lies dormant it stays cold, but the moment its sap begins to run under
the rays of the spring sun it rises in temperature above its winter
surroundings. All it needs to this awakening is sun and water, and both it
gets in its place in the polar cap after the passing of the vernal equinox. The
time, therefore, is suitable, for it is not till after that equinox is passed that
any of the above phenomena occur. In consequence the snow about it melts
and the plants themselves show as dark rifts splitting the cap.
This quite unexpected identity of two seemingly diverse phenomena, and
the unsolicited support its only explanation lends to the general theory, is an
instance of what is constantly occurring as observation of the planet is
pushed farther and farther. Facts every little while arise which prove to fit
into place in the scheme when neither the facts nor their fitness could have
been foreseen.

CHAPTER XXVII
OASES: KINEMATIC

S ubject to change also are the oases; and in the same manner apparently
as the canals. They grow less evident at a like season of the Martian
year. They do this seemingly by decreasing in size. Whereas in the full
expanse of their maturity they show as round spots of appreciable diameter,
as the season wanes they contract to the smallest discernible of dots. All but
the kernel, as it were, fades out, and even this may disappear from sight.
The Phœnix Lake in its summer time is a very dark circular spot, small
indeed yet of definite extension; in its winter it shrinks to a pin point, and is
often not visible at all. Sometimes the husk apparently persists, a ghostlike
reminiscence of what it was, with the kernel showing dark-pointed in its
centre. Thus the Lucus Lunae appeared at the opposition of 1905. A faint
wash betokened the presence of the Lucus, through which now and again a
black pin-point pierced.
In this visible decrease of size we get a revelation as to what takes place
impossible in the case of the canals, the tenuous character of which
precludes more than inference as to the process.
Like the canals, latitude, together with the suitable season of the planet’s
year, are the determining factors in their development. In what
corresponded to our July of the northern hemisphere the oases in the sub-
arctic and north temperate zones were conspicuous; black spots that showed
in profusion along the parallels of 40°, 50°, and 60° north. At the same time
the equatorial ones, those along the Eumenides-Orcus, which had been most
evident in 1894, hardly came out. It had been their time then as it was that
of the others now. The law of development is not so simple as on the earth,
depending, like that of the canals, not only upon the return of the sun, but
upon the advent of the water let loose from about the polar caps. Thus the

equatorial oases are subject to two seasonal quickenings, one from the
north, the other from the south.
In regard to their method of evolution or devolution a most curious
observation happened to me in 1903. Usually the oases are of solid tone
throughout; equally sombre from centre to circumference. But in this case
such uniform complexion found exception. On March 1, 1903, the Ascraeus
Lucus came out strangely differentiated, a dark rim inclosing a less dark
kernel. The sight was odd enough to command comment in the shape of a
sketch which accompanied the note, and the further remark that other spots
had similarly that year affected the like look. That the effect was optical did
not seem to me the case. Other spots at other times showed nothing of the
sort. If it was due to objective cause it gathers circumstance from what was
then the Martian time of year. For the season was such that the spot should
then have been in process of waning; and the effect would indicate that in
so doing the tone of the centre went first, that of the circumference fading
last. This would be in accordance with a growth proceeding outward and a
decay that followed in its steps.
When to this we add the look of the oases at the antithetic season,—often
a faint shading only, with or without a darker pin-point at its core,—we are
led to the belief that the area of the oasis is unchangeable and that its
growth means a deepening of tint.
So far, then, as it is possible to particularize them, the oases develop from
a small nucleus, perhaps twenty miles in diameter, perhaps less, and from
this spread radially till they attain a width of seventy-five or one hundred
miles. If the oasis be associated with a double canal, this maximum width
exactly fits the space between the twin lines. Even when no double enters
the oasis, the size is about the same. This size attained, they hold it for some
months. Then they proceed to fade out to their initial nucleus, and after a
sufficient rest the process starts over again.
With the carets something of the same sort seems to take place—if we
may consider as betokening a general law the fact that in 1894 the carets at
the mouths of the Phison and Euphrates developed before their affiliated
canals. But about them much less is yet known, and we must be content to
say that the observations of 1905 made at the opposite season of the canal’s
year seem to bear this out.

PART IV
EXPLANATION

CHAPTER XXVIII
CONSTITUTION OF THE CANALS AND OASES

A s rational science does not rest content with raw results, it now becomes
obligatory, by marshaling the facts to suitable discussion, to seek to find
out what they mean. Now, so soon as we scan these phenomena for some
self-interpretation, we perceive one characteristic of the lines which at once
appears to direct us to their nature and justifies itself as a signpost with
increasing certainty as we read on. This trait is the very simple yet most
significant one of showing intrinsic change: the lines alter in visibility with
time. This primary proclivity we do not even need the cartouches to
establish. That the lines change is palpable to any one who will watch them
long enough. Schiaparelli was struck by the fact early in his study of the
planet, and it forces itself on the notice of any careful observer who
compares his own observations with one another at intervals. But though
the cartouches are not needed to a first revelation of mutability, they serve
to certify and precise it to much further information on the subject. For, that
these changes are not extrinsic, that is, are not caused by varying definition,
distance, or illumination, they make patent even to those who have never
seen the things themselves by disclosing respective differences of behavior
in lines similarly circumstanced optically. The change is therefore intrinsic,
and the question arises to what can such intrinsic change be due.
In searching for cause, attention is at once attracted by another series of
transmutations that manifests itself upon the disk, in the orderly melting of
the polar caps. For the existence of the two sets of metamorphoses suggests
the possibility of a connection between them. The inference is strengthened
when we note that not only are both periodic, but that furthermore the
period of the two is the same. Each polar cap runs through its gamut of
change in a Martian year; the canals also complete their cycle of growth and
decay in a Martian twelvemonth. The only difference between the two is

that each polar cap has but one maximum and one minimum in the course
of this time, while most of the canals have two of each, though the maxima
are not alike nor the minima either.
Not only is the period of the two series of changes the same, but the one
follows the other. For the development of the canals does not begin till the
melting of the polar cap is well under way. Now, as the polar cap
disintegrates it gives rise, as we have seen, to a dark belt of blue-green
which fringes its outer edge and retreats with it as it shrinks. This tells,
directly or indirectly, of a product let loose. After this belt has been formed
the canals nearest to it proceed to darken, then those a little farther off
follow suit, and so the wave of visibility rolls in regular routine down the
disk. Here, then, at the outset we have a chronic connection between the
two phenomena, the disintegration of the cap and the integration of the
canals.
Of water we saw that the caps were undoubtedly composed, and to water,
then, let loose by the melting of the cap, we may inferably ascribe the
thaumaturgy in the development of the canals. But it is not necessary to
suppose that this is done directly. That the increased visibility of the canals
can be due to a bodily transference of water seems doubtful, if for no other
reason than the delay in the action. Considerable time intervenes between
the disappearance of the cap and the appearance of the canals, except in the
case of such as have been covered by it. Transformation consequent upon
transference, however, would account for hesitancy. A quickening to vegetal
growth would produce the counterpart of what we see. If, set free from the
winter locking up, the water accumulated in the cap then percolated
equatorward, starting vegetation in its course, this would cause the
increased visibility of the canals and at the same time explain the seeming
delay, by allowing for the time necessary for this vegetation to sprout. This
is certainly the most satisfactory explanation of the phenomena.
Thus started, the vegetal quickening would pass down the planet’s
surface and give rise to what we mark as seasonal change. But, though in
one sense of seasonal character, a little consideration will show that it
would be quite unlike the seasonal change which we know on earth.
Could we see our earth from some standpoint in space, we should mark,
with the advent of spring, a wave of verdure sweep over its face. If freedom
from cloud permitted of an unimpeded view, this flush of waking from
winter’s sleep would be quite evident and could be seen to spread. Starting

from the equator so soon as the sun turned north, it, too, would travel
northward, and, distancing the sun, arrive by midsummer well into the
arctic zone. Here, then, we should note, much as we note it on Mars, a tint
of blue-green superpose itself successively upon the ochre ground; but the
mundane and the Martian vegetal awakening would differ in one
fundamental respect; the earthly wave would be seen to travel from equator
to pole, while the Arian travels from pole to equator. Though clearly
seasonal in character, both of them, the transformations would be opposite
in action. Some other cause, then, must be at work from what we are
familiar with on earth. This other cause is the presence or absence of
moisture.
Two factors are necessary to the begetting of vegetal life, the raw
material and the reacting agent. Oxygen, nitrogen, water, and a few salts
make up the first desideratum, the sun supplies the second. Unless both be
present, the quickening to life never comes. Now, the one may be there and
the other not, or the other there and the one not. On earth the material
including water is, except in certain destitute localities, always present; the
sun it is that periodically withdraws. Observant upon the return of the sun is
therefore the annual recurrence of vegetal growth.
On Mars, on the contrary, water is lacking. This we now know
conclusively from other phenomena the disk presents which have no
connection with the present investigation and are, therefore, unprejudiced
witnesses to the fact. No permanent bodies of water stud its surface. That
the so-called seas are traversed by dark lines permanent in place is one of
several proofs of this. The only surface water the planet knows comes from
the melting of its polar caps. Vegetation cannot start until this water reaches
it. Consequently, though the sun be ready, vegetation must wait upon the
coming of the water, and starting from near the pole follow the frugal flood
equatorward.

Phenology Curves—Earth.
* = Dead Point of Vegetation.
(From paper in Proc. Amer. Phil.
Soc., by Percival Lowell.)

Phenology Curves—Mars.
* = Dead Point of Vegetation.
(From paper in Proc. Amer. Phil.
Soc., by Percival Lowell.)

Now, such contrariety of progression to what we should observe in the
case of the earth could we view it from afar is exactly what the curves of
visibility of the canals exhibit. Timed primarily, not to the return of the sun
but to the advent of the water, vegetal quickening there follows, not the
former up the latitudes but the latter down the disk. For better
understanding, the two curves of phenological quickening, the mundane and
the Martian, are shown in the diagrams. The plates represent the surfaces of
the two planets, that of the earth being shown upside down with south at the
top so as to agree with the telescopic depiction of the topography of Mars.
The stars mark the epoch of the dead-point of vegetation at successive
latitudes; the time increasing toward the right. The curves, it will be
noticed, are bowed in opposite ways. The bowed effect is due in part to
Mercator’s projection; in part it may represent a real decrease in speed with
time. But what is strikingly noticeable is the opposite character of the
advance to the right, the one curve running up the disk, the other down it.
This shows that the development of vegetation proceeded in opposite
directions over the surface.

Thus is the opposed action upon the two planets accounted for, and we
are led to the conclusion that the canals are strips of vegetation fed by water
from the polar caps, and that the floral seasons there as affecting the canals
are conditioned, not as they would be with us, directly upon the return of
the sun, but indirectly so through its direct effect upon the polar snows.
Once adventured on the idea of vegetation, we find that it explains much
more than the time taken by the wave of canal-development down the disk.
It accounts at once for the behavior of the canals in the three northern
zones: the polar, arctic, and sub-arctic. The mean cartouches of these three
zones dip down at their latter end instead of rising there, as is the case with
the cartouches of the mean canals farther south. This dip denotes that the
most northern canals were waning already by the middle of their August,
though the others showed no such tendency; while the date of the
deposition of the frost in these northern latitudes shows that they were
started upon their course toward extinction before the snow itself had
covered them. In other words, they were not obliterated but snuffed out.
That their decline was thus preparatory to the coming of the first snowfall
or frost-fall, sufficiently severe to whiten the ground so that it did not melt
the next day, is suggestive of their constitution. It is clear that they were not
abruptly cut off by the frost, but were timed by nature to such extinction.
Vegetation would behave in just this way, since evolution would
accommodate the career of a plant to its environment.
The first question to present itself chronologically in the canals’ annual
history is connected with the size of the cap. Unfortunately for the
simplicity of the phenomena, the cap is not an extensionless source of flow,
but an extended surface melting from the outer edge in. It would seem,
therefore, that water liberated from the outer parts should have an effect
before the main body of it were ready to begin its general march down the
disk. There should be, one would think, at least a partial action, locally,
before the main action got under way. Now, there are certain canals that
show cartouches increasing apparently from the time observations began,
and the most pronounced is the Jaxartes, which lies of all the canals
observed the farthest north. Now, the cartouches were founded on canals
quickened from the north polar cap. The farther north the canal, therefore,
the greater the likelihood of its showing the phenomena.
That we note such canals is therefore not only not subversive, but
actually corroboratory, of the law it seems at first to shake. That all the

canals of these zones do not show a like cartouche-profile is not necessary,
a part of them being dependent, not upon the earlier, but upon the later
liberated flow, and thus partaking in the general law, which grows uniform
lower down the latitudes.
As the action from one polar cap proceeds, not only down to the equator,
but across it into the planet’s other hemisphere, it appears that much, at
least, of the surface of Mars has two seasons of vegetal growth, the one
quickened of the north polar cap, the other of the southern. How far the
polar spheres of action overlap it is not possible at present to affirm, as the
canals at this opposition were only visible to 35° south latitude. That the
north polar quickening goes down so far is vouched for, and it is probable
from other observed phenomena that it goes farther.
The alternate semi-annual quickening also discloses itself directly in the
cartouches; the previous semestral growth from the south polar cap actually
showing in them before the impulse from the north began. The slow falling
of their curves to the minimum preceding their later rise is nothing less than
the dying out of the effect started six months before from the south. The
gentler gradient of their fall proclaims a gradual lapse, just as the
subsequent sharper rise points to the advent of a fresh impulse. And this
deduction seems to be borne out by another circumstance. There is some
evidence of decrease in the pre-minimal gradient southward. This is telling
testimony to the source whence the impulse came. For if it originated at the
south and traveled northward, the southern canals would be the first to be
affected and the first to die out, and thus show a longer dead season,
exhibited in the cartouches as a more level stretch.
Lastly, the explanation of the canals as threads of vegetation fays in with
the one which has been found to meet the requirements of the blue-green
areas; while the fact that they prove to develop as they do, reversely to what
would take place on earth, is exactly what all we have latterly learnt about
the surface conditions of the planet would lead us to expect.
From what has just been said we see that the latest observations at
Flagstaff confirm the earlier ones, and, what is especially corroborative,
they do so along another line. The former were chiefly static, the latter
kinematic. In other words, the behavior of the canals in action bears out the
testimony of their appearance at rest.

CHAPTER XXIX
LIFE

S tudy of the fundamental features of Martian topography has disclosed, as
we have seen, the existence of vegetation on the planet as the only
rational explanation of the dark markings there, considered not simply on
the score of their appearance momentarily, but judged by the changes that
appearance undergoes at successive seasons of the Martian year. Thus we
are assured that plant life exists on the planet. We are made aware of the
fact in more ways than one, but most unanswerably for that trait to which
vegetation owes its very name,—its periodic quickening to life. Thus the
characteristic which has seemed here most distinctive of this phase of the
organic, so that man even christened it in accordance, has proved equally
telltale there.
Important as a conclusion this is no less pregnant as a premise. For the
assurance that plant life exists on Mars leads to a further step in
extramundane acquaintance of far-reaching import. It introduces us at once
to the probability of life there of a higher and more immediately appealing
kind, not with the vagueness of general analogy, but with the definiteness of
specific deduction. For the presence of a flora is itself ground for suspecting
a fauna.
Of a bond connecting the two we get our first hint the moment we look
inquiringly into the world about us, that of our own earth. Common
experience witnesses to a coexistence which grows curious and compelling
as we consider it. For it is not confined to life of any special order, but
extends through the whole range of organisms of both kinds from the lowest
to the highest. Algæ and monera, orchid and mammal, occur side by side
and with a certain considerate poverty or richness, as the case may be.
Luxuriance in the one is matched by abundance in the other; while a scanty
flora means a poor fauna. This of which we have been aware in regions

round about us from childhood grows in universality as we explore.
Wherever man penetrates out of his proper sphere he finds the same dual
possession of the land or the sea, and a similar curtailing or expanding of
both tenantries together. No mountain top so cold but that if it grow plants,
it supports insects and animals, too, after its kind; no desert so arid but that
creeping things find it as possible a habitat as life that does not stir. Even in
almost boiling geysers animalcula and confervæ share and share alike. Only
where extreme conditions preclude the one do they equally debar the other.
Proceeding now from the fact to its factors we perceive reasons for this
tenure in common of the land by the vegetal and animal kingdoms.
Examination proves the two great divisions of the organic to be inextricably
connected. It strikes our notice first in the relation of plants to animals. It is
of everyday notoriety that animals eat plants, though it is less universally
understood that in the ultimate they exist on nothing else. Plants furnish the
food of animals; not as a matter of partial preference but of fundamental
necessity. For the plant is the indispensable intermediary in the process of
metabolism. Without plants animals would soon cease to exist, since they
are unable to manufacture their own plasm out of the raw material offered
by inorganic nature. They must make it out of the already prepared plasm of
plants or out of other animals who have made it from plants. So that in the
end it all comes back to plant production. The plant is able to build its
plasm out of chemical substances; the animal cannot, except in the case of
the nitro-bacteria, begin thus at the lowest rung of the alimentary ladder.
But the converse of this dependence is also largely true. Plants are
beholden to animals for processes that in return make their own life
possible. The latter minister to the former with unconscious service all the
time, and with no more arrogant independence than do our domestics
generally nowadays. The inconspicuous earthworm is the fieldhand of
nature’s crops, who gets his own living by making theirs. Without this day
and night laborer the soil for want of stirring had remained less capable of
grass. Above ground it is the same story. Deprived of the ministrations of
insects many kinds of plants would incontinently perish. By the solicited
visits of bees and other hymenoptera—what generically may be classed by
the layman as flutter-bys—is the plant’s propagation made possible.
Peculiarly well named, indeed, are the hymenoptera, seeing that they are the
great matrimonial go-betweens, carrying pollen from one individual to
another and thus uniting what otherwise could not meet. Spectacular as this

widespread commerce is, it forms but portion of the daily drama in which
animals and plants alike take part. From forthright bargainings of honey for
help, we pass to less direct but no less effective alliance where plants are
beholden to animals for life by the killing of their enemies or the weeding-
out of their competitors, and from this to generic furtherance where the
interdependence becomes broadcast. In the matter of metabolism the
advantage is not all upon one side. In the katabolic process of that which
each discards are the two classes of life mutually complimentary,—the
waste of the one being the want of the other,—carbonic acid gas being
given off by the animal, oxygen by the plant. In biologic economy it is daily
more demonstrable that both are necessary constituents to an advancing
whole, and that each pays for what it gets by what it gives in return.
That they are thus ancillary as well as coexistent today leads us to
confront for them a community of origin in the past; and further study
confirms the inference. Both paleontology and entomology, or the science
of the aged and the science of the young, prove such ancestry to be a fact.
By going back from the present into the past, or, what amounts to
substantially the same thing, by descending in the scale of life to the lowest
known forms of organism, we find proof of concomitance, cogent because
congenital. At the time when inorganic chemical compounds first passed by
evolution into organic ones, the change was of so general a character that
even such tardy representatives of it as survive today tax erudition to tell to
which of the two great kingdoms they belong, the vegetal or the animal.
Simplest and most primitive of known organisms are the chromacea,
unnucleated single cells as Haeckel has shown, and next to them in order
come many of the bacteria, also of simple unnucleated plasm. So little do
the majority of the bacteria differ morphologically from the chromacea, that
on the score of structure the two are not to be catalogued apart. Both are as
elemental as anything well can be, which only their diet serves to divide.
Each is an organism without organs, thus belying the dictionary definition
of both animals and plants. Etymologically they are not organic yet
manifestly are alive, and only in their action are unlike. The chromacea are
plasm-forming beings, and therefore they are plants; the bacteria are plasm-
eating beings, and so are animals. Even this distinction is not always
preserved. As Haeckel tells us: “the nitro-bacteria which dwell in the earth
having the vegetal property of converting ammonia by oxidation into
nitrous acid and this into nitric acid, using as their source of carbon the

carbonic acid gas of the atmosphere. They feed, like the chromacea, on
simple inorganic compounds.” Here, then, we have, close to the threshold
of organic life, unorganized organisms, roughly speaking coeval and
differing in a sense but little, either of them, from inorganic crystals; and
yet the one is an animal, the other a plant. Progenitors of the two great
divisions of life, they were themselves concomitantly evolved, either side
by side or as offshoots both of a common stock. Now, if the ancestors of the
two great organic kingdoms were thus simultaneously produced here, we
are warranted in believing that they would similarly be produced elsewhere,
given conditions suitably alike. In consequence, if we detect the presence of
the one, we already have an argument for inferring the other. Not to
complete our syllogism would be to flaunt a lack of logic in nature’s face.
Rationally viewed, then, the general problem of life in other worlds
reduces itself to a question of conditions. Since certain physical results
follow inevitably upon certain physical premises, if we can assure ourselves
of the proper premises we may look to nature for their conclusion. A priori,
then, the possibility of life becomes one of habitat. If the environment be
suitable life will ensue. What makes for such a mediary milieu is, like most
cosmic processes, in its fundamentals of interesting simplicity; for the
production of a proper nidus depends primarily upon the mere size of the
body parentally concerned. If a planet be big enough it will inevitably bring
forth life, because of conditions suitable to its generating; if too small it will
remain sterile to the end of time.
That size should be the determining factor whether a planet shall be
fecund or barren may seem at first thought strange. Yet that it is so admits
of no rational doubt. All that we see of bodies about us shows its truth, and
what we have learnt of cosmic process enables us in some sort to discern
why. In order for evolution, such as we mark it upon the earth, to be
possible, the parent body must have been at one time at a high temperature,
since only under great heat can the primal processes occur. But for this
generation of caloric the aggregate mass of the particles, the falling together
of which makes the planet, and their stoppage its internal heat, must be
large. The sun’s rays alone are insufficient to cause the necessary
temperature; the heat must come from within, though it be helped from
without. Even here the action is abetted by a large body. For a planet to
entrap the sun’s rays or even to preserve its own internal warmth, an
atmosphere is needed, and it takes a large body to retain an atmospheric

covering sufficiently long. Yet without it not only would there be no
suitable state, but no medium in which organic or even inorganic reactions
could go on. Lastly, water, the essential nidus for the organism’s early
stages, has its presence similarly conditioned. For this, like the atmosphere,
would from a small body speedily vanish away. Thus the planet itself is the
life-producing body, although the sun furthers the process when once
begun.
That the needed substances are planetarily present, what we know of the
distribution of matter astronomically sufficiently attests. What we find in
meteorites shows that the catastrophe which preceded our present solar
system’s birth scattered its elemental constituents throughout its domain,
and thus when they came to be gathered up again into planets that these
must have been materially the same. The manner, not the matter, then, is
alone that about which we are concerned.
Now, if the mass of matter gravitating together to form a planet be
sufficient to produce the proper inorganic conditions, the organic must
follow as a matter of course. That the organic springs from the inorganic is
not only shown by what has taken place on earth, but is the necessary
logical deduction from its decay back into the inorganic again. As Nägeli
admirably observes: “The origin of the organic from the inorganic is, in the
first place, not a question of experience and experiment, but a fact deduced
from the law of the constancy of matter and force. If all things in the
material world are causally related, if all phenomena proceed on natural
principles, organisms which are formed of and decay into the same matter
must have been derived originally from inorganic compounds.”
The original oneness of the two, the fact that the organic sprang from the
inorganic, is shown by the cousinly closeness of the lowest organic with the
highest inorganic substances. The monera are suggestive of crystals in their
uniformity of structure. Both are homogeneous or approximately so. Again,
both grow by taking from what they come in contact with that which they
find suitable and so add to their body by homogeneous accretion. Finally,
when grown too large for single life, they part into similar crystals or split
into identical cells. The difference between the division of the crystal and
the fission of the cell is small in kind; much less than that later
differentiation in genesis into parthenogenesis and sexual reproduction. Yet
here we unhesitatingly trace an assured relationship. It were straining at a
gnat to swallow a camel to doubt it in the other.

Just as the two behave analogically alike in their own action, so do they
observe a like attitude toward nature. They thus point to their common
origin. The monera are resemblant of chemical compounds in their
superiority to external influences. To outward conditions of temperature and
humidity the chromacea are much as sticks and stones. Some species may
remain for long frozen in ice, Haeckel observes, and yet wake to activity so
soon as it thaws. Others may be completely desiccated, and then resume
their life when put in water after a lapse of several years. Thus both in their
deathlike lives and in their living immortality the chromacea are close to
inorganic things.
From preference, however, these lowest forms of life affect what to us
would be unbearable temperatures. Many of the chromacea live in hot
springs at temperatures of 123° to 176° Fahrenheit, in which no other, that
is, no higher, organism can dwell. This choice of habitat is in line with the
other details of their evolutionary career. For it, too, is in keeping with the
conditions of crystalline growth, halfway as it were on the road to them; the
forming of crystals beginning at a temperature higher still. And we perceive
from it that the passing of the inorganic into the organic is brought about by
a lowering of the temperature of the parent planet. This again, is in line with
the evolution of chemical complexity. Let the heat become less, and higher
and higher chemical compounds, finally the organic ones, become possible.
That evolution is nothing else than such a gradually increasing chemical
synthesis is forced on one by study of the facts. Once started, life, as
paleontology shows, develops along both the floral and the faunal lines side
by side, taking on complexity with time. It begins so soon as secular
cooling has condensed water vapor to its liquid state; chromacea and
confervæ coming into being high up toward the boiling-point. Then, with
lowering temperature come the seaweeds and the rhizopods, then the land
plants and the lunged vertebrates. Hand in hand the fauna and flora climb to
more intricate perfecting, life rising as temperature lowers.
We perceive then that, considered a priori, the possibility of life on a
planet is merely a question of the planet’s size; and then pursuantly that the
character of that life is a matter of the planet’s age. But age again is a
question of size. For the smaller its mass the quicker the body cools, and
with a planet, growing cold means growing old. Within the bounds that
make life possible, the smaller the body the quicker it ages and the more
advanced its denizens must be. Just how far the advance goes we may not

assert dogmatically in a given case, since not relative age alone but absolute
time as well is concerned in it. It may be that nature’s processes cannot be
hurried, and that for want of time development may in part be missed. But
from general considerations the limit of the time needed seems well within
most planetary careers.
Now, the aspect of the surface of Mars shows that both these conditions
have been fulfilled. Mars is large enough to have begotten vegetation and
small enough to be already old. All that we know of the physical state of the
planet points to the possibility of both vegetal and animal life existing there,
and furthermore, that this life should be of a relatively high order is
possible. Nothing contradicts this, and the observations of the last ten years
have rendered the conclusion then advanced only the more conclusive.
Even the evidence of the past state of the planet confirms that given by its
present one. That with us life came out of the seas finds its possible parallel
in the fact that seas seem once to have existed there, leaving their mark
discernible to-day. Life, then, had there as here the wherewith to begin. That
we find air and water in both shows that it had the means to continue once
begun. That it then ran a like course is further witnessed by what we now
detect. The necessary premises, then, are there. More than this. One half of
the conclusion, vegetal life, gives evidence of itself.

CHAPTER XXX
EVIDENCE

O f the existence of animal life upon a far planet any evidence must, of
necessity, assume a different guise from what its flora would present.
Plant life should be, as on Mars we perceive it is, recognizable as part and
parcel of the main features of the planet’s face. In no such forthright manner
could we expect an animal revelation. The sort of testimony which would
render the one patent would leave the other obstinately hid.
So long as animate life was in the lowest sense animal, it would not be
seen at all, though it were as widespread as the vegetal life all about it.
Reason for this lies in their receptive character. Plants are fixtures; where
they start they stay; while from the nature of their food, derived directly
from the soil and from the air, and conditioned chiefly by warmth and
moisture, like forms inhabit large areas and by their massed effect make far
impression. With animals it is otherwise. They feed by forage, from beetle
to buffalo, roaming the land for sustenance. Thus, both for paucity of
number and from not abiding in one stay they must escape notice at a
distance such that as individuals they fail to show; to say nothing of the fact
that the flora usually overtop the fauna, and so help to hide the latter while
appearing itself distinct. Any far view of our earth gives instance of this.
Seen from some panoramic height, forest and moorland lie patently
outspread to view, yet imagination is taxed to believe them tenanted at all.
Unless man have marred the landscape not a sign appears of any living
thing. One must be near indeed to note even such unusual sights as a herd
of buffalo in the plains or those immense flights of pigeons, that in former
years occurred like clouds darkening the air. From the standpoint of another
planet, through any such direct showing animal existence would still remain
unknown.

Not until the creatures had reached a certain phase in evolution would
their presence become perceptible; and not then directly, but by the results
such presence brought to pass. Occupancy would be first evidenced by its
imprint on the land; discernible thus initially not so much by the bodily as
by the mind’s eye. For not till the animal had learnt to dominate nature and
fashion it to his needs and ends would his existence betray itself. By the
transformation he wrought in the landscape would he be known. It is thus
we should make our own far acquaintance; and by the disarrangement of
nature first have inkling of man.
That it is thus we should betray ourselves, a consideration of man’s
history will show. While he still remained of savage simplicity, a mere child
of nature, he might come and go unmarked by an outsider, but so soon as he
started in to possess the earth his handicraft would reveal him. From the
moment he bethought him to till the ground, he entered upon a course of
world-subjugation of which we cannot foresee the end; but he has already
advanced far enough to give us an idea of the process. It began with
agriculture. Deforestation with its subsequent quartering of crops signalized
his acquisition of real estate. His impress at first was sporadic and irregular,
and in so far followed that of nature itself; but as it advanced it took on a
methodism of plan. Husbandry begot thrift, and augmented wants
demanded an increasing return for toil; and to this desirable end
systematization became a necessity. At the same time gregariousness grew
and still further emphasized the need for economy of space and time. In part
unconsciously, man learnt the laws that govern the expenditure of force and
more and more consciously applied them. Geometry, unloosed of Euclid,
became a part of everyday life as insidiously as M. Jourdain found that he
had been talking prose. Regularity rules to-day, to the lament of art. The
railroad is straighter than the turnpike, as that is straighter than the trail.
Communication is now too urgent in its demands to know anything but law
and take other than the shortest path to its destination. Tillage has
undergone a like rectification. To one used to the patchwork quilting of the
crops in older lands the methodical rectangles of the farms of the Great
West are painfully exact. Yet it is more than probable that these material
manifestations would be the first signs of intelligence to one considering the
earth from far. Our towns would in all likelihood constitute the next; and,
lastly, the great arteries of travel that minister to their wants. Their scale,
too, would render them the first objects to be observed. Farming as now

practiced in Kansas or Dakota gives it a certain cosmical concern; fields for
miles turning in hue with the rhythm of the drilled should impress an eye, if
armed with our appliances, many millions of miles away.
Even now we should know ourselves cosmically by our geometrical
designs. To interplanetary understanding it is this quality that would speak.
Still more so will it tell as time goes on. As yet we are but at the beginning
of our subjugation of the globe. We have hardly explored it all, still less
occupied it. When we do so, and space shall have become enhancedly
precious, directness of purpose with economy of result will have partitioned
so regularly the surface of the earth as to impart to it an artificiality of
appearance, and it becomes one vast coördinated expanse subservient
entirely to the wants of its possessors. Centres of population and lines of
communication, with tillage carried on in the most economic way; to this it
must come in the end.
Nor is this outcome in any sense a circumstance accidental to the earth; it
is an inevitable phase in the evolution of organisms. As the organism
develops brain it is able to circumvent the adversities of condition; and by
overcoming more pronounced inhospitality of environment not only to
survive but spread. Evidence of this thought will be stamped more and more
visibly upon the face of its habitat. On earth, for all our pride of intellect,
we have not yet progressed very far from the lowly animal state that leaves
no records of itself. It is only in the last two centuries that our self-
registration upon our surroundings has been marked. With another planet
the like course must in all probability be pursued, and the older the life
relatively to its habitat the more its signs of occupation should show.
Intelligence on other worlds could then only make its presence known by
such material revelation, and the sign-manuals of itself would appear more
artificial in look as that life was high in rank. Given the certainty of plant-
life, such markings are what one would look to find. Criticism which
refuses to credit detail of the sort because too bizarre to be true writes itself
down as unacquainted with the character of the problem. For it is precisely
such detail which should show if any evidence at all were forthcoming.
If, now, we turn our inquiry to Mars, we shall be fairly startled at what its
disk discloses. For we find ourselves confronted in the canals and oases by
precisely the appearances a priori reasoning proves should show were the
planet inhabited. Our abstract prognostications have taken concrete form.
Here in these rectilineal lines and roundish spots we have spread out our

centres of effort and our lines of communication. For the oases are clearly
ganglia to which the canals play the part of nerves. The strange
geometricism which proves inexplicable on any other hypothesis now
shows itself of the essence of the solution. The appearance of artificiality
cast up at the phenomena in disproof vindicates itself as the vital point in
the whole matter. Like the cachet of an architect, it is the thing about the
building that established the authorship.
Though the Earth and Mars agree in being planets, they differ
constitutionally in several important respects. Even to us the curious
network that enshrouds the Martian disk suggests handicraft; it implies it
much more when considered from a Martian standpoint.

CHAPTER XXXI
THE HUSBANDING OF WATER

T hat the canals and oases are of artificial origin is thus suggested by their
very look; when we come to go further and inquire into what may be
their office in the planet’s economy, we find that the idea in addition to its
general probability now acquires particular support. For this we are
indebted in part to study of their static aspect, but chiefly to what has been
learnt of their kinematic action.
Dearth of water is the key to their character. Water is very scarce on the
planet. We know this by the absence of any bodies of it of any size upon the
surface. So far as we can see the only available water is what comes from
the semi-annual melting at one or the other cap of the snow accumulated
there during the previous winter. Beyond this there is none except for what
may be present in the air. Now, water is absolutely essential to all forms of
life; no organisms can exist without it.
But as a planet ages, it loses its oceans as has before been explained, and
gradually its whole water supply. Life upon its surface is confronted by a
growing scarcity of this essential to existence. For its fauna to survive it
must utilize all it can get. To this end it would be obliged to put forth its
chief endeavors, and the outcome of such work would result in a
deformation of the disk indicative of its presence. Lines of communication
for water purposes, between the polar caps, on the one hand, and the centres
of population, on the other, would be the artificial markings we should
expect to perceive.
Now, it is not a little startling that the semblance of just such signs of
intelligent interference with nature is what we discern on the face of Mars,
—in the canals and oases. So dominant in its mien is the pencil-like
directness of the canals as to be the trait that primarily strikes an
unprejudiced observer who beholds this astounding system of lines under