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Title: Pumps and Hydraulics, Part 1 (of 2)

Author: N. Hawkins

Release date: January 8, 2018 [eBook #56339]

Language: English

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PUMPS
AND

HYDRAULICS.
IN TWO PARTS.

Part One.

“There are many fingers pointing to the value of a training in
science, as the one thing needful to make the man, who shall rise
above his fellows.”—Frank Allen.

“The motto marked upon our foreheads, written upon our door-
posts, channeled in the earth, and wafted upon the waves is and must

be, ‘Labour is honorable and Idleness is dishonorable.’”—Carlyle.

This work is respectfully dedicated to
Maj. ABRAM B. GARNER,
of Newark, N. J.,

—AND—

ALBERTO H. CAFFEE, Esq.,
of New York City.

‘Gentlemen without fear and without reproach.’

“Thought is the principal factor in all mechanical work; the mechanical effort is an incident
rather than the principal equipment in any trade or occupation.”

“Any trade is easily learned by an apt scholar who uses his reasoning faculties and makes a study
of cause and effect.”—CHAS. J. MASON.

PUMPS

—AND—

HYDRAULICS

—BY—

WILLIAM ROGERS
Author of “Drawing and Design,” etc.

RELATING TO
HAND PUMPS; POWER PUMPS; PARTS OF PUMPS; ELECTRICALLY DRIVEN PUMPS;
STEAM PUMPS, SINGLE, DUPLEX AND COMPOUND; PUMPING ENGINES, HIGH DUTY
AND TRIPLE EXPANSION; THE STEAM FIRE ENGINE; UNDERWRITERS’ PUMPS; MINING
PUMPS; AIR AND VACUUM PUMPS; COMPRESSORS; CENTRIFUGAL AND ROTARY
PUMPS; THE PULSOMETER; JET PUMPS AND THE INJECTOR; UTILITIES AND
ACCESSORIES; VALVE SETTING; MANAGEMENT; CALCULATIONS, RULES AND
TABLES.

WITH ILLUSTRATIONS.

ALSO

GENERAL CONSIDERATIONS; GLOSSARY OF PUMP TERMS; HISTORICAL
INTRODUCTION, WITH ILLUSTRATIONS; THE ELEMENTS OF HYDRO-MECHANICS,
HYDROSTATICS AND PNEUMATICS; GRAVITY AND FRICTION; HYDRAULIC
MEMORANDA; LAWS GOVERNING FLUIDS; WATER PRESSURE MACHINES; PUMPS AS
HYDRAULIC MACHINES, ETC.

PART ONE.

PUBLISHED BY

THEO. AUDEL & COMPANY

72 FIFTH AVE.,
NEW YORK, U.S.A.

7, IMPERIAL ARCADE,
LUDGATE CIRCUS, E.C.,
LONDON, ENG.

Copyrighted, 1905, by
THEO. AUDEL & CO., NEW YORK.
Entered at Stationers Hall, London, England.

Protected by International Copyright in Great Britain and all
her Colonies, and, under the provisions of the
Berne Convention, in

Belgium, France, Germany, Italy, Spain, Switzerland, Tunis,
Hayti, Luxembourg, Monaco, Montinegro
and Norway.

Printed in the United States.

TABLE OF CONTENTS

Part ONE.
The divisions of Part One are represented by the following headings: each
subject is fully treated and illustrated on the pages shown:
PAGES
Introductory Considerations 1-16
Glossary of Pump and Hydraulic Terms 17-34
Historical Introduction 35-70
Elementary Hydraulics 70-104
Flow of Water Under Pressure 105-116
Water Pressure Machines 117-154
Water Wheels 119-125
126-135, 141-
Turbine Water Wheels
144
Turbine Pumps 136-139
Water Pressure Engines 145-147
Hydraulic Motors 147-154
Hydraulic Apparatus 155-184
Hydraulic Jack 159-168
Hydraulic Press 169-170
Hydraulic Accumulator 171-173
Hydraulic Ram 175-180
Pumps as Hydraulic Apparatus 181-184
Classification of Pumps 185-345
Hand Pumps 189-204
Power Pumps 205-224
Belted Pumps 225-240
The Electric Pump 241-276
The Steam Pump 227-330
The Duplex Pump 331-343
Underwriter Fire Pumps 344
Specifications of the National Board of Fire Underwriters Relating
347-398
to the Duplex Fire Pumps

Ready Reference Index to Part One

“Among the first things a practical engineer should know, and among the last things he
will, after becoming such, forget, is that in handling water within pipes he has a fluid
which, while it is flexible to the greatest extent and is susceptible of the influence of
power, or force, of greater or less intensity, and while it may be drawn from below and
raised to the heights above, can be turned to the right or to the left at will, and while,
with a seeming docility which is as flattering as it is deceptive, it bends itself to the will
of the engineer, still there are some things it will not do, and which all the complicated
appliances of the engineer have as yet failed to compel it to do. When inclosed within
chambers and pipes, to an extent that fills them, it will not permit the introduction of an
added atom without bursting its bounds. While inclosed within long lines of pipes it will
not suddenly start into motion, or when in motion suddenly come to a rest, without
shocks or strains more or less disastrous; and so, while it seems to be handled with the
greatest ease, it is only in the manner it chooses to go, and all mechanical appliances
not designed with reference to following these imperative laws are sure to meet trouble,
if not disaster. In other words, when an unyielding force meets an unyielding resistance,
their coming together means a shock to all about.”

INTRODUCTORY

CONSIDERATIONS

“Whenever a full mind meets an empty one, it is a call to teach, not
to scoff.”—Anon.

Orifices of Pipes, etc., Symbolical of Irrigation.

“He who sedulously attends, pointedly asks, calmly speaks, coolly
answers and ceases when he has no more to say, is in possession of
some of the best requisites of man.”—Levater.

PREFACE.

It should be a matter of thankfulness to author and reader, or rather to
both instructor and student, for this is designed to be an educational work,
that the Laws of Nature are unchangeable.
From age to age and co-extensive with the globe the immutable
principles underlying and actuating the physical states of all matter remain
steadfast; gaseous bodies expand by unchanging laws which are obeyed
down to the merest atom, fluids flow by law and the earth to the smallest
particle remains firm, all things at all times responsive to the mandates of
the Author of Creation.
The silent, mighty, unanswering physical characteristics of Gravity,
Cohesion, Tenacity, furnish an agreeable contrast to the din, discord and
frequent argument, to the verge of hatred, that have too often accompanied
the efforts of mankind to co-operate with the forces of Nature. But now,
between author and reader, let it be hoped, that in the unfolding of the
subject-matter of this work that kind consideration will be extended and that
some of that peacefulness and trust which existed on the earth, when flints
were the weapons and the gourds the only goblets, may prevail from
beginning to the “finis” of the volumes.
The author in planning the outlines of this work has aimed to keep close
to real things belonging to the practical side of hydraulics, pumps,
pumping-engines, and to the simple explanation of the Natural Laws
pertaining to their industrial application. A knowledge of the real things in
the objective world about us and the laws that govern them in their inter-
relations is of practical value to every man; all branches of science are
simply branches of one great science and all phases of human activity are
touched by it; man is so constituted that he must have something to be
interested in, and if he has no resources within himself he looks elsewhere,
and often to his own disadvantage.

And so, the author has aimed to make the subjects of this book
interesting as well as useful; 1, by their self-help arrangement; 2, by the
illustrations, and 3, by leaving very much to the further research and
investigation of the reader, as, in a well-told story, many things are left to
the imagination of the listeners.
It should be borne in mind by the reader, that the work is designed to be
seriously Educational in its plan and scope, and Progressive in the
presentation of its subject-matter; nothing has been withheld that might add
to its lasting value.
This is said in the way of an introduction to the Table of Contents to
which the student is referred as showing the method of treatment, in the
wide range of the theory and practice, of this important branch of Industrial
Science.
In the back of the volume may be found a Ready Reference Index which
by its admirable method of arrangement affords a speedy key to the
contents of the book when occasion requires.

WHAT A STEAM PUMP WOULD SAY IF IT COULD TALK.

The well-known pump expert, Mr. F. Meriam Wheeler, writes us saying
that if the manufacturers of steam pumps would send out with their pumps a
card reading something like the following, it would probably impress the
men who run the pumps more forcibly than anything that could be said or
written in the ordinary way of giving instructions:
“Please do not gorge me with oil, as it will give my steam chest
indigestion. What I like is a steady diet and thus enable my valves to work
smoothly and with durability. A very small amount of oil fed to me steadily
is the thing—it saves oil and repair bills.
“Two or three times a year give me a good dose of kerosene, to clean out
any obstructions that may have accumulated in the passageways of my
steam chest, or on the face or working parts of the valve and valve-seat, or
on the chest piston.
“Do all you can to help me make a full length of stroke, as it means that I
will use less steam and do better work. The adjustable collars on the valve
rod will allow you to regulate the length of my stroke to a nicety.
“By allowing me to make short strokes, you prevent my steam piston from
getting in its proper cushion, which it would do if it could complete its full
stroke. My steam piston is supposed to run up to the end of the cylinder and
pass across the exhaust port, cushioning on the confined steam between
said port and the cylinder cover.
“The hand wheels on the side of my steam cylinder are for controlling the
amount of this cushion. For slow speeds these cushion valves should be shut
tight. When running at ordinary speed or a high rate of speed, these
cushion valves should be slightly opened.
“Once in a while take a look at my water cylinder. See that the packing of
the water piston is not set up so tight that it makes me grunt, producing
unnecessary friction and wear. Or, perhaps the packing is too loose a fit, or
is worn out and needs renewing.
“Please see that my water valves are seating properly, because if they are
not tight I cannot pump as much water as I ought to do for a given speed.

Sometimes the springs on the backs of my water valves need renewing or
looking after.
“If you have not already provided a good suction air chamber for my
water cylinder, you ought to do it, because it will prevent the water column
in the suction pipe from slapping the face of my water piston at the end of
each stroke in a harsh manner and so produce ‘water hammer.’ A good
suction air chamber, properly located, saves wear and tear, and makes a
pump quiet running.
“Please keep me nice and clean. I may not be of as much importance as
your big engine, but there is no reason why I should not be kept free from
dirt and grease. I hate to have oil slobbered all over my steam chest, or my
stuffing-boxes left leaking.
“You will find it pays to keep me in good condition, like a well-groomed
horse. Treat me well and I’ll serve you well and long!!!”—The Engineer.

GLOSSARY OF PUMP AND HYDRAULIC
TERMS.
Air-bound. This word applies to both pump and piping and expresses the
confinement of air between the discharge valve of the pump and the
check-valve or the point of delivery.
Air-cock. Is the same as a pet-cock and is used to relieve pipes that are air-
bound.
Annular Valve. From annular—a ring—i.e., a
round valve with a hole in the middle.
Area. The extent of surface, as the area of a
piston.
Assembling. Putting together the parts of a
machine.
Atmospheric Pressure. The pressure of
atmospheric air, not only downward but in Air Cock.
every direction, this amounts to about 14.7
lbs. per square inch at the sea level. Usually taken at 15 lbs. to facilitate
calculations.
Auxiliary. Something to “help out,” as an auxiliary cylinder or an auxiliary
piston.
Ball Check-valve. One in which a metal ball is used in place of a poppet-
valve.
Balanced Valve. A valve having an equal pressure
on all sides. See equilibrium valve.
Basket. The outer casing or netting of a foot valve
which forms a strainer on a pump suction pipe.
Bends. In pipe, the turns in lines of pipe may be
angle bends (called “elbows“) or offset bends.

Ball Check-Valve. Bibb-cock. This is a plug cock having an elbow or
curved outlet directing the outflow downward.

Bibb Compression. A
bibb-cock having in
place of the plug a
stem with thread and
handle to open by
unscrewing; the
Bibb-Cock. valve contains
fibrous packing and
is made tight by compression.
Bonnets. These are covers for the opening into Bibb Compression.
valve chambers of pumps.
Boss. Any round protuberance on a casting to support a stud or to
strengthen a steam chest cover, etc.
Bushing. A nut used in pipe fitting, threaded inside and outside to
accommodate two sizes of pipe.
Check Valve. A valve through which fluid can pass only in one
direction; used between pump and reservoir or boiler. See
swing-check.
Check-Nut. A second nut screwed against the first to hold it
Bushing. firmly in place; also called a lock-nut.
Circulating Pump. A pump arranged to force water through the tubes of a
surface condenser. Frequently a centrifugal pump is used as a circulating
pump.
Clack Valve. This takes its name from the noise it makes in seating; it is
made of leather with a metal weight on top, the leather forming a hinge
on one side. In the cut the lifted valve is the “clack.”
Clearance. The space or distance by which one piece clears another. The
space between piston and cylinder head.
Cock. A faucet or device for opening or closing a passage. The illustration
shows a straight-way cock.

Column Pipe. A column may be
considered as a beam set on end and a
column pipe may, similarly, be defined
as a pipe set on end. The pipes leading
from a water column to boiler.
Compression Gauge Cock. A device
Plain Cock.
having a threaded steam spindle and
made tight by compression. The figure exhibits an
outside view of a locomotive compression gauge cock. Clack Valve.

Corrosion. Rusting or wasting away
of the surfaces of metals.
Crow. A claw with a screw attached
to support and feed a drill brace
for drilling holes in pipes.
Cup Leather Packing. The leather
packing used around the ram of a
Compression Gauge Cock.
press. In section it resembles a
cup—hence the name.
Cushioning. This term applied to the operation of
pumps, etc., is the imprisoning of steam, water
or air between the piston and cylinder head to
prevent the piston from impact with the head.
Cup Leather Packing.
Cylinder Head or Cylinder Cover. A plate which
encloses or covers the end of a cylinder.
Dead end of a pipe. The closed end of a pipe or system of pipes.
Disk or Disc. A cylinder, whose length is very short in proportion to its
diameter; a round plate with a hole in its center.
Double-eye or Knuckle Joint. A joint formed of two forks or jaws with a
cube of iron between them, with a bolt or pin through each jaw and the
cube at right angles. Will work freely in all positions from a straight line
up to 45°.
Double seated poppet valve. A poppet valve having two valves on one stem,
with two seats in the same shell.

Drafting water. Another term for “raising“
water by suction, in distinction to
“forcing water.”
Drip-pipe. A device used to draw off the
water of condensation from systems of
piping, steam cylinders, heaters, etc.
Drain-cocks are used for similar
purposes.
Double-Seated Poppet Valve.
“Dutchman.” A piece “fitted in” to restore
a worn part or to hide a defect.
Duct. A passage or conduit.
“Duty” of pumps. This indicates the measurement of the work performed
by pumps. “Duty trials” are careful tests of the work done by the larger
pumping-engines.
Elbow. This fitting is used for uniting two pipes together at right angles. The
illustration shows a malleable-iron gas-pipe elbow.
Equilibrium Valve. A valve balanced by an equal
pressure on both ends.
Expansion Joint. A telescopic slip joint having a
packed stuffing box, permitting the parts it connects
to expand and contract under variations of
temperature.
Face. The broadest flat surface of a Elbow.
piece of work, or the one having
the greatest area.
Factor of Safety. When a calculation of the ultimate
strength of a machine is to be made it is necessary to
provide for contingencies—this takes the form of a
multiplier, and is called the factor of safety, or the
Expansion Joint. margin of safety.
Feather, or sunk key. A key that is fast in one piece of work, and an easy fit
in the other, as a feather in a shaft.

Flow. Motion of a fluid or liquid in one direction. “Flow-gate“ is a term
sometimes applied to a riser.
Flume. An open trough for conveying water.
Gate Valve. A valve
which opens the
full area of the
pipe, on the
principle of a gate
in a water flume.
Globe Valve. A valve
having a round
ball-like shell as
shown in the
engraving.
Gland. The sliding
bushing for
holding packing
into a stuffing box,
Gate Valve. adjusted by studs Globe Valve.
and nuts.
Goose neck. A pipe fitting having two bends in opposite directions which
resemble the neck of a goose.
Gridiron Valve. A type of slide valve familiarly called a “grid,” which may
be circular or rectangular, consisting of alternate bars and spaces, sliding
over a similarly formed seat, the object being to obtain the necessary
steam way with a diminished amount of valve travel.
Hand-Nut. A nut having wings or projections so that it may be screwed up
by hand without the aid of a wrench.
Head of water. In hydraulics “head“ means
pressure due to height of column of water.
Heat Units. The unit of heat is the amount of
heat required to raise one pound of water one
degree, usually from 32° to 33° Fahr.

“Hesitates.” A pump is said to “hesitate” when Hand-Nut.
the motion becomes uncertain.
Horse-power of a pump. Is the same as is used to designate that of a steam
engine, with this exception: the initial pressure in the pump remains
constant throughout the stroke. Formula is the same as for a steam
engine.
“Hump.” This is an arch or bend which causes an “air pocket” in a water-
pipe line.
Hydrant. A valve and spout connecting with a street main.
Hydraulic Belt. An endless woolen band for raising water. The lower bight
is immersed in water, and the upper bight passes over a roller. The belt
travels about 1,000 feet per minute, and discharges at its upper turn.
Hydraulic Jack. A lifting device in which a ram, a
pump, and liquid is used instead of a screw.
Hydraulic Pivot. A “slippery liquid support” for an
upright shaft, a film of water being introduced
beneath it by pressure to support the weight thereof
and prevent the usual friction of the shaft on its
step.
Hydraulic Shears. A machine for shearing or cutting
metals, etc., by the force of water pressure
operating cutters.
Hydraulic Valve. A valve for regulating the
distribution of water in the cylinders of hydraulic
elevators, cranes and other water pressure machines
and devices.
Hydraulic Jack. Hydraulic Wheel. One for raising water by applied
power, as the Noria Scoop wheel, tympanum, etc.
See illustrations in section relating to the history of the pump.
Impact. The single instantaneous shock of a body in motion when it strikes
against another body either in motion or at rest.
Leakage. The loss of water from any cause.

“Lift and drop of a valve.” This term indicates the amount of “play” up and
down, designed to be given to a valve by its designer.
Liner. A piece of iron or other metal put behind or on a piece to take up its
wear.
Lost Motion. Motion that is not transmitted on
account of the looseness of the parts, hence it is
lost.
“Losing water.” A term used when the pump stops,
caused by air leaking into the suction pipe, or
foreign matter clogging the strainer at the end of
the suction pipe.
Low pressure steam. Steam which is either below 30
lbs., or but a few pounds in excess of the
atmospheric pressure.
Lug. That which projects like an ear, especially that
by which anything is supported, or against which
anything bears, or through which a belt passes.
Main. A principal pipe or duct as distinguished from
lesser ones, especially a principal pipe leading to or
from a reservoir or a fire-main; a “forcing main” is Mississippi River
the delivery pipe of a pump. Gauge Cock.
Mean gradient. The grade of a pipe-line which should
be made as nearly straight as possible to avoid air pockets.
Miner’s Inch. The amount of water that will flow per minute through an
opening one inch square in a plank two inches thick, under a head of four
inches of water above the upper edge of the opening, and is equal to nine
United States gallons.
Mississippi River gauge cock. A cock without a handle or thread upon the
stem and designed to be opened by pressure upon the top end of the stem
as shown.
“Modulus” of a steam pump. The measure or multiplier of power used in
operating pumps. Modulus has nearly the same meaning as measure.

Nipple. A short connecting piece of pipe threaded upon both ends.
Outboard delivery pipe. The pipe which leads, in steam vessels, from the
condenser through the side of the ship.
Pipette. A small tube used to withdraw
and transfer fluids or gases from one
vessel to another. The shape differs
with the special use to which it is
adapted: some are graduated to measure Nipple.
fluids accurately as well as to transfer
them.
Penstock. The barrel of a pump in which the piston plays and through which
the water presses up; also the conduit or trough from the source of supply
to a water wheel.
Pet-cock. This is an air-cock. See air-cock.
Pipe-clamp. A device for connecting
one pipe to another without cutting
the pipe and inserting a tee; a pipe-
saddle performs the same office as
the above, but for larger pipes.
Pitcher Pump. A hand pump which
takes its name from the shape of
its discharge.
Plug-valve. This is a tapering plug
which turns in a shell, example,
the plug of a faucet. See Cock. A
Pitcher Pump. fire-plug is a street hydrant to Plumb Bob.
which a hose may be attached.
Plumb-bob. This is a device for testing whether anything stands exactly
vertical; a plumb-rule contains a plumb-bob.
Pressure-reducing Valve. A valve for reducing high boiler pressure to low
pressure, for steam heating, etc.
Priming. To fill a pump with water when it refuses to lift of its own action,
is called “priming the pump.”

Pump-brake. The handle or lever by which a pump is worked.
Pump-box. A cap or case covering the top of a pump; the casings of the
upper and lower valves are the upper and lower pump boxes.
Pump-chain. An endless
chain with discs
forming valves at
proper distances,
working on two
wheels, one above and
one below, and passing
down outside and
returning upward
through a wooden tube
like a belt.
Pump-cheeks. A forked
piece serving as a
Pressure Reducing Valve. fulcrum for the handle Section.
of a pump.
Pump-well. A compartment extending from a ship’s bottom to the lower or
the upper deck, as the case may be, to contain the pump stocks, etc. The
bilge water collects in the limbers and is discharged through a spout
called the pump-dale.
Rain-gauge. A vessel graduated to measure the fall of rain in a given period.
Reducing-coupling. A fitting for connecting two sizes of threaded pipe.
Resistance. The force that a pump has to work against, caused by gravity,
friction, head of water, etc.
Right-hand Thread. A screw thread in which, with
the threaded end of the bolt towards you, the top of
the nut must revolve from left to right like the
hands of a watch, in order to cause the nut to
screw upon the bolt.
Rope-socket. A device fastened to the end of a rope
Reducing Coupling.
by means of which the rope may be attached to its

load. The socket may be open or closed.
Rust-joint. A joint which is made by being filled with sifted cast-iron
borings, mixed with sal ammoniac, sulphur and water; this causes the
cuttings to rust and form a solid cement.

Rope Sockets.

Sea Injection. The pipe and valve through which sea water is injected into
the condenser of a marine engine.
Screw jack or lifting jack. A screw working in a
threaded base or stationary nut and turned by
a lever inserted into holes near the top, of
which there are usually four. A loose plate or
swivel is placed on top of screw.
“Slams” and “Shocks.” Banging, clanking and
jarring noises indicating a derangement of the
action of a pump. Screw Jacks.
Sleeve-coupling. A threaded connection for
uniting the two ends of pipes of equal size.

“Slippage.” The difference between the calculated
and actual work performed by a pump.
Sluice. A water-gate; a channel to run off waste
water.
Sleeve Coupling. Slurry pump. A special pump for handling a
mixture of earth water.
Socket-wrench. A wrench for turning nuts, having a socket in the end made
to a special size and shape of the nut to be turned.
Spanner. Is a wrench for turning round nuts having holes or slots.
Spline or feather. A key made fast in a shaft.
Split-pin or cutter. An iron pin divided at the end
which is to be spread apart after inserting in Spanner.
the hole.
“Spread.” A term used to indicate the distance from center to center of the
cylinders of a duplex pump.
Spring-seat. An elastic seat for a valve.
Steam thrown valves. Valves moved by steam only.
Steam end of a pump. The end operated by steam.
“Sticking of valves.” Inability to work caused by the introduction into the
valves of sand, soil, etc.; or it may be caused by too tight a fit of the
moving parts, rust or corrosion.
Street elbow. An elbow having an extension piece at one
end.
“Stroke” of pump. The distance traveled by the piston in
one motion.
Stud-bolt. A piece of
round bar metal with
a thread upon each
end. A represents
thread for nut; B
Street Elbow. body of bolt and C Stud-Bolt.

thread to fit in casting.
Stub-end. Either end of a connecting rod.
Strainer. A device for separating solid particles from the liquid which
contains them.
Stuffing box. A recess to receive the packing around piston rods, plungers
and valve stems.
Submerged pump. A pump which works under water.
“Sucking wind.” A leakage
of air into the suction part
of a pump.
Supplemental piston. The
piston which operates the
Stub-End. main valve in the steam
pump.
Swing check valve. One which swings upon a pivot or
hinge in opening and closing.
Strainer.
Switch cock or valve. A device for conducting exhaust
steam into the smoke stack or atmosphere. A three-way cock.
Syphon Cock. A cock having a combined chamber which is partially filled
with water of condensation, attached to a steam gauge to keep steam
from entering and damaging the works of the instrument.

Switch Cock.
Swing Check Valve.

Syphon Cock.

Thumb-Nut.

Thumb-nut. The same as a wing-nut, but a smaller size of the two, shown
above, applied to hand-vice.
Tobin-bronze. An alloy of copper, tin and zinc treated in a special manner; it
is non-corrosive, has great tensile strength and can be forged at a cherry
red heat.
“Trailing Water.” Water can be trailed, i.e., carried through pipes to pumps a
very great distance so long as “the lift” is not over 25 to 33 feet.
“Trompe.” The term used to designate a water-blast—a form of pump.
Turbine. A water wheel driven by the impact or reaction of streams of water
flowing through it or by the impact and reaction combined; it is also
distinguished by the manner in which it discharges the water, as outward,
vertical or central discharge turbine wheels.

Turbine-pump. A pump in which water is raised by the action of a turbine
wheel driven by exterior power in the opposite direction from that in
which it is turned when used as a motor.

Tube-Plug.

Tube-plug. A tube stopper to be used in case of a leak in a boiler tube; it
consists of two wood pistons joined together so that the leak will come
between them. Tube plugs are frequently made of turned tapered cast
iron, one of which is to be driven into each end of a leaking tube.
Union. A fitting designed to unite the two screwed ends
of a pipe, with a single nut to secure them.
Vacuum. A void space; an inclosed chamber from which
the air (or other gas) has been very nearly removed, as
by an air pump.

Union. Valve. Any device or appliance used to control the flow
of a liquid, vapor, or gas, or loose material, through a
pipe, outlet or inlet; the term includes air, gas, steam and water-cocks of
all kinds; water-gates, air-gates, etc. One hundred and fifty of such
devices are named by Knight in his “Mechanical Dictionary.”
Viscosity. Glutinous, adhering, or sticky, as tar, gums, molasses. Internal
friction or resistance to change of shape.
V thread. A thread on a rod or bolt cut in the form of a letter V.
Washer. A circular piece of leather, rubber, metal, or other material with a
hole in its center, through which a rod or bolt may pass.
Water Arch. A chamber of plates or of pipes over the furnace door of brick
set boilers to take the place of the usual cast iron or fire brick arch, and

connected with the boiler to supply it with water. The feed water is often
introduced through the water arch.
Water-bellows. A form of pump, like a bellows—of great antiquity.
Water-cap. The cover for discharge valves on a steam pump.
Water-end. The pump end of a steam-pump; in distinction from the steam
end.
Water-hammer. A noise caused by the pulsative motion of water inside a
steam pipe, resembling the blows of a hammer.
Water Ram. A hydraulic ram.
Working Barrel. The water end of a pump.
Whirlpool-chamber. A chamber attached
to the discharge end of the centrifugal
pump in which the whirling water
gradually loses its rotation, thereby
reducing friction.
Wing-nut. An iron nut having a wing at
each side. Sometimes called a Yoke.
“butterfly nut.”
Yoke. A branch pipe, or a two-way coupling for pipes, particularly twin hot
and cold-water pipes that unite in their discharge.
Y.—A pipe fitting for uniting two pipes at an angle of 45°.

HISTORICAL INTRODUCTION.
The very small degree of antiquity to
which machine tools can lay claim
appears forcibly in the sparse records of
the state of the mechanic arts a century
ago.
A few tools of a rude kind, such as
Gourd, Cauldron and Pipkin. trip-hammers (worked by water wheels),
and a few special ones, which aimed at
accuracy but were of limited application, such as “mills” for boring cannon,
or “engines” for cutting the teeth of clock wheels, were almost their only
representatives.
The transmission of power was unthought of, except for the very limited
distances which were possible with the ill-fitted “gudgeons” and “lanterns
and trundles” of the old millwrights.
The steam-engine, however, changed all this; on the one hand the hitherto
unheard of accuracy of fit required by its working parts created a demand
for tools of increased power and precision, and on the other it rendered the
use of such tools possible in almost any situation.
Thus, acting and re-acting on each other, machine tools and steam
engines have grown side by side, although the first steps were costly and
difficult to a degree which is not now easy to realize. James Watt, for
instance, in 1779 was fain to be content with a cylinder for his “fire-
engine,” of which, though it was but 18 inches in the bore, the diameter in
one place exceeded that at another by about 3⁄8 of an inch; its piston was not
unnaturally leaky; though he packed it with “paper, cork, putty, pasteboard
and old hat.”
The early history of the pumping-engine is the history of the steam-
engine, for originally and for many years the only way in which the steam-
engine was utilized was for pumping water out of the coal mines of England
and from the low lands of the Netherlands.

In 1698 Capt. Thomas Savery secured Letters Patent for a machine for
raising water by steam. It consisted of two boilers and two receivers for the
steam, with valves and the needful pipes. One of the receivers being filled
with steam, its communication with the boiler was then cut off and the
steam condensed with cold water outside of it; into the vacuum thus formed
the atmosphere forced the water from below, when the steam was again
caused to press upon the water and drive it still higher.
This engine was used extensively for draining mines and the water was,
in some instances, made to turn a water wheel, by which lathes and other
machinery were driven.
In 1705 Thomas Newcomen, with his associates, patented an engine
which combined, for the first time, the cylinder and piston and separate
boiler. This soon became extensively introduced for draining mines and
collieries, and the engines grew to be of gigantic size, with cylinders 60
inches in diameter and other parts in proportion.
This engine was, in course of years, used in connection with the Cornish
pump, whose performance in raising water from mines came to be a matter
of the nicest scientific investigation, and adopted as the standard for the
duty or work, by which to compare the multitudinous experimental
machines very soon introduced by many inventors.
But there is an earlier history which long antedates the achievements of
Savery, Newcomen and Watt, which belongs, however, principally to the
domain of hydraulics. Before proceeding to discuss the advancements made
within the memory of men now living, it may be well to take a glance
backward and occupy a few pages with their appropriate illustrations, with
the facts recorded in history.
It were vain to even try, to trace the advances made toward the mammoth
city pumping stations, from the early beginning hereafter described, which
have inspired the words recorded by J. F. Holloway, M. E.:

“In looking upon the ponderous pumping engines which lift a
volume of water equal to the flow of a river, sending it with each
throbbing beat of their pulsating plungers through the arteries and
veins that now reach out in every direction in our great cities, bringing
health, comfort, cleanliness and protection to every home therein, we

cannot but wonder what is the history of their beginning, what the
process of their evolution out from the crude appliances of long ago.
Just who the first man was, and by what stream he sat gazing on his
parched fields, on which the cloudless skies of the Orient shed no rain,
and where the early rising sun with eager haste lapped up the dew
drops which the more kindly night in pity over his hard lot had shed,
and who, looking on his withering grain stalks on the one side and the
life-giving waters which flowed by on the other, first caught the
inspiring thought that if one could only be brought to the other, how
great would be the harvest, we shall never know. Knowing, as we do,
that such still is the problem that confronts the toiler on the plains of
that far-off Eastern land where man’s necessities first prompted man’s
invention, it does not require a great stretch of the imagination to
conceive of such a situation, and to believe that, acting on the impulse
of the moment, he called his mate, and tying thongs to the feet of a
sheep-skin and standing on either side of the brook, with alternate
swingings of the suspended skin they lifted the waters of the stream to
the thirsty field, making its blanched furrows to bloom with
vegetation, and at the same time introducing to the world the first
hydraulic apparatus ever invented, and certainly the first hydraulic
ram ever used.”

The figures shown on the opening page of this section of the work
represent the very first utensils used for collecting and containing water.
The gourd or calabash was undoubtedly the very first; it was common
among the ancient Romans, Mexicans and Egyptians, and in the most
modern times continues to be in use in Africa, South America and other
warm countries. The New Zealanders possessed no other vessels for
holding liquids, and the same remark is applicable to numerous other
savage tribes.
Although not strictly connected with the subject, it may be observed that
the gourd is probably the original vessel for heating water, cooking, etc. In
these and other applications the neck is sometimes used as a handle and an
opening made into the body by removing a portion of it, as shown in the
engraving, its exterior being kept moistened by water while on the fire,
while others apply a coating of clay to protect it from the effects of the

flame. When in process of time vessels for heating water were formed
wholly of clay, they were fashioned after the cauldron as shown.

Figs. 47-52.

The above illustrations are representations of ancient vases; it is curious
to note their conformation to the figure of the gourd. The first three on the
left are from Thebes. Golden ewers of a similar form were used by rich
Egyptians for containing water to wash the hands and feet of their guests.
Similar shaped vessels of the Greeks, Romans and other people might be
easily produced.
In Egypt, India, Chaldea and China the clepsydra or water-clocks date
back beyond all records. Plutarch mentions them in his life of Alcibiades
who flourished in the Fifth Century B. C. when they were employed in the
tribunals at Athens to measure the time to which the orators were limited in
their addresses to the judges. Julius Cæsar found the Britons in possession
of them.
The clepsydra is a device for measuring time by the amount of water
discharged from a vessel through a small aperture, the quantity discharged
in a given unit of time, as an hour being first determined. In the earlier
clepsydras the hours were measured by the sinking of the surface of the
water in the vessel containing it. In others the water ran from one vessel to
another, there being in the lower a cork or piece of light wood which as the

vessel filled, rose and thus indicated the
hour. In later clepsydras the hour has been
indicated by a dial.

Fig. 53.—Water-Clock.
Fig. 53 shows a water-clock described by Hero of Alexandria, Egypt,
made to govern the quantities of fluids flowing from a vessel. The note
below gives the exact wording of the description which has come down to
us.
“A vessel containing wine, and provided with an open spout, stands upon a pedestal: it is
required by shifting a weight to cause the spout to pour forth a given quantity,—
sometimes, for instance, a half cotyle (1⁄4 pint), sometimes a cotyle (1⁄2 pint), and in short,
whatever quantity we please. A B (fig. 53), is the vessel into which wine is to be poured:
near the bottom is a spout D: the neck is closed by the partition E F, and through E F is
inserted a tube, G H, reaching nearly to the bottom of the vessel, but so as to allow of the
passage of water. K L M N is the pedestal on which the vessel stands, and O X another
tube reaching within a little of the partition and extending into the pedestal in which water
is placed so as to cover the orifice O, of the tube. Fix a rod, P R, one-half within, and the
other without the pedestal, moving like the beam of a lever about the point S; and from the
extremity P of the rod suspend a water-clock, T, having a hole in the bottom. The spout D
having been first closed, the vessel should be filled through the tube G H before water is
poured into the pedestal, that the air may escape through the tube X O; then pour water into
the pedestal, through a hole, until the orifice O is closed, and set the spout D free. It is
evident that the wine will not flow, as there is no opening through which air can be
introduced: but if we depress the extremity R of the rod, a portion of the water-clock will
be raised from the water, and, the vent O being uncovered, the spout D will run until the
water suspended in the water-clock has flowed back and closed the vent O. If, when the
water-clock is filled again, we depress the extremity R still further, the liquid suspended in
the water-clock will take a longer time to flow out, and there will be a longer discharge
from D: and if the water-clock be entirely raised above the water, the discharge will last
considerably longer. To avoid the necessity of depressing the extremity R of the rod with

the hand, take a weight Q, sliding along the outer portion of the rod, R W, and able, if
placed at R, to lift the whole water-clock; if at a distance from R, some smaller portion of
it. Then, having obtained by trial the quantities which we wish to flow from D, we must
make notches in the rod R W and register the quantities; so that, when we wish a given
quantity to flow out, we have only to bring the weight to the corresponding notch and leave
the discharge to take place.”

THE SYPHON.

The Syphon is a bent pipe or tube with legs of unequal length, used for
drawing liquid out of a vessel by causing it to rise in the tube over the rim
or top. For this purpose the shorter leg is inserted in the liquid, and the air is
exhausted by being drawn through the longer leg. The liquid then rises by
the pressure of the atmosphere and fills the tube and the flow begins from
the lower end.
The general method of use is to fill the tube in the first place with the
liquid, and then, stopping the mouth of the longer leg, to insert the shorter
leg in the vessel; upon removal of the stop, the liquid will immediately
begin to run. The flow depends upon the difference in vertical height of the
two columns of the liquids, measured respectively from the bend of the
tube, to the level of the water in the vessel and to the open end of the tube.
The flow ceases as soon as, by the lowering of the level in the vessel, these
columns become of equal height or when this level descends to the end of
the shorter leg.
The atmospheric pressure is essential to the support of the column of
liquid from the vessel up to the top of the bend of the tube, and this height
is consequently limited; at sea height the maximum height is a little less
than 34 feet for water, but this varies according to the density of the fluid.

Syphons are necessary in numerous manipulations of the laboratory, and
modern researches in chemistry have given rise to several beautiful devices
for charging them, and also for interrupting and renewing their action.
When corrosive liquids or those of high temperatures are to be transferred
by syphons, it is often inconvenient, and sometimes dangerous to put them
in operation by the lungs. Moreover cocks and valves of metal are acted on
by acids, and in some cases would affect or destroy the properties of the
fluids themselves.
Fig. 54 shows how hot or corrosive liquids may be drawn off from a wide
mouthed bottle or jar. The short leg of a syphon is inserted through the cork,
and also a small tube, through which the operator blows, and by the
pressure of his breath forces the liquid through the syphon.
Fig. 55 represents a syphon sometimes employed by chemists. When
used, the short leg is first placed in the fluid to be decanted, the flame of a
lamp or candle is then applied to the underside of the bulb; the heat rarefies
the air, and consequently drives out the greater part of it through the
discharging orifice. The finger is applied to this orifice, and as the bulb
becomes cool the atmosphere drives up the liquid into the void and puts the
instrument in operation.
Fig. 56 is a syphon charged by pouring a quantity of the fluid to be
decanted into the funnel, the bent pipe attached to which terminates near the
top of the discharging leg. The fluid in descending through this leg bears
down the air within it, on the principle of the trompe, and the atmosphere
drives up the liquid in the reservoir through the short leg.
Fig. 57 is a glass syphon for decanting acids, &c. It is charged by
sucking, and to guard against the contents entering the mouth, a bulb is
blown on the sucking tube. The accumulation of a liquid in this bulb being
visible, the operator can always withdraw his lips in time to prevent his
tasting it.
Fig. 58 is designed to retain its contents when not in use, so that on
plunging the short leg deep into a liquid the instrument will operate. This
effect however will not follow if the end of the discharging leg descend
below the bend near it, and if its orifice be not contracted nearly to that of a
capillary tube.

Fig. 59 is a syphon by which liquids may be drawn at intervals, viz., by
raising and lowering the end of the discharging leg according to the surface
of the liquid in the cistern.
Figs. 60, 61, 62 are syphons
described by Hero of Alexandria
who lived 120 B. C.; the
descriptions of the figures are the
translation of the original.
Let A B C D (Fig. 60) be a vessel
open at the top, and through its
bottom pass a tube, either an
inclosed pipe as E F G, or a bent
syphon G H K. When the vessel
A B C D is filled, and the water
runs over, a discharge will begin
and continue till the vessel is empty,
Fig. 60. if the interior opening is so near the
bottom of the vessel as only to
leave a passage for the water.
As before, let there be a vessel, A B (Fig. 61), containing water. Through
its bottom insert a tube, C D, soldered into the bottom and projecting below.
Let the aperture C of the syphon approach to the mouth of the vessel A B,
and let another tube, E F, inclose the tube C D, the distance between the
tubes being everywhere equal, and the mouth of the outer tube being closed
by a plate, E G, a little above the mouth C. If we exhaust, by suction
through the mouth D, the air in the tube C D, we shall draw into it the water
in the vessel A B, so that it will flow out through the projection of the
syphon until the water is exhausted. For the air contained between the liquid
and the tube E F, being but little, can pass into the tube C D, and the water
can then be drawn after it. And the water will not cease flowing because of
the projection of the syphon below:—if, indeed, the tube E F were removed,
the discharge would cease on the surface of the water arriving at C, in spite
of the projection below; but when E F is entirely immersed no air can enter
the syphon in place of that drawn off, since the air which enters the vessel
takes the place of the water as it passes out.

Let A B C (Fig. 62), be a bent syphon, or
tube, of which the leg A B is plunged into a
vessel D E containing water. If the surface of the
water is in F G, the leg of the syphon, A B, will
be filled with water as high as the surface, that
is, up to H, the portion H B C remaining full of
air. If, then we draw off the air by suction
through the aperture C, the liquid also will
follow. And if the aperture C be level with the
surface of the water, the syphon, though full,
will not discharge the water, but will remain
full: so that, although it is contrary to nature for
water to rise, it has risen so as to fill the tube
A B C; and the water will remain in equilibrium,
like the beams of a balance, the portion H B
being raised on high, and the portion B C
suspended. But if the outer mouth of the syphon
be lower than the surface F G, as at K, the water Fig. 61.
flows out, for the liquid in K B, being heavier,
overpowers and draws toward it the liquid B H. The discharge, however,
continues only until the surface of the water is on a level with the mouth K,
when, for the same reason as before, the efflux ceases. But if the outer
mouth of the tube be lower than K, as at L, the discharge continues until the
surface of the water reaches the mouth A.
The Syringe is an instrument of very high antiquity
and was probably the first machine consisting of a
cylinder and piston that was especially designed to
force liquids. In the closed end a short conical pipe is
attached whose dimensions are adapted to the
particular purpose for which the instrument is to be
used. The piston is solid and covered with a piece of
soft leather, hemp, woolen listing, or any similar
substance that readily imbibes moisture, in order to
prevent air or water from passing between it and the
sides of the cylinder. When the end of the pipe is
placed in a liquid and the piston drawn back, the
atmosphere drives the liquid into the cylinder; whence

Fig. 62. it is expelled through the same orifice by pushing the
piston down: in the former case the syringe acts as a
sucking pump: in the latter as a forcing one. They are formed of silver,
brass, pewter, glass, and sometimes of wood. For some purposes the small
pipe is dispensed with, the end of the cylinder being closed by a perforated
plate, as in those instruments with which gardeners syringe their plants.

WELLS.

Long before pumping devices were conceived,
wells existed as the invention of prehistoric man.
Herewith is a sectional view of Joseph’s Well to be
seen at the present time at Cairo, Egypt. Scientists
think it the production of the same people that
built the pyramids and the unrivaled monuments
of Thebes, Dendaroh and Ebsambone. The
magnitude of the well and the skill displayed in its
construction is perfectly unique.
This stupendous well is an oblong square,
twenty four feet by eighteen, being sufficiently
capacious to admit within its mouth a moderate
sized house. It is excavated (of these dimensions)
through solid rock to the depth of one hundred and
sixty-five feet, where it is enlarged into a
capacious chamber, in the bottom of which is
formed a basin or reservoir, to receive the water
raised from below (for this chamber is not the
bottom of the well). On one side of the reservoir
another shaft is continued, one hundred and thirty
feet lower, where it emerges through the rock into
a bed of gravel, in which the water is found, the
whole depth being two hundred and ninety-seven
feet; the lower shaft is not in the same vertical line
with the upper one, nor is it so large, being fifteen
feet by nine.
Joseph’s Well. As the water is first raised into the basin, by
means of machinery propelled by horses or oxen
within the chamber, it may be asked, how are these animals conveyed to
that depth in this tremendous pit, and by what means do they ascend? A
spiral passage-way is cut through the rock, from the surface of the ground
to the chamber, independent of the well, round which it winds with so
gentle a descent, that persons sometimes ride up or down upon asses or

mules. It is six feet four inches wide, and seven feet two inches high.
Between it and the interior of the well, a wall of rock is left, to prevent
persons falling into, or even looking down it (which in some cases would be
equally fatal), except through certain openings or windows, by means of
which it is faintly lighted from the interior of the well. The animals descend
by this passage to drive the machinery that raises the water from the lower
shaft into the reservoir or basin, from which it is again elevated by similar
machinery and other oxen on the surface of the ground. In the lower shaft a
path is also cut down to the water, but as no partition is left between it and
the well, it is extremely perilous for strangers to descend.

Twelfth Century.

Asiatic Pulley and Bucket.
Note.—However old and numerous wells with stairs in them may be, most of the
ancient ones were constructed without them; hence the necessity of some mode of raising
the water. From the earliest ages, a vessel suspended by a cord, has been used by all nations
—a device more simple and more extensively employed than any other, and one which was
undoubtedly the germ of the most useful hydraulic machine of the ancients. The figures
shown on this and a few succeeding pages are from the collection made by Ewbank—to
whom reference has been made in another portion of this work.

The square openings represented on each
side of the upper shaft are sections of the
spiral passage, and the zig-zag lines indicate
its direction. The wheels at the top carry
endless ropes, the lower parts of which reach
down into the water; to these, earthenware
vases are secured by ligatures (see A A) at

Pulley and Two Buckets. equal distances through the whole of their
(ANCIENT.) length, so that when the machinery moves
these vessels ascend full of water on one
side of the wheels, discharge it into troughs as they pass over them and
descend in an inverted position on the other side.
This celebrated production of former
times, as will be perceived, resembles an
enormous hollow screw, the center of
which forms the well and the threads a
winding stair-case around it. To erect of
granite, a flight of “geometrical” or “well
stairs,” two or three hundred feet high, on
the surface of the ground, would require
extraordinary skill, although in its
execution every aid from rules, measures,
and the light of day, would guide the
workmen at every step; but to begin such Chinese Windlass.
a work at the top, and construct it
downwards by excavation alone, in the dark bowels of the earth, is a more
arduous undertaking, especially as deviations from the correct lines could
not be remedied; yet in Joseph’s well, the partition of rock between the pit
and the passage-way, and the uniform inclination of the latter, seem to have
been ascertained with equal precision, as if the whole had been constructed
of cut stone on the surface. Was the pit, or the passage, formed first; or were
they simultaneously carried on, and the excavated masses from both borne
up the passage, are unanswered questions.
The extreme thinness of the partition wall,
excited the astonishment of M. Jomard, whose
account of the well is inserted in the second
volume of Memoirs in Napoleon’s great work
on Egypt. It is, according to him, but sixteen
centimetres thick, [about six inches!] He justly
remarks that it must have required singular care
to leave and preserve so small a portion while
excavating the rock from both sides of it. It
would seem no stronger in proportion, than

sheets of paste-board placed on edge, to support Anglo-Saxon Crane.
one end of the stairs of a modern built house, for
it should be borne in mind, that the massive roof of the spiral passage next
the well, has nothing but this film of rock to support it, or to prevent from
falling, such portions as are loosened by fissures, or such, as from changes
in the direction of the strata, are not firmly united to the general mass. But
this is not all: thin and insufficient as it may seem, the bold designer has
pierced it through its whole extent with semi-circular openings, to admit
light from the well: those on one side are shown in the engraving.
Aqueducts, fountains, cisterns and
wells, are in numerous instances the only
remains of some of the most celebrated
cities of the ancient world. Of Heliopolis,
Syene and Babylon in Egypt; of Tyre,
Sidon, Palmyra, Nineveh, Carthage,
Utica, Barca, and many others. “The
features of nature,” says Dr. Clarke,
Swape or Sweep, A. D. 1493. “continue the same, though works of art
may be done away: the ‘beautiful gate’ of
the Jerusalem temple is no more, but Siloah’s fountain still flows, and
Kedron still murmurs in the valley of Jehoshaphat.” According to
Chateaubriand, the Pool of Bethesda, a reservoir, one hundred and fifty feet
by forty, constructed of large stones cramped with iron, and lined with flints
embedded in cement, is the only specimen remaining of the ancient
architecture of that city.
Note.—Roman wells are found in every country which that people conquered. Their
armies had constant recourse to them when other sources of water failed. Pompey and
Cæsar often preserved their troops from destruction by having provided them. It was
Pompey’s superior knowledge in thus obtaining water, which enabled him to overthrow
Mithridates, by retaining possession of an important post.

Picotah of Hindostan.

Note.—The operation of this primitive device may be thus described—Near the well or
tank, a piece of wood is fixed, forked at the top; in this fork another piece of wood is fixed
to form a swape, which is formed by a peg, and steps cut out at the bottom, that the person
who works the machine may easily get up and down. Commonly, the lower part of the
swape is the trunk of a tree; to the upper end is fixed a pole, at the end of which hangs a
leather bucket. A man gets up the steps to the top of the swape, and supports himself by a
bamboo screen erected by the sides of the machine. He plunges the bucket into the water,
and draws it up by his weight; while another person stands ready to empty it.

Ephesus, too, is no more; and the temple of Diana, that according to
Pliny was 220 years in building, and upon which was lavished the talent
and treasure of the east; the pride of all Asia, also one of the wonders of the
world, has vanished, while the fountains which furnished the citizens with
water, remain as fresh and perfect as ever. Cisterns have been discovered in
the oldest citadels in Greece. The fountains of Bounarbashi are perhaps the
only objects remaining that can be relied on, in locating the palace of Priam
and the site of ancient Troy. And the well near the outer walls of the temple

of the sun at Palmyra, will, in all probability, furnish men with water, when
other relics of Tadmor in the wilderness have disappeared; a great number
of the wells of the ancient world still supply man with water, although their
history generally, is lost in the night of time.
We are now to examine the modes practised by the ancients, in obtaining
water from wells. In all cases of moderate depth, the most simple and
efficient, was to form an inclined plane or passage, from the surface of the
ground to the water; a method by which the principal advantages of an open
spring on the surface were retained, and one by which domestic animals
could procure water for themselves without the aid or attendance of man.
But when in process of time, these became too deep for exterior passages
of this kind to be convenient or practicable, the wells themselves were
enlarged, and stairs for descending to the water, constructed within them.
Historical Note.—One of the most appalling facts that is recorded of suffering from
thirst occurred in 1805. A caravan proceeding from Timbuctoo to Talifet, was disappointed
in not finding water at the usual watering places; when, horrible to relate, all the persons
belonging to it, two thousand in number, besides eighteen hundred camels perished by
thirst! Occurrences like this, account for the vast quantities of human and other bones,
which are found heaped together in various parts of the desert. While the crusaders
besieged Jerusalem, great numbers perished of thirst, for the Turks had filled the wells in
the vicinity. Memorials of their sufferings may yet be found in the heraldic bearings of
their descendants. The charge of a foraging party “for water,” we are told, “was an office of
distinction;” hence, some of the commanders on these occasions, subsequently adopted
water buckets in their coats of arms, as emblems of their labors in Palestine.

Wells with stairs by which to descend to the water, are still common. The
inhabitants of Arkeko in Abyssinia, are supplied with water from six wells,
which are twenty feet deep and fifteen in diameter. The water is collected
and carried up a broken ascent by men, women and children. Fryer in his
Travels in India speaks of “deep wells many fathoms underground, with
stately stone stairs.” Near the village of Futtehpore, is a large well, ninety
feet in circumference, with a broad stone staircase which is about thirty feet
deep to descend to the water. The fountain of Siloam is reached by a
descent of thirty steps cut in the solid rock, and the inhabitants of Libya,
where the wells often contain little water, “draw it out in little buckets,
made of the shank bones of camels.”
Wells with stairs are not only of very remote origin, but they appear to
have been used by all the nations of antiquity. They were common chiefly,
among the Greeks and Romans.

Italian Mode of Raising Water to the Upper Floors of a House.

As a matter of interest some six or eight representations of the early
forms of wells, have been introduced; but little need to be written relating to
them—the cuts with the titles speak for themselves and also indicate their
manner of use. (See note.)
In Syria and Palestine at the present time the antique bucket and rope, in
modified form, is still used in raising water from wells for irrigation. The
buckets are attached to the ropes at regular intervals and pass over large
drums going down empty and rising full. They discharge at the top into a
large open trough, which conveys the water to the irrigating ditches.

Roman Screw.—Fig. 72.

A method much used where rivers are available is the wheel and bucket,
in which the buckets are mounted on the rim of a large wheel which is of a
diameter equal to the height to which the water is to be raised. The
processes although extremely crude are well adapted to countries where
labor is inexpensive as the running expense of the devices is very small.
Note.—The source from which many of these have been derived is “Eubank’s
Hydraulics,” to which work credit is gladly given for nearly all the historical data so far
used in this volume. The author of the book named gave many years of research into the
early records of all relating to hydraulics and water machines and kindred subjects.

WATER-LIFTING INVENTIONS.

The raising of water is one of the early arts; beginning in ancient times
with devices of the crudest form it has followed the progress of civilization
with ever-increasing importance. In the present era, it demands engineering
ability of the highest order and the finest of machinery.
Important epochs in the gradual inventions relating to pumps and
hydraulics are: (1) The “force pump,” due to Ctesibius 200 B. C.; (2) the
“double-acting pump,” invented by La Hire in 1718; (3) the “hydraulic
ram,” by Whitehurst in 1772; (4) the “hydraulic press,” introduced by
Joseph Bramah in 1802.
Most of the machines hitherto noticed, raise water by means of flexible
cords or chains, and are generally applicable to wells of great depth. We
now enter upon the examination of another variety, which, with one
exception (the chain of pots), are composed of inflexible materials, and
raise water to limited heights only.
In preceding machines, the “mechanical powers” are distinct from the
hydraulic apparatus, i.e., the wheels, pulleys, windlass, capstan, etc., form
no essential part of the machines proper for raising the water, but are merely
employed to transmit motion to them; whereas those we are now about to
describe, are made in the form of levers, wheels, etc., and are propelled as
such.
The Roman Screw delineated upon the opposite page, if not the earliest
hydraulic engine that was composed of tubes, or in the construction of
which they were introduced, is certainly the oldest one known of that
description; in its mode of operation it differs essentially from all other
ancient tube machines; in the latter the tubes merely serve as conduits for
the ascending water, and as such are at rest; while in the screw it is the tubes
themselves in motion that raises the liquid.
Fig. 73 represents one of the earliest forms of a double gutter, placed
across a trough or reservoir designed to receive the water. A partition is
formed in the center, and two openings made through the bottom on each of
its sides, through which the water that is raised escapes. The machine is

worked by one or more men, who alternately plunge the ends into the water,
and thus produce a continuous discharge.

Fig. 73.

Sometimes, openings are made in the bottom next the laborers, and
covered by flaps, to admit the water without the necessity of wholly
immersing those ends; machines of this kind probably date from remote
antiquity; they are obviously modifications of the Jantu of Hindostan and
other parts of Asia. The jantu is a machine extensively used in parts of
India, to raise water for the irrigation of land, and is thus described: “It
consists of a hollow trough of wood, about fifteen feet long, six inches
wide, and ten inches deep, and is placed on a horizontal beam lying on
bamboos fixed in the bank of a pond or river.
One end of the trough as shown in the figure rests upon the bank where a
gutter is prepared to carry off the water, and the other end is dipped in the
water, by a man standing on a stage, plunging it in with his foot. A long
bamboo with a large weight of earth at the farther end of it, is fastened to
the end of the jantu near the river, and passing over the gallows, poises up
the jantu full of water, and causes it to empty itself into the gutter. This
machine raises water three feet, but by placing a series of them one above
another, it may be raised to any height, the water being discharged into
small reservoirs, sufficiently deep to admit the jantu above, to be plunged
low enough to fill it;” water is thus conveyed over rising ground to the

distance of a mile and more. In some parts of Bengal, they have different
methods of raising water, but the principle is the same.
The Tympanum. This is a water raising current wheel originally made in
the form of a drum, hence the name. It is now a circular open frame wheel,
fitted with radial partitions as shown in Fig. 74, so curved as to point
upward on the rising side of the wheel and downward on the descending
side. The wheel is so suspended that its lower edge is just submerged and is
turned by the current (or by other power), the partitions scooping up a
quantity of water which, as the wheel revolves, runs back to the axis of the
wheel where it is discharged; or it may discharge at some point of the
periphery; while one of the most ancient forms of water lifting machines it
is still used in drawing works.
A little study of the figure (74) will
explain its operation.
S, is the shaft; G G, the gutters; A, a
trough to take away the water. The arrow
indicates the direction in which the wheel
turns; each gutter, as it revolves scoops up
a portion of water and elevates it, till by
the inclination to the axle, it flows
towards the latter, and is discharged
through one end of it.
The prominent defect of the tympanum
Fig. 74. arises from the water being always at the
extremity of a radius of the wheel, by
which its resistance increases as it ascends to a level with the axis, being
raised at the end of levers which virtually lengthen till the water is
discharged from them; this has been remedied by making the arms curving
as shown in the Scoop Wheel (Fig. 75.) As this revolves in the direction of
the arrow the extremities of the partitions dip into the water and scoop it up
and as they ascend discharge it into a trough placed under one end of the
shaft which is hollowed into as many compartments as there are partitions
or scoops.
Fig. 76 represents a sectional view of an improved tympanum; this was
invented by De La Faye; the illustration will be readily understood. As

shown in Figs. 74 and 75 the wheel is
driven by the current of a stream
impinging upon what in later times came
to be known as boards or floats on the
circumference of the wheel.
Within the enclosure are arranged four
scrolls of suitable proportions, dipping the
water, at one end, and emptying it out at
the center of the wheel as more clearly
shown in Figs. 74 and 75.
The Noria or Egyptian Wheel. The
Fig. 75. tympanum has been described as an
assemblage of gutters, and
the Noria may be considered
as a number of revolving
swapes. It consists of a series
of poles united like the arms
of a wheel to a horizontal
shaft. To the extremity of
each, a vessel is attached
which fills as it dips into the
water, and is discharged into
a reservoir or gutter at the
upper part of the circle which
it describes. Hence, the
former raises water only
through half a diameter,
while this elevates it through
a whole one. (Fig. 77.) Fig. 76.
The Chinese make the noria, in what would seem to have been its
primitive form, and with an admirable degree of economy, simplicity, and
skill. With the exception of the axle and two posts to support it, the whole is
of bamboo, and not a nail used in its construction. Even the vessels, are
often joints of the same, being generally about four feet long and two or
three inches in diameter. They are attached to the poles by ligatures at such

an angle, as to fill nearly when in the water, and to discharge their contents
when at, or near the top.
The periphery of the wheel is composed of three rings of unequal
diameter and so arranged as to form a frustrum of a cone. The smallest one,
to which the open ends of the tubes are attached, being next the bank over
which the water is conveyed. By this arrangement their contents are
necessarily discharged into the gutter as they pass the end of it. When
employed to raise water from running streams they are propelled by the
current in the usual way—the paddles being formed of woven bamboo. The
sizes of these wheels, vary from twenty to seventy feet in diameter; some
raise over three hundred tons of water in twenty-four hours. A writer
mentions others which raise a hundred and fifty tons to the height of forty
feet during the same time.
Note.—The mode of constructing and moving the noria by the Romans, is thus
described by Vitruvius, who lived about the beginning of the Christian Era. “When water is
to be raised higher than by the tympanum, a wheel is made round on axis of such a
magnitude as the height to which the water is to be raised requires. Around the extremity of
the side of the wheel, square buckets cemented with pitch and wax are fixed; so that when
the wheel is turned by the walking of men, the filled buckets being raised to the top and
turning again toward the bottom, discharge of themselves what they have brought into the
reservoir.”

The Persian Wheel. Two prominent
defects exist in the noria. First, part of the
water escapes after being raised nearly to
the required elevation. Second, a large
portion is raised higher than the reservoir
placed to receive it, into which it is
discharged after the vessels begin to
descend; to obviate this the Persian wheel
was devised.
The vessels in which the water is
raised, instead of being fastened to the
rim, or forming part of it, as in the
preceding figures, are suspended from
Fig. 77.
pins, on which they turn, and thereby
retain a vertical position through their entire ascent; and when at the top are
inverted by their lower part coming in contact with a pin or roller attached

to the edge of the gutter or reservoir, as represented in the figure. By this
arrangement no water escapes in rising, nor is it elevated any higher than
the edge of the reservoir; hence, the defects in the noria are avoided. It is
believed, to have been used in Europe ever since the time of the Romans.

Fig. 78.

GAINING AND LOSING BUCKETS.

In the latter part of the Sixteenth, or beginning of the
Seventeenth Century a machine which is entitled to
particular notice on account of its being, as claimed, the
first one of the kind to be self-acting, for raising water
was in use in Italy. It is ascribed to Gironimo Finugio
who put one in operation at Rome in 1616.
Between the illustration and the following description
its operation may be clearly understood. On a pulley S,
are suspended by a rope two buckets A and B, of unequal
dimensions. The smaller one B, is made heavier than A
when both are empty, but lighter when they are filled. It
is required to raise by them part of the water from the
spring or reservoir E, into the cistern Z. As the smaller
Bucket B, by its superior gravity, descends into E, (a flap
valve in its bottom admitting the water), it consequently
raises A into the position represented in the figure. A pipe
F, then conveys water from the reservoir into A, the
orifice or bore of which pipe is so proportioned, that both
vessels are filled simultaneously. The larger bucket then
preponderates, descending to O, and B at the same time
rising to the upper edge of Z, when the projecting pins O
O, catch against others on the lower sides of the buckets,
and overturn them at the same moment. The bails or handles are attached by
swivels to the sides, a little above their center of gravity. As soon as both
buckets are emptied, B again preponderates, and the operation is repeated
without any attendance, so long as there is water in E and the apparatus
continues in order.
In Moxon’s machine, the buckets were filled by two separate tubes of
unequal bore; the orifices being covered by valves to prevent the escape of
water while the buckets were in motion; these valves were opened and
closed by means of cords attached to the buckets. The efflux through F in
the figure, may easily be stopped as soon as A begins to descend, by the
action of either bucket on the end of a lever attached to a valve, or by other

obvious contrivances. The water discharged from A, runs to waste through a
channel provided for that purpose. These machines are of limited
application, since they require a fall for the descent of A, equal to the
elevation to which the liquid is raised in B. They may however be modified
to suit locations where a less descent only can be obtained. Thus, by
connecting the rope of B to the periphery of a large wheel, while that of A is
united to a smaller one on the same axis, water may be raised higher than
the larger bucket falls, but the quantity raised will of course be
proportionally diminished. In the face of these securing advantages it has
fallen into disuse; it was much too complex and cumbersome, and of too
limited application.
The principle of self-action in all these machines is no modern discovery,
for it was described by Hero of Alexandria, who applied it to the opening
and closing the doors of a temple, and to other purposes.

THE PULLEY AND WINDLASS.

In those vast periods preceding the dawn of history, water was as heavy
and as necessary for the use of mankind and animals as it is to-day; the toil
and labor in securing it must indeed have been hard. Doubtless, the first
inventions of the primitive man were first made—perhaps, after weapons of
defence—to relieve himself of the painful endeavor of supplying the
precious liquid.
There are reasons which render it probable that the single pulley was
devised to raise water and earth from wells; the latter are not only of the
highest antiquity but they are the only known works of man in early times
in which the pulley could have been required or applied. That it preceded
the invention of ships and the erection of lofty buildings of stone, is all but
certain; but for what purpose, save for raising of water, the pulley could
have been previously required it would be difficult to divine; it seems to
have been the first addition made to those primitive implements, the cord
and the bucket.
By it the friction of the rope in rubbing against the curb and the
consequent loss of a portion of the power expended in raising the water,
were avoided, and by it also a beneficial change in the direction of the
power was attained; instead of being exerted in an ascending direction, it is
applied more conveniently and efficiently in a descending motion as shown
in the various figures and illustrations in the preceding pages.
But the grand advantage of the pulley in the early ages was this:—by it
the vertical direction in which men exerted their strength, could be directly
changed into a horizontal line, by which change animals could be
employed.
The wells of Asia, frequently varying from two to three, and even four
hundred feet in depth, obviously required more than one person to raise the
contents of an ordinary sized vessel; and where numbers of people
depended on such wells, not merely to supply their domestic wants, but for
the purposes of irrigation, the substitution of animals in place of men to
raise water, became a matter almost of necessity, and was certainly adopted
at a very early period. In employing an ox for this purpose, the simplest

way and one which deviated the least from their accustomed method, was
merely to attach the end of the rope to the yoke, after passing it over a
pulley fixed sufficiently high above the mouth of the well, and then driving
the animal a distance equal to its depth, in a direct line from it, when the
bucket charged with the liquid would be raised from the bottom.
Although it may never be known to whom the world is indebted for the
windlass, there are circumstances which point to the construction of wells
and raising of water from them, as among the first uses to which it as well
as the pulley, was applied. The windlass possesses an important advantage
over the single pulley in lifting weights, or overcoming any resistance since
the intensity of the force transmitted through it can be modified, either by
varying the length of the crank, or the circumference of the roller on which
the rope is coiled. Sometimes a single vessel and rope, but frequently two,
are employed as shown in several of the preceding illustrations; one of
these is the Chinese Windlass. This furnishes the means of increasing
mechanical energy to almost any extent, and as it is used to raise water from
some of those prodigiously deep wells already noticed, a figure of it, page
47, has been inserted. The roller consists of two parts of unequal diameters,
to the extremities of which the ends of the rope are fastened on opposite
sides, so as to wind round both parts in different directions. As the load to
be raised is suspended to a pulley, every turn of the roller raises a portion of
the rope equal to the circumference of the thicker part, but at the same time
lets down a portion equal to that of the smaller; consequently the weight is
raised at each turn, through a space equal only to half the difference
between the circumferences of the two parts of the roller. The action of this
machine is therefore slow, but the mechanical advantages are
proportionately great.
The fusee windlass is shown in Fig. 79. This is an early invention
designed to overcome in a mechanical method the greater weight which the
rope hung at its extremity has, as compared to what it is when nearly wound
up. At the bottom of the well the rope then being at its heaviest period is
wound upon the small end of the fusee; and as the length diminishes it coils
round the larger part. (See Fig. 79), which is however inaccurately drawn—
as the bucket is at the top of the well; it should have been represented as
suspended from the large end of the fusee.

The value of a device like this will be
appreciated when the great depth of some
wells is considered and the consequent
additional weight of the chains. In the
fortress of Dresden is a well eighteen
hundred feet deep; at Augustburgh is a
well in which half an hour is required to
raise the bucket; and at Nuremburgh
another, sixteen hundred feet deep. In all
these, the water is raised by chains, and
the weight of the one used in the latter is
Fig. 79. stated to be upwards of a ton.
The tympanum and noria in all their
modifications have been considered as
originating in the gutter or jantu, and the swape;
while the machine we are now to examine is
evidently derived from the primitive cord and
bucket. The first improvement of the latter was
the introduction of a pulley or sheave over
which the cord was directed—the next was the
addition of another vessel, so as to have one at
each end of the rope, and the last and most
important consisted in uniting the ends of the
rope, and securing to it a number of vessels at
equal distances through the whole of its length
—and the chain of pots was the result. (See Fig.
80.)
The general construction of this machine will
appear from an examination of those which are
Fig. 80. employed to raise water from Joseph’s well at
Cairo, represented on page 45. Above the mouth
of each shaft a vertical wheel is placed, over which two endless ropes pass
and are suspended from it. These are kept parallel to, and at a short distance
from each other, by rungs secured to them at regular intervals, so that when
thus united, they form an endless ladder of ropes. The rungs are sometimes
of wood, but more frequently of cord like the shrouds of a ship, and the

whole is of such a length that the lowest part hangs two or three feet below
the surface of the water that is to be raised. Between the rungs, earthenware
vases (of the design shown at A A) are secured by cords round the neck, and
also round a knob formed on the bottom for that purpose.

WHEEL AND AXLE.

In all the preceding machines the roller
is used in a horizontal position; but at
some unknown period of past ages,
another modification was devised, one by
which the power could be applied at any
distance from the center. Instead of
placing the roller as before, over the
well’s mouth, it was removed a short
Fig. 81. distance from it, and secured in a vertical
position, by which it was converted into
the wheel or capstan. One or more horizontal bars were attached to it, of a
length adapted to the power employed, whether of men or animals; and an
alternating rotary movement imparted to it, as in the common wheel or
capstan, represented in the figure. It appears that machines of this kind, and
worked by men were common in Europe previous to, and at the time he
wrote. Sometimes the shaft was placed in the edge of the well, so that the
person who moved it walked round the latter, and thus occupied less space.

SUCCESSIVE INVENTIONS.

With the wide acceptance in practical use of the Duplex steam pump,
may be dated the beginning of the modern inventive period of pumping
machinery; this introduction of the Duplex pump was only one of five
successive advances which it were well for the student to memorize:
1. The Cornish,

2. The Rotative,

3. The Direct Acting,

4. The Duplex, and

5. The Compounded Steam Pump.
The Cornish engines have been alluded to in connection with the
Newcomen engine. Probably no large pumping engines in the past have
held, and deservedly so, as high repute as have the Cornish engines when
used for deep mine pumping. Their construction, with the rude appliances at
hand, is not only a marvel but as well a high tribute to the ingenuity of those
who designed them and to the skill of the workmen who built them. A rather
full illustrated description of this almost unexcelled machine will be found
later on in the book.
The next class of large steam pumping-engines which have played an
important part in the history of hydraulic engineering may be grouped
together as “rotative engines.” What is here meant by the term “rotative” is
engines in which there are parts which make complete and continuous
rotary motion and in which are used, in some way or another, shafts, cranks
and fly-wheels.
These engines vary greatly in their design and in the details of their
construction. They are of varying sizes, including some of the largest and
most expensive in the world. As a general thing they are employed in
supplying towns and cities with water, and in some cases freeing shallow
mines of water. The application of the power of the steam used in the steam

cylinders in this class of engines to drive the plungers or pistons in the
pumps, varies greatly, both as to the general design upon which they are
built, and in the detail of their construction. In some instances it is through
the use of long or short beams or bell cranks, sometimes through gearing,
and occasionally through the plunger or piston of the pump direct; but in all
cases the limit of the stroke of the steam piston, and of the pump plunger, is
governed by a crank on a revolving shaft.
Attached to the revolving shaft is a fly-wheel of greater or less diameter
and weight, which, in addition to assisting the crank to pass the center at
each end of its stroke, is employed to store up at the beginning of each
stroke of the steam piston, whatever excess of power or impulse there may
be imparted to it, beyond that required to steadily move the water column,
and to give out again, toward the latter part of the stroke, when the power
of the steam is of itself below that required to move the water column, the
power previously stored in it. In this respect the function of a revolving fly-
wheel on a rotative engine is the same as is the weighted plunger in the
Cornish engine; both being used for the purpose of permitting the steam to
be cut off at a portion of its stroke in the steam cylinder, and expanded
during the rest of the stroke.
In short, these devices, as employed in both the classes of pumping
engines described, were used in order that the best economy in the
consumption of steam by means of early cutoff and a high grade of
expansion, might be attained.
The succeeding class of pumps to be described, driven by steam are
direct acting steam-pumps.
What is here meant as “direct-acting,” is a steam-driven pump in which
there are no revolving parts, such as shafts, cranks and fly-wheels; pumps in
which the power of the steam in the steam cylinder is transferred to the
piston or plunger in the pump in a direct line, and through the use of a
continuous rod or connection. (Fig. 82.)
The introduction of the direct-acting steam-pump marked a point of
deviation, and it entered the field almost without a rival, and at a time when
economy was overshadowed by its convenience.

In the brief description given of these three most prominent classes of
pumping engines, no attempt has been made to describe any of the
peculiarities of their general construction, beyond what was necessary to
describe their action and the principles upon which they operate.

Fig. 82.

In pumps of this construction there are no weights in the moving parts
other than that required to produce sufficient strength in such part for the
work they are expected to perform, and, as there is consequently no
opportunity to store up power in one part of the stroke, to be given out at
another, it is impossible to cut off the steam in the steam cylinder during
any part of its stroke. The uniform and steady action of the direct-acting
steam-pump is dependent alone on the use of a steady uniform pressure of
steam through the entire stroke of the piston against a steady, uniform
resistance of water pressure in the pump; the difference between the power
exerted in the steam cylinders over the resistance in the pump governing the
rate of speed at which the piston or plunger of the pump will move. The
length of the stroke of the steam piston, within the steam cylinders of this
class of pumps, is limited and controlled alone by the admission,
suppression and release of the steam used in the cylinders.
Note.—Up to the introduction of the direct-acting steam pump, all the other pumping
machinery of the world then in use was the outcome of evolution. It had been developed by
slow stages, in which one engineer after another aided by the experience of others and of
his own, supplemented by his inventive faculties, added here and there slight

improvements to which other engineers, with increased experience, were enabled to add
still other improvements, so that each new engine constructed under more favorable
circumstances, and with increasing expenditures, was supposed to excel all previously
built; until at this time we have, as it is fair to suppose, pumping engines which combine all
the wisdom of the past, and which leave little or no room for further improvements in their
respective classes.

The history of the Direct-Acting Steam Pump differs from all others from
the fact that it was the invention of one man, and was in the main perfected
during his lifetime. It was so strikingly different from all that had preceded
it, that there was nothing in the way of precedent, either in ancient or
modern practice, of which the inventor could avail himself by which to aid
or guide him to success.
The date of the first patent on these pumps was September 7, 1841. It
was issued on a small pump used for supplying feed water to a steam boiler,
and consisted of one steam cylinder connected to a force pump, and so
arranged that by the use of levers, trips, springs, and other connections
between the piston rod and the slide valve, the movement of the piston rod
controlled the movements of the slide valve to an extent that not only
regulated the length of the stroke of the piston, but reversed its motion. This
pump was placed alongside of the steam boiler, and was so connected by
means of pipes and levers and floats within the boiler, that when the water
fell below the proper level in the boiler, it would start the pump, and stop it
when the water rose too high.
Note.—At the head of a list consisting of two names only, who, on the foremost pages
of “The American Society of Mechanical Engineers,” are recorded as the “Honorary
Members in Perpetuity” of that large society, and standing as well at the head of that long
and increasing list of members who have accomplished their work on earth, may be seen
the name of Henry Rossiter Worthington, the inventor and original builder of the “direct-
acting steam pump.”

Feeling how incomplete was an invention which did not provide against
the intermittent action of the pump, Mr. Worthington devoted much time
and study to correct this trouble, and a few years later he brought out an
improved pump which, in its simplicity of parts, certainty of action, and
cheapness of construction more than rivaled the original invention itself.
This pump is now universally known as the “Direct-Acting Duplex Steam
Pump.”
In the main, the construction of the steam ends and the water ends of the
duplex pump differs but slightly from those of the single-acting pump, but

the mechanism which operates the steam valves is different, and the effect
on the water column was marvelously different; the principle upon which it
operates is this:
Two pumps of similar construction are placed side by side, a lever
attached to the piston rod of each pump connects to the slide valve of the
opposite steam cylinder; thus the movement of each piston, instead of
operating its own slide valve as in the single pump, operates the slide valve
of the opposite cylinder. The effect of this arrangement is, that as the piston
or plunger of one pump arrives near the end of its stroke, the plunger or
piston of the other begins its movement, thus alternately taking up the load
of the water column, producing a regular, steady, onward flow of water,
without the unusual strains induced by such a column when suddenly
arrested or started in motion.
While the “duplex steam pump” overcame one of the greatest objections
to the former single pump, there still remained in this class of pumping
machinery one other difficulty. It did not use steam expansively.
This not only debarred it from competing with other engines where a
large quantity of water was required to be raised, and where the cost of fuel
was an item of importance, but as well prevented the pump from taking
rank among the hydraulic appliances required in supplying towns and cities.
This objection was one which seemed insurmountable, steam in them
could not be used economically. Applied to the propulsion of the plunger or
piston of this pump it must be of sufficient quantity, and pressure, to
overcome the height of the column of water on the pump, together with its
friction through the pump and its connections, at the very beginning of the
stroke; and it must be maintained, both as to its volume, and its pressure up
to the very last part of the stroke. Any diminution, either of volume or
pressure, during any part of the stroke would simply bring the pump to a
stop. This apparent inability to cut off the steam in the steam cylinder, and
to complete the stroke of the pump by the aid of the steam remaining in the
cylinder, and by its expansive force, had debarred this pump from coming
into general use for large water works. How this, the only remaining
objection to their use for such purposes, was overcome, forms an interesting
chapter in the history of the “Direct-Acting Steam Pump.”

It was when this question had assumed a most formidable, importance,
that the principle of using steam in compound steam engines had engaged
the careful consideration of the most eminent engineers of this and other
countries; its adjustment to the Duplex pumps was made, and while it was
easily done, owing to their peculiar construction, its application produced a
most wonderful result in their working, and their speedy introduction for
water works use.
Note.—At this time the man who had invented and built the little steam pump for the
canal boat, who had watched its growth and development, supplemented one device after
another to help it on through the trial period of its existence, had merged it at last into the
dual or duplex stage of its advancement, had added to it the compound feature, had seen it
expanding in size and importance until, growing up and out of the day of small things, it
had come to take its well-earned place alongside those old and massive machines whose
invention and origin was lost amid the musty records of the past—it was, at this time, and
of which any man might well have been proud, that his lifelong labors came to an end Dec.
18., 1880, at the Everett House, New York City.

ELEMENTARY

HYDRAULICS

ELEMENTARY HYDRAULICS.
There are three physical states or conditions of matter, which are the
solid, liquid and gaseous, which in this connection apply to Ice, Water and
Steam. A solid offers resistance both to change of shape and to change of
bulk.
A Fluid offers no resistance to change of shape. Again fluids can be
divided into liquids and vapors or gases. Water is the most familiar example
of a liquid. A liquid can be poured out in drops while a gas or vapor flows
in a stream or streams.
Gas is a term at first used as meaning the same as the name air, but is
now restricted to fluids supposed to be permanently elastic, as oxygen,
hydrogen, etc., in distinction from vapor such as steam which become
liquid upon a reduction of temperature.
It is important to note that experiment proves that every vapor becomes a
gas at a sufficiently high temperature or low pressure, while, on the other
hand, every gas becomes a vapor at sufficiently low and high pressures. In
present popular usage the term gas applies to any substance in the aeriform
elastic condition.
Hydraulics is that branch of science or of engineering which treats of the
motion of liquids, especially of water and of the laws by which it is
regulated.
As a science, hydraulics includes hydrodynamics or the principles of
mechanics applicable to the motion of water.
As a branch of engineering, hydraulics consists in the practical
application of the mechanics of fluids, to the control and management of
water, with reference to the wants of man, including water works, hydraulic
machines, pumps, water wheels, etc.
The term hydraulics, so familiar in daily use, is formed from two Greek
words meaning: 1, water; 2, a pipe; hence, it will be observed with interest
how close the original meaning follows the development of the science in

its practical adaptation; there is always the “pipe” or holding vessel and the
“water” or its equivalent.
From the same elementary word meaning water, in the Greek language,
has been formed very many other words in common use, for example
hydrophobia, hydrogen, hydrant, hygrometer, etc., as well as the following:
Hydromechanics is that branch of natural philosophy which treats of the
mechanics of liquid bodies, or in other words, of their laws of equilibrium
and motion. Hydromechanics comprises properly those phenomena of
liquids by which these bodies differ from solids or from bodies at large;
hence, its foundation is laid in the properties that distinguish the liquid from
other states of bodies, viz.: the presence of cohesion, with great mobility of
parts, and perfect elasticity.
Hydrostatics is that branch of science which relates to the pressure and
equilibrium of non-elastic fluids, as water, mercury, etc.; thus, the
hydrostatic press is a machine in which great force with slow motion is
action communicated to a large plunger by means of water forced into the
cylinder in which it moves, by a forcing pump. Statics treats of forces that
keep bodies at rest or in equilibrium, the water through which the force
operates in the hydrostatic press always remaining at rest serves as a good
illustration.
Pneumatics is that branch of science, which relates to air, or gases in
general or their properties; also of employing (compressed) air or other gas
as a motive power. The use of pneumatic pumping machinery is constantly
increasing, especially of the direct pressure types; under the section of this
work relating to Air Pumps additional data will be presented.
Hydropneumatics is defined as involving the combined action of water
and air, or gas, as shown, for example, in the hydropneumatic accumulator.
The word is a compound formed of the Greek words meaning water and air.
Semi-liquids. All the results stated in reference to water are further
modified in those semi-liquids which have greater or less viscidity, as pitch,
syrup, fixed oils, etc. Viscosity may be defined as the quality of flowing
slowly, thus the viscosity of such liquids as have been named is very great
as compared with that of a mobile liquid like alcohol.

HYDRODYNAMICS.

Water, considered from a chemical standpoint, is a compound substance
consisting of hydrogen and oxygen, in the proportion of two volumes of the
former gas to one volume of the latter; or by weight it is composed of two
parts of hydrogen united with sixteen parts of oxygen. It should be noted
that the union of these two gases is effected by chemical action and not by
mechanical mixture. Pure water is transparent, inodorous and tasteless.
Under ordinary conditions water passes the liquid form only at
temperatures lying between 32° F. and 212° F.; it assumes a solid form, that
of ice or snow at 32° F., and it takes the form of vapor or steam at 212° F.
There are four notable temperatures for water, namely:

32° F., or 0° C. = the freezing point under one atmosphere.
39°·1 or 4° = the point of maximum density.
62° or 16°·66 = the standard temperature.
212° or 100° = the boiling point, under one atmosphere.

The temperature 62° F. is the temperature of water used in calculating the
specific gravity of bodies, with respect to the gravity or density of water as
a basis, or as unity.
Weight of one cubic foot of Pure Water.

At 32° F. = 62·418 pounds.
At 39°·1. = 62·425 „
At 62° (Standard temperature) = 62·355 „
At 212° = 59·640 „

The weight of a cubic foot of water is, it may be added, about 1000
ounces (exactly 998·8 ounces), at the temperature of maximum density.
The weight of a cylindrical foot of water at 62° F. is 48·973 pounds.
Weight of one cubic inch of Pure Water.

At 32° F. = ·03612 pound,or 0·5779 ounce.

At 37°·1 = ·036125 „ „ 0·5780 „
At 62° = ·03608 „ „ 0·5773 „ or 252·595 grains.
At 212° = ·03451 „ „ 0·5522 „
The weight of one cylindrical inch of pure water at 62° F. is ·02833
pounds, or 0·4533 ounce.
Volume of one pound of Pure Water.

At 32° F. = ·016021 cubic foot, or 27·684 cubic inches.
At 39°·1 = ·016019 „ „ 27·680 „
At 62° = ·016037 „ „ 27·712 „
At 212° = ·016770 „ „ 28·978 „

The volume of one ounce of pure water at 62° F. is 1·732 cubic inches.
The weight of water is usually taken in round numbers, for ordinary
calculations, at 62·4 lbs. per cubic foot, which is the weight at 52°·3 F.; or it
is taken at 621⁄2 lbs. per cubic foot.
Salt water boils at a higher temperature than fresh water owing to its
greater density, and because the boiling point of water is increased by any
substance that enters into chemical combination with it. The density of
water decreases as the temperature increases, since heat destroys cohesion
and expands the particles, causing them to occupy greater space, where
precision is not required; the pressure on a square foot at different ocean
depths are approximate, in the following
TABLE.
Depth in feet. Pressure on sq. foot.
8 500 lbs.
16 1000 „
24 1500 „
32 2000 „
40 2500 „
48 3000 „
56 3500 „
64 4000 „
72 4500 „
80 5000 „

88 5500 „
96 6000 „

1 mile, or 5,280 feet, 330,000 lbs.
5 miles, 1,650,000 „

This table is based upon an allowance of 621⁄2 lbs. of water to the cubic
foot, thus 8 feet × 621⁄2 = 500, etc.

HYDRAULIC DATA.

Water is practically non-elastic. A pressure of 30,000 lbs. to the square
inch has been applied and its contraction has been found to be less than
one-twelfth. Experiment appears to show that for each atmosphere of
pressure it is condensed 471⁄2 millionth of its bulk.
The mechanical properties of liquids are determined on the hypothesis
that liquids are incompressible; according to known general principles this
is found to be for all practical purposes true, yet liquids are more
compressible than solids. If water be confined in a perfectly rigid
cylindrical vessel, its compression would equal 1⁄300000 of its length for
every pound per unit of area of the end pressure.
Water is nearly 100 times as compressible as steel,
yet for almost all practical purposes, liquids may be
considered as non-elastic bodies without involving
sensible error.
The pressure upon the horizontal base of any vessel
containing a fluid, is equal to the weight of a column
of the fluid, found by multiplying the area of the base
into the perpendicular height of the column, whatever
be the shape of the vessel.
This follows, since here the distance of the center of
gravity of the base from the surface of the fluid, is the
same as the perpendicular height of the column. With
a given base and height, therefore, the pressure is the
same whether the vessel is larger or smaller above,
whether its figure is regular or irregular, whether it

Fig. 84. rises to the given height in a broad open funnel, or is
carried up in a slender tube.
Hence, any quantity of water, however small, may be made to balance
any quantity, however great. This is called the hydrostatic paradox. The
experiment is usually performed by means of a water-bellows, as
represented in Fig. 84. When the pipe AD is filled with water, the pressure
upon the surface of the bellows, and consequently the force with which it
raises the weights laid on it, will be equal to the weight of a cylinder of
water, whose base is the surface of the bellows, and height that of the
column AD. Therefore, by making the tube small, and the bellows large, the
power of a given quantity of water, however small, may be increased
indefinitely. The pressure of the column of water in this case corresponds to
the force applied by the piston in the hydrostatic press.
We have already seen that the pressure on the
bottom of a vessel depends neither on the form of the
vessel nor on the quantity of the liquid, but simply on
the height of the liquid above the bottom. But the
pressure thus exerted must not be confounded with the
pressure which the vessel itself exerts on the body
which supports it. The latter is always equal to the
combined weight of the liquid and the vessel in which
it is contained, while the former may be either smaller
or greater than this weight, according to the form of
Fig. 85. the vessel. This fact is often termed the hydrostatic
paradox, because at first sight it appears paradoxical.
CD (Fig. 85) is a vessel composed of two cylindrical parts of unequal
diameters, and filled with water to a. From what has been said before, the
bottom of the vessel CD supports the same pressure as if its diameter were
everywhere the same as that of its lower part; and it would at first sight
seem that the scale MN of the balance, in which the vessel CD is placed,
ought to show the same weight as if there had been placed in it a cylindrical
vessel having the same weight of water, and having the diameter of the part
D. But the pressure exerted on the bottom of the vessel is not all transmitted
to the scale MN; for the upward pressure upon the surface n o of the vessel
is precisely equal to the weight of the extra quantity of water which a
cylindrical vessel would contain, and balances an equal portion of the

downward pressure on m. Consequently the pressure on the plate MN is
simply equal to the weight of the vessel CD and of the water which it
contains.
Pressure exerted anywhere upon a mass of liquid is transmitted
undiminished in all directions, and acts with the same force on all equal
surfaces, and in a direction at right angles to those surfaces.
To get a clearer idea of the truth of this principle, let us conceive a vessel
of any given form in the sides of which are placed various cylindrical
apertures, all of equal size, and closed by movable pistons. Let us, further,
imagine this vessel to be filled with liquid and unaffected by the action of
gravity; the pistons will, obviously, have no tendency to move. If now a
weight of P pounds be placed upon the piston A (Fig. 86), which has a
surface A, it will be pressed inwards, and the pressure will be transmitted to
the internal faces of each of the pistons B, C, D, and E, which will each be
forced outwards by a pressure P, their surfaces being equal to that of the
first piston. Since each of the pistons undergoes a pressure, P, equal to that
on A, let us suppose two of the pistons united so as to constitute a surface
2a; it will have to support a pressure 2P. Similarly, if the piston were equal
to 3a, it would experience a pressure of 3P; and if its area were 100 or
1,000 times that of a, it would sustain a pressure of 100 or 1,000 times P. In
other words, the pressure on any part of the internal walls of the vessel
would be proportional to the surface.
The principle of the equality of pressure is assumed as a consequence of
the constitution of fluids.
By the following experiment it can be shown that pressure is transmitted
in all directions; a cylinder provided with a piston is fitted into a hollow
sphere (Fig. 87). in which small cylindrical jets are placed perpendicular to
the sides. The sphere and the cylinder being both filled with water, when the
piston is moved the liquid spouts forth from all the orifices, and not merely
from that which is opposite to the piston.
The reason why a satisfactory quantitative experimental demonstration of
the principle of the equality of pressure cannot be given is that the influence
of the weight of the liquid and of the friction of the pistons cannot be
altogether eliminated.

Note.—The
influence of the
weight (or gravity)
of water and its
fractional
resistance in
practical use is so
great upon all the
processes of
numbers and of the
application of the Fig. 87.
natural laws
Fig. 86. governing the operation of fluids, as stated under the heading of
Hydraulic Data, that separate pages will hereafter be found devoted
to a more extended explanation of this subject of gravity and friction of water.

Yet an approximate verification may be effected by the experiment
represented in Fig. 88. Two cylinders of different diameters are joined by a
tube and filled with water. On the surface of the liquid are two pistons, P
and p, which hermetically close the cylinders, but move without friction.
Let the area of the large piston, P, be, for instance, thirty times that of the
smaller one, p. That being assumed, let a weight, say of two pounds, be
placed upon the small piston; this pressure will be transmitted to the water
and to the large piston, and as this pressure amounts to two pounds on each
portion of its surface equal to that of the small piston, the large piston must
be exposed to an upward pressure thirty times as much, or of sixty pounds.
If now, this weight be placed upon the large piston, both will remain in
equilibrium; but if the weight is greater or less, this is no longer the case.
It is important to observe that in
speaking of the transmission of pressure
to the sides of the containing vessel, these
pressures must always be supposed to be
perpendicular to the sides.
Equilibrium or state of rest of
superposed liquids. In order that there
Fig. 88. should be equilibrium when several
heterogeneous liquids are superposed in
the same vessel, each of them must satisfy the conditions necessary for a
single liquid, and further there will be a stable state of rest only when the
liquids are arranged in the order of their decreasing densities from the
bottom upwards.

The last condition is experimentally demonstrated by means of the phial
of four elements. This consists of a long narrow bottle containing mercury,
water, colored red, saturated with carbonate of potash, alcohol, and
petroleum. When the phial is shaken the liquids mix, but when it is allowed
to rest they separate; the mercury sinks to the bottom, then comes the water,
then the alcohol, and then the petroleum. This is the order of the decreasing
densities of the bodies. The water is saturated with carbonate of potash to
prevent its mixing with the alcohol.
This separation of the liquids is due to the same cause as that which
enables solid bodies to float on the surface of a liquid of greater density
than their own. It is also on this account that fresh water, at the mouths of
rivers, floats for a long time on the denser salt water of the sea; and it is for
the same reason that cream, which is lighter than milk, rises to the surface.
The pressure upon any particle of a fluid of uniform density is
proportioned to its depth below the surface.
Example 1. Let the column of fluid ABCD
Fig. (1) be perpendicular to the horizon. Take
any points, x and y, at different depths, and
conceive the column to be divided into a
number of equal spaces by horizontal planes.
Then, since the density of the fluid is uniform
throughout, the pressure upon x and y,
respectively, must be in proportion to the
number of equal spaces above them, and
consequently in proportion to their depths.
Fig. 89.
Example 2. Let the column be of the same
perpendicular height as before, but inclined as is Fig. (2); then its quantity,
and of course its weight, is increased in the same ratio as its length exceeds
its height; but since the column is partly supported by the plane, like any
other heavy body, the force of gravity acting upon it is diminished on this
account in the same ratio as its length exceeds its height; therefore as much
as the pressure on the base would be augmented by the increased length of
the column, just so much it is lessened by the action of the inclined plane;
and the pressure on any part of Cc will be, as before, proportioned to its

perpendicular depth; and the pressure of the inclined column ACac will be
the same as that of the perpendicular column ABCD.
Fluids rise to the same level in the opposite arms of a recurved tube.
Let ABC, (Fig. 90) be a recurved tube: if water be
poured into one arm of the tube, it will rise to the same
height in the other arm. For, the pressure acting upon the
lowest part at B, in opposite directions, is proportioned to
its depth below the surface of the fluid. Therefore, these
depths must be equal, that is, the height of the two
columns must be equal, in order that the fluid at B may be
at rest; and unless this part is at rest, the other parts of the
column cannot be at rest. Moreover, since the equilibrium
depends on nothing else than the heights of the respective
columns, therefore, the opposite columns may differ to
any degree in quantity, shape, or inclination to the
horizon. Thus, if vessels and tubes very diverse in shape
Fig. 90. and capacity, as in Fig. p. 84 be connected with a
reservoir, and water be poured into any one of them, it
will rise to the same level in them all.
The reason of this fact will be further understood from the application of
the principle of equal momenta, for it will be seen that the velocity of the
columns, when in motion, will be as much greater in the smaller than in the
larger columns, as the quantity of matter is less; and hence the opposite
momenta will be constantly equal.
Hence, water conveyed in aqueducts or running in natural channels, will
rise just as high as its source. Between the place where the water of an
aqueduct is delivered and the spring, the ground may rise into hills and
descend into valleys, and the pipes which convey the water may follow all
the undulations of the country, and the water will run freely, provided no
pipe is laid higher than the spring.
Pressure of water due to its weight. The pressure on any particle of water
is proportioned to its depth below the surface. The pressure of still water in
pounds per square inch against the sides of any pipe, channel, or vessel of
any shape whatever, is due solely to the “head” or height of the level
surface of the water above the point at which the pressure is considered and

is equal to ·43302 lbs. per square foot, every foot of head or 62·355 lbs. per
square foot for every foot of head at 62° F.
The pressure per square inch is equal in all directions downwards,
upwards or sideways and is independent of the shape or size of the
containing vessel; for example, the pressure on a plug forced inward on a
square inch of the surface of water is suddenly communicated to every
square inch of the vessel’s surface, however great and to every inch of the
surface of any body immersed in it.

It is this principle which operates with such astonishing effect in
hydrostatic presses, of which familiar examples are found in the hydraulic
pumps, by the use of which boilers are tested. By the mere weight of a
man’s body when leaning on the extremity of a lever, a pressure may be
produced of upwards of 20 tons; it is the simplest and most easily
applicable of all contrivances for increasing human power, and it is only
limited by want of materials of sufficient strength to utilize it.

UNIVERSAL GRAVITATION.

Gravity or Gravitation is that species of attraction, or force by which, all
bodies or particles of matter in the universe tend towards each other; it is
also called attraction of gravitation and universal gravity; gravity, in a
more limited, sense is the tendency of a mass of matter toward a center of
attraction especially the tendency of a body toward the center of the earth.

This influence is conveyed from one body to another without any
perceptible interval of time. If the action of gravitation is not instantaneous,
it comes very nearly to it by moving more than fifty millions of times faster
than light.
Gravity extends to all known bodies in the universe, from the smallest to
the greatest; by it all bodies are drawn toward the center of the earth, not
because there is any peculiar property or power in the center, but because
the earth being a sphere, the aggregate effect of the attractions exerted by
all its parts upon any body exterior to it, is such as to influence that body
toward the center.
This property manifests itself, not only in the motion of falling bodies,
but in the pressure exerted by one portion of matter upon another which
sustains it; and bodies descending freely under its influence, whatever be
their figure, dimensions or texture, all are equally accelerated in right lines
perpendicular to the plane of the horizon. The apparent inequality of the
action of gravity upon different species of matter near the surface of the
earth arises entirely from the resistance which they meet with in their
passage through the air. When this resistance is removed (as in the
exhausted receiver of an air-pump), the inequality likewise disappears.
The law of gravity, discovered by Sir Isaac Newton, toward the end of the
seventeenth century, may be stated as follows:
Every particle of matter in the universe attracts every other particle with
a force whose direction is that of a line joining the two particles considered,
and whose magnitude is directly as the product of the masses and inversely
as the square of the distance between them.
As a groundwork for this great generalization, Newton employed the
results of two of the greatest astronomers who preceded him, Copernicus
and Kepler. About 1500 A. D. Copernicus perceived and announced that the
apparent rotation of the heavens about the earth could be explained by
supposing the earth to rotate on an axis once in twenty-four hours. Previous
to this time the earth had been regarded as the center of the universe. He
also showed that nearly all the motions of the planets, including the earth,
could be explained on the assumption that these revolved in circular orbits
about the sun, whose position in the circle, however, was slightly eccentric.

Thus, building somewhat upon the labors of the two parties named,
Newton was the first to prove the law of the forces which would account for
the motions of all the bodies in the solar system.

LAWS OF FALLING BODIES.

Since a body falls to the ground in consequence of the earth’s attraction
on each of its molecules, it follows that, all other things being equal, all
bodies, great and small, light and heavy, ought to fall with equal rapidity,
and a lump of sand without cohesion should during its fall retain its original
form as perfectly as if it were compact stone. The fact that a stone falls
more rapidly than a feather is due solely to the unequal resistances opposed
by the air to the descent of these bodies; in a vacuum all bodies fall with
equal velocity.
In a vacuum, however, liquids fall like solids without separation of their
molecules. The water-hammer, a model used in scientific schools, illustrates
this: the instrument consists of a thick glass tube about a foot long, half
filled with water, the air having been expelled by ebullition previous to
closing one extremity with the blow-pipe. When such a tube is suddenly
inverted, the water falls in one undivided mass against the other extremity
of the tube, and produces a sharp metallic sound, resembling that which
accompanies the shock of two solid bodies coming suddenly together.
Note.—The resistance opposed by the air to falling bodies is especially remarkable in
the case of liquids. The Staubbach in Switzerland is a good illustration; an immense mass
of water is seen falling over a high precipice, but before reaching the bottom it is shattered
by the air into the finest mist. See Parker’s Philosophy, pp. 69-70.

It has been ascertained, by experiment, that from rest, a body falling
freely will descend 161⁄12 feet in the first second of time, and will then have
acquired a velocity, which being continued uniformly, will carry it through
321⁄6 feet in the next second. Therefore if the first series of numbers be
expressed in seconds, 1″, 2″, 3″, &c., the velocities in feet will be 321⁄6,
641⁄3, 961⁄2, &c.; the spaces passed through as 161⁄12, 641⁄3, 1443⁄4, &c., and
the spaces for each second, 161⁄2, 481⁄4, 805⁄12, &c.

TABLE.

Showing the Relation of Time, Space and Velocity.
Time in Velocity Space fallen Whole Space
seconds of acquired at through fallen through in
Squares. Space.
the body’s the end of in that the last second
fall. that time. time. of the fall.
1 32·16 1 16·08 1 16·08
2 64·33 4 64·33 3 48·25
3 96·5 9 144·75 5 80·41
4 128·66 16 257·33 7 112·58
5 160·83 25 402·08 9 144·75
6 193· 36 579· 11 176·91
7 225·17 49 788·08 13 209·08
8 257·33 64 1029·33 15 241·25
9 289·5 81 1302·75 17 273·42
10 321·66 100 1946·08 19 305·58

Experience has shown that the measurement of all physical quantities
may be expressed in terms of three fundamental magnitudes. Those
commonly chosen for this purpose are time, length and mass or quantity of
matter. It may be assumed that our ideas of time and space are sufficiently
exact for all practical purposes. The subject of matter, however, requires
more particular consideration. Of the three magnitudes named, matter alone
is directly cognizable by the senses, and invested with a variety of
interesting properties.
For present purposes matter may be defined as anything that can be
weighed, and the quantity of matter as proportional to its weight; i.e., its
attraction towards the earth. The weight of a body is the force it exerts in
consequence of its gravity, and is measured by its mechanical effects, such
as bending a spring. We weigh a body by ascertaining the force required to
hold it up, or to keep it from descending. Hence, weights are nothing more
than measures of the force of gravity in different bodies.
Again, Gravitation, the most feeble of physical actions between small masses, is almost
imperceptible; yet it is an energy abundant in proportion to the quantity of matter in the
universe, and fully competent, by its gradual condensing agency, to account for the
origination of planetary systems and their movements. It is not strange, therefore, that by
some physicists this energy is supposed to be the beginning of that of which all other forms
of force are residues or metamorphoses. Gravity is the name especially given to its
terrestrial manifestations. A particle or body without a sphere or spheroid, solid or hollow,
is attracted to the center of the mass of such body; within a hollow sphere, it will remain at
rest at any point. At different depths below the earth’s surface, a body will be attracted with
a force diminishing as the distance from its center decreases. The slight variation in the

gravitating force of the same falling body at different heights is in practice usually
disregarded. The weight of a body, as the measure of its gravitating tendency, must vary
both with mass and with the force acting on it; hence, from the form of the earth, the same
body at the sea level will weigh less and less as it is removed from either pole toward the
equator. An elevation above the sea level gives a like result. A stone falls through a less
distance in a given time on a mountain than in the valley below, less at the equator than at
either pole. The loss of weight in these cases cannot be tested by lever scales, in which this
loss is equal on both sides; but it may be by the spring balance, in which bodies are
weighed by the pull they exert against the elasticity of a coiled wire. The effect of
centrifugal force, increasing from the pole to the equator, co-operates with increasing
removal from the earth’s center to lessen weight; the result of the combined action of these
two causes is, that a body weighing 195 lbs. at either pole will weigh but 194 over the
equator. The line of a falling body, called also the line of direction, is interesting as being
that direction in space at any point of the earth’s surface with reference to which all other
directions are named, and by which they are to be determined.

A few points remain to be named. The flow of water is the result of the
force of gravity; the importance of this fact and its wide influence cannot be
over stated; the gently falling dew, the mighty currents in the unfathomable
depths of the ocean, as well as the rivulet merrily falling over the rocks to a
lower level are all subject to the laws of terrestrial gravity.
The upper surface of a liquid in a vessel exposed to the atmosphere is
called the free surface and is pressed downwards by the air under about 15
lbs. pressure per square inch. The free surface of a small body of a perfect
liquid, at rest, is horizontal and perpendicular to the action of gravity
although in large bodies of liquid, as lakes and ponds, the free surface is
spherical, assuming the curvature of the earth’s surface.

RULES RELATING TO THE VELOCITY OF FALLING
BODIES.

1.—To find the Velocity a falling Body will acquire in any given time.
Multiply the time, in seconds, by 321⁄6, and it will give the velocity
acquired in feet, per second.
Example. Required the velocity in seven seconds.
321⁄6 × 7 = 2251⁄6 feet. Ans.

2.—To find the Velocity a Body will acquire by falling from any given
height.

Multiply the space, in feet, by 641⁄3, the square root of the product will be
the velocity acquired, in feet, per second.
Example. Required the velocity which a ball has acquired in descending
through 201 feet.
641⁄3 × 201 = 12931; √12931 = 113·7 feet. Ans.

3.—To find the Space through which a Body will fall in any given time.
Multiply the square of the time, in seconds, by 161⁄12, and it will give the
space in feet.
Example. Required the space fallen through in seven seconds.
161⁄12 × 7² = 7881⁄12 feet. Ans.

4.—To find the Time which a Body will occupy in falling through a given
space.
Divide the square root of the space fallen through by 4, and the quotient
will be the time in which it was falling.
Example. Required the time a body will take in falling through 402.08
feet of space.
√402·08 = 20·049, and 20·049 ÷ 4 = 5·012. Ans.

5.—The Velocity being given, to find the Space fallen through.
Divide the velocity by 8, and the square of the quotient will be the
distance fallen through to acquire that velocity.
Example. If the velocity of a cannon ball be 660 feet per second, from
what height must a body fall to acquire the same velocity?
660 ÷ 8 = 82·5² = 6806·25 feet. Ans.

6.—To find the Time, the Velocity per second being given.

Divide the given velocity by 8, and one-fourth part of the quotient will be
the answer.
Example. How long must a bullet be falling, to acquire a velocity of 480
feet per second?
480 ÷ 8 = 60 ÷ 4 = 15 seconds. Ans.

SPECIFIC GRAVITY.

Specific Gravity is the proportion of the weight of a body to that of an
equal volume of some other substance adopted as a standard of reference.
For solids and liquids the standard is pure water, at a temperature of 60° F.,
the barometer being at 30 inches.
Aëriform bodies are referred to the air as their standard. A cubic foot of
water weighs 1,000 ounces; if the same bulk of another substance, as for
instance cast iron, is found to weigh 7,200 ounces, its proportional weight
or specific gravity is 7·2. It is convenient to know the figures representing
this proportion for every substance in common use, that the weight of any
given bulk may be readily determined. For all substances the specific
gravity is used in various tests for the purpose of distinguishing bodies from
each other, the same substance being found, under the equal conditions of
temperature, &c., to retain its peculiar proportional weight or density.
Hence tables of specific gravities of bodies are prepared for reference,
and in every scientific description of substances the specific gravity is
mentioned. In practical use, the weight of a cubic foot is obtained from the
figures representing the density by moving the decimal point three figures to
the right, which obviously from the example above, gives the ounces, and
these divided by 16 gives the pounds avoirdupois, in the cubic foot.
Different methods may be employed to ascertain the specific gravity of
solids. That by measuring the bulk and weighing, is rarely practicable; as a
body immersed in water must displace its own bulk of the fluid, the specific
gravity may be ascertained by introducing a body, after weighing it, into a
suitable vessel exactly filled with water, and then weighing the fluid which
overflows. The proportional weight is thus at once obtained. Wax will cause
its own weight of water to overflow; its specific gravity is then 1. Platinum,

according to the condition it is in, will cause only from 1⁄21 to 1⁄21·5 of its
weight of water to overflow, showing its specific gravity to be from 21 to
21·5. But a more exact method than this is commonly employed. The
difference of weight of the same substance weighed in air and when
immersed in water, is exactly that of the water it displaces, and may
consequently be taken as the weight of its own bulk of water. See Fig. 93
and rule and example on page 95.

Fig. 91.

The specific gravity is then obtained by weighing the body first in air, and
then, suspended by a fibre of silk or a hair, in water, and dividing the weight
in air by the difference. It is hardly necessary to say that the substance
examined must be free from mixture of foreign matters, and especially from
cavities that may contain air.
Note.—Hydrometers are instruments for determining the relative density of fluids;
distilled water is usually referred to as the standard of comparison. They consist usually of
a bulb or float weighted at bottom so as to float upright, and having an elongated stem
graduated to indicate the density of the liquid by the depth to which they sink therein.

THE HYDROSTATIC BALANCE.

Every body immersed in a liquid is submitted to the action of two forces:
gravity which tends to lower it, and the buoyancy of the liquid which tends
to raise it with a force equal to the weight of the liquid displaced. The
weight of the body is either totally or partially overcome by its buoyancy,
by which it is concluded that a body immersed in a liquid loses a part of its
weight equal to the weight of the displaced liquid.
This principle, which is the basis of the theory of immersed and floating
bodies, is called the principle of Archimedes, after the discoverer. It may be
shown experimentally by means of the hydrostatic balance (Fig. 92). This is
an ordinary balance, each pan of which is provided with a hook; the beam
being raised, a hollow brass cylinder is suspended from one of the pans, and
below this a solid cylinder whose volume is exactly equal to the capacity of
the first cylinder; lastly, an equipoise is placed in the other pan. If now the
hollow cylinder be filled with water, the equilibrium is disturbed; but if at
the same time the beam is lowered so that the solid cylinder becomes
immersed in a vessel of water placed beneath it, the equilibrium will be
restored. By being immersed in water the solid cylinder loses a portion of
its weight equal to that of the water in the hollow cylinder. Now, as the
capacity of the hollow cylinder is exactly equal to the volume of the solid
cylinder the principle which has been before laid down is proved.
Minerals, if suspected of containing spaces, should be coarsely
pulverized, and then the second method may be conveniently applied to
determine their density—thus prepared, a higher result will be obtained, and
even metals when pulverized were found to give a greater specific gravity
than when this is determined from samples in their ordinary state. Very fine
powders may also be examined by the method in use for ascertaining the
specific gravity of fluids, viz.: by comparing the weight of a measured
quantity with that of the same quantity of water.
A glass vessel called a specific gravity bottle is commonly employed,
which is furnished with a slender neck, upon which is a mark indicating the
height reached by 1,000 grains of water. The substance to be examined is
introduced till it reaches the same mark, and, the weight of the bottle being
known, only one weighing is required to obtain the result.

The specific gravity of fluids is
also taken by the instrument called
a hydrometer or alcometer. Such
instruments are much used for
ascertaining the specific gravity of
spirituous and other liquors, as an
indication of their strength. If the
solid body to be tested is lighter
than water, it must be attached to
some heavy substance to cause it to
sink. Its specific gravity is then
calculated by dividing its weight in
the air by the sum of the weights of
the attached body both in air and in
water, first subtracting from this
sum the weight of the two bodies
together in the water.
Bodies soluble in water may be Fig. 92.
weighed in some other fluid, as
alcohol, ether, olive oil, &c., and their proportional weight to that of this
fluid being thus ascertained, their density compared with that of water is
readily calculated or they may be enveloped in wax or other suitable
substance to protect them, and then treated by the method just given for
substances lighter than water. Gaseous bodies are weighed in a thin glass
flask or other vessel made for the purpose, and provided with a stop-cock.
The vessel is exhausted of air before the introduction of the gas.
Rule for finding the Specific Gravity of a Solid Body.
Weigh the solid in air and then in pure water.
The difference is the weight of water displaced, whose specific gravity is
1.000.
Then, as the difference of weight is to 1·000, so is the weight in air to the
specific gravity; or divide the weight of the body in air by the difference
between the weights in air and in water.
Example.

A lump of glass is found to weigh in air 577 grains; it is then suspended
by a horse hair from the bottom of the scale pan, and immersed in a vessel
of pure water, when it is found to weigh 399.4 grains. What is its specific
gravity?
577.0 Then, as 177.6 : 1 :: 577.0 : sp. gravity.
399.4 1
—— ——
177·6 the difference 177·6)577·0(3·248, Ans.
532·8
——–
4420
3552
——–
8680
7104
——–
15760
14208
——–
1552

Fig. 93.

Note.—The above figures are introduced to show more vividly the comparison between
bulk and weight, the size of the different substances, of course, being merely approximate.
A study of the Table of Specific Gravities to be found in the next page is worthy of the time
and attention.

TABLE OF SPECIFIC GRAVITIES.

Metals.
Iron, (cast) 7·207
„ (wrought) 7·688
Steel (soft) 7·780
„ (tempered) 7·840
Lead (cast) 11·400
„ (sheet) 11·407
Brass (cast) 8·384
„ (wire drawn) 8·544
Copper (sheet) 8·767
„ (cast) 8·607
Gold (cast) 19·238
„ (hammered) 19·361
Gold (22 carats) 17·481
„ (20 „ ) 15·709
Silver (pure, cast) 10·474
„ (hammered) 10·511
Mercury (60°) 13·580
Pewter 7·248
Tin 7·293
Zinc (cast) 7·215
Platinum 21·500
Antimony 6·712
Arsenic 5·763
Bronze (gun metal) 8·700
Stones and Earth.
Coal (Bituminous) 1·256
1·436
„ (Anthracite) { 1·640
Charcoal ·441
Brick 1·900

Clay 1·930
Common Soil 1·984
Emery 4·000
Glass (plalte) 3·248
Ivory 1·822
Grindstone 2·143
Diamond 3·521
Gypsum 2·168
Lime 2·720
Granite 2·625
Marble 2·708
Mica 2·800
Millstone 2·484
Nitre 1·900
Porcelain 2·385
Phosphorus 1·770
Pumice Stone ·915
Salt 2·130
Sand 1·800
Slate 2·672
Sulphur 2·033
Woods.
Ash ·845
Beech ·852
Birch ·720
Oak 1·120
Pine (yellow) ·660
„ (white) ·554
Cherry ·715
Cork ·240
Elm ·671
Poplar ·383
Walnut ·671
Willow ·585

Liquids.
Acid Sulphuric 1·851
„ Muriatic 1·200
Spirits of Wine ·917
Alcohol ·790
Oil (turpentine) ·870
„ (olive) ·915
Oil (linseed) ·932
„ (castor) ·961
Pure water 1·000
Vinegar 1·080
Milk 1·032
Sea water 1·029
To Find the Weight of a Cubic Foot of Anything Contained in these
Tables.
Rule. Multiply 62·5 lbs. (the weight of a cubic foot of pure water) by the
specific gravity of the given body.
Example. What is the weight of a cubic foot of sea water?
62·5 lbs.
1·029 sp. gravity.
——–
5625
1250
625
———–
Answer, 64·3125 lbs. is the actual weight: but 64 lbs. is taken in
practice as the weight of a cubic foot of sea water.
Example. How many cubic feet of sea water will weigh a ton?
Divide 2240 lbs. (1 ton) by 64 lbs.
{ _8)2240
64 { ——
{ 8) 280

——
Ans. 35
Example. What is the weight of a cubic foot of wrought iron?
62·5 lbs.
7·69 sp. gravity.
——–
5625
3750
4375
———-
Answer, 480·625 lbs.
480 lbs. in practice is the weight of 1 cubic foot of wrought iron.
Note.—35 cubic feet of sea water is accounted to be a ton, as in sea water ballast for
steamers, and in calculating displacement of ships.

Example. What is the average weight of a cubic foot of Bituminous coal?
1·256 sp. gravity.
62·5 lbs.
——–
6280
2512
7536
———–
Answer, 78·5000 lbs.
This 78·5 lbs. is the weight of a cubic foot in a solid block, but loose, as
used for fuel, a cubic foot weighs about 49.7 lbs. which is the average of 13
kinds.
Example. What is the weight of a solid cast cylinder of copper, 4 inches
diameter and 6 inches high?
8·607 sp. gravity.
62·5 lbs.
——-
43035
17214
51642

————
537·9375 lbs. per cub. ft.
————
Say 538 lbs.

·7854
16 diam. squared.
——–
47124
7854
——–
12·5664 area of base.
6 high
———–
75·3984 cu. in. in volume
———–
Say 75·4 cubic inches.

cub. in. cub. in. lbs.
Then, as 1728 : 75·4 :: 538 : Answer.
538
——
6032
2262
3770
————
{ 12)40565·2
{ ————–
1728 { 12)3380·433
{————–
{ 12) 281·702
———–
23·475 lbs.
Answer, 231⁄2 lbs. nearly.

FRICTION AND VISCOSITY OF FLUIDS.

Frictional Resistance.—The resistance with which bodies oppose the
movement of one surface on another is termed friction. It depends on the
nature, and the roughness of the surfaces in contact; at the commencement
of the sliding, it is greater than when the motion is continued.
Friction is in effect an equivalent force exerted in a direction opposite to
that in which the sliding occurs. Its whole amount is the product of two
factors: the first of these, which sums up the effect of the nature and
condition of the surfaces, is called the coefficient of friction; the second,
which is the sum of all pressures, as weight strain, and the adhesion due to
magnetism (when employed), which act to urge the two bodies together,
i.e., perpendicularly to the surface of contact, is called the normal pressure.
But this law holds only where, with dry surfaces, the pressure is not enough
to indent or abrade either; or, with wet surfaces, not enough to force out the
unguent. In either of these cases, the friction increases more rapidly than the
ratio of normal pressure.
No surfaces can be made absolutely hard or smooth; when one surface is
made to slide over another, the slight roughness of the one interlock with
those of the other, so that the surfaces must be separated or the points
abraded to allow of the motion; but if one surface roll upon another, the
prominent points are successively raised, without the need of complete
lifting of the body or wearing off those points. Hence, there are two kinds of
friction, the sliding and the rolling. The former of these in amount greatly
exceeds the latter; it is a leading element in the stability of structures and
fabrics of all lands, and the most important resistance and source of waste
in all machinery, and is therefore a chief object of regard in the arts of
construction and the science of engineering.
Sliding friction increases with the roughness of the surfaces in contact;
hence, it is in practice diminished as these surfaces become worn, also by
polishing, and by the use of lubricants, which smooth the rubbing surfaces
by filling their depressions. It increases, almost universally, in exact
proportion with the entire pressure, owing to weight or other causes, with
which the two surfaces are held together; but at very great pressures,
somewhat less rapidly. Consequently, in all ordinary cases, so long as the

entire weight or pressure remains the same, the friction is, in general,
entirely independent of the extent of the surfaces in contact.
The exceptions are, some increase when the rubbing surfaces under the
same total pressure are very greatly extended, or when either surface is
comparatively soft; and considerable lessening of friction when the bodies
are very small, as in the runners of skates upon ice. For ordinary rates of
motion, the total friction within a given space or distance is in like manner
entirely independent of the velocity with which one surface is caused to
move over the other; but in very slow motions it is increased, and in very
rapid motions perceptibly diminished.
Friction is also increased in proportion to the tendency of the surfaces to
adhere; hence, it is usually found greater between bodies of the same kind
(steel on steel proving almost an exception) than between those of different
kinds; it is usually greater when the surfaces have been long in contact, and
at the beginning of motion, and always so, unless corrected by lubricants,
between metallic surfaces so highly polished that air may be excluded from
between them.
The frictional resistance retarding the flow of water is subject to three
laws:
1. It is proportioned to the amount of surface in contact.
2. It is independent of the pressure.
3. It is proportional to the square of the velocity.
It should be remembered that the laws relating to friction, between solid
bodies operate quite differently from what they do when applied to liquids;
hence, the large mass of data relating to the general subject of friction must
be disregarded in the consideration of hydromechanics and allied subjects.
For all fluids, whether liquids or gaseous, the resistance is independent of
the pressure between the masses in contact. This is in accordance with the
second law as stated.
The friction for all fluids (liquid or gaseous) is in proportion to the area
of the rubbing surface; this follows from the first law and as the sectional
area of a circle is the least, pipes from their circular form present the
smallest resistance to the flow of water.

From the third law, in practice we desire the making of pipes as large as
possible; experiment having proved that low speeds are preferable to
moderate and still more so, as compared to high speeds in proportioning the
piping of hydraulic apparatus.
Friction of fluids is also independent of the nature of the solid against
which the stream may flow, but dependent to some extent upon their degree
of roughness.
Friction for all fluids is also proportional to the density of the fluid, and
related in some way to its adhesiveness.
Water flowing through a pipe tends to drag the pipe along with it on
account of friction; in all actual fluids there is viscosity or internal friction,
but if the relative motion is only slow enough it makes little difference
whether the fluid is viscous or not.
Ordinary fluids will change in shape under the action of a force, however
small, if enough time is given for the change to take place, and the rate of
change of shape is a measure of its viscosity.
The laws of friction, both for solids and liquids, have been established
from experiments endlessly varied. In investigating these principles we first
proceed on the supposition that the forces in question act without any
impediments. Great simplicity is attained by first bringing the subject to this
ideal standard of perfection, and afterwards making suitable allowances for
all these causes which operate in any given case to prevent the perfect
application of the law.
Several tables and other data relating to the friction of water will be
found in the other sections of this work, reference to which is made in the
Index.
The term viscosity has been described in the Glossary at the beginning of
this work; a perfect fluid is incapable of resisting—except by its weight or
inertia—a change of shape. Such a substance does not actually exist for all
fluids have viscosity or internal friction.
This is defined as a resistance to a change of shape depending on the rate
at which the change is effected, but, as the fluids which engineers have to
deal with are water and vapors and gases, it simplifies nearly all the
calculations to assume that they have no internal viscosity or friction.

A slow continuous change of the shape of solids or semi-solids under the
action of gravity, or external force, is also by the extension of the term
called viscosity, as the viscosity of ice, as observed in the slow movement
of those rivers of ice, the glaciers.
The viscosity of liquids arises from the mutual attractions of the
molecules and is diminished by the effect of the wandering molecules (C.
D.). The viscosity of gases increases while that of liquids diminishes as the
temperature is raised.
The viscosity of fluids presents a certain analogy with the malleability of
solids.
Vis Viva is equivalent to active or living force; temperature is the Vis Viva
of the smallest particles of a body; in bodies of the same temperature the
atoms have the same vis viva, the smaller mass of the lighter atoms being
compensated by their greater velocity.
This term, which is often met with in scientific treatises, was invented by
Leibnitz. It is well known that water in rapid circulation will absorb more
heat than when stagnant or moving slowly; this is caused by Vis Viva of the
atoms.

CAPILLARY ATTRACTION.

Capillary attraction is the attraction which causes the ascent of fluids in
small tubes. This word is derived from the Latin capillus—a hair.
The tubes must be less than one-tenth of an inch in diameter in order to
produce the most satisfactory results, and tubes whose bores are no larger
than a hair present the phenomenon the most strikingly. But though the rise
of water above its natural level, is most manifest in small tubes, it appears,
in a degree, in vessels of all sizes and shapes, by a ring of water formed
around the sides with a concavity upward.
The following are the leading facts respecting capillary attraction.
(1.) When small tubes, open at both ends, are immersed perpendicularly
in any liquid, the liquid rises in them, to a height which is inversely as the
diameter of the bore. Though tubes of glass are usually employed in
experiments on this subject, yet tubes made of any other material exhibit the
same property. Nor does the thickness of the solid part of the tube, or its
quantity of matter, make the least difference, the effect depending solely on
the attraction of the surface, and consequently extending only to a very
small distance.
(2.) Different fluids are raised to unequal heights by the same tube. Thus,
according to experiment, a tube which will raise water 23 inches will raise
alcohol only 9 inches.
(3.) A tube 1⁄100 of an inch in diameter raises water 5.3 inches; and since
the height is reciprocally as the diameter, the product of the diameter into
the height is a constant quantity, namely, the .053th part of an inch square.
(4.) Fluids rise in a similar manner between plates of glass, metal, &c.,
placed perpendicularly in the fluids, and near to one another. If the plates
are parallel, the height to which a fluid will rise, is inversely as the distance
between the plates; and the whole ascent is just half that which takes place
in a tube of the same diameter. If the plates be placed edge to edge, so as to
form an angle, and they be immersed in water, with the line of their
intersection vertical, the water will ascend between them in a curve having

its vertex at the angle of intersection. This curve is found to have the
properties and form of the hyperbola.
In the adjustment of the stems of barometers and the thermometer an
allowance is made to compensate for the influence of capillary attraction.

Figs. 94-96.

Such are the leading facts ascertained respecting capillary attraction.
Various explanations of them have been attempted but that of La Place is
most generally received. According to this high authority, the action of the
sides of the tube draws up the film of fluid nearest to it, and that film draws
along with it the film immediately below it, and so each film drags along
with it the next below, until the weight of the volume of fluid raised exactly
balances all the forces which act upon it. The fact that the elevation of the
water between the parallel plates is exactly half that in a tube of the same
diameter, clearly indicates that the force resides in the surrounding body;
and the additional fact that the thickness or quantity of that body makes no
difference, proves that the force resides in the surface, and that the action
extends only to a very small distance.
Note.—Several familiar examples of capillary attraction may be added. A piece of
sponge, or a lump of sugar, touching water at its lowest corner, soon becomes moistened
throughout. The wick of a lamp lifts the oil to supply the flame, to the height of several
inches. A capillary glass tube, bent in the form of a syphon, and having its shorter end
inserted in a vessel of water, will fill itself and deliver over the water in drops. A lock of
thread or of candle-wick, inserted in a vessel of water in a similar manner, with one end
hanging over the vessel, will exhibit the same result. An immense weight or mass may be
raised through a small space, by first stretching a dry rope between it and a support, and
then wetting the rope.
The several figures above need no explanation to the attentive reader.

FLOW OF WATER UNDER PRESSURE.
Under this head three general cases are to be considered: 1, that of liquids
issuing from orifices; 2, their flow through tubes, or in streams; and, 3, the
effects of the momentum and impact of liquids. The principles governing the
action of the two last will be introduced, 2, under that portion of the work
relating to “piping,” and, 3, under the sections pertaining to the jet pump.
Throughout the different portions of the book will the three cases be still
further elucidated.
Now, as to the laws governing the escape of liquids under pressure
through an opening, it may be understood that when the liquid escapes from
a vessel, owing to the excess of the internal pressure, the volume which
escapes depends on the section of the orifice and the velocity with which the
liquid molecules move at the moment of their escape from it.
This velocity depends upon the density of the liquid, the excess of
pressure at the opening, and the friction of the liquid, both at the opening
and against the walls. When the aperture is made in a very thin wall of a
large vessel, so as to remove, as much as possible, the causes tending to
modify the motion of the escaping fluid, the laws of the escape are
comprised in the following theorem, discovered by Torricelli, in 1643, as a
consequence of the law of the fall of bodies discovered by Galileo: “Liquid
molecules, flowing from an orifice, have the same velocity, as if they fell
freely in vacuo from a height equal to the vertical distance from the surface
to the center of the orifice.”
Deductions from the above:—1, the velocity depends on the depth of the
orifice from the surface, and is independent of the density of the liquid.
Water and mercury in vacuo would fall from the same height in the same
time; and so escaping from an orifice at the same depth, below the surface,
would pass out with equal velocity; but mercury, being 13·5 times as heavy
as water, the pressure exerted at the aperture of a vessel filled with mercury,
will be 13·5 times as great as the pressure exerted at the aperture of a vessel
filled with water; 2, the velocity of liquids is as the square roots of the
depths of the orifices below the surfaces of the liquids.

Note.—Torricelli discovered, in the early part of the 17th century, the remarkable fact
that a fluid issues from a small orifice with the same velocity (friction and atmospheric
resistance excluded) which it would have acquired in falling through the depth from its
surface. This was one of a long series of discoveries leading toward the now almost exact
science of hydro-mechanics.

Thus stating, the velocity of a liquid escaping from an orifice one foot
below the surface to be one; from a similar orifice four feet below the
surface, it will be two, and at nine feet three, at sixteen feet four, and so on.
From comparative experiments made by a great number of observers, it
is learned that the actual flow is only about two-thirds of the theoretical
flow. See note.
The form and constitution of liquid veins have been studied and found to
be:
1.—That the fluid issuing vertically from an orifice made in a plane and
thin horizontal wall, is always composed of two distinct parts, Fig. 97, the
portion nearest the orifice is calm and transparent, like a rod of glass,
gradually decreasing in diameter. The lower part, on the contrary, is always
agitated, and takes an irregular form, in which are regularly distributed
elongated swellings, called ventres, whose maximum diameter is greater
than that of the orifice.
Note.—Theoretical and actual flow.—The actual flow from an orifice, is the volume of
liquid which escapes from it in a given time. The theoretical flow, is a volume equal to that
of a cylinder which has for its base the orifice, and for its height the velocity, furnished by
the discovery of Torricelli. That is, the theoretical flow is the product of the area of the
orifice multiplied by the theoretical velocity. It is observed that the vein escaping from an
orifice, contracts quite rapidly, so that its diameter is soon only about two-thirds of the
diameter of the orifice. If there was no contraction of the vein after leaving the orifice, and
its velocity was the theoretical velocity, the actual flow would be the same as that indicated
by theory. But its section is much less than at the orifice, and its velocity is not so great as
the theoretical velocity, so that the actual flow is much less than the theoretical flow; and in
order to reduce this to the first, it is necessary to multiply it by a fraction.

2.—In the lower part of the vein, the liquid is not continuous; for if we
employ an opaque liquid, as mercury, we can see through the vein, Fig. 98.
The apparent continuity in a vein of water is owing to the fact that the
globules which constitute it succeed each other at a distance inappreciable
to the eye.
The time it takes by a vessel to empty itself is to the time required, when it
is kept constantly full, to discharge the same quantity of water, as 2 to 1,

and the spaces described by the surface in its descent
in a column of equal size throughout, are as the odd
numbers, 9, 7, 5, 3, 1. Thus these spaces measure
equal times. Since liquids are not perfectly mobile,
and their exit at an orifice must be retarded by
cohesion and friction, the results thus far given are
much modified in practice.
When a liquid flows through an orifice in a vessel,
eddies are formed about the sides of the orifice,
preventing the escape of a jet equivalent to its full
size; and owing to these, and to acceleration of
velocity, if the jet be downward, it rapidly contracts in
its diameter. At a distance outside about equal to
diameter of the opening, it is contracted to 2⁄3 or 5⁄7 its
original area; and this part has been called the
“contracted vein.” It has been shown, that below this
the stream still contracts, though less rapidly.
These swellings separate more widely as they
descend with increased rapidity; but falling through
great heights, the whole may finally be dissipated in a
Figs. 97, 98. mist.
Note.—The annular swellings contain air and arise from a periodical succession of
pulsations near the orifice, which must be produced by very small oscillations of the entire
mass of the liquid, so that the velocity of the flow is periodically variable. The sucking,
whistling noise which is often heard in the descent of water through an orifice is caused by
air drawn in by the whirling motion. See Fig. 103.

If an orifice in a vessel looks downward, and the column of liquid over it
be short, this will simply drop out by its own weight, starting at a velocity
of o. But if a considerable depth of liquid be above, its gravity produces a
corresponding pressure on its base, or on that liquid which is near it; so that,
if a plug be removed from an orifice in or close to the base, the liquid starts
at once into rapid motion.
Each particle of a jet A issuing from the side of a vessel moves
horizontally with the velocity above mentioned, but it is at once drawn
downward by the force of gravity in the same manner as a bullet fired from
a gun, with its axis horizontal. It is well known that the bullet describes a

parabola with a vertical axis, the
vertex being the muzzle of the gun.
Now, since each particle of the jet
moves in the same curve, this jet C
takes the parabolic form. In every
parabola there is a certain point
called the focus, and the distance
from the vertex to the focus fixes
the magnitude of a parabola in
much the same manner as the
Fig. 99. distance from the center to the
circumference fixes the magnitude
of a circle.
Now it can be proved that the focus B is as much below as the surface of
the water is above the orifice. Accordingly, if water issues through orifices
which are small in comparison with the contents of the vessel, the jets from
orifices at different depths below the surface take different forms, as shown
at D. If these curves are traced on paper held behind the jet, then, knowing
the horizontal distance and the vertical height, it is easy to demonstrate that
the jet forms a parabola.
Quantity of Efflux.—If we suppose the bottom of a vessel containing
water to be thin, and the orifice to be a small circle whose area is A (see Fig.
100) where A B represents an orifice in the bottom of a vessel.
Every particle above
A B tries to pass out of the
vessel, at once and in so
doing exerts a pressure on
those nearest. Those that
issue near A and B exert
pressures in the directions
M M and N N; those near
the center of the orifice in
the direction R Q, those in
the intermediate parts in
the directions P Q, P Q. In
consequence, the water

Fig. 100. within the space P Q P is Fig. 101.
unable to escape, and that
which does escape, instead of assuming a cylindrical form, at first contracts,
and takes the form of a truncated cone.
It is found that the escaping jet continues to contract until at a distance
from the orifice about equal to the diameter of the orifice; this part of the jet
is called the vena contracta or contracted vein, as explained on a previous
page.
Influence of tubes on the quantity of efflux.—The result before given has
reference to an aperture in a thin wall. If a cylindrical or conical efflux tube
is fitted to the aperture, the amount of the flow is considerably increased. A
short tube, whose length is from two to three times its diameter, has been
found to increase the actual efflux per second to about 82 per cent. of the
theoretical. In this case the water on entering the tube forms a contracted
vein, Fig. 101. just as it would do on issuing freely into the air; but
afterwards it expands, and, in consequence of the adhesion of the water to
the interior surface of the tube, has, on leaving the tube, a section greater
than that of the contracted vein. The contraction of the jet within the tube
causes a partial vacuum shown in black in the figure.
Now, if an aperture is made in the tube, near the point of greatest
contraction, and is carefully fitted with a vertical tube, the lower end of
which dips into water, Fig. 101, it is found that water rises in the vertical
tube, thereby proving conclusively the formation of a partial vacuum.
If the nozzle has the form of a conic frustum whose larger end is at the
aperture, the efflux in a second may be raised to 92 per cent., provided the
dimensions are properly chosen. If the smaller end of a frustum of a cone of
suitable dimensions be fitted to the orifice, the efflux may be still further
increased, which will fall very little short of the theoretical amount.

Fig. 102.

Velocities of streams.—The velocity of streams varies greatly. The slower
flow of rivers has a velocity of less than three feet per second, and the more
rapid, as much as six feet per second, which gives respectively about two
and four miles per hour. The velocities vary in different parts of the same
transverse section of a stream, for the air upon the surface of the water, as
well also as the solid bottom of the stream, has a certain effect in retarding
the current. The velocity is found to be greatest in the middle, where the
water is deepest, Fig. 102, somewhere in m, below the surface; then it
decreases with the depth towards the sides, being least at a and b.
Appearance of the surface during a discharge.—A vessel
containing a liquid, discharging itself through an orifice, does
not always preserve a horizontal surface. When the vein
issues from an orifice in the bottom of a vessel, and the level
of the liquid is near the orifice, the liquid forms a whirlpool,
Fig. 103. If the liquid has a rotary movement, the funnel is
formed sooner; if the orifice is at the side of the vessel, there
Fig. 103. is a depression of the surface upon that side, above the orifice,
Fig. 104. These movements depend upon the form of the
vessel, the height of the liquid in it, and the dimensions and form of the
orifice.
In order to verify many of the laws of hydraulics in an
accurate manner, it is necessary to maintain a uniform
pressure on the escaping liquid, thereby obtaining a constant
velocity at the orifice. This may be done in various ways, as
by allowing the water to flow into the vessel in a little larger
quantity than can escape from the orifice, the excess being Fig. 104.

discharged over the upper edge of the vessel; also by means of the syphon.
By suspending solid particles, such as charred paper, pulverized in the
water, we render the currents that are formed visible. These solid particles
arrange themselves, in curved lines, towards and into the orifice, as a center
of attraction, Fig. 105. The particles in immediate contact with the orifice,
not moving so easily as those within, must cause contraction; so, also, we
can see that gravity in accelerating the velocity, must cause continual
decrease in the section of the jet.
Upward jets of water.—As the velocity of a liquid
escaping from an orifice is the same as that which a body
acquires, falling from a height equal to the distance from the
level of the liquid to the orifice, a jet of water escaping from
a horizontal opening upwards, should theoretically reach the
level of the liquid in the vessel. But this never takes place,
Fig. 105. Fig. 106, because of—1st, the friction in the conducting
tubes destroying the velocity. 2nd, the resistance of the air.
3rd, the returning water falling upon that which is rising. The height of the
jet is increased by having the orifices very small, in comparison with the
conducting tube; piercing them in a very thin wall, and inclining the jet a
little, thus avoiding the effect of the returning water.
Height of the jet.—If a jet issuing from an
orifice in a vertical direction has the same
velocity as a body would have which fell from
the surface of the liquid to that orifice, the jet
ought to rise to the level of the liquid. It does
not, however, reach this; for the particles which
fall hinder it. But by inclining the jet at a small
angle with the vertical it reaches about 9⁄10 of the
theoretical height, the difference being due to
friction and to the resistance of the air. Fig. 106.
The quantities of water which issue from
orifices of different areas are very nearly proportional to the size of the
orifice, provided the level remains constant, and this is true irrespective of
the form of the opening which may be round, square, or any other shape.

Escape of liquids through short tubes.—We often place in an orifice, to
increase the flow, a short tube (called an adjutage) either cylindrical or
conical. If the vein pass through the tube without adhering to it, the flow is
not modified; if the vein adhere (the liquid wetting the interior walls) the
contracted part is dilated, and the flow is increased.
In the last case, and with a cylindrical adjutage, its length not being more
than four times its diameter, the flow is augmented about one-third. Conical
pipes, converging towards the exterior, increase the flow still more than the
preceding, the flow and velocity of the vein varying with the angle.
Escape of liquids through long tubes.—When a liquid passes through a
long straight tube, the flow soon diminishes greatly in velocity, because of
the friction which takes place between the liquid particles and the walls. If
there be any bends or curves in the tube, it is still further diminished by the
same cause. The discharge is then much less than it would be from an
orifice in a thin wall, and therefore the tube is generally inclined; the liquid
then passes down this inclined plane, or it is forced through by pressure,
applied at the opposite end.
Direction of the jet from lateral orifices.—From the principle of the equal
transmission of pressure, water issues from an orifice in the side of a vessel
with the same velocity as from an aperture in the bottom of a vessel at the
same depth.

MEASUREMENT OF WATER PRESSURE.

In reference to the table on the next page, it may be well to say that it has
two uses; by it when the “head” is known the pressure can be ascertained to
a fraction, thus, Ex. 1, If the head is 140 feet, then the pressure is 60·64
pounds per square inch. Again, Ex. 2, If the pressure is 15·16 per square
inch, then the head is 35 feet.

Inside. (See Page 115.) Outside.

PRESSURE OF WATER.
The pressure of water in pounds per square inch for every foot in height to 300 feet; and then by
intervals, to 1000 feet head· By this table, from the pounds pressure per square inch, the feet head is
readily obtained; and vice versa.

Feet Head. Pressure per
square inch.
1 0·43
2 0·86
3 1·30
4 1·73
5 2·16
6 2·59
7 3·03
8 3·46
9 3·89
10 4·33
11 4·76
12 5·20
13 5·63
14 6·06
15 6·49
16 6·93

17 7·36
18 7·79
19 8·22
20 8·66
21 9·09
22 9·53
23 9·96
24 10·39
25 10·82
26 11·26
27 11·69
28 12·12
29 12·55
30 12·99
31 13·42
32 13·86
33 14·29
34 14·72
35 15·16
36 15·59
37 16·02
38 16·45
39 16·89
40 17·32
41 17·75
42 18·19
43 18·62
44 19·05
45 19·49
46 19·92
47 20·35
48 20·79
49 21·22
50 21·65
51 22·09
52 22·52
53 22·95
54 23·39
55 23·82
56 24·26
57 24·69
58 25·12
59 25·55
60 25·99
61 26·42

62 26·85
63 27·29
64 27·72
65 28·15
66 28·58
67 29·02
68 29·45
69 29·88
70 30·32
71 30·75
72 31·18
73 31·62
74 32·05
75 32·48
76 32·92
77 33·35
78 33·78
79 34·21
80 34·65
81 35·08
82 35·52
83 35·95
84 36·39
85 36·82
86 37·25
87 37·68
88 38·12
89 38·55
90 38·98
91 39·42
92 39·85
93 40·28
94 40·72
95 41·15
96 41·58
97 42·01
98 42·45
99 42·88
100 43·31
101 43·75
102 44·18
103 44·61
104 45·05
105 45·48
106 45·91

107 46·34
108 46·78
109 47·21
110 47·64
111 48·08
112 48·51
113 48·94
114 49·38
115 49·81
116 50·24
117 50·68
118 51·11
119 51·54
120 51·98
121 52·41
122 52·84
123 53·28
124 53·71
125 54·15
126 54·58
127 55·01
128 55·44
129 55·88
130 56·31
131 56·74
132 57·18
133 57·61
134 58·04
135 58·48
136 58·91
137 59·34
138 59·77
139 60·21
140 60·64
141 61·07
142 61·51
143 61·94
144 62·37
145 62·81
146 63·24
147 63·67
148 64·10
149 64·54
150 64·97
151 65·40

152 65·84
153 66·27
154 66·70
155 67·14
156 67·57
157 68·00
158 68·43
159 68·87
160 69·31
161 69·74
162 70·17
163 70·61
164 71·04
165 71·47
166 71·91
167 72·34
168 72·77
169 73·20
170 73·64
171 74·07
172 74·50
173 74·94
174 75·37
175 75·80
176 76·23
177 76·67
178 77·10
179 77·53
180 77·97
181 78·40
182 78·84
183 79·27
184 79·70
185 80·14
186 80·57
187 81·00
188 81·43
189 81·87
190 82·30
191 82·73
192 83·17
193 83·60
194 84·03
195 84·47
196 84·90

197 85·33
198 85·76
199 86·20
200 86·63
201 87·07
202 87·50
203 87·93
204 88·36
205 88·80
206 89·23
207 89·66
208 90·10
209 90·53
210 90·96
211 91·39
212 91·83
213 92·26
214 92·69
215 93·13
216 93·56
217 93·99
218 94·43
219 94·86
220 95·30
221 95·73
222 96·16
223 96·60
224 97·03
225 97·46
226 97·90
227 98·33
228 98·76
229 99·20
230 99·63
231 100·06
232 100·49
233 100·93
234 101·36
235 101·79
236 102·23
237 102·66
238 103·09
239 103·53
240 103·96
241 104·39

242 104·83
243 105·26
244 105·69
245 106·13
246 106·56
247 106·99
248 107·43
249 107·86
250 108·29
251 108·73
252 109·16
253 109·59
254 110·03
255 110·46
256 110·89
257 111·32
258 111·76
259 112·19
260 112·62
261 113·06
262 113·49
263 113·92
264 114·36
265 114·79
266 115·22
267 115·66
268 116·09
269 116·52
270 116·96
271 117·39
272 117·82
273 118·26
274 118·69
275 119·12
276 119·56
277 119·99
278 120·42
279 120·85
280 121·29
281 121·72
282 122·15
283 122·59
284 123·02
285 123·45
286 123·89

287 124·32
288 124·75
289 125·18
290 125·62
291 126·05
292 126·48
293 126·92
294 127·35
295 127·78
296 128·22
297 128·65
298 129·08
299 129·51
300 129·95
310 134·28
320 138·62
330 142·95
340 147·28
350 151·61
360 155·94
370 160·27
380 164·61
390 168·94
400 173·27
500 216·58
600 259·90
700 303·22
800 346·54
900 389·86
1000 433·18

HYDRAULIC GAUGES.

The Piezometer, or pressure gauge, is an instrument for measuring the
pressure of water in a pipe.
It may be broadly stated that all
pressures and weights relating to water,
steam, gases, etc., are now recorded by
gauges.
The principle of construction of the dial
gauge is that the pressure may be
indicated by means of a spring and pointer
upon a divided dial similar to a clock face,
but marked in divisions, indicating
pounds, hundreds, etc., pressure instead of
hours and minutes. The more approved
forms of gauges are now constructed upon
Fig. 107.
the principle of the Bourdon spring or
metallic barometer invented in 1849. (See page 113 for illus.)
The essential principle—or discovery—
is this: that a metal curved tube—oval
cross section, under pressure, tends to
straighten itself according to the force
exerted by the pressure inside. Figs. 107
and 108 show the ordinary style of gauge
which consists of an elliptical tube,
connected at one end to a pipe in
communication with the pressure, and at
the other end with toothed arc and pinion
to a pointer spindle as shown in cuts.
Note.—Hydraulic gauges are indispensable as it Fig. 108.
is often necessary to stop the pressure at points
below that at which the safety valve has been set.

Within the gauges—or cases, is a small coiled tube closed at one end,
while the other end is attached to the socket through which the water is
admitted; this tube has a tendency to straighten when under pressure, and

thus its free closed end moves, and this motion is communicated to the
pointer; when the pressure is relieved the tube assumes its original position
and the pointer returns to zero. There are many modifications and special
adaptations of the Bourdon discovery, but the principle remains, and the
same useful results are obtained with both single and double tubes, the latter
being the most resensitive.
Fig. 107 shows the dial of a hydraulic gauge which is graduated to suit
the work to which it is related. These gauges are made for pressures from
1,000 to 20,000 pounds per square inch. The springs are formed of heavy
solid bar steel turned and bored to size and are of the Bourdon style. They
are in use in large railroad shops, sugar refineries and cotton-seed oil mills.
These gauges are also made with connections through the back of the case.
The gauge illustrated in Fig. 108 is used in connection with hot water
heaters, denoting the height of column of water in the tank or reservoir, one
hand being painted red and the other black. As it is necessary to have at all
times in the tank or reservoir a certain height of water, the red hand is set at
the point on the dial which denotes this height. The black hand is connected
with the working parts of the gauge and indicates on the dial the actual
height of water in the tank or reservoir.
The dial of this gauge is graduated in feet, instead of pounds.
A check valve is almost indispensable in using a hydraulic gauge, as the
pressure is often suddenly removed and the momentum of the hand will
throw the pinion out of gear with the toothed arc, and is liable to break the
hair-spring. A check valve prevents any trouble of this kind and should
always be used.

WATER PRESSURE
MACHINES

WATER WHEELS.

Hydraulic machinery may be broadly divided into
1. Motor machines, and,
2. Pumps.
Water motors may be divided into
1. Water wheels,
2. Turbines, and,
3. Water pressure engines.
In hydraulic motor machines a quantity of water descending from a
higher to a lower level, or from a higher to a lower pressure, drives a
machine which receives energy from the water and applies it to overcoming
the resistances of other machines doing work.
In the next general class, work done on the machine by a steam engine or
other source of energy is employed in lifting water from a lower to a higher
level. A few machines such as the ram and jet pump combine the functions
of both motors and pumps.
The subject of water wheels is but a continuation of much that has been
illustrated and defined in the historical introduction to which is now added
the following summary.
In every system of machinery deriving energy from a natural water-fall
there exist the following parts:
(1) A supply channel, leading the water from the highest accessible level,
to the site of the machine; this may be an open channel of earth, masonry, or
wood, or it may be a closed cast or wrought-iron pipe; in some cases part of
the head race is an open channel, part a closed pipe.
(2) Leading from the motor there is a tail race, culvert, or discharge pipe
delivering the water after it has done its work.
(3) A waste channel placed on or at the origin of the head race by which
surplus water, in floods, escapes.

(4) The motor itself, which either overcomes a useful resistance directly,
as in the case of a ram acting on a lift or crane chain, or indirectly by
actuating transmissive machinery, as when a turbine drives the shafting,
belting, and gearing of a mill. With the motor is usually combined
regulating machinery for adjusting the power and speed, to the work done.
The great convenience and simplicity of water motors has led to their
adoption in certain cases, where no natural source of water power is
available. In these cases, an artificial source of water power is created by
using a steam engine to pump water to a reservoir at a great elevation, or to
pump water into a closed reservoir in which there is great pressure.
Water flowing from the reservoir through hydraulic engines gives back
the energy expended, less so much as has been wasted in friction. Where a
continuously acting steam engine stores up energy by pumping the water,
while the work done by the hydraulic engines is done intermittently,—this
arrangement is considered the most useful.
Note.—“Wherever a stream flows from a higher to a lower level it is possible to erect a
water motor. The amount of power obtainable depends on the available head and the
supply of water. In choosing a site the engineer will select a portion of the stream where
there is an abrupt natural fall, or at least a considerable slope of the bed. He will have
regard to the facility of constructing the channels which are to convey the water, and will
take advantage of any bend in the river which enables him to shorten them. He will have
accurate measurements made of the quantity of water flowing in the stream, and he will
endeavor to ascertain the average quantity available throughout the year, the minimum
quantity in dry seasons, and the maximum for which bye-wash channels must be provided.
In many cases the natural fall can be increased by a dam or weir thrown across the stream.
The engineer will also examine to what extent the head may vary in different seasons, and
whether it is necessary to sacrifice part of the fall and give a steep slope to the tail race to
prevent the motor being flooded by backwater in freshet time.
In designing or selecting a water motor it is sufficient to consider only its efficiency in
normal working conditions. It is generally quite as important to know how it will act with a
scanty water supply or a diminished head. The greatest difference in water motors is in
their adaptability to varying working conditions.”—Encyc. Brit.

Water wheels are large vertical wheels
driven by water falling from a higher to a
lower level: they are motors on which the
water acts, partly by weight, partly by
impulse. Turbines are wheels, generally of
small size compared with water wheels,
driven chiefly by the impulse of the water.

Fig. 110. Before entering the moving part of the
turbine, the water is allowed to acquire a
considerable velocity; during its action on the wheel this velocity is
diminished, and the impulse due to the change of momentum drives the
turbine. Roughly speaking, the fluid acts in a water-pressure engine directly
by its pressure, in a water wheel chiefly by its weight causing a pressure.
A flutter-wheel is shown in Fig. 110. This is a water wheel of moderate
diameter placed at the bottom of a chute so as to receive the impact of the
head of water in the chute and penstock. Its name is derived from its rapid
motion, the effect of which is to cause a commotion of the water like “the
fluttering” of a fowl.
Impact Wheels.—The simplest and most imperfect of the horizontal
wheels are the so-called impact wheels or impact turbines, such as shown in
Fig. 111.
They consist of 16 or 20 rectangular
blades fastened to the wheel at an
inclination of 50° to 70° with the horizon.
The water is brought on through a race of
40° to 20° inclination, so that it strikes at
about right angles upon the blades.
These wheels are used in falls from 10
to 20 ft., where a large number of
revolutions is necessary, as in grain mills, Fig. 111.
where the moving millstone is hung on
the vertical shaft of the wheel, hence intermediate gearing is unnecessary.
These crude machines are found in Southern Europe, North Africa, in the
Alps, Pyrenees, and in Algiers. They are about 5 ft. in diameter, and the
blades are 15 inches high and 8 to 10 inches long (measured radially).
Fig. 112 shows an “undershot water
wheel.” In this style of wheel, the work is
done by impact alone, as the running
water acts only on a few immersed
buckets on the under side of the wheel.

In the breast wheel, Fig. 113, the water Fig. 112.
is admitted on a level or slightly above the
center of the shaft, so that the water acts by impact and weight.

Fig. 113.

Note.—“A weir is a dam erected across a river to stop and raise the water, as for the
purpose of taking fish, of conveying a stream to a mill, of maintaining the water at a level
required for navigating it, or for the purposes of irrigation.”
For facilitating the computation of the quantity of water flowing over weirs, Weir Tables,
are used, based upon approved formulas, of which “Francis’ Formula” is perhaps the most
reliable. These tables are applicable to the subject of water wheels but cannot be printed in
this work.

Fig 114 represents an over-shot water wheel (F G H L, with axis at O) in
which the water flows upon the top of the wheel at h, in the same direction
in which it revolves, therefore the impact of the water is utilized upon the
upper buckets H, a, b, after which the weight of the water acts in the
buckets c, d, e, F, e´, d´ and c´. At b´ the buckets begin to overflow and
empty themselves as shown at a´. It will be seen that the water acts upon
almost one-half the circumference of this wheel, thus realizing the greatest
mechanical effect with the smallest quantity of water.
The current-wheel is perhaps the first application of the force of water in
motion, to drive machinery. In the first century B. C., water-wheels for

driving mills were used in Asia Minor and
on the Tiber. In the former case we
suppose, but in the latter case we know,
that these were current-wheels.

Fig. 114.

Fig. 115.

The tide or current wheel, (Fig. 115) erected in the vicinity of the north
end of London Bridge, and subsequently under its northern arch, was
erected by Peter Morice, a Dutchman, in 1582, and operated force-pumps
which supplied a part of London with water. The stand-pipe from the pump
was 120 feet high, and conducted the water to a cistern at that height. The

amount raised was about 216 gallons per minute. The wheel worked sixteen
pumps, each 7 inches in diameter, and having a uniform stroke of 30 inches.
During the seventeenth and eighteenth centuries the works were extended
from time to time, and occupied one after another of the arches. In the first
arch of the bridge was one wheel working sixteen force-pumps. In the third
arch were three wheels, working fifty-two pumps. The united effect was
2,052 gallons per minute, raised 120 feet high.
In 1767 Smeaton added wheels in the fifth arch. Steam-engines were
added about this time to assist at low water and at neap-tides. Thus the
matter remained till 1821. Stow, the antiquarian and historian, describes the
works in 1600; and Beighton in 1731 gives an account of them at that date.
The water-wheels at that time were placed under several of the arches.
The axis of these wheels was 19 feet long 3 feet diameter. The radial arms
supported the rings and twenty-six floats, 14 feet long by 18 inches wide.
The axis turned on brass gudgeons supported by counterpoised levers,
which permitted the vertical adjustment of the wheel as the tide rose and
fell. On the axis of the wheel was a cog-wheel 8 feet in diameter and having
forty-four cogs; meshing into a trundle-wheel 41⁄2 feet in diameter and
having 20 rounds, or pins and whose iron axle revolved in brasses.
The axis of the trundle was prolonged at each end, and had quadruple
cranks which connected by rods to the ends of four walking beams 24 feet
long, whose other ends worked the piston-rods of the pumps. The axis of
oscillation of the lever supporting the wheel, and by which it was adjusted
to the height of the tide, was coincident with the axis of the trundle, so that
the latter engaged the 8-feet cog-wheel in all conditions of vertical
adjustment. Cranks operated one end of the beams while pumps were
attached to the other end.

Fig. 116.

Fig. 116 exhibits an overshot water wheel employed at Laxey, Isle of
Man, for driving the pumps which drain the mines at that village; these
have an extreme depth of 1,380 feet. The wheel is 72 feet 6 inches in
diameter, 6 feet in breadth, exerts a force of about 200 horse-power and is
capable of pumping 250 gallons per min. from a depth of 1,200 feet. Its
crank-stroke is 10 feet. The water for driving it is conducted by pipes from
a reservoir on a neighboring hill, and ascends in the column of masonry

shown to the left of the wheel. (Knight Vol. III.) An extra crank appears to
be shown in the foreground of this reproduction of an old drawing.

TURBINE WATER WHEELS.

The word turbine is derived from the Latin, “turbo”—that which spins or
whirls around—a whirlwind.
The turbine is a horizontal water wheel,
and is similar to the hydraulic tourniquet
or reaction wheel shown in Fig. 117. This
consists of a glass vessel, M, containing
water and capable of moving about its
vertical axis. At the lower part there is a
tube, C, bent horizontally in opposite
direction at the two ends. If the vessel
were full of water and the tubes closed,
the pressure of the sides of C would
balance each other, being equal and acting
in contrary direction: but, being open, the
water runs out and the pressure is not
exerted on the open part but only on the
opposite side, as shown in the figure A.
And this pressure, not being neutralized
Fig. 117. by an opposite pressure, imparts a rotary
motion in the direction of the arrow, the
velocity of which increases with the height of the liquid and the size of the
aperture. This description and the illustration gives an idea of the crude
reaction wheel invented by Barker about 1740; again a turbine is simply a
centrifugal pump reversed, but the turbine is usually furnished with curved
guide vanes to guide the water as it enters the wheel.
Note.—The steam turbine has come into common use and competes in its economical
performance with the simpler and less economical types of the steam engine; it is impelled
by steam jets, the steam impinging upon vanes or buckets on the circumference of a
rotating disc or cylinder.

In those turbines which are without guide blades—i. e., which have a
high fall—the discharged water still possesses a great velocity and the
wheel is thereby deprived of a considerable part of mechanical power. This

loss can, however, be obviated or lessened by using the energy of this
discharged water to drive a second wheel.
A construction of this sort has been carried out by Ober-Bergrath Althaus
in the tanning mill at Vallendar near Ehrenbreitstein. The essential parts of
the arrangement can be seen in Fig. 118. A E A is an ordinary reaction
wheel with four curved revolving pipes and a fall of 124 ft., and B B is a
larger wheel with floats which is set in rotation by the water issuing from A.
A. Since the two wheels turn in opposite directions, they must be connected
together by a special form of wheel-work. The outer wheel affords the
additional advantage of serving at the same time as a fly-wheel, thereby
giving a more uniform rate of motion to the whole machinery.
Turbines are variously constructed, but
all have curved floats or buckets against
which the water acts by its impulse or
reaction in flowing either outward from a
1 central chamber, 2 inward from an
external casing, 3 from above downward,
and, 4 from below; these constructions are
either divided into outward, vertical or
central discharge wheels.
Turbines may also be divided into
reaction turbines, or those actuated
Fig. 118. substantially by the water passing through
them (their buckets moving in a direction
opposite to that of the flow); impulse turbines or those principally driven by
impact against their blades or buckets (the buckets moving with the flow);
and combined reaction and impulse wheels which include the best modern
types of turbines. In reaction turbines the wheel passages are designed to be
always full and therefore the water under pressure; in the impulse turbine
the passages are not usually full.
Turbines in which the water flows in a direction parallel to the axis are
called parallel flow turbines—or journal turbines.
The turbine-dynamometer is a device used for measurings or testing the
power delivered by turbines (whence its name).

Fourneyron’s Turbine. This is, in
its latest form, when properly
constructed, the nearest perfect of
the horizontal water-wheels. It
revolves either in the air or under
water, and may be either high or
low pressure. For the low-pressure
wheel, the water enters the flume
from the open reservoir, with free
surface, as in Fig. 119. For high
pressure, the reservoir is boxed up
and the water brought in at the side
through a pipe, as shown in Fig.
124, page 136. The first is for low
and the second for high falls.
Note.—The early history of the turbine
is one of considerable interest especially in
view of the development of the steam, from
the water turbine.
“M. Fourneyron, who began his
experiments in 1823, erected his first Fig. 119.
turbine in 1827, at Pont sur l’Ognon, in
France. The result far exceeded his expectations, but he had much prejudice to contend
with, and it was not until 1834 that he constructed another, in Franche Comté at the iron-
works of M. Caron, to blow a furnace. It was of 7 or 8 horse-power, and worked at times
with a fall of only 9 inches. Its performance was so satisfactory that the same proprietor
had afterwards another of 50 horse-power erected, to replace 2 water-wheels, which
together, were equal to 30 horse-power. The fall of water was 4 feet 3 inches, and the
useful effect, varied with the head and the immersion of the turbine, 65 to 80 per cent.
Several others were now erected: 2 for falls of seven feet; 1 at Inval, near Gisors, for a fall
of 6 feet 6 inches, the power being nearly 40-horse, on the river Epté, expending 35 cubic
feet of water per second, the useful effect being 71 per cent. of the force employed.”

Fig. 120.

The Leffel-Samson turbine wheel is shown in the engraving, Fig. 120,
page 129, where N.N. represents the bottom casting of the case flanged to
support the wheel by resting upon the bottom of the penstock.
The draft tube I is of conical shape as represented at J. J. to reduce the
friction of discharge water which after performing its work in the wheel
escapes at the bottom of the draft tube. This tube must always project into
the tail water at least two or three inches. The gates H.H.H. are pivoted at

the center so that they are balanced and are opened and closed with the least
possible friction. These gates are operated by rods L. L., connecting with a
rack and pinion which are manipulated by the operator as occasion requires,
by an extension shaft from the coupling K, having a hand-wheel on top.

Fig. 121.

Power is transmitted from the wheel shaft F to the gears and pulleys
connected with the coupling above; the manner of setting turbine wheels in

openstocks is shown a few pages further on.
From the construction of gates and guides upon turbine wheels one may
readily see the absolute necessity of carefully guarding the flume against
the admission of sticks and other solid materials that might wreck the wheel
or jam the gates so that they could not be operated; this is best
accomplished by placing a water rack in front of the head gate at the
entrance to the flume.
These water racks are best made of flat bars of wrought iron placed
edgewise in a vertical position, or what is better, let the top incline say one
foot or two (depending upon the size of flume) towards the head gates.
When placed in an inclined position it is very much easier to clean the rack
from drift wood and the like than when placed in a vertical position as by
means of a hoe or scraper these obstructions may be hauled up over the top
of the inclined rack.
The racks should be made very strong and substantial to guard against
being broken by ice in the winter, for should the rack give way at any
inopportune time the admission of sticks and other rubbish might wreck the
wheel.
The “runner” which is the revolving part, as shown in Fig. 121, is
composed of two separate and distinct types of wheels, and has two
diameters, as shown. Each wheel or set of buckets receives its separate
quantity of water from one and the same set of guides but each set acts only
once and independently upon the water used, hence the water does not act
twice upon the combined wheel as might be supposed, as in the compound
steam engine.
The upper wheel G receives the water as shown by the arrows at A, and
has a central and downward discharge, while the lower wheel C receives
the water as shown by the arrows at B and has an inward, downward and
outward discharge as shown by the arrows at D.
These two sets of buckets need to be exceedingly strong. The lower set B
are made of heavy flanged steel plate and are cast into their places by being
placed in the sand mould, and the cast iron flows around them forming the
heavy ring C, surrounding the outer and lower edges. This ring is a part of
the diaphragm which separates the two wheels. The upper edge of the ring

C is beveled to form a neat joint which prevents any unnecessary loss of
water.
This runner is balanced and secured to a hammered iron or steel shaft F.
It is supported usually by a step of the best specially selected hard wood
thoroughly soaked in oil for months before use. The lower end of the shaft
is dished out at E, forming a true arc of a circle—concave—while the
wooden step is made spherical—convex—to fit into the end of the shaft.
The step is formed in this way so that no sand can lodge between the
bearing surfaces, and cut them out. The resident oil in the wood combined
with the water make a most durable means of lubrication, and these steps
last for many months where the water is clear.
To get at the exact quantity of
water consumed by a turbine wheel,
one cannot make an accurate
calculation from the openings
through the wheels but the water is
measured after it has passed
through the wheel, as it flows away
into the tail race. Any slight
variation in the form of buckets or
admission apertures will make an
appreciable variation in the quantity
of water discharged by a turbine
wheel.
These wheels are made either for
vertical or horizontal shafts and are
also made single or double. The
engraving, Fig. 122, shows a
Hercules turbine within the case
and gate ready to set in the
penstock.
Up to the year 1876 this make of
wheel tested at the flume of the
Holyoke Water Works showed the
highest efficiency at all stages of

Fig. 122. gate, namely 87 per cent. (page 97,
Emerson’s tests).
The design of case will naturally lead the reader to conclude that this
wheel has, 1, an inward, 2, downward and, 3, an outward discharge which is
correct. The gate is simply a curb or hollow cylinder which forms a sleeve
outside the case and is raised and lowered by the gearing and rack shewn in
the engraving. As this sleeve rises it gradually uncovers the openings shown
which admits water into the wheel.
Horizontal Turbine—The turbine of 10,500 horse power installed in the
Shawinigan plant, Canada, see IV Pt. 2. is of the horizontal type, the water
entering at, A, the lowest part of the turbine and flows around and fills the
outer special tube, passes through an annular gate, flows radially through
the wheel thence out through two draft tubes, B, one on each side. The
weight of the water wheel is 182 tons, the shaft weighing 10 tons and the
bronze runner 5 tons. It is 30 feet from base to top and 32 feet 21⁄2 inches
wide over all. The shaft, C, is of solid forged steel, 22 inches diameter in
the middle, tapering down to 10 inches diameter on one end and 16 inches
diameter on the other, the distance between bearings being 27 feet. The
intake is 10 feet in diameter and the quantity of water going through the
turbine when developing full power is 395,000 gallons a minute. The speed
of the wheel is 180 revolutions per minute with a head of water acting on
the turbine of 125 to 135 feet.
Fig 123 is designed to show The Setting of a turbine wheel in a wooden
penstock.

Fig. 123.

The principal and most essential dimensions necessary to be considered
in setting turbines are indicated by letters, each size having its own
particular dimensions.
In setting the wheel in the ordinary penstock it is necessary in the first
place, to have the floor exactly level, and it is generally more convenient to
lay down a ring of soft wood around the hole in the floor, as it will be much
easier to dress off with a plane than the plank floor. The floor should be

supported by posts under the timbers around the hole, so that there will be
no settling of the floor after being once made level. As the flange on which
the wheel rests is turned true, the wheel will, when placed on this level
floor, stand in the exact position required, i.e., the shaft will be exactly
vertical.
If the wheel is a large one and was taken apart for shipment, the draft
tube is first erected in position, then the wheel is placed on its step, the
other parts being put on in their order. The step and other bearings are
adjusted before leaving the shop, but it will sometimes happen that they will
in some way get shifted, and as the wheel is being put together, they should
be inspected and readjusted, if necessary. The only change that can occur in
the step is its vertical adjustment, which is regulated by screws. When the
right height is found, the broad flange around the lower part of the wheel
should stand about one-sixteenth of an inch below the under side of the base
of the guide rim where it rests upon the draft tube. The adjustable bearing
on the top of the cover plate should be fitted up closely around the shaft, but
not screwed so tightly as to bind it.
All these wheels above fifteen inches in diameter are provided with
chains and weights to counterbalance the weight of the gate, so that it will
move easily. It is best, when it can be done without much trouble, to carry
the weights outside of the flume, but they can be used inside where the
height is sufficient, although it will require a little more weight to be as
effective. When the wheel is not likely to be started up at once, it is a good
plan, when putting it together, to smear the step and the shaft at the bearing
with tallow, as a protection against rust while it remains idle.
It is sometimes necessary to use a draft tube longer than is ordinarily
attached to the wheel. If properly constructed and applied there will be no
sensible loss of power, but it must be air tight, and when of considerable
length it is better enlarged gradually toward the lower end, especially in
cases where it may be necessary to carry this tube near the pit bottom.
Iron cases for Turbines. Fig. 124 shows the setting of a Hercules wheel
within an iron case.

Fig 124.

Although the expense of iron is as a rule considerably greater than wood,
the results obtained by the use of iron cases and penstocks are much better
than could be possible with wood, on account of their durability and
freedom from leakage.
It is generally conceded that there is a great risk of the step becoming
heated and burning out when placed in a draft tube above the tail-water, and
a jet of water is required to counteract this tendency to overheat. As all such

fixtures are liable to derangement and often fail to operate, we are in favor
of setting the wheel with the step immersed, whenever it can be done
without too great expense.
This case consists of two cast iron heads with boiler iron sides and is
provided with a cover, so that the wheel may be taken out entire. This cover
is fitted with stuffing boxes for both wheel and gate shafts, and a manhole
affords easy access to the wheel. The bearing surfaces of the heads are
nicely turned, insuring tight joints, and all holes for rivets are accurately
spaced and drilled. The heads of the larger cases are made to clamp, the two
halves being planed together; the cases are fitted with mouthpieces having
cast iron flanges for feeder connections, to secure by bolts to either iron or
wooden feeders.
Where two wheels of the same or different diameters are to be used,
corresponding cases connected in the centre with one common feeder
connection, or are placed in cases provided with separate feeders. In
connection with these cases an iron draft tube of any desired length may be
used. The wheel is usually fitted to the case before leaving the works, and in
erecting the smaller wheels, all that remains to be done is to set the case on
the foundations provided for it and make the necessary connections as
stated in explanation previously made for Figs. 122 and 123.
The general arrangements required for the proper erection of turbines are
well understood by competent millwrights and do not in ordinary cases
present any serious difficulties. It may be of interest to many, and to the
advantage of some who may consider the use of water power, if a few
general remarks on this subject are added.
In practice there is almost always a little loss of head due to the velocity
with which the water passes through the channels leading to and away from
the wheel, and it should be the aim in constructing flumes to bring the loss
to a minimum. When the size of the wheel and the quantity of water to be
used have been determined, 1, the size of the conduit for carrying the water
to the wheel, 2, the width and depth of the wheel-pit and tail-race, and 3, the
dimensions and location of the flume for the wheel are to be considered and
properly arranged.
All of these should be of such dimensions as to insure the flow of water
through them at a moderate velocity, and with as little change of direction

as may be practicable.
The larger the pipe or canal the better, but there must be a limit in
practice, and it may be laid down as a general rule that a velocity of three
feet per second is good practice in short tubes of uniform section of not
more than fifty feet in length; but the velocity should be reduced as the
distance increases, until in a length of 200 feet, it should not exceed two
feet per second.
The same rule applies to the tail-race, except that the velocity should be
somewhat lower in ditches cut through rock or earth and having the
naturally resulting roughness of sides and bottom.
The width and depth of the pit below the wheel may, for a given wheel,
vary somewhat as the water discharged into it is greater or less; therefore,
the dimensions should increase with a greater head for the same wheel. The
following is an approximate rule for the dimensions of the pit, say for a
head of twenty feet: width of pit equal to four times the diameter of wheel,
depth below the level of tail-water one and a half times the diameter of
wheel. The flume for the wheel should be about three times the diameter of
the wheel in its width or diameter, and if it is decked over at the top it
should be high enough inside to clear the coupling on the wheel shaft.
The Watertight Turbine is a special machine designed to keep the case
tight by the pressure of the water against the gates at the sides, no matter
how much these gates wear.
Fig. 125 shows the plan of chutes, gate-seats, gates, and buckets of the
wheel. Part of the gates are shown open, and others are closed. The gates
make a quarter of a turn in opening, and the same in shutting, and to open
all the gates, the gate wheel makes half a revolution. The upper half of case
shows the gate-wheel and pinion for operating its parts.

Fig. 125.

The small illustration is a perspective view of the gate and
gate segment used on the watertight turbine. The part cut away
forms part of the chute when the gate is open as shown in the
lower left-hand side of the figure. The sharp edge of the gate
cuts off sticks and rubbish which are liable to get in the wheel,
which is an obvious advantage. Another desirable feature
claimed for this wheel is the plan of operating the gates in opposite pairs;
by this means 2, 4, 6, 8 or 10 full gates may be opened at will, according to
the power required.

The Niagara Falls Turbine.—Fig. 126.

Turbines at Niagara Falls. A number of turbines installed at Niagara
Falls, N. Y., are here briefly described; they are about 5,000 horse-power
each; a canal leads water from the river to the wheel pit. The water is
carried down the pit through steel penstocks to the turbines, which are
placed 136 feet below the water level in the canal. After passing through the
wheels the waste water is conveyed to the river below by a tunnel 7,000 feet
long. The “plan” Fig. 126 shows a cross-section of the wheel pit, with an
end view of a penstock, wheel case and shaft. Fig. 126 exhibits part of a

vertical section of the wheel pit and a side view of this penstock, with the
enclosing case and shaft of the turbine.

Top View or Plan of Fig. 126.

This turbine has a rock-surface wheel pit, but this surface is protected by
a brick lining having a thickness of about 15 inches. The width of the wheel
pit is 20 feet at the top and 16 feet at the bottom, and the cylindrical
penstock is 71⁄2 feet in diameter. The shaft of the turbine is a steel tube 38
inches in diameter, built in three sections, and connected by short solid steel
shafts 11 inches in diameter, which revolve in bearings. On the top of each
shaft is a dynamo for generating the electric power.
In Fig. 126 is shown a vertical section of the lower part of the penstock,
shaft, and twin wheels. The water fills the casing around the shaft, passes

both upward and downward to the guide passages, through which it enters
the two wheels, causes them to revolve, and then drops down to the tail race
at the entrance to the tunnel, which carries it away to the river. The gate for
regulating the supply is seen upon the outside of these wheels, both at the
top and bottom, Fig. 126.
Fig. 128 gives a larger vertical section of the lower wheel with the
guides, shaft, and connecting members. The guide passages, and the wheel
passages, are triple as shown so that the latter may be filled not only at full
gate, but also when it is one-third or two-thirds open, thus avoiding the loss
of energy due to sudden enlargement of the flowing stream. The two
horizontal partitions in the wheel are also advantageous in strengthening it.
The inner radius of the wheel is 311⁄2 inches and the outer radius is 371⁄2
inches, while the depth is about 12 inches. In this figure the gate is
represented closed and to open, it moves downward uncovering the guide
passages as shown in Fig. 126, the position it occupies loaded.
In Fig. 127 is shown a half-plan of one of the wheels, in a part of which
are seen the guides and vanes, there being 36 of the former and 32 of the
latter. Although the water on leaving the wheel is discharged into the air, the
very small annular space between the guides and vanes, together with the
decreasing area between the vanes from the entrance to the exit orifices,
ensures that the wheels move like reaction turbines for the three positions of
the gates correspond to the three horizontal stages or openings through the
guides as shown in Fig. 128, i.e., three stages of gate.
Note.—A test of one of these wheels, made in 1895, developed 5,498 electrical horse-
power, generated by an expenditure of 447·2 cubic feet of water per second under a head of
135·1 feet. The efficiency of the dynamo being 97 per cent., the efficiency of the wheel and
approaches was 821⁄2 per cent.

The average discharge through one of these twin turbines is about 430
cubic feet per second, and the theoretic power due to this discharge is 6,645
horse-power. Hence if 5,000 horse-power be utilized the efficiency is 75.2
per cent. Under this discharge the mean velocity of water in the penstock is
nearly 10 feet per second, but the loss of head due to friction in the
penstock will be but a small fraction of a foot. The pressure-head in the
wheel case is then practically that due to the actual static head, or closely
1411⁄2 feet upon the lower and 130 feet upon the upper wheel.

The absolute velocity of
the water when entering the
wheel is about 66 feet per
second, so that the pressure-
head in the guide passages of
the upper wheel is nearly 66
feet. The mean absolute
velocity of the water when
leaving the wheels is about
19 feet per second, so that the
loss due to this is only about
4 per cent. of the total head.
Note.—The above description
refers to the ten turbines in wheel
pit No. 1. The illustrations are
those of the wheels called units 1,
2, and 3 which were installed in
1894 and 1895. Units 4 to 10,
inclusive, installed in 1898-1900,
are of the same type except that
both the penstock and wheel case
have cast-iron ribs on their sides
which rest on massive castings
built into the masonry of the side
walls. This arrangement dispenses
with the supporting girders shown
in Fig. 126 and gives much
greater rigidity to both penstocks
and wheels.

Fig. 127.

Fig. 128.—Enlarged Vertical Section of Lower Wheel, Showing
Gates.

The weight of the dynamo, shaft, and turbine is balanced, when the
wheels are in motion, by the upward pressure of the water in the wheel case
on a piston placed above the upper wheel. The upper disc containing the
guides is, for this purpose, perforated, so that the water pressure can be
equalized.

WATER PRESSURE ENGINES.

Water pressure engines are machines with a cylinder and piston or ram,
in principle identical with the corresponding part of a steam engine; the
water is alternately admitted to and discharged from the cylinder, causing a
reciprocating action of the piston or ram. It is admitted at a high pressure
and after doing its work on the piston is discharged.
The water in some of these machines acquires a high velocity; the useful
work is due to the difference in the pressure of admission and discharge,
whether that pressure is due to the weight of a column of water of more or
less considerable height, or is artificially produced.
When an incompressible fluid such as water, is used to actuate piston
engines, two special difficulties arise. One is that the lost work in friction is
very great, if the water attains a considerable velocity; another is that there
is over-straining action on the machinery. The violent straining action due
to the more or less sudden arrest of the motion of water in machinery is
termed hydraulic shock. For these reasons the maximum velocity of flow of
water in reciprocating hydraulic machines should generally not exceed 5 to
10 feet per second.
Under high pressure, where there is less object in saving and it is very
important to keep the dimensions of the machinery small, Mr. Anderson
gives 24 feet per second as the limit of velocity. In large water-pressure
engines used for pumping mines the average piston speed does not exceed
1
⁄2 to 2 feet per second.
The suitability of water for the transmission of power has been fully
recognized in recent years; the facility with which water under pressure is
capable of being utilized, and the advantages that attend its use in motors
have resulted in many practical difficulties being overcome, which were at
first considered insurmountable.
At the outset of the employment of water pressure it was feared that the
water in the pipes and machinery might freeze. This, however, has been
found not to be a difficulty where well-known precautions are taken. The
working parts should, where possible, be placed under ground, or should be

cased in, if they are above ground. The water should be run out of all valves
and cylinders which cannot be cased in, and protected as soon as the
working of the machine ceases.
A very small gas jet or lamp placed near the unprotected parts will
prevent freezing.
Experiments have also shown that a mixture of glycerine and water
prevents the effects of frost at a temperature as low as 16° Fahr., provided
the glycerine has a specific gravity of 1.125, and that it is mixed in the
proportion of one part of glycerine by weight to four parts of water.
Where water is used over again in the machines (by returning the exhaust
water from the machines to a reservoir), such addition of glycerine is more
easily resorted to. Where moderate risks of frost have to be dealt with, the
proportion of one gallon of glycerine to 300 gallons of water proves
effectual. If the water is at a high pressure, such as 1,500 lbs. to the square
inch, it is less liable to freeze than when used at a low pressure.
Again, it was at first feared that accidents might be frequent from the
bursting of hydraulic pipes and cylinders under high pressure. Such,
however, has been proved not to be the case in practice, and even where
pipes or cylinders do burst, the pressure is at once dissipated, as the body of
water which can escape at the opening is but slight.
It is desirable to use water which is as free as possible either from
suspended matter or from chemical impurity. The former increases the wear
and tear of the packing, and is otherwise inconvenient, and the latter acts
injuriously on the seats and fittings of valves. Sea-water can be used for
hydraulic machinery, but on account of its corrosion, fresh-water is better.
Water-pressure has sometimes been applied to operate machines which
are worked continuously and not intermittently, and to continuous working
rotary machines. This is unwise, for in applying hydraulic power to the
continuous working of shafting or shop tools, the amount of power
developed by the hydraulic engine cannot be varied to suit the work to be
done, neither can the speed be regulated with sufficient nicety.

HYDRAULIC MOTORS.

Pressure or Hydraulic Motors form an interesting variety of hydraulic
devices; they consist of working cylinders with valves and pistons, and
resemble forcing pumps in their construction, but differ from them in their
operation; the pistons not being moved by any external force applied to
them through cranks, levers, etc., but by the weight or pressure of a column
of water acting directly upon or against the pistons. Pressure engines or
motors are applicable to locations—such as afford a suitable supply of
water for the motive column; but where-ever refuse, impure, salt or other
water can be obtained from a sufficient elevation, such may be used to raise
a quantity of fresh water by these machines.
The stress considered in hydro-mechanics is always a pressure, as liquids
are in general capable of sustaining only a slight tension without disruption:
the intensity of the pressure is measured by the number of units of force per
unit of area. Thus we say, one thousand pounds of pressure per square inch
of piston—the pounds and the square inches are the units used in these
calculations.

Figs. 129, 130.
For description see page 151.

The invention of pressure engines brought to light a new mode of
employing water as a motive agent: and also the means of applying it in
locations where it could not otherwise be used; with pressure engines the
motive agent may be taken to the machine itself. In valleys or lowlands,
having no natural fall of water, but where that liquid can be conveyed in
tubes from a sufficient elevation (no matter how distant the source may be),
such water, by these machines, may be made to propel others; unlike the
steam engine, a pressure engine is inexpensive, and simple in construction
—it requires neither chimneys, furnaces nor fuel; neither firemen nor
engineers, nor is there any danger of explosions. It may be placed in the
comer of a room, or be concealed under a counter or a table. It may be set in
operation in a moment, by opening a cock, and the instant the work is done,
it may be stopped by shutting the same, and thus prevent waste of power.
Pressure engines afford an illustration of the variety of purposes to which
a piston and cylinder may be applied. These were probably first used in
piston bellows; next in the syringe; subsequently in pumps of every variety;
and then in water-pressure and steam engines. The moving piston is the
nucleus or elemental part that gives efficiency to them all; and the apparatus
that surround it in some of them, are but its parts.
The history of machines composed of pistons and cylinders also
illustrates the process by which some simple inventions have become
applied to purposes, foreign to those for which they were originally
designed—each application opening the way for a different one.
In another form hydraulic motors have been adopted, in favorable
locations, as first movers of machinery, and when thus used, they exhibit a
very striking resemblance to high pressure steam engines. Indeed, the
elemental features of steam and pressure engines are the same, and the
modes of employing the motive agents in both are identical—it is the
different properties of the agents that induces a slight variation in the
machines—one being an elastic fluid, the other a non-elastic liquid.

Fig. 131.

Fig. 132.

In steam engines a piston is alternately pushed forward and back in its
cylinder by steam; and by means of the rod to which the piston is secured,
motion is communicated to a crank and fly-wheel, and through these to the
machinery to be driven: it is the same with pressure engines when used to
move other machines, except that instead of the elastic vapor of water, a
column of that liquid drives the pistons to and fro.
Note.—“The hydraulic engine of Huelgoat, in Brittany, is used to drain a mine; is
single-acting, and acts directly to lift the piston of the pump. It makes five and a half
strokes per minute, the stroke being a little more than eight feet in length. The piston-rod is
767 feet long, and it weighs 16 tons. The power of the engine is derived from a source at a
height 370 feet above its own level.”—Knight.

In default of a natural head of sufficient pressure, the head is sometimes
established in an accumulator of power; this is a body of water driven into
a reservoir under heavy pressure, by forcing pumps worked by power. In
cities where the water distribution is from elevated reservoirs, and in which
the water supply is sufficiently abundant to justify the application of a
portion of it to industrial uses, the water-engine or motor is recommended.
The following description of a water engine of world-wide adaptation
will, if attentively studied, show the working of an approved type of this
machine:
Ramsbottom’s hydraulic engine (Figs. 129 and 130), is oscillating, and
employs two cylinders b, l, operating one crank-shaft, a, by means of two
cranks at right angles to each other. In one of the accompanying figures the
channels of induction are marked j and are cast on the cylinders; the dotted
circle c shows the position of the supply and discharge pipes; in the other
figure these pipes are indicated by arrows. The two views are vertical cross-
sections at right angles to each other, one being through the axis of the
cylinders and the other through the middle post in which the inner trunnions
of the cylinders are journaled. The apertures of induction are seen at h and
those of eduction at i, and have the form of truncated circular sectors,
whose center is the center of motion.
The induction and eduction spaces are divided by a sectoral partition; the
apertures of admission and discharge on the sides of the cylinders are of
similar construction. The surfaces of contact between the cylinders b, l and
the support d are planed and polished and are made water-tight by the
adjusting screws m m of the pivots. When the piston p is at the end of its

course in either direction the cylinder and crank are vertical, and the valves
all momentarily closed, the openings by which the channels j j
communicate with the discharge and supply pipes presenting themselves
exactly opposite the solid sectors which separate h from i.
In the next moment the flow of water will recommence, the cylinder
discharging itself from the full side of the piston, and filling anew from the
opposite side. Air chambers and relief-valves are used as a provision against
counter-pressure and hydraulic shocks.
The Brotherhood three-cylinder reciprocating engine is an appliance for
producing rotary motion by water-pressure.
The working parts of the Brotherhood three-cylinder hydraulic engine
consist only of the three pistons and connecting rods, one crank and one
rotating balanced valve and spindle which fits into the driver and is turned
direct from the crank-pin; there are no glands, stuffing boxes, or oscillating
joints.
It is shown by Figs. 131, 132. The three cylinders, A (made in one
casting) are always open at their inner ends, and are attached to a central
chamber, B. They contain three pistons, P, which transmit motion to the
crank-pin through the rods, C. The water is admitted and exhausted by
means of the circular disc valve, V, having a lignum-vitæ seat. The valve is
rotated by the eccentric pin, E. A face view of this valve is shown above the
steam chest. It has segmental ports which, in rotating, pass over apertures in
the valve seat. There being no dead centers, the engine will start from all
positions of the crank-pin, and a uniform motion of the shaft is produced
without a flywheel.
The pressure is always on the outer end of the piston, so that the rods, C,
are in compression, and take up their own wear. This engine is well adapted
for transmitting pressure to appliances which are worked intermittently, as,
owing to the great speed at which it can be run, it will not only save the loss
from friction (where gearing is employed), but will also reduce the friction
in the machine itself by enabling the gearing for increasing speed to be
dispensed with. The production of this simple hydraulic rotary engine led to
its wide application to capstans.

Fig. 133 represents a small hydraulic engine—The Compton Hydraulic
Motor—attached to and operating a gas-compressor. It shows a style of
water motor in large use in connection with city water-mains. A pressure of
15 to 20 lbs. per square inch is sufficient to operate it; the motor here
illustrated occupies a floor space of 9 x 23 inches; it will supply gas burners
to the extent of 6,000 candle-power.

Fig. 133.

The valve motion on the motor is unique in this, the outlets and inlets
have a positive motion by which they are simultaneously opened and closed
by the motion of the piston; this valve motion is designed to overcome the
back pressure; it has a governor, incorporated in the valve-motion for the
purpose of maintaining uniform pressure on the main pipes.

HYDRAULIC PACKINGS.

Generally speaking a packing is a contrivance or a material to close a
joint. Various greasy materials with gaskets, flax, hemp, etc., are used in
joints which are screwed down, also collars of rubber, red lead, luting,
graphite, etc.

A most important part in the practical
working of nearly all water-pressure machines
is the leather collar, the invention of which by
Bramah removed the difficulties which had
been experienced in making the large ram
“U” Packing—Fig. 134. work water-tight when submitted to great
pressure.
It consists of a circular piece of stout leather (see cut page 20), in the
center of which a circular hole is cut. This piece of leather is thoroughly
soaked in water and is pressed into a metallic mould and so that a section of
it represents a reversed U, and is fitted into a groove made in the neck of the
cylinder. This collar being concave downwards, then in proportion as the
pressure increases, the edge nearest the ram being trimmed down, it fits the
more tightly against the ram plunger on one side and the neck of the
cylinder on the other. It should be saturated with Neatsfoot or Castor oil so
as to be impervious to water.
When the least amount of friction possible
is desired in the operating of a hydraulic
plunger, there is no form of packing which can
surpass a properly prepared and applied
Leather “U” Packing (Fig. 134), and in
practice its position is according to conditions,
either in a groove near the upper end of the Cup Packing—Fig. 135.
cylinder, or at the lower end of the ram.
When for any reason it is not desired to use the outer lip of the packing,
the resulting form is known as a Cup Packing, (Fig. 135), and when the
inner lip is used then we have the Hat or Flange Packing. Fig. 136.
When the water pressure is not over 2,000
lbs. to the square inch, and a greater
allowance for friction is not important, a
fibrous packing can be used, which is easier
of application than these for large sized
Flange Packing. Fig. 136.
cylinders.
The loss of power by the best of leather packings is 1 per cent. on 4 in.
ram, 1⁄2 per cent. with 8 in. ram and 1⁄4 per cent. with 16 in. ram.

HYDRAULIC

APPARATUS

HYDRAULIC APPARATUS.
Apparatus is another name for machinery but it also carries the particular
meaning of a complete collection of instruments or devices prepared for a
particular use, hence, hydraulic apparatus may be said to include very
many combinations of machines to utilize the pressure or weight of water.
A number of these devices are illustrated in the succeeding pages. It were
vain to attempt to describe all.
Knight in his Mechanical Dictionary has grouped some six hundred and
seventy five terms and names under the heading of “Hydraulic Engineering
and Devices.” In the note are given some terms, the definition of which the
student may, perhaps, look up; thus: Gyle (the first term given) is a large
cistern or vat. The liquor gyle in a brewery is the water-vat or gyle-tun.
Hydraulic apparatus has been developed mainly from two sources. The
“cut and try” method, which of course was the first and second from
scientific calculations, based upon both the experiments and upon the
mathematics of hydraulics.
It is difficult at this date to say to which procedure the world is the most
indebted, but it is plainly discernable that the two methods have been
necessary as a check upon each other. Untold thousands of practical
experiments and an almost equal number of tables, rules and calculations
have been made. The result has been that out of many failures the point of
economy and efficiency, aimed at, of hydraulic apparatus is well defined.

Note.—Terms relating to hydraulics named by Edward H. Knight, Civil and Mechanical
Engineer, as above. Gyle; Sluice Valve; The Sough; Stade; Worm-safe; Weel; Water-twist;
Water-lute; Water-gilding; Vineficatur; Tun; Tide-lock; Tail-bag; Swash-bank; Sump; Stop-
plank; Sterhydraulic apparatus; Staith; Rip-rap; Quay; Puffer; Psychrometer; Levee; Leam;
Leach; Land tank; Kiddle; Kimelin; Keir; Jetty; Invert Burette; Hydraulic Blower, etc.
Some of these terms go “way back,” and the above are a specimen only of the 675
headings.

Fig. 137.
Section of Claw Type Hydraulic Jack.

HYDRAULIC JACK.

A Lifting-Jack is a contrivance for raising great weights by force from
below; also called a jack-screw. From its derivation from Jack, equivalent
to lad or boy, has arisen its modern use as denoting a contrivance which is
subject to rough usage. It is operated by a screw, whereas—a hydraulic jack
is a jack or lifting apparatus operated by some liquid, usually oil, acting
against a piston or plunger, the pressure on the liquid being produced by a
force pump. The hydraulic jack consists of, 1, a cylinder; 2, a ram or
plunger; and 3, a pump. One of these machines is shown and described in
the Glossary, page 24, another is illustrated by Fig. 138. The Fig. 137 on the
opposite page shows the inside view of Fig. 138 but on a different scale.
The names of the parts are particularly to be noted.
Movable hydraulic, or screw, jacks serve on
numerous occasions most effectively for lifting or
propping-up of less accessible parts. Eye-bolts and
jack-bolts are arranged for, in all parts that are likely to
be handled, to facilitate and accelerate the work in
necessarily crowded quarters.
The base or foot is usually made of cast iron or cast
steel and may be either round or square to suit
requirements. The cylinder is bored from a seamless
steel ingot and having a thread upon its lower end is
screwed into the base.
The ram is also a tube of seamless steel having a
thread at the top and is screwed into the head or cap
which is made either of cast iron or cast steel. The
lower end of the ram has a thread inside to receive the
Fig. 138. pump plug which contains the delivery valve, while
upon its outside is placed the cup leather packing and
the ram packing ring. The pump for operating the ram is from five-eighths
to three-quarters of an inch in diameter depending upon the capacity of the
jack, and has a plunger packed with a cup leather.

A suction valve is contained within the plunger. A short arm is fitted upon
a socket which enters through the side of the head or reservoir. This arm is
connected by a pin to the pump inside the ram while the outer end of the
socket has a tapered rectangular hole through it to receive the jack-lever. A
leather collar packing makes the socket tight where it enters the side of the
reservoir.
To properly use a hydraulic jack. Place the head under the weight to be
raised, be careful to set the jack plumb with a good solid footing; put the
lever into the socket with its projection on the bottom side; work the lever
until the weight has been raised to the desired height or an escape of liquid
blows out of the safety vent. Hold the lever up or raise it to its highest
position and remove it from the socket to prevent the valve from opening.
In lowering insert the lever in the socket with the projection underneath and
then cautiously press it slowly down until it brings up against the stop;
remove the lever and turn it over with the projection on top; insert the lever
in the socket and gently but firmly press it on the end with the right hand
clasping the ram with the fore finger, and thumb of the left hand: thus the
workman has full control of the jack and can lower and stop as frequently
as may be found necessary.
If from any cause the valves stick a few sharp quick strokes of the lever
will usually release it and cause it to work, if not, it should be thoroughly
cleaned.
Before shipping the brass filling screw should always be screwed down
tight, and before using this screw should always be loosened to let the air
out and in.
Note.—A prominent firm making these tools says: “In our Jacks, rams are cut and
cylinders bored from solid high carbon steel. We have nearly 300 styles for pushing,
pulling or lifting.” This shows the wide use to which hydraulic jacks are put; the style
shown in the Glossary with its broad base is to be used when the jack stands upon a light
board on the ground and can be placed under the work, or where steadiness is required.
Fig. 139 shows a style to be used when there is not room enough to get the head of the jack
under the work, and is the style generally used for moving engines, boilers, machinery, etc.

In repairing hydraulic jacks the following points should be carefully
observed; before attempting to repair a hydraulic jack the trouble should be
definitely located, next:

Put the jack under a weight and attempt to raise it, carefully watching its
action. Should the liquid leak out around the lever socket, the gland should
be tightened slightly until this leak disappears. If the packing is worn out
unscrew the set screw at the back of the head about one-quarter inch, then
withdraw the socket not more than one inch, unscrew the gland and put in a
new packing of lamp wick braided and well oiled with mineral oil, which is
free from gum. Afterwards put the socket back to its former place and
tighten the set screw.
When the pump valve leaks the lever can be worked up and down
without raising the ram. This is also true when the plunger packing becomes
worn. If the trouble is found with the valve it can be ground by taking out
the pump plug and unscrewing the brass bonnet which covers the valve.

Fig. 139.

Sometimes the jack will become air bound by reason of the accumulation
of dirt around the filling plug; this must be removed before the jack will
work. Sometimes the liquid will all have been displaced before the ram is
half way up, in this emergency the reservoir must be refilled. It often
happens that when the workman stops working the lever it will persist in
rising to its highest position. This indicates the presence of dirt under the
lower or delivery valve. One or two sharp quick strokes of the lever will
generally dislodge such obstructions; if this does not bring relief the valve
is probably worn so as to need regrinding. When a jack has been taken
apart each part should be thoroughly washed in clean water.
While using, if the liquid escapes over the top of the cylinder the ram
packing is too loose, and may be set out by inserting a strip or strips of tin

or any sheet metal between the leather and the ram packing ring; all leathers
should be kept soft and pliable by saturating with a proper leather dressing
such as Frank Miller’s Leather Preservative or Shoemakers’ Dubbing.
Castor Oil is excellent as well.
One man can exert upon the lever all the pressure that the jack is capable
of raising and this pressure should not exceed 150 lbs. Beyond this the jack
will be strained.
To repack the pump remove the pump plug, and unscrew the set screw in
the head, then withdraw the socket far enough to permit it to revolve clear
of the lug, on the head, which brings the piston head out of the pump.
After the new packing is in place the piston should be worked in and out
a few strokes to see if it is right, then replace the plug.
To fill the reservoir remove the filling screw in the top of the head, and
fill with a mixture of proof alcohol (95 per cent.), two parts and water three
parts for winter use, or for summer use one part alcohol to four parts water.
When not in use the ram in a hydraulic jack should be kept in its lowest
position, that is to say, all the way down, or in, as the case may be.

Important.—Jacks should never be filled with kerosene oil,
water or wood alcohol, for the following reasons: Kerosene oil
destroys the leather packing, water will rust the parts and make
them rough, while wood alcohol attacks the smooth steel surfaces,
and thus destroys both the cylinder and ram. All liquids should be
well strained before putting them into the reservoir and great care
should be exercised to prevent any dirt from getting into this
reservoir.
The Pulling Jack.—The pulling jack, Fig. 139, is used in connection with
travelling cranes over wheel presses, quartering machines, planers, drill
presses and lathes. Its operation is the reverse of lifting jacks.
This Jack has an improved force-pump on the outside, worked by a lever,
which draws the liquid from the upper end and forces it into the space on

the opposite side of the piston. The piston rod has one of the rings attached
at the end.
By this operation the rings are drawn together and with them the body to
be lifted or moved, for it will be understood that this style of jack works
either in a horizontal or vertical position. Hooks are furnished instead of
rings when desired.
The liquid is introduced into a hole in the side of cylinder, care, being
observed to push the piston into the cylinder. The proportions of filling
liquid are proof alcohol two parts and water three parts.
To use this jack extend it as far as it can be pulled apart, first opening the
valve in the side of force-pump. Now close this valve and work the pump
lever.
This jack appeals particularly to the marine engineer, to be attached to the
trolley over the engine for the purpose of raising pistons, rods and lifting
various parts of the machinery.
Horizontal Jack.—The accompanying
engraving, Fig. 140, shows a horizontal
type for pulling armatures on to shafts,
putting in cranks pins, and marine work.
The directions given for the care and
handling of the regular hydraulic jack
apply also to this as well as other devices
of the same description.
This pump has two plungers of
different diameters, the small one inside
of the large, so that by throwing a clutch,
both plungers may work together as one,
or they may be separated, and the smaller
one used; as for example, in starting, the
larger pump is used as far as possible, i.e.,
until the pressure becomes too great for
the large plunger, then the clutch is Fig. 140.
thrown and the smaller one finishes the
work.

The speed of this appliance may be changed to three times greater, and its
power reduced to one-third of the maximum by throwing the clutch which
brings the large plunger into operation. A rack and pinion with handle is
connected with the main ram to cause its return when forced out to its full
length. The size shown in Fig. 140 represents a capacity of 200 tons and its
approximate weight is 1,200 lbs.

Fig. 141.

The Hydraulic Bolt Extractor.—Much harm is done to coupling bolts in
driving them out with a hammer or sledge. The hydraulic bolt extractor
shown in Fig. 141 is an admirable device to do this work without injuring
the bolts or threads. This same apparatus may be used for other purposes as
well as that for which it was designed, as will appear from time to time.
The Hydraulic Punch.—The hydraulic punch has been found of greatest
utility in the erection of steel structures, such as buildings, bridges and ship
building. It consists of a hydraulic jack attached to a “punching bear”
instead of the usual screw to operate the punch. By an ingenious device the
punch can be shoved down close upon the work without pumping all the

way, as in the earlier styles of hydraulic punches; this means a considerable
saving of time and muscle.
The construction and
operation of working parts of
this punch will be easily
understood by referring to the
engraving, Fig. 142 where 18
represents the body or
“punching bear,” 17 the ram, 19
the raising and lowering pinion
to move the ram quickly to its
work; 20 shows the die with
punch in place above it, secured
by its gland; 3 the punch head
cistern, the screwed cover
having a hole in its center to
guide the end 2 of pump
plunger 9, having cup leather
packing 10, at its lower end; 5
represents the lower socket
which carries the arm 4 to
operate the piston 6. The
suction valve 11 is supported by
the spring underneath; 12 is the
safety vent; 13 the release or
lowering valve operated by the
stem 7 which is pushed
downward by the projection of
the piston 6 whenever the lever
is turned and pressed Fig. 142.
downwards as described in
lowering the lifting jacks. The relief valve is kept seated by the spring 14. 8
represents the body of the pump 16 its packing and 15 the ram packing ring.
No. 16 does not move, but the ram 17 does, having a cup leather reversed at
its upper end applied in the same way and manner as 16, with screwed
packing ring. The discharge valve is located behind the pump plunger 9 and
is, therefore, invisible.

A hydraulic punch mounted upon three legs or supports is shown in Fig.
143, and it also has a shackle at its back to suspend the punch in mid air as
occasion requires.

Fig. 143.

The details of this punch are like Fig. 142. It has two guards, one each
side of the punch to pull the material operated upon off the punch as it is
raised by the lower lever. Another very convenient style of hydraulic punch
is shown in Fig. 144 where A represents the body of punch, B the operating
lever with the lowering or adjusting lever shown broken off. The punch
proper is shown at C. The center of gravity of this punch has been so nicely
located that by suspending from the handle the ram hangs plumb.

Fig. 144.

Fig. 145.

THE HYDRAULIC PRESS.

The hydraulic press consists of
1. A Lever,
2. A Pump,
3. and a Ram working in a
4. Cylinder.
Bramah in the year 1796 brought out a very interesting apparatus which
illustrates the law of the equality of pressure which has been widely
adopted in the practical use of the hydraulic press. The principle upon
which this press works is due to Pascal but it remained for Bramah to put it
to practical use. Enormous pressures are developed by operating the hand
lever shown at M in Fig. 145, which is connected with pump plunger P. The
pump barrel A is very thick and receives its supply from the cistern H
through the suction pipe a.

Fig. 146.

Water is delivered from the pump A through a heavy lead pipe into the
cylinder B of the hydraulic press. The ram P is made tight by the leather
packing n and has a table or platform attached to its upper end as shown.
The stationary part Q consists of a heavy cast-iron plate supported by four
wrought-iron or machinery steel columns. By operating the handle M of the

pump any substances placed between the table on the ram P and the plate Q
may be compressed to any reasonable extent.
The pressure which can be obtained by this press depends on the relation
of the ram P to that of the plunger P. If the former has a transverse section
fifty or a hundred times as large as the latter, the upward pressure on the
ram will be fifty or a hundred times that exerted upon the pump plunger. By
means of the lever M an additional advantage is obtained.
If the distance from the fulcrum to the point where the power is applied is
five times the distance from the fulcrum to the plunger P the pressure on it
will be five times the power. Thus, if a man acts on M with a force of sixty
pounds, the force transmitted by the plunger P will be 300 pounds, and the
force which tends to raise the ram will be 3,000, supposing the section of
ram is a hundred times that of the pump plunger.
Over-pressure, is prevented by safety-valve shown in front of the pump
A. Fig. 146 shows an enlarged section of the pump used in connection with
this press. When the plunger P rises a partial vacuum is formed below it and
the suction valve O rises allowing the pump barrel to fill with water through
the strainer and suction pipe in the cistern.
When the plunger descends the valve O closes and the water passes
through the discharge valve h into the pipe K, thence into the cylinder B of
the press where it acts upon the ram. When the press has done its work the
ram may be lowered by opening the relief valve r. The safety valve is
shown at i. By removing the plug h the discharge valve can be reached to
grind it in when necessary.
Note.—Hydraulic Pressure Transmission. Water under high pressure—500 to 3000 lbs.
per square inch and upwards—affords a very satisfactory method of transmitting power to
a distance, especially for the movement of heavy loads at small velocities, as by cranes and
elevators. The system consists usually of one or more pumps capable of developing the
required pressure; 2, accumulators, described on the next page; 3, the distributing pipes,
and 4, the presses, cranes, or other machinery to be operated. This property of fluids
invests us with a power of increasing the intensity of a pressure exerted by a comparatively
small force, without any other limit than that of the strength of the materials of which the
engine itself is constructed. It also enables us with great facility to transmit the motion and
force of one machine to another, in cases where local circumstances preclude the
possibility of instituting any ordinary mechanical connection between the two machines.
Thus, merely by means of water-pipes, the force of a machine may be transmitted to any
distance, and over inequalities of ground, or through any other obstructions.

THE HYDRAULIC ACCUMULATOR.

This useful and indispensable apparatus was designed by Sir William
Armstrong. Its use was to secure a uniform pressure of water in a reservoir
by weight so that however much or little of this water was used the pressure
would remain constant.
In the first accumulator which is still in use the ram
was attached to the foundation while the cylinder rose
and fell as the pressure was utilized. The weights were
annular in shape and were hung upon the outside of
cylinder. In the modern types of accumulators the
cylinder is stationary and the ram supporting the
weights is made to rise and fall.
By means of a hydraulic accumulator a uniform
pressure can be established and maintained on all parts
of a hydraulic main or system.
The volume of water which is
used intermittently for the
purpose of operating presses—
draw-benches for brass and
copper tubing and the like is
replaced by a pump or pumps
which are started and stopped
automatically by a connection PLAN AT BOTTOM.
between the accumulator and the Fig. 148.
throttle or belt shifter of the
pump. The accumulator is used for a double purpose of
maintaining a constant pressure and to store up any
ELEVATION.
surplus force of the pumps. The friction loss in the
Fig. 147.
transmission of power by water through mains is very
small, as for example: It has been found that water under a pressure of 700
lbs. per square inch may be transmitted through well proportioned mains,
one mile with a loss of only two per cent.

The useful work stored in an accumulator may be calculated by the
following rule: Multiply the area of ram in square inches by the length of
the stroke in inches by the pressure m pounds per square inch divided by
33,000 lbs. the equivalent of one H. P.
This represents the work done by one full stroke of the accumulator ram
in descending from its highest position to its lowest.
Example. Required the work done by one stroke of a ram twelve inches
in diameter, and a stroke of twenty-two feet, under a pressure of 750 lbs. to
the square inch. Area of 12 ram = 113·097 square inches. No. of ins. in 22
ft. = 264. Then
113·097 × 264 × 750
————————– = 678·582 H.P.
33,000
Mr. Tweddel designed the accumulator shown in Figs. 147 and 148 to
furnish the varying demand for water where only one appliance of this kind
is used in connection with a hydraulic system of shop tools more especially
where these tools are numerous.
The ram or spindle A is fixed top and bottom and acts as a guide for the
cylinder B which slides up and down upon it.
This cylinder is loaded with weights marked to indicate the pressure
which the accumulator will balance with those weights in use. The water is
pumped into the bottom through the pipe C, and fills the annular space
around the spindle. The entire weight of cylinder is raised by the pressure of
water acting only on the area of the end of brass sleeve D D, which is only
1
⁄2 inch thick all around the center spindle, and extends down through the
bottom packing in cylinder, as shown in sectional view. Fig. 149.
A compact arrangement is thus gained and any reasonable, required
cubical capacity may be reached by lengthening the stroke.
The accumulator is supplied by two pumps having plungers 13⁄8″ diam.
by 31⁄2″ stroke, speed 100 to 120 rev. per minute.
When the loaded cylinder B reaches the top of its stroke, by means of a
small chain it closes the suction cock E, which shuts off the water supply of
the pumps.

To put in a new bottom packing, the cylinder is
let down to rest on the wooden blocks G, and the
spindle is lifted out of its tapered seat at the
bottom by a tackle hooked into the eye-bolt at the
top. To renew the top leather the bracket holding
the top end of spindle A, has to be removed.
This accumulator (having only a small area)
falls quickly when the water is withdrawn, thus
producing a combined blow and squeeze, which is
of great advantage in hydraulic riveting.
The Hydraulic Intensifier is a cylinder having
two diameters, in principle very like the tandem
compound engine. It is used for increasing the
pressure of water in hydraulic mains, pipes, or
machines, using only the energy of the pressure
water to effect the change. But for this distinction
a steam pump would be an intensifier. An
intensifier worked the reverse way is a
“diminisher” as a hydraulic pump usually is,
giving a reduced pressure.
The intensifier is in some respects analogous to
the electric transformer. VERTICAL SECTION.

The intensifier as used in connection with Fig. 149.
hydraulic apparatus was patented in the year 1869
by Mr. Aschroft, but the principle upon which it works is very much older.
Intensifiers are made both single and double acting.
PERCENTAGE OF THE TOTAL AMOUNT OF WATER
TAKEN FROM THE RESERVOIR.
Elevation of discharge above
Height delivery valve of ram in feet.
of fall
15 18 21 24 27
in feet.
Percentage.
2 ·0724 ·0583 ·0402 ·0307 ·0255
3 ·1327 ·1020 ·0807 ·0651 ·0532
4 ·1960 ·1535 ·1234 ·1020 ·0854

5 ·2614 ·2068 ·1686 ·1404 ·1189
6 ·3282 ·2614 ·2146 ·1800 ·1535
7 ·3960 ·3170 ·2614 ·2203 ·1885
8 ·4647 ·3733 ·3090 ·2614 ·2248
9 ·5341 ·4303 ·3572 ·3030 ·2614
10 ·6040 ·4877 ·4058 ·3450 ·2984
11 ·6745 ·5459 ·4549 ·3874 ·3357
12 ·7453 ·6040 ·5043 ·4302 ·3733
13 ·8166 ·6627 ·5540 ·4732 ·4112
14 ·8881 ·7217 ·6040 ·5166 ·4494
15 ·9600 ·7809 ·6543 ·5601 ·4877
16 — ·8404 ·7048 ·6040 ·5263
17 — ·9001 ·7555 ·6480 ·5650
18 — ·9600 ·8064 ·6921 ·6040
19 — — ·8574 ·7364 ·6430
20 — — ·9086 ·7800 ·6823
21 — — ·9600 ·8254 ·7217
22 — — — ·8701 ·7612
23 — — — ·9150 ·8007
24 — — — ·9600 ·8404
Elevation of discharge above
Height delivery valve of ram in feet.
of fall
30 35 40 45 50
in feet.
Percentage.
2 ·0181 ·0112 ·0063 ·0027 —
3 ·0441 ·0326 ·0243 ·0181 ·0132
4 ·0724 ·0560 ·0441 ·0348 ·0281
5 ·1020 ·0807 ·0652 ·0533 ·0441
6 ·1327 ·1063 ·0870 ·0724 ·0608
7 ·1640 ·1327 ·1096 ·0920 ·0782
8 ·1960 ·1595 ·1327 ·1121 ·0960
9 ·2285 ·1868 ·1561 ·1327 ·1142
10 ·2614 ·2145 ·1800 ·1535 ·1327
11 ·2947 ·2425 ·2041 ·1746 ·1514
12 ·3282 ·2708 ·2285 ·1960 ·1704
13 ·3620 ·2994 ·2532 ·2177 ·1896
14 ·3960 ·3282 ·2780 ·2395 ·2090
15 ·4303 ·3572 ·3030 ·2614 ·2285
16 ·4647 ·3863 ·3282 ·2835 ·2482
17 ·4993 ·4157 ·3535 ·3058 ·2680
18 ·5341 ·4451 ·3790 ·3232 ·2380
19 ·5690 ·4746 ·4046 ·3507 ·3081
20 ·6040 ·5042 ·4303 ·3733 ·3282
21 ·6392 ·5340 ·4561 ·3960 ·3486
22 ·6745 ·5640 ·4820 ·4188 ·3688

23 ·7098 ·5940 ·5080 ·4417 ·3892
24 ·7433 ·6241 ·5341 ·4657 ·4097
Elevation of discharge above
Height delivery valve of ram in feet.
of fall
60 70 80 90 100
in feet.
Percentage.
2 — — — — —
3 ·0063 ·0017 — — —
4 ·0180 ·0112 ·0063 ·0027 —
5 ·0307 ·0217 ·0150 ·0099 ·0063
6 ·0441 ·0325 ·0243 ·0180 ·0132
7 ·0580 ·0441 ·0340 ·0264 ·0205
8 ·0724 ·0560 ·0441 ·0351 ·0281
9 ·0870 ·0682 ·0545 ·0441 ·0360
10 ·1020 ·0807 ·0651 ·0533 ·0441
11 ·1172 ·0934 ·0760 ·0627 ·0524
12 ·1327 ·1063 ·0870 ·0723 ·0608
13 ·1483 ·1194 ·0983 ·0821 ·0694
14 ·1640 ·1327 ·1096 ·0920 ·0782
15 ·1800 ·1460 ·1211 ·1020 ·0870
16 ·1960 ·1595 ·1327 ·1121 ·0960
17 ·2123 ·1731 ·1444 ·1223 ·1050
18 ·2286 ·1868 ·1561 ·1327 ·1142
19 ·2449 ·2006 ·1680 ·1430 ·1262
20 ·2614 ·2145 ·1800 ·1535 ·1327
21 ·2780 ·2286 ·1920 ·1640 ·1420
22 ·2947 ·2425 ·2041 ·1746 ·1514
23 ·3114 ·2567 ·2163 ·1853 ·1609
24 ·3282 ·2708 ·2185 ·1960 ·1704

For explanation of these tables see page 177.

HYDRAULIC RAM.

A hydraulic ram or water-ram is a substitute for a pump for raising water
by means of the energy of the moving water, of which a portion is to be
raised. It was considered a notable discovery when it was demonstrated by
Daniel Bernovilli, in the beginning of the 18th century, that water flowing
through a pipe, and arriving at a part in which the pipe is suddenly
contracted, would have its velocity at first very greatly increased.
The hydraulic ram owes its efficacy to the fact that when a flow of water
in a pipe is suddenly stopped, a considerable force is generated by the
momentum of the water, by its change from a state of motion to a state of
rest. In practice, the pipe conveying water from the reservoir or head,
connects with a chamber which has a valve opening downward, or outlet
valve, allowing the current of water to pass on or escape when the valve is
open; but on flowing the current in the pipe acquires sufficient force to
close this valve, which checks the flow in the pipe.
The current is thus suddenly stopped; this causes a reaction, which
produces pressure sufficient to open another valve (inlet valve) between the
current-pipe and an air chamber, and a portion of water enters by means of
the force of the current, but by so doing the current has spent its force; the
outlet valve at the end of the chamber falls by its own weight, and the
pressure in the pipe ceasing, the inlet valve in the air-chamber falls and
closes the opening. The condition of things is then restored; the water then
acquires a momentum which closes the outlet valve and forces more water
again into the chamber. A very slight descending column is capable of
raising one ascending very high. In all cases the drive-pipe or inlet pipe
must be sufficiently long to prevent water being forced back into the
reservoir. The air-chamber serves to keep up a steady supply from the
reservoir, preventing spasmodic action. To prevent admixture of air with the
water in the air chamber, which is caused by pressure of water when raised
to a great height, a small hole should be made on the upper side of the inlet
pipe, immediately in front of the same. By the action of the ram at each
stroke, a partial vacuum is formed below the air chamber, and the air
rushing through the small hole in the inlet pipe, passes into the air chamber,
making good that which the water absorbs.

Note.—In 1797 Matthew Boulton (manufacturer and practical engineer, and in later life
a partner of Jas. Watt, the Father of the steam engine) obtained a patent for a mode of
raising water by impulse. The apparatus had excited much attention in France, under the
name of Montgolfier’s hydraulic ram, and Boulton added to it a number of ingenious
modifications, which were the basis of his patent.

Fig. 150 shows in
section the construction
of the ram in its
simplest form in which
E is the reservoir, A the
pipe in which the water
falls, B the channel, a
and b the valves, C the
air-chamber, and D the
discharge. Water first
Fig. 150. flows out in quantity
through the valve a,
and as soon as it has acquired a certain velocity it raises that valve, closing
the aperture. The impact thus produced, acting on the sides of the pipe and
the valve b, raises this valve, and a quantity of water passes into the air-
chamber shutting off air and compressing it in the space above the mouth d
of the discharge D. This air by its electric force closes the valve b, and the
water which has entered is raised in the discharge D.
As soon as the impulsive action is over, and the water in the channel A
comes to rest, the valve a again falls by its own weight, the flow begins
afresh, and when it has acquired sufficient velocity the valve b again closes,
and the whole process is repeated.
The efficiency of hydraulic rams has been much discussed; exhaustive
practical tests have been made and the results have been reduced to
formulas. Whittaker’s Mechanical Engineer’s Pocket Book gives the
following:
G×H
E = ——–
g×h

where E = the efficiency;
G = gallons of drive water used;

g = gallons of water raised;
H = height of fall, in feet;
h = height to which the water is raised, in feet.
The Table given on page 174 is from the American Engineer. Its use is
apparent, thus: when the height of fall in feet is, say 12 feet, and the
elevation of discharge above the delivery valve of ram, in feet, is 30 feet,
the efficiency or per cent., is ·3282. (Example) of 100 gallons 3282⁄100
gallons would be delivered.
The double hydraulic ram is shown in Fig.
151. A sectional view of the same device is
shown in Fig. 152, the cuts represent the Rife
hydraulic engine, or ram,—a so-called double
acting or double supply type of the water ram. It
is more clearly described by considering it, first,
as a single machine by disregarding its double
supply feature.
First, suppose the opening at H, Fig. 152, to
be closed, the valve B being open, the water
from the source of supply from more or less
elevation above the machine flows down the
drive pipe, A, and escapes through the opening
at B until the pressure due to the increasing
velocity of the water is sufficient to close the
Fig. 151. valve, B. When the flow through this valve
ceases, the inertia of the moving column of
water produces a reaction, called the ramming stroke, which opens the
valve at C, and compresses the air in the air chamber, D, until the pressure
of the air plus the pressure due to the head of the water in the main, is
sufficient to overcome the inertia of the moving column of water in the
drive pipe. This motion may be likened to the oscillation of water in a U
shaped tube. The instant the column of water in the drive pipe comes to rest,
and the air pressure being greater than the static head alone, the motion of
the moving column is reversed, and the valve, C, closes. The water in the
drive pipe then moves backward, and with the closing of valve C a partial
vacuum is formed at the base of the drive pipe. This negative pressure

causes the valve, B, to open again, and completes the cycle of operations. At
the moment negative pressure appears the little snifting valve, E, admits a
small quantity of air, and at the following stroke this air rises into the air
chamber D, which would otherwise gradually fill with water, or the air is
gradually absorbed by the water.
In this machine the valve, B, is made as light as is consistent with the
necessary strength, and the negative pressure at the completion of the stroke
opens the valve. In the largest size of these machines this valve is 18 inches
in diameter, with a head of 8 feet, which is a common head for use with
hydraulic rams; the static pressure on the under side of this valve is 883
pounds; it is seen that so great a shock in a valve of this weight would
rapidly destroy both valve and seat.
The waste in a mechanism
of the Rife engine consists of
a large port with ample
opening and a large rubber
valve or overflow with a
balance counterweight and
spring seat, which removes
almost entirely the jar of
closing. The valve, C, in the
air chamber consists of a Fig. 152.
rubber disc with gridiron
ports and convex seats fastened at the center and lips around its
circumference. The object of this arrangement is to transfer the shock from
the power of the driving water to the air cushion with the smallest possible
friction and vibration.
After the valve, C, closes, the pressure in the air chamber forces the
water in the air chamber out into the delivery pipes. The Rife engine is
claimed to elevate water 30 feet for each foot of fall in the driving head; the
machine is built in sizes to elevate as much as 150,000 gallons per day, the
efficiency being about 82 per cent.
When a water supply pipe is attached to H, the engine is called double
acting; spring water, or that which is purer than the water used to drive the
engine, may then be supplied through the supplemental drive pipe I, and by

a proper adjustment of the relative flow of the impure driving water, and
that of the pure supply, the engine may be made to deliver only the pure
water into the mains. This method is employed where the supply of pure
water is limited.
The most important detail in which the Rife engine differs from the
ordinary hydraulic ram is the waste valve. It will be seen in the engraving
that the counterweight on the projecting arm of this valve permits the
adjustment of this valve to suit varying heads and lengths of drive pipe. By
adjusting the counterweight so that the valve is nearly balanced, the valve
comes to its seat very quickly after the flow past it begins. The result is that
the ram makes a great number of short, quick strokes, which are much
easier on the valves and seats than slower and heavier strokes. The stroke
must be sufficiently powerful to act efficiently in overcoming the head in
the delivery pipe. The adjustable weight permits this to be effected with
great nicety.
Note.—The engine illustrated weighs approximately 2,800 pounds; the capacity of the
air chamber is 203⁄4 cubic feet; diameter of drive pipe, 8 inches; diameter of the waste
valve, 18 inches; weight of waste valve, 50 pounds; diameter of delivery pipe, 4 inches;
height to top of air chamber, 71⁄2 feet.

Lifts and Cranes. These, as hydraulic machines, are adapted to very many
places where other power apparatus is too slow; they operate on the same
principle as the hydraulic press; having a cylinder and a ram: they have
chain wheels attached to the outer end of the ram, as shown in the
illustration.

As the ram advances the chain is shortened and when it recedes the chain
is lengthened, thus, the weight attached to the end of the chain is raised and
lowered. The hydraulic “lift” in passenger elevators operates upon the same
principle and this gives an idea of the rapid motion capable of being
imparted to the load. It is by the adaptation of hydraulic lifts and cranes in
steel mills that such economical results have been attained.

PUMPS AS HYDRAULIC APPARATUS.

In Figs. 153 and 154 are shown representations of certain apparatus, long
used in schools, to explain the rather obscure operation, of even the
simplest of pumps; these models are made of glass so that all the
movements of the valves, etc., may be clearly noted. Credit is due to
Monsieur Ganot, author of Elements of Physics, for the following.
Fig. 153 represents a model of a suction-pump such as is used in lectures,
but which has essentially the same arrangement as the pumps in common
use. It consists, 1st, of a glass cylinder, B, at the bottom of which is a valve,
S, opening upwards; 2nd, of a suction-tube, A, which dips into the reservoir
from which water is to be raised; 3rd, of a piston, which is moved up and
down by a rod worked by a handle, P. The piston has a hole in its center;
this upper aperture is closed by a valve, O opening upwards.
When the piston rises from the bottom of the cylinder B, a vacuum is
produced below, and the valve O is kept closed by the atmospheric
pressure, while the air in the pipe A, in consequence of its elasticity, raises
the valve S, and part of it passes into the cylinder. The air being thus
rarefied, water rises in the pipe until the pressure of the liquid column,
together with the pressure of the rarefied air which remains in the tube,
counterbalances the pressure of the atmosphere on the water in the
reservoir.
When the piston descends, the valve S closes by its own weight, and
prevents the return of the air from the cylinder into the tube A. The air
compressed by the piston opens the valve O, and escapes into the
atmosphere by the pipe C. With a second stroke, the same series of
phenomena is produced, until after a few strokes the water reaches the
cylinder. The effect is now somewhat modified; during the descent of the
piston the valve S closes, and the water raises the valve O, and passes above
the piston by which it is lifted into the upper reservoir D. There is now no
more air in the pump, and the water forced by the atmospheric pressure
rises with the piston, provided that when it is at the summit of its course it is
not more than 34 feet above the level of the water into which the tube A
dips.

In practice the height of the tube
A does not exceed 26 to 28 feet; for
although the atmospheric pressure
can support a higher column, the
vacuum produced in the barrel is
not perfect, owing to the fact that
the piston does not fit exactly on the
bottom of the barrel. But when the
water has passed the piston, it is the
ascending force of the latter which
raises it, and the height to which it
can be brought depends on the
power which works the piston.
The action of this pump, a model
of which is represented in Fig. 154,
depends both on exhaustion and on
pressure. At the base of the barrel,
where it is connected with the tube
A, there is a valve, S, which opens
upwards. Another valve, O, opening
in the same direction, closes the
aperture of a conduit, which
discharges from a hole, o, near the
valve S, into a vessel, M, which is
Fig. 153. called the air-chamber. From this
chamber there is another tube, D,
up which the water is forced.
At each ascent of the piston B, which is solid, the water rises through the
tube A into the barrel. When the piston sinks the valve S closes, the water is
forced through the valve O into the reservoir M, and thence into the tube D.
The height to which it can be elevated in this tube depends solely on the
motive power which works the pump.
If the tube D were a prolongation of the tube Jao, the flow would be
intermittent; it would take place when the piston descended, and would
cease as soon as it ascended. But between these motions there is an interval,
which, by means of the air in the reservoir M, ensures a continuous flow.

The water forced into the
reservoir M separates into
two parts, one of which,
rising in D, presses on the
water in the reservoir by its
weight; while the other, by
virtue of this pressure, rises
in the reservoir above the
lower orifice of the tube D,
compressing the air above.
Consequently, when the
piston ascends, it no longer
forces the water into M, the
air of the reservoir, by the
pressure it has received,
reacts on the liquid, and
raises it in the tube D, until
the piston again descends, so
that the jet is continuous.

Fig. 154. Hydraulic Machine Tools.
Probably in no department of
engineering has the use of hydraulic power met with more success than in
its application to certain machine tools. This success is owing to the
peculiar suitability of pressure—water as the motive agent for the
performance of a certain class of operations requiring the exertion of a great
force with comparative slow motion, as in punching, riveting, forging and
the like.
The wide spread and successful use of hydraulic machines—of which a
few only have been described and illustrated upon the pages of this book—
is due to the necessity for such tools and the inventive ability of our tool
designers.
A large fixed hydraulic riveter is shown in Fig. below; it is capable of
exerting on the rivet a pressure of 40 tons or more; the machine has a
working pressure of 1,500 pounds per square inch. Working pressures of
5,000 to 10,000 pounds per square inch are used in hydraulic forging
presses, but in the riveter much less pressure is required.

Note.—The proportions of this machine are immense. The platform weighs 22,500 lbs.
and is operated by a single lever shown in the side view. The “gap” is 8 feet across. The
machine has a large steel “stake” carrying the stationary die; this is held in tension strain by
the two steel bolts shown, one upon each side of the machine. The other part of the jaw is
cast iron.

CLASSIFICATION

OF PUMPS

Fig. 155.—The Bellows Pump.

CLASSIFICATION OF PUMPS AND PUMPING
ENGINES.
The simplest division of the subject matter relating to this branch of
practical mechanics is that which goes back to the very earliest of times; it
is thus:
1. Hand Pumps.
2. Power Pumps.
The names indicate the dividing line between the two. The following are
more modern divisions, indicating the method of action distinguishing each:
1. Suction or Lift Pumps.
2. Force Pumps.
3. Suction and Force Pumps.
These again may be reciprocating or rotary. The powers actuating pumps
are, in the main, as follows:
1. Manual.
2. Animal.
3. Belts.
4. Water.
5. Wind.
6. Steam.
7. Gas.
8. Electricity.
These various motors give distinct names to general classes, thus, electric
pumps, belt pumps, elevator pumps, etc. A sub-division of titles indicating
differences in construction are these:
1. Vertical Pumps.
2. Horizontal Pumps, or again
1. Single Acting Pumps.
2. Double Acting Pumps.

The list is still further extended, as pumps vary in design to suit their
several uses, and are defined as rope, chain, diaphragm, jet, centrifugal,
rotary, oscillating, cylinder. It is with the last named with which this volume
has principally to deal; cylinder pumps cause the last given classification, as
they are either single or double acting.
A single acting pump does its work through one end of the cylinder or
barrel of the pump.
In double acting pumps the motion of the piston in one direction causes
an inflow of water, and a discharge at the same time, in the other; and on
the return stroke this action is renewed as the discharge end alternately
becomes the suction end; the pump is thus double acting.
Finally pumps may be classified with reference to particular uses to
which they are specifically adapted by their form and the materials they are
required to handle.
Pumps now raise, convey and deliver beer, molasses, acids, oils, and
melted asphalt. They also handle such gases as air, ammonia, lighting gas
and even oxygen.
In the orderly progress of the contents of the volume, it will be seen that
the main subject, occupying many pages with illustrations, is that relating to
“Steam pumps;” those having a steam-end and a water-end and which
consist of pump and steam-motor combined. An interesting class under
Vacuum-pumps will be found, 1, the combined vacuum and feed; 2, the
combined vacuum and circulating and, 3, the combined vacuum and
refrigerating pumps.
Under Pumping Engines and the Steam Fire Engine will be found a
description of the most brilliant and fascinating of modern scientific and
mechanical achievements; these two sections relate to hydraulic
engineering in its highest development.

HAND PUMPS.

The theoretical action of a pump has already been described and
illustrated;—the practical operation is described in the note below. The
subject is important enough to justify the space it takes to present these two
descriptions of the action of a pump.
The parts of which a pump is composed are: 1, the
barrel or cylinder; 2, the plunger or piston; 3, the
valves; 4, the pipes.
The barrel of a modern pump is a tube of metal
having a water tight plunger or piston which moves
freely up and down at the pleasure of the operator.
This plunger is in its simplest form made of cast iron
in two parts. The upper part consists of an arched part
having a hole in its center to receive a bolt which
passes through it and a jaw on the lower end of the
pitman or connecting rod. The upper end of this
pitman is attached to the pump handle by means of a
bolt. The inside of the upper part of the plunger is
Fig. 156. threaded to receive the lower part with a cup leather
packing and contains a valve of metal having a conical
seat. Fig. 156 shows a design of a pump in common use in the 14th century.
Note.—The action of a pump is as follows: The piston or plunger by moving to one end,
or out of the pump cylinder, leaves the space it occupied, or passed through, to be filled by
something. As there is little or no air therein a partial vacuum is formed unless the supply
to the pump is of sufficient force to follow the piston or plunger of its own accord. If this is
not the case, however, as it is when the water level from which the pump obtains its supply
is below the pump itself, there being a partial vacuum produced, the atmospheric pressure
forces the water into the space displaced by the plunger or piston, continuing its flow until
the end of stroke is reached.
The water then ceases to flow in, and the suction valve of the pump closes, forbidding
the water flowing back the route it came. The piston or plunger then begins to return into
the space it has just vacated, and which has become filled with water, and immediately
meets with a resistance which would be insurmountable were the water not allowed to go
somewhere. (See next page.)
Its only egress is by raising the discharge valve by its own pressure, and passing out
through it. This discharge valve is in a pipe leading to the boiler, and in going out of the
cylinder by that route the water must overcome boiler pressure and its own friction along

the passages. Water is inert and cannot act of itself; so it must derive this power to flow
into the feed pipe and boiler from the steam acting upon the steam piston of the pump. The
steam piston and pump piston are at the two ends of the same rod. Therefore the steam
pressure exerted upon the steam piston will be exerted upon the pump piston direct.

Between the upper and lower parts of the plunger a cup leather is
introduced before these parts are screwed together. This cup leather, while it
allows the plunger to move freely, also makes a water-tight joint.
The lower valve consists of a piece of cast-iron flat on the bottom and
circular in shape about three-eighths inch thick with a curved toe at one
side. This iron disc is secured to the flat leather valve by a screw that passes
through the valve and is threaded in the disc.

Fig. 157.

The object of this toe upon the disc is to open the lower valve by means
of raising the pump handle as far as it will go which lowers the plunger
upon the toe and tips the lower valve upon its seat. This same operation also
lifts the valve in the plunger off its seat, so that all the water in the barrel
drains back into the well so the pump is kept from freezing up in winter.
The leather which forms the lower valve is held in place by clamping the
pump barrel upon it, so that it is held between the barrel and the base plate.
Hand pumps are primarily divided into: 1, suction or lift pumps; 2, force
pumps, and 3, suction and forcing pumps; 4, also pumps for exhausting air

from vessels.
Of the first class, the common single-acting
house-pumps shown in Figs. 157 and 158 are
examples; the pumps are simply modifications
of the suction-pump; a common form of lift-
pump has a pitman-rod which pushes the water
up instead of lifting it through a spout at or near
the top of the cylinder.
The details of the suction-pump are as follows
—at the bottom of the cylinder is a pipe
communicating with the liquid to be raised, and
a valve which opens from beneath. A similar
valve is placed in the piston.
A force-pump is shown in Fig. 159; from the
two figures the difference between the lift and Fig. 158.
the force-pump may be understood; while the
former raises the liquid above its piston from which it flows under no
pressure, the latter forces it out of the barrel under a varying pressure which
depends upon circumstances. When the piston rises the suction valve opens,
and the valve in the piston closes by the air-pressure. The liquid then enters
the barrel beneath the piston. On the descending stroke the suction valve
closes, and the liquid flows upward into the discharge pipe.
In Fig. 160 is shown an air-chamber attached to a force-pump for the
purpose of preventing shocks in the discharge, and for producing a steady
flow; air-chambers are also frequently attached to suction pipes for a similar
purpose.
According to the underlying principles of action thus far explained
hundreds of thousands of pumps have been constructed and operated. It is
beyond the limits of this volume—or any single book to give the names and
details of these so-called “hand-pumps,” however, three approved styles are
shown in Figs. 161, 162, 163.
Fig. 161 represents a double acting force pump used extensively on ship-
board, wharves, around factories, mills, etc., and in residences, for tank
pumping. On ships these pumps perform the three-fold purpose of filling

boilers when cold, washing down decks and to satisfy
government inspection as to fire protection; in service
in mines they are unaffected by mine water, the
working parts being made non-corrosive. It is claimed
that a three-inch diameter cylinder with a stroke of
four and a half inches with a 11⁄4-inch suction pipe and
1-inch discharge pipe will lift and force water 150 ft.
high and has a capacity of ·28 gallons for each stroke,
with the water not more than twenty-five feet below
the pump.

Fig. 159.

Fig. 160.

Fig. 162 represents a two cylinder force pump; this has vertical single
acting pistons actuated by one lever, producing the same results as a double-
acting pump. It is claimed that the total lift and force, from supply to point
of delivery, with the pump not more than twenty-five feet above water will
attain one hundred feet; that a 3-inch × 4 inch cylinder, 11⁄2-inch suction
and 11⁄4-inch discharge will deliver ·24 gallons of water for each stroke.
Fig. 163 represents a widely used type of suction pump, it is designed for
vessels of not more than fifteen to twenty feet deep; for contractors who
wish to pump large quantities of water from excavations, etc.; for irrigation
or any other purpose where a compact and capacious pump is desired.
The lever may be worked from three different points as shown by lugs on
the illustration. The lever socket is made at such an angle that the bent
wrought iron lever when put in one side up, is right for ordinary pumping
and by simply changing it the other side up, it becomes a vertical lever. The

valves are accessible and removable by hand from above. It is claimed that
with 81⁄2-in. diameter cylinder and 6-in. stroke that the capacity is 147⁄100
gallons for each stroke, with 20 feet lift—the suction pipe being 3-in. in
diameter.
In the illustrations (Figs. 161 and 162)
it will be noticed that the discharge is
conveniently arranged to receive either
fire hose, or iron pipe connections for
other uses, as in mines and on ship-board.
Being made in large factories, there are
immense numbers in world-wide use;
every detail of these pumps is carefully
considered; the sizes manufactured range
from 2 inches to 6 inches diameter of
cylinders, with strokes 4, 41⁄2 and 5
inches.
The capacity of each pump is also
given in the published lists by the makers;
this is given under the heading “Capacity
per Revolution” with the added
information as to the best sizes to be used
for the suction and discharge pipes.

Fig. 161.

Fig. 162.

Note.—It were well for the student to know that in case of breakage or worn out parts of
an otherwise serviceable apparatus that the makers have provided for their repairs as will
be indicated by the following taken from the catalogue of a well known manufacturer. “In
the following lists will be found descriptions of pieces for all the staple pumps, which will
prove of decided convenience. In this connection we desire to impress most emphatically
on the minds of dealers that the threads are cut to exact and accurate gauges; all holes in
flanges, etc., drilled to templets; all castings made from exact metal patterns, similar parts
being always the same. Therefore, repairs will invariably take the place of the broken
parts.”

Fig. 163 represents a Pitcher Spout Pump, of large size for contractors,
and Fig. 164 the parts of a common house pump. The two figures show
pumps substantially the same.

The smallest size “listed” of this pump
has a cylinder diameter of 21⁄2 inches,
fitted with 11⁄4 in. pipe and it has a
capacity of ·09 gal. per stroke and it takes
more than eleven strokes to pump a single
gallon. With a cylinder 41⁄2 inches, with
pipe 11⁄2 in. diam., the pump has a
capacity of ·34 gal. per stroke.
The
engraving 164
shows a
pitcher pump
dissected, in
which A
represents the
Fig. 163. lever or
handle, B the
plunger which contains the discharge valve and
is made tight by a cup leather packing, C is the
fulcrum for the lever, D the barrel or cylinder, E
the lower or suction valve, F the base which
supports the pump. The leather which forms the
valve E also makes the joint between the
cylinder and the base.
Fig. 165 represents a Two-Cylinder Suction
and Force Pump arranged with extension levers.
When these levers are put in place, they afford
room for a large force of men to work, renders
this pump a most powerful engine for throwing
water on fires, or supplying it for many uses Fig. 164.
about factories, warehouses, wharves, etc.
The discharge hose can be fitted both ends for wrought-iron pipe or either
end for hose. The Table below gives the makers’ numbers, the diameter of
the cylinders, etc., and also distance to which the water can be lifted or
forced.

Fig. 165.

TABLE OF SIZES, CAPACITIES, ETC.
Diameter Capacity *Lift and
No. Stroke Discharge Suction
Cylinder per Rev. Force
4 3 in. 61⁄2 in. ·40 gal. 11⁄4 hose in. 11⁄2 pipe in. 100 ft.
6 31⁄2 „ 61⁄2 „ ·54 „ 11⁄2 „ 2 „ 75 „
8 4 „ 8 „ ·87 „ 2 „ 21⁄2 „ 75 „
10 41⁄2 „ 8 „ 1·10 „ 2 „ 21⁄2 „ 75 „
12 5 „ 8 „ 1·36 „ 2 „ 21⁄2 „ 75 „
16 6 „ 7 „ 1·96 „ 21⁄2 „ 4 „ 50 „

* Total lift and force from supply to point of delivery, Pump not more
than 25 feet above water.
Fig. 166 represents a hand, rotary force pump provided with a balance
wheel. A sectional view of this pump is given in Fig. 167; these pumps are
adapted for almost any place or purpose where lift or force pumps can be
used, they can be moved to any place where water is within suction distance
and immediately operated.

The provision of a foot valve at the end
of the suction pipe will keep it always
filled.
In the rotary pump there are no pistons.
As will be seen in the Fig. 167, there are
two pinions of extremely coarse pitch
meshing into one another with neat fit in
the case; the joints become practically air-
tight by the water which surrounds them
and passes through the case.
Both
pinions are
supported by a
journal at each
end, the shaft
of one being
extended to
Fig. 167. receive a
pulley or hand Fig. 166.
wheel as shown in Fig. 166, hence, one
pinion causes the other to revolve. The teeth on the bottom side of the
pinions move away from each other and form a partial vacuum which the
water fills and is carried around between the teeth of the pinions on
opposite sides and is discharged through a central opening in the case at the
top, thence through the discharge pipe into the tank or reservoir.
In the small sizes of the rotary pump there is no trouble from leakage,
until the parts become much worn.
Bag Pump. This is a form of bellows-pump in which the valve disc A,
which takes the place of the bucket, is connected with the base of the barrel
by an elastic bag distended at intervals by rings. This bag may be made of
leather or of double canvas. The upper end of the bag should be firmly tied
with a cord in a groove gouged out of the rim of the board at A. Into this
board is fixed the fork of the piston rod, and the bag is kept distended by a
number of wooden hoops or rings of wire, fixed to it at a few inches
distance from one another, and kept at equal distances by three or four cords

binding them together and stretching from the top to the
bottom of the bag. Now let this trunk be immersed in the
water: it is evident that if the bag be stretched from the
compressed form which its own weight will give it by
drawing up the piston rod, its capacity will be enlarged, the
valve A will be shut by its own weight, the air in the bag will
be rarefied, and the atmosphere will press the water into the
bag. When the rod is thrust down again, the water will come
out at the valve A, and fill part of the trunk. A repetition of
the operation will have a similar effect; the trunk will be
filled, and the water will at last be discharged at the spout.
Fig. 168. Bellows-pump
(Page 186). This is
an atmospheric pump in which the
part of the piston is played by the
top leaf of the bellows. A very
simple method of describing an
invention, from which great good in
drainage of waste lands in Europe,
was realized. “There was of course
a valve covering the interior orifice
of the nozzle and opening outwards,
to prevent the air from entering
when the upper board was raised.
This valve is not shown because the
art of representing the interior of
machines by section, was not then
understood, or not practiced. The
lower board is fastened to the
Fig. 169.
ground by a platform while the
suction pipe dips into the water. A weight is placed on the upper board to
assist in expelling the water.”
Fig. 169 represents a Double Lantern Bellows-Pump as used in the 16th
century. This engraving is plain and requires no description. Fig. 170 shows
a diaphragm pump in which a sheet of rubber or its equivalent is used as a
substitute for a piston in a cylinder.

Note.—When an ox or a horse plunges
his mouth into a stream, he dilates his
chest and the atmosphere forces the liquid
up into his stomach precisely as up the
pipe of a pump. It is indeed in imitation of
these natural pumps that water is raised in
artificial ones. The thorax is the pump; the
muscular energy of the animal, the power
that works it; the throat is the pipe, the
lower orifice of which is the mouth, and
which he must necessarily insert into the
liquid he thus pumps into his stomach. The
capacious chest of the tall camel, or of the
still taller cameleopard or giraffe, whose
head sometimes moves twenty feet from
the ground, is a large bellows-pump which
raises water through the long channel or
pipe in his neck. The elephant by a similar
pneumatic apparatus, elevates the liquid
through that flexible “suction pipe,” his
proboscis; and those nimble engineers, the
common house-flies, raise it through their
minikin trunks in the manner of the
gigantic animals which in remote ages
roamed over this planet, and which
quenched their thirst as the ox does. There
Fig. 170. could have been none which stood so high
as to have their stomachs thirty feet above
the water they thus raised into them.

Rope Pump. This machine consists of one or more endless ropes, all
stretched on two pulleys as shown in Figs. 171 and 172. These pulleys have
grooves formed in their surfaces for the reception of the ropes. A rapid
rotary motion is communicated to the upper pulley, by a multiplying wheel,
and the ascending side of each rope carries up the water absorbed by it, and
which is separated from it while passing over the upper pulley, partly by
centrifugal force, and partly by being squeezed in the deep groove.
In the beginning of the motion, the column of water adhering to the rope,
is always less than when it has been worked for some time, and continues to
increase till the surrounding air partakes of its motion. By the utmost efforts
of a man, nine gallons of water were raised by one of these machines from a
well, ninety-five feet deep, in one minute. (Adam’s Philos.)
The hydraulic belt is a similar contrivance. It is an endless double band
of woolen cloth, passing over two rollers, not here shown. It is driven with a

velocity of not less than a
thousand feet per minute; when
the water contained between the
two surfaces is carried up and
discharged as it passes over the
upper roller, by the pressure of
the band. Some machines of this
kind are stated to have produced
an effect equal to seventy-five
per cent. of the power expended,
while that of ordinary pumps
seldom exceeds sixty per cent.
(Lon. Mechan. Mag.)
Spray Pump. Fig. 173 exhibits
a carefully designed pump made
to spray trees, plants, etc. All the
working parts are of brass, the
valves are metal; the air chamber
Fig. 171.
is made of galvanized iron or Fig. 172.
copper and has large capacity. It
will hold sufficient compressed air to keep the spray going from six to ten
minutes after the pumping stops. The “agitators” are placed so that they
keep the liquid thoroughly stirred. The plungers can be easily removed and
packed without the necessity of taking the pump to a shop.
The pump is fastened to the bottom of the barrel by a bolt passing
through the barrel and secured by a nut underneath, with packing to prevent
leakage, and by an iron plate at the top covering the opening through which
the pump is placed in the barrel. This pump is arranged with one, or two
levers, and for one or two lines of discharge hose. The cylinders are 21⁄2
inches diameter with stroke 3 inches; its capacity per stroke is 0·13 gal.
Combined Pump and Horse Power. The “horse power” (apparatus) with
its “pole” for one horse and two poles for two horses and its wrought iron
“tumbling shaft” has been so modified that a horse operates the pump, by
means of a “sweep,” direct connected to the pump crank shaft.

The animal will make three to
four circuits per minute, giving the
pump crank shaft a speed of 40 to
50 revolutions per minute. The
capacity of a 4 in. plunger and 8 in.
stroke is given as 3·120 gallons per
hour; the suction pipe is given as
31⁄2 in. diam. and the discharge as 3
in. pipe.

Fig. 173.

DRIVEN OR TUBE WELLS.

Aside from the wells described on page 45
and those following it, there are wells made
by forcing iron tubing down into the earth
until a water supply is reached. Within
reasonable distances and in a remarkably
large proportion, these pipe wells are directly
connected with the suction part of hand
pumps.
Note.—“When a well fails to yield a fair amount of oil
or water, an increase in the flow is often effected by means
of the Roberts torpedo. This is a thin water-tight cylinder of
metal or paper, 4 to 6 ft. long and 2 or 3 in. in diameter,
charged with powder, gun-cotton or nitro-glycerine. It is
lowered to the bottom of the well, or to a depth that will
bring it opposite the desired stratum, and the well is then
flooded. The charge is exploded by a cap or electric spark,
and the explosion often clears away the obstruction from
the oil or water vein. This applies particularly to deep
wells.”

To this class also belong the famous oil
Fig. 175. and artesian wells which penetrate through Fig. 175-A.
earth and rock thousands of feet, many of
them operated by power pumping machines.
The process of driving tube-wells resembles
pile-driving, but with this distinction, that while
piles receive the blows of the “monkey” on their
Fig. 176. heads, the tubes are not struck at all, the blow
Fig. 177. being communicated by the clamp, which
receives the blow near the ground. The tube-
well, as in ordinary use, is not intended for piercing rock or solid
formations, but is quite capable of penetrating very hard and compact soils,
and can be also successfully driven through chalk, breaking through the
flints which may obstruct its passage downward. When solid masses of rock
or stone are reached, special means of drilling have to be provided for it.
When coming upon rock or stone, the best plan is to pull up the tube and try

in another spot. This applies also when deep beds of clay are driven into;
for, by going a little distance off, and testing again, in many cases water will
be found.
The operation is as follows: The first or pioneer tube,
shown in Fig. 175 is furnished with a steel point of bulbous
form, and perforated with holes varying from one-eighth to an
inch, extending from 15 in. to 3 ft. from the point, Fig. 178.
The enlargement of the point serves to clear a passage for the
couplings by which the tubes are screwed together. On this
tube the clamp Fig. 176 is held about 3 ft. from the point by
two bolts; the clamp is of wrought iron with steel bushing
screwed internally so as to form teeth to grip the tube. Next,
the cast-iron driving-weight or monkey is slipped on to the
tube above the clamp. The monkey is operated with ropes.
Sucker-Rod Couplings. These couplings are usually made
of iron galvanized and are used to connect the ends of wooden
sucker rods for deep well pumps. Each half of coupling is
secured to the end of wooden rods by three bolts; the ends of
the couplings are joined by male and female threads in the
usual way.
Either bolts or rivets may be used to attach the rods to the
couplings. (See Fig. 179.)

Fig. 178.

Fig. 179.

POINTS FOR ERECTING AND OPERATING HAND PUMPS.

Foundation—For the smaller sizes a foundation is not necessary, other
than a good floor. With the large sizes it is advisable to have a substantial
foundation. Concrete, well rammed into place, surmounted by a capstone, is
as good as any. The foundation allows the pump to be run at a higher speed;
a plan showing location of bolt-holes, position of flanges, and general
dimensions, so that there may be no delay in setting the pump upon arrival
at its destination.
Suction Pipe—The suction pipe should be as short
and direct as possible, avoiding all turns not necessary.
Place a strainer and foot-valve, Fig. 180, on the
suction pipe. It is better for the pump to have a slight
suction except when hot water is pumped, than to
supply the water to the pump under a slight head.
Discharge Pipe—Make the discharge piping as
Fig. 180. straight as possible, using long bends.
Packing—The stuffing boxes should be carefully
packed and the gland brought up firmly against the packing; screwing up
the gland by hand should be sufficient.
Large sizes of suction and discharge pipe are desirable, because the
friction of the water in the pipes thus reduced makes the pump work easier.

POWER PUMPS

POWER DRIVEN PUMPS.

By a power-driven pump is meant one actuated by Belt, Rope-
transmission, Gear, Shafting, Electric-motor, Water-wheel, Friction, or by
direct connection to a power shaft. It thus becomes very frequently a
question which apparatus is most desirable.
These are classified, thus—
1. Single power pumps,
2. Duplex power pumps,
3. Triplex (triple) power pumps,
4. Quadruplex, etc. Where the sizes still further increase they
are named from the number of barrels or water cylinders, but when of much
larger size than the Triplex they come under the classification of pumping
engines.
Where power can be had from a shaft in motion there is no pump so
economical as the power or belt driven pump. This fact is shown by the
rapid increase in the number of applications of this type of pump: the
reduced cost of manufacture in making the teeth of the gear wheels, the use
of automatic machinery, the production of interchangeable parts have
tended to produce a high grade of machine at an attractive price.
The energy expended in operating the power driven pump is obtained at
the same economy as that required by the machinery in the mill or factory,
and as a modern automatic cutoff engine will develop a horse power with
considerable less steam than the direct acting steam pump the cost of the
power required by the power driven pump is correspondingly less; it
participates in the economy of the steam engine using from one and a half
pounds of coal to five or six pounds per H. P. per hour.
For this reason the power driven pump is oftentimes the more
economical, and especially where shafting is adjacent to the location of the
pump, or can be conveniently arranged by simply adding another length of
shafting with the necessary pulleys, or even by cutting suitable openings
through the walls for the belts.

Single, duplex and triplex power pumps are described and illustrated
upon the succeeding pages; power pumps are built with one, two, three,
four or five cylinders and for either high or low pressure or general service,
and their sizes, capacities, and the materials they handle are no more
numerous than their combinations in erection.
The portion of this work devoted to power pumps should be especially
interesting and instructive to the attendants operating steam, compressed air
and power driven pumps. Particular attention has been given to single-
cylinder steam pumps because of the great variety of steam-actuated valves
to be found in practice, each differing from the other in one or more
essential features.
It is due very largely to the numerous designs of steam valves, that
difficulty has been encountered in managing single-cylinder pumps as
successfully as those of the duplex type, the similarity of construction in the
latter type, even in minor details, being much more marked.
The successful operation of a pump depends to a great extent upon the
intelligence displayed in its management, and an engineer can scarcely hope
to obtain quiet and smooth running pumps and freedom from breakdowns
and perplexing delays except by a thorough knowledge of the details of
construction and operation.
It must be remembered that power pumps are to be illustrated and
explained in a class entirely excluding steam pumps; the latter are pumps in
which the moving force is steam.
Electric Pumps are properly power pumps in which the moving force is
electricity which is conducted to the pumps by wires.

PUMP PARTS.

Water Ends. There are properly speaking four
kinds of water ends to steam and power pumps:
1, A solid plunger, with a stuffing box used
for heavy pressings in hydraulic apparatus, or as
shown in Fig. 182, for larger plungers.
2, A piston packed with fibrous material
within the cylinder. See Fig. 181. The letter P in
Fig. 182 and the following cuts indicates the
plunger.
3, A plunger packed with a metal ring around
the outside, as illustrated in Fig. 183.
4, Two plungers, Fig. 184, connected outside
of the cylinder with a stuffing box in two
Fig. 181.
cylinder heads, through which the plungers
work. These are more fully explained and illustrated as they occur in many
examples as they are referred to in the oncoming chapters of this work.
The construction of the water ends of single cylinder and duplex pumps
is practically the same; any slight differences which may be found are
confined to minor details, which in no way affect the general design or
operation of the pump.
The steam or power ends of numerous and varied makes of pumps are
also as shown in the following pages of this work; all pumps actuated by
power—steam, electric, etc.—are possessed of these two distinguishing
features—1, a steam or power end, and 2, the water end.
Note.—This statement has exception in the cases of large pumping engines having a fly
wheel or supplemental cylinders attached to an accumulator, in which case the steam is
worked expansively.

Fig. 182.

Fig. 183.

The steam end of the ordinary single steam pump, and also of the duplex
pump, differs from the steam cylinder of the steam engine in that the former
has four ports to each cylinder, i. e., two steam ports and two cushioning
ports as shown hereafter in figures.
Under the division of the work allotted to the “Steam Pump” will be
found all necessary further notice of the steam ends of Pumps.
Pump Valves. The valve apparatus is perhaps the most important part of
any form of pump and its design has a material bearing upon its efficiency.

Fig. 184.

The valves shown in Fig. 181 are carried by two plates or decks, the
suction valves being attached to the lower plate and the delivery valves to
the upper one. The upper deck, and sometimes both decks, are removable.
The valves are secured to the plates by means of bolts or long machine

screws, which, in turn, are screwed into the bridge
across the board in the plate, as shown in Figs. 185
and 186 or capped as in Fig. 187. The valves in all
pumps except the large sizes, which may properly be
classed with pumping engines, are of the flat rubber
disc type, with a hole in the center to enable the valve
to rise easily on the bolt, the latter serving as a guide.
A conical spring is employed to hold the valve firmly
to its seat, the spring being held in position by the
head of the bolt, or cap, as shown.
Fig. 185. Certain improvements in pump-valves have been
made which tend to increase the durability and to
prevent the liability of sticking, which is not an uncommon occurrence after
the valves have become badly worn. The improved forms of pump valves
are shown in Figs. 186 and 187.
When these valves leak
through wear the disc may be
reversed, using the upper side of
the disc next to the valve seat.
This can be done with ordinary
valves also, provided the spring
Fig. 186. has not injured the upper surface
of the disc. Valve seats are
generally pressed into the plates, although instances
may be found where they are screwed. When pressed
in they may be withdrawn by substituting a bolt
having longer screw threads than the regular bolt, and
Fig. 187.
provided with a nut, as shown in Fig. 188. The bolt is
slipped through a yoke and screwed into the bridge. By turning the nut the
seat can generally be started without difficulty.
Fig. 189 represents the customary gland and stuffing-box in which the
gland is adjusted by the nuts C and D upon two studs. After the adjustment
has been properly made lock-nuts are tightened which leaves the gland free
yet preserves the alignment.

It has been proven by practice—after
long and costly experiments—that a
number of small valves instead of one
large one are far the most durable;
durability being the question. Corliss,
Leavitt, Holly and other leading pump
builders had occasion to find the truth of
this statement early in their careers. The
“slamming” of large valves under
moderate speeds proved itself an almost
Fig. 188. insurmountable difficulty until the
principle of keeping the valve area as low
as possible within reasonable limits had been fully demonstrated.
To illustrate the advantage of having a number of
comparatively small valves instead of one large one,
suppose a pump to be fitted with four 31⁄2-inch
delivery valves at each end, the valves covering ports
21⁄2 inches in diameter. The area of each port is 4·9
square inches. In order to provide an equal area
between the valve and the seat the valve must rise a
distance equal to one-fourth the diameter of the port.
The combined area of the four ports is 19·6 square Fig. 189.
inches, which corresponds to the area of a circular
opening 5 inches in diameter, one-fourth of which is 11⁄4 inches. It will be
understood that the smaller valves can seat much more quickly and with
less jar than the larger one, hence a larger number of small valves is not
only better because of the great reduction in slippage, but they are also
more economical, being subjected to less wear and tear.
The lift of valves for moderate or low speed pumps is seen in Fig. 190
and those for higher speeds in Fig. 191. These engravings clearly show the
relative position of the suction and discharge valves during the movements
of the piston.

Fig. 190.

Fig. 191.

Pump slip or slippage is a term used to denote the difference between the
calculated and the actual discharge of a pump, and is generally expressed as
a percentage of the calculated discharge. Thus, when the slippage is given
as 15 per cent. it indicates that the loss due to slip amounts to 15 per cent. of

the calculated discharge. Slippage is due to two causes, the time required
for the suction and discharge valves to seat.
When pumps run very fast the piston speed is so high that the water
cannot enter the pump fast enough to completely fill the cylinder and
consequently a partial cylinder full of water is delivered at each stroke.
High speeds also increase slippage, due to the seating of the valves. Fig.
191 represents a sectional view of the water end of a pump, showing the
position of the valves during a quick reversal in the direction of the arrows,
which illustrates the position of the valves corresponding to high speed. The
valves in a pump, like almost every other detail in the operation of
machinery, do not act instantaneously, but require time to reach the seats.
When pumps run at high speed the piston will move a considerable
distance, while the valves are descending to their seats, and water flows
back into the pump cylinder until the valves are tightly closed. The valves
will remain in the raised position shown in Fig. 191 until the piston stops at
the end of the stroke, and under high speed the piston will reach the position
on the return stroke indicated by the dotted line L by the time the valves are
closed. The cylinder will be filled up to this point with water from the
delivery chamber so that no vacuum can be formed until after the piston
reaches this position. The volume of water that can be drawn into the
cylinder must necessarily be represented by the cubic inches cf space,
minus the quantity which flows back during the time the valves are closing.
It will thus be seen that the actual volume of water discharged is
considerably less than a cylinderful, and the difference, whatever it may
prove to be, is called, and is due to slippage.
Fig. 190 represents the same pump running at a comparatively low speed.
It will be noticed that the valves have not been raised as high as in Fig. 191,
because a longer time being allowed for the discharge of the water, a
smaller orifice is sufficient. It will be seen also that the piston, moving at a
lower velocity, cannot travel as far in Fig. 190 before the valves seat, and
consequently a vacuum can be created in the cylinder earlier in the stroke,
and a larger volume of water can therefore be drawn in during the return
stroke. In the latter case it is evident that the volume of water drawn into the
cylinder will be nearly equal to a cylinderful and consequently the loss by
slippage must be correspondingly less.

In order to reduce the loss by
slippage several valves are used
instead of a single valve of equal
area. A flat disc valve will rise a
distance equal to one-fourth the
diameter of the port or of the
opening in the seat to discharge the
same volume of water that can flow
through the port in the same time.
In practice the rise exceeds this
proportion of one-fourth a trifle,
owing to the friction of the water,
and this is especially true at high
Fig. 192. speeds.
Reinforced pump valves. Where
pure gum has been used for pump
valves it has always proved too soft
and when it has been compounded
with other substances it has been
found too hard to withstand the
severe duty to which it is subjected
as a material for pump valves.
In the accompanying Fig. 192 is
shown the Braden pump valve, Fig. 193.
which is made of composition of
rubber having wire rings embedded in the center of the disc. The
composition has been removed from a section to show these rings. A ferrule
of composition metal forms a hub around the center through which the bolt
or stud passes to guide the valve and to prevent excessive wear of the hole.
Its wire coil frame work clothed with rubber maintains a due amount of
stiffness, with a degree of flexibility which prevents its bulging into the
holes in the seats, or sticking therein, and thus impairing the suction and
discharge. Both sides, the upper as well as the lower, are made available for
service. These qualities of stiffness and flexibility combined, permit this
valve to adjust itself to form a water-tight seat.

Figs. 194, 195, 198.

Armored pump valves. As
represented in Fig. 193 this is a
valve made by stamping a metal
disc out of steel which is then
plated with copper to protect the
surface and secure the adhesion of
the rubber. Marginal notches are left
on the inside and outside edges of
the plate and rubber is moulded
Figs. 196, 197. around these, and vulcanized to the
required hardness; a brass or copper
plate may be used instead of steel and the plates may be corrugated radially
to increase their stiffness when the area of the valve is large.
Experience proves that the water valve adopted together with its location,
has a material bearing upon the efficiency of any pump; easy seating valves
are subject to more or less slippage, owing to tardy seating; the location of
water valves should be above the pump cylinder, inasmuch as in operation
the pump is always primed, while if suction valves are placed below, any
wear on the valves or valve seats, or obstruction under the valves, will
cause the water to leak entirely out of the water cylinder, making it
necessary to prime the pump before it can be started.
Note.—The screwed seat is shown in Fig. 194, Stud Fig. 195, Metal Valve Fig. 196,
Spring Fig. 197, and all put together in Fig. 198.

Fig. 199.

Valve seats, bolts and springs should be of the best composition or gun-
metal; and valves of composition, or hard or soft rubber, to suit the duty
such pump is required to perform. These valve seats are screwed into the
valve plate, and valves may be changed from composition to rubber by
merely removing bolt, and substituting one for the other without removing
the seat. This is of great advantage where a pump is to be used for hot water
after being used for cold water.

Fig. 200.

Fig. 201.

Air chambers are placed upon the top of a pump, see Figs. 199 and 200,
and contain air for the purpose of introducing an air cushion to counteract
the solidity of the water, thus preventing shocks as the water flows through
the valves; and also for the purpose of securing a steady discharge of water.
The water being under pressure in the discharge chamber, compresses the
air in the air chamber during each stroke of the water piston and, when the
piston stops momentarily at the end of the stroke, the air expands to a
certain extent and tends to produce a gradual stopping of the flow of water,
thus permitting the valves to seat easily and without shock or jar.
The capacity of the air chamber varies in different makes of pumps from
2 to 31⁄2 times the volume of the water cylinder in single cylinder pumps,
and from 1 to 21⁄2 times the volume of the water cylinder in the duplex type.
The volume of the water cylinder is represented by the area of the water
piston multiplied by the length of stroke.

For single-cylinder, boiler-feed pumps and those employed for elevator
and similar service the volume of the air chamber should be 3 times the
volume of the water cylinder, and for duplex pumps, not less than twice the
volume of the water cylinder. High speed pumps, such as fire pumps,
should be provided with air chambers containing from 5 to 6 times the
volume of the water cylinder.
The diameter of the neck should not exceed one-third the diameter of the
chamber. When the pumps work under pressure exceeding 85 or 90 pounds
per square inch, it is frequently found that the air gradually disappears from
the air chamber, the air passing off with the water by absorption. In this
case air should be supplied to the air chamber unless the pump runs at very
low speeds, say, from 10 to 20 strokes for the smaller sizes and from 3 to 5
strokes per minute for pumping engines. At higher speed and with no air in
the air chamber the valves are apt to seat heavily and cause more or less jar
and noise, and the flow of water will not be uniform. The water level in the
air chamber should be kept down to from one-fourth to one-third the height
of the air chamber for smooth running at medium and high speeds.
Note.—In large pumping plants small air pumps are employed for keeping the air
chambers properly charged. In smaller plants an ordinary bicycle pump and a piece of
rubber tubing are used to good advantage.

Vacuum chambers are shown in Figs. 199, 200 and 201. These devices
are attached to the suction pipe. When the column of water in the suction
pipe of a pump is once set in motion, it is quite important, especially under
high speeds, to keep the water in full motion, and when it is stopped, to stop
it gradually and easily. This is accomplished by placing a vacuum chamber
on the suction pipe, as shown in the figures.
The location of the vacuum chamber may be varied to suit the
convenience of the engine room arrangements. Fig. 199 represents the
vacuum chamber at the side of the pump, Fig. 200 shows it opposite the
suction and Fig. 201 represents its position at the end of the pump.
Vacuum chambers are practically of two designs, as shown in Figs. 202
and 203. The one shown in Fig. 203 should be placed in such position as to
receive the impact of the column of water in the suction pipe. In order to do
this effectively it should be placed in the position shown in Figs. 199, 200
or 201. The chamber illustrated in Fig. 202 is placed in the suction pipe
below, but close to the pump.

The action of the vacuum chamber is
practically the reverse of that of the air
chamber. The object of the vacuum
chamber is to facilitate changing
continuous into intermittent motion.
The moving column of water
compresses the air in the vacuum
chamber at the ends of the stroke of the
piston, and when the piston starts the
air expands (thus creating a partial
vacuum above the water) and aids the
piston in setting the column of water in
motion again.
Fig. 202.
Thus the flow of water into the
Fig. 203.
suction chamber of the pump is much more uniform
during each stroke of the piston than without the vacuum chamber, and
consequently the pump can be run at higher speeds without increasing the
loss due to slippage and without “slamming” of the valves. Vacuum
chambers should be slightly larger than the suction pipe and of considerable
length rather than of large diameter and short. The size of the neck is
substantially the same as in the air chamber.

Fig. 204.

PIPING A PUMP.

Fig. 204 on the opposite page represents the pipe connections, etc., of a
pump with the delivery opening on the opposite side. D represents the foot
valve and strainer placed on the lower end of the suction, which should be
not less than a foot from the bottom of the well; the distance named
provides for the gradual filling of the well. C is the suction pipe proper,
screwed into the elbow, E, which changes its direction into the suction
chamber, which contains the strainer, A. This strainer can be removed for
cleaning by lifting the bonnet secured by stud bolts on top. In connecting
large pumps it is customary to attach a vacuum chamber, F, which in the
absence of any regular pattern, may be made of a piece of pipe of the same
diameter as the suction and screwed into a T, instead of the elbow, E, with a
regulation screwed cap on top as shown in the dotted lines.
A priming pipe is shown by the letter J, often used to fill the pump on
starting. The discharge pipe connection is shown at G with the air chamber
attached.
This figure is introduced for the purpose of showing an approved method
of piping a pump. It may be observed that the flange joints in this design are
so arranged that they may be disconnected without unscrewing any part of
the suction pipe; this feature is almost essential in view of needed repairs.
The foregoing description of the parts of a pump relate to the water end
solely; there remain the more complex and widely differing parts of the
steam-end which constitute the distinguishing characteristics of the pumps
built by the different makers. There remain also the particular parts
belonging to the large pumping engines, air-pumps, etc.
These will be described under their respective chapters with much added
and essential matter. Particular details as to the conditions of service under
which it is proposed to operate pumps are to be found on the next page.

CONDITIONS OF SERVICE REQUIRED OF A PUMP.

It is especially important that the makers and also the sellers of pumps
and pumping machinery should be informed regarding the proper type, size,
pattern and proportion of parts for any peculiar service, as well as to the
plan of their connections and the kind of material to be used in their
construction.
This information regarding the conditions of the service under which the
pump is to be worked is quite pertinent to the foregoing pages regarding the
parts of pumps. The following questions are extracted from the catalogue of
an extensive manufacturer.
First—To what service is it to be applied?
Second—The quality of the liquid to be pumped, whether salt, fresh,
acid, clear or gritty, and whether cold or hot?
Third—To what height is the water to be lifted by suction, and what are
the length and diameter of the suction and discharge pipes?
Fourth—Of what material is the suction pipe, and what is its general
arrangement as regards other pipes leading into it, etc.?
Fifth—Will the supply be taken from a driven well? If not, from what
source?
Sixth—To what height, or against what pressure, is the water to be
pumped?
Seventh—What is the greatest quantity of water to be delivered per hour?
Eighth—What boiler pressure of steam is carried?
Ninth—Will the pump exhaust into the atmosphere, into a condenser, or
against a back pressure? If the latter, how much?

BELTED PUMPS.

Fig. 205 represents an approved form of
steam boiler feed pump, single acting. It has a
crank shaft and a tight and loose pulley. It may
be driven direct from any line shaft, a
countershaft being unnecessary.
This is a compact form of a boiler feed pump;
formerly the pump crank shaft was attached to
floor beams or timbers above and connected by
a long pitman to the pump which stood upon the
floor; the objections to the older system of
apparatus were found to be the vibration of the
long pitman and the springing of the floors.
To obviate these two difficulties the pump
and countershaft were attached to a post
bringing them nearer together but finally
resulting in the design of pump here shown. The
broad base insures great stability in the
operation of the pump especially when fixed to
Fig. 205.
a rigid floor or timber foundation.
In the Table below are given some details furnished by the makers
relating to six sizes of this style of pump, to which may be added that the
speed ordinarily used varies from 100 revolutions per minute for the small
sizes, to 20 revolutions for the larger sizes.

Table.
No. Size piston. Suction fitted for. Discharge fitted for. Stroke. Size pulleys, in.
1 2 in. 1 in. pipe 1 in. pipe 3 in. 16 × 4
2 21⁄2 „ 1 „ „ 1 „ „ 3 „ 16 × 4
3 3 „ 11⁄4 „ „ 11⁄4 „ „ 3 „ 16 × 4
4 2 „ 11⁄4 „ „ 11⁄4 „ „ 6 „ 18 × 4
5 21⁄2 „ 11⁄4 „ „ 11⁄4 „ „ 6 „ 18 × 4

6 3 „ 11⁄2 „ „ 11⁄2 „ „ 6 „ 18 × 4

Fig. 206 exhibits two independent pumps.
The description of the pump shown in Fig. 205
will apply to the left-hand pump which is a
boiler feed pump. The improvement consists in
the addition of another pump at the right-hand
side; this is a suction force pump with an air
chamber and is used to draw water from a well
and discharge it into a tank from which it is
taken by the other pump and forced into the
boiler, as occasion requires.
These two pumps work simultaneously, being
driven from the same shaft with cranks set
opposite each other. Like the pump previously
described this has a tight and loose pulley. The
larger sizes are geared, having a pinion on the
pulley shaft and a spur wheel on the crank shaft.
These two pumps represent a high service and
Fig. 206. a low service, the left-hand pump working under
high pressure, against that in the boiler and the
right one against the head of water in the tank. Each pump has its own
separate connections—one or more—to suit the required conditions.
The right-hand pump is double acting; the plunger-rod is guided by a
steadiment which holds it in line and preserves this alignment and the
power is transmitted through a forked connecting rod. The Table below
refers to both these pumps.

Table.
BOILER PUMP. DBLE.-ACTING FORCE PUMP.
Diam. Suc. and Gal. per Diam. Suc. and Gal. per
cyl. dis. stroke cyl. dis. rev.
21⁄2 in. 11⁄4 in. 1—8 3 in. 11⁄2 in. 2—5

21⁄2 „ 11⁄4 „ 1—8 4 „ 2 „ 4—5

In Fig. 207 is shown a double acting power pump used principally for
feeding boilers but may be employed for any purpose in forcing water or
other liquids against pressure. This pump is double acting, is made with
four check valves, as shown in engraving, and will draw water through 25
feet of suction pipe. On a high lift like the foregoing a foot valve (as shown
at D in Fig. 204) should be used.
The form of
valves used in this
type of pump are the
regular commercial
check valves, made
of steam-metal, extra
heavy; the valve
proper is of the wing
pattern as shown in
Straight Wings. the small cuts. There
are four of these
wings on each valve,
at right angles to one
another forming a
cross with arms of
equal lengths.
The seat of the
valve has an angle of
45° to which the
Spiral Wings. valve is adjusted. A Fig. 207.
part of this valve
projects above the top and has a slot, shown by the dotted line in it to
receive the edge of a screw-driver, held in a bit stock to grind the valve seat
in refitting. The lift of the valve is regulated by the distance between the top
of the stem and the bottom of the covering nut or cap.
In hydraulic pumps it is found to be good practice to give the wings of
these valves a twist, or pitch, so that the water in passing through will cause
the valve to rotate and fall in a new position every time it comes in contact
with the seat.

Fig. 208 represents a very compact design of double acting low service
belt driven pump. The water cylinder is bored and has a piston fitted to it;
both ends of this cylinder are covered with “heads,” one of which has a
stuffing box through which the piston operates; the outer end of this piston
rod is fitted to a slotted yoke which slides upon a guide at the bottom.
This mechanism, just described, takes the place of a pitman connection
and occupies very much less space. The crank shaft is supported at each end
in pillow blocks and is driven by a belt having a tight and loose pulley;
larger sizes are geared. Access to the two sets of valves can be had by
slacking up four nuts upon the long belts, two of which are shown in the
engraving. The broad base secures great stability for this size pump.

Fig. 208.

Fig. 209.

Fig. 210.

Fig. 209 exhibits two single acting plunger pumps actuated by one shaft
having a crank upon each end with crank pins opposite to one another. This
shaft is supported on the top of two pillars which form a part of the solid
cast iron frame. The boxes are babbited. The crank shaft has a cast iron spur
gear keyed to it and meshes into a pinion upon the pulley shaft. The teeth
are cut to insure smooth and quiet running. The power is transmitted
through a belt upon a tight and loose pulley. Each pump is secured to the
frame by four bolts. The lower end of the pitman has an arrangement to take
up the wear by means of two set screws with lock-nuts as shown in the
figure on the top of each plunger. This pump is largely used as a boiler feed
pump. These pumps can be used separately or together and with single or
compound connections.

Duplex Power Pump. This engraving, Fig. 210, shows a special boiler
feed pump having ball valves, as shown in section, and which is also
intended for use in pulp mills and in other places where it is necessary to
pump sandy or muddy water, or chemicals, soap and other heavy bodied
liquids. These pumps have composition ball valves, composition plungers
and composition lined cylinders and glands.
The two barrels or cylinders of this pump are brought together so as to
occupy as little space as possible. Instead of cranks eccentrics are used
having very large wearing surfaces. Each pitman has a ball at its lower
extremity forming a “ball and socket” joint, which is adjustable to
compensate for wear. All the bearings are Babbitted and like the last pump
described the gears have cut teeth. It is belt driven.
If there are two cranks as in the duplex power pump they are placed
opposite to one another or 180° apart, the circle described by the crank-pin
containing 360 degrees. In the triplex pump this circle is divided into three
equal parts of 120° each which is represented by the position of the cranks;
a quadruplex or two duplex pumps attached to the same shaft the cranks
will be 90° apart. This arrangement effects a uniform distribution of load on
the crank shaft and one of the pumps is continuously discharging at its
maximum capacity.
This duplex power pump should not be confounded with the “Duplex
Pump” so called. The latter has two steam cylinders and two water
cylinders and is double acting while the former is single acting.
The successful operation and durability of these, as of all power pumps,
depends largely upon the judicious selection and application of a proper
packing to the stuffing boxes. As for example, plaited flax dipped in a
mixture of warm graphite and tallow, braided rawhide, Selden’s packing,
etc., have proved by long service to have a low co-efficient of friction and
are not liable to cut the plungers.
The triplex power gang pump is shown in Fig. 211. The engraving
represents two triplex pumps bolted to one bed, and having an extended
pulley shaft with pinions near each end to drive all of the pumps.

Fig. 211.

Table.
No. 1 2 3 4 5
Size of
Plunger 21⁄4 3 41⁄2 6 8
in inches
Length of
Stroke 23⁄4 31⁄4 43⁄4 61⁄2 81⁄2
in Inches
Gallons
per Stroke .28 .58 1.96 4·76 11.08
or 1 Rev.
Revolutions
per 20 to 50 10 to 40 10 to 40 10 to 30 10 to 25
Minute

Size of
Suction 11⁄4 11⁄2 21⁄2 4 5
in Inches
Size of
Discharge 11⁄4 11⁄2 2 31⁄2 4
in Inches
Size of
ACCORDING TO DUTY REQUIRED
Pulleys
{ *16 } { *16 } { *13 } { *20 } { *20 }
Geared
{ 72# } { 80# } { 71# } { 89# } { 80# }
Pressure
175 175 170 165 160
Pounds

* Teeth in Pinion. # Teeth in Spur Gear.
The description of the duplex power pump just given, applies to this type
also. The exception is that the triplex has three plungers and barrels instead
of two. There are two spur wheels and two pinions on each pump to
equalize the power to better advantage, as by this arrangement one eccentric
is placed between each pair of spur wheels and two eccentrics outside. The
pinion shaft is in one piece having tight and loose pulleys.

Fig. 212.

The eccentrics—six in number—are set at 60°, and an even strain on the
belt at all points of the stroke is thus obtained, and connecting both
discharges together insures a steady flow without shock. Where light duty
only is required, these pumps are made without gears to run with the belt
over pulleys.
Fig. 212 represents a single acting triplex plunger pump actuated by a
belt over a tight and loose pulley.

The principal characteristic of this pump is the long connecting rods.
These have at their upper ends regular connecting rod straps with brasses
fitted to them and adjusted by wedges and set screws. At the plunger or
lower ends of these rods bronze bushings and steel pins are used.
These pumps are largely employed for pumping semi-liquids such as tar,
soap, mud, tan-liquor, oils, chemicals, sewage, etc.
The teeth of the pinion and the meshing part of the two gears are
protected by a shield to prevent clothing being caught or parts of the body
from being injured.
For these various materials different valves are necessary to be used each
suited to the substance to be elevated or conveyed.
The removal of one cover, in this pump, exposes all the discharge valves
and a plate uncovers each of the three groups of suction valves, as shown.
The suction pipe may be attached at either end of the suction chamber while
the discharge pipe may be connected with one or both ends of the discharge
chamber.
The pump here represented has barrels 8-inch in diameter by 10-inch
stroke. The air chamber is very large in proportion to the pump.
Table.
Plungers Capacity one Sizes of Pipe Tight
Revolution of Geared and Loose
Diameter Stroke Crank Shaft Suction Discharge Pulleys
4 in. 4 in. 0·65 gals. 3 in. 3 in. 5 to 1 20 × 3 in.
4 „ 6 „ 1· „ 3 „ 3 „ 5 to 1 20 × 3 „
5 „ 6 „ 1·5 „ 4 „ 4 „ 4 to 1 20 × 4 „
5 „ 8 „ 2· „ 4 „ 4 „ 4 to 1 20 × 4 „
7 „ 8 „ 4· „ 5 „ 5 „ 4 to 1 30 × 5 „
8 „ 10 „ 6·5 „ 6 „ 6 „ 5 to 1 36 × 6 „
8 „ 12 „ 7·8 „ 6 „ 6 „ 5 to 1 36 × 6 „

The Deane single acting triplex power pump is shown in Fig. 213. Pumps
of this type are used for general service in places where a large quantity of
water is to be obtained in a short time and delivered under high pressure;
they are adapted for tank service, water works, boiler feed, etc.

Fig. 213.

The pillar, or column design of frame is employed in this pump which
secures great strength with the least weight of material, and at the same
time is accessible for adjustment or repairs. The bearings for both the steel
shafts are unusually long, which reduces the pressure per square inch below
the factor of safety and increases the durability. The crankpins are set 120
degrees with one another so that the strokes successively overlap, which
promotes an easy flow of water through the delivery pipe. The crank shaft is
of the composite design, the center crank pin is of equal diameter and

forming a part of the shaft, with discs and crank pins attached to each end
by shrinking fits and keys. Either disc, crank, or their crank pins, can be
duplicated without sacrificing any other part, which in itself is a great
advantage.
The connecting rods have solid ends with adjustable boxes, with
adjustment by means of wedge and screws. The brasses are lined with a
special anti-friction metal bored to exact size.
The crossheads are of the box design with adjustable shoes having large
wearing surfaces in bored guides. These guides are secured to the frame by
studs and nuts.
The plungers are outside packed, the cylinders are submerged, thus
keeping the pump primed at all times. The plungers are bolted to the
crossheads and are readily removed when necessary. The cylinders are
single acting and are cast separate from the base and other parts of the
machine, so that repairs can be made at small cost, and, furthermore, should
it be desirable to use the pump for moving liquids which would be injurious
to cast iron, cylinders of other metals are substituted. The water chest is cast
separate from the cylinders and is provided with large handholes, affording
easy access to the interior and to the valves for inspection and cleaning. The
handholes are located so that one valve may be removed independent of the
others.
Improved grease cups are placed on all the bearings. This pump is very
popular with the users of power driven pumps and is generally selected for
high pressures and for hot or gritty water. Its simplicity of design and
construction, together with the convenient arrangement of working parts,
renders it desirable in isolated places where little attention is given to any
kind of pumps.

Fig. 214.

Fig. 214 represents the Gould triplex single acting power pump and is
one of many designs of this class of power pumps. The frame consists of
two standards, which contain the two end cylinders, and the seats to which
the outside crosshead guides are bolted. These are held together by two
castings, one containing the center crosshead guide, and the other the center
cylinder. The crankshaft is a solid steel forging, while the bearings are of
phosphor bronze, and the pinion shaft bearings Babbitted.

The gear wheels are machine cut, the pinion and the adjacent teeth of the
large gear are covered by suitable guards.
The crossheads are provided with adjustable shoes or gibs, which work in
bored guides. The connecting rods are fitted with straps and bronze boxes,
which are adjustable for wear by means of wedge and set screws, the
wristpin brasses being of the marine type. The cylinders are provided with
bronze liners, which are readily removable when necessary for repairs, the
plungers being ground to size, present a smooth polished surface to resist
the wear.
The valve boxes are separate castings, and each contains a set of suction
and discharge valves. These valves are rubber discs, held firmly against the
bronze seats by cylindrically wound springs. All of these pumps are
furnished with air chambers, and vacuum chambers are provided when the
nature of the service demands it. All valves and other working parts of the
pump are accessible for inspection, cleaning and repairs, all internal parts
being arranged within easy reach through the large handholes.
The pumps here shown are intended for moderately light pressures as for
example not to exceed 150 lbs. per square inch, but they are also made in
heavier proportions for very high pressures (5,000 lbs. to 15,000 lbs.) such
as is necessary to operate hydraulic presses, draw benches for brass and
copper tubing and that class of work.
A very simple automatic regulator and by-pass connection (shown in the
chapter on accessories) can be attached to these pumps in situations where a
constant pressure is to be maintained and allow the pump to run
continuously at its maximum speed. This regulator is adjusted to open the
by-pass valve whenever the pressure in the compression tank or pipe system
exceeds the limit pressure, and so fills the office of a safety valve by
allowing the surplus water to return to the tank.
The Riedler belt driven pump is shown in Fig. 215.
The principal feature of this pump is its valve; there is but one valve for
the suction and one for the discharge, which greatly simplifies the pump
end. When working against high pressures, the ordinary rubber or leather
faced valves are oftentimes pounded to pieces, but in this pump, on account
of the mechanical control, the valves work well under all pressures.

Fig. 215.

This valve and valve seat are circular in form, and made of bronze, as
shown in Fig. 216. The valve has a lift of from 1 to 2 inches, and an area
sufficiently large to reduce the velocity of the water flowing through it to a
few feet per second.
At the beginning of the stroke the valve opens automatically, controlled,
however, by a very simple and effective mechanical device, and it remains

open practically during the entire stroke. When near the end, it is positively
closed at the proper moment by the controller.
This valve, see Fig. 216, may be briefly described as follows. The seat,
A, is turned to slip into its place in the pump and is made tight by a round
rubber hydraulic packing, B, in a groove near the bottom. A spindle or stud,
C, in the center of this seat supports and guides the valve, D, which is made
tight by a leather seal, E. The rubber collar or buffer spring holds the valve
above its seat, and this valve unlike ordinary pump valves, always remains
open except when pressure is brought to bear to close it. The valve bonnet,
G, also forms the bearing for the valve stem with fork, which spans the
spindle, C, at one end and having the valve lever and pin, H, for operating
at the other end. The valve stem is made tight by a stuffing-box and gland
as shown. The operation of this valve is substantially as follows.

Fig. 216.

At the beginning of the suction stroke the valve is opened by the rubber
spring, F, the pressure upon the collar being relieved by lifting of the valve
fork arms through motion of the eccentric.
It will be observed from an inspection of Fig. 215 that both the suction
valve and the discharge valve are controlled by an eccentric—rock arm—
and valve levers similar to the motion of Corliss valves.
As the plunger nears the end of its stroke and before it starts on the return
stroke, the valve fork closes the valve, and thus prevents slip and avoids
pounding, so common in pumps having valves that close by their own
weight. In case of any obstruction between the valve and its seat the rubber
buffer spring will be compressed thus preventing all injury to mechanism.
The lost work expended in closing the valves is hardly worth any
consideration as it is practically the friction only of the eccentric and the
members of the valve gearing, the bearings of which are all small.
The motion for these valve gears is usually taken from an eccentric on
the main shaft.
The standard speed of the Riedler pumps is about 150 revolutions per
minute. Smaller pumps run even faster than this.
It may be desired to connect a pump directly to a high speed electric
motor or water wheel already installed. To meet these conditions, a special
design known as the Riedler Express pump, is built.
The chief feature of this pump, is its suction valve. This valve is
concentric with, and outside of the plunger, and lifts in the opposite
direction to that of the plunger when on its suction stroke. At the end of the
suction stroke, the plunger presses the valve to its seat, thus making it
certain that the valve is seated when the plunger starts on its delivery stroke,
allowing practically no slip. A high air suction chamber containing a
column of water is placed immediately before the suction valve, so it is
certain that the pump will fill as the plunger moves. Ordinarily the pump
would not completely fill, owing to the high speed of the plunger.
These pumps are also built with steam cylinders both of the plain slide
valve and Corliss designs.

THE ELECTRIC
PUMP

Compass Needle—See Page 266.

ELECTRICITY AND ELECTRICAL MACHINERY.

Each kind of power requires its own special machinery so constructed
and adapted as to utilize it; hence, to be serviceable to mankind, electricity
demands machinery suited to its nature; what that is, will be indicated in the
following few paragraphs.
Electricity is a name derived from the Greek word electron—amber. It
was discovered more than 2,000 years ago that amber when rubbed with a
Fox’s tail possessed the curious property of attracting light bodies. It was
discovered afterwards that this property could be produced in a dry steam
jet by friction, and in A. D. 1600 or thereabouts, that glass, sealing-wax,
etc., were also affected by rubbing, producing electricity.
Whatever electricity is, it is impossible to say, but for the present it is
convenient to consider it as a kind of invisible something which pervades
all bodies. While the nature and source of electricity are a mystery, and a
constant challenge to the inquirer, many things about it have become known
—thus, it is positively assured that electricity never manifests itself except
when there is some mechanical disturbance in ordinary matter, and every
exhibition of electricity in any of its multitudinous ways may always be
traced back to a mass of matter.
Note.—The great forces of the world are invisible and impalpable; we cannot grasp or
handle them; and though they are real enough, they have the appearance of being very
unreal. Electricity and gravity are as subtle as they are mighty; they elude the eye and hand
of the most skillful philosopher. In view of this, it is well for the average man not to try to
fathom, too deeply, the science of either. To take the machines and appliances as they are
“on the market,” and to acquire the skill to operate them, is the longest step toward the
reason for doing it, and why the desired results follow.

Electricity, it is also conceded, is without weight, and, while electricity is,
without doubt, one and the same, it is for convenience sometimes classified
according to its motion, as—
1. Static electricity, or electricity at rest.
2. Current electricity, or electricity in motion.
3. Magnetism, or electricity in rotation.
4. Electricity in vibration.
Other useful divisions are into—

1. Frictional and
2. Dynamical,
And into—
1. Static, as the opposite of
2. Dynamic electricity.
There are still other definitions or divisions which are in every-day use,
such as “vitreous” electricity, “atmospheric” electricity, “resinous”
electricity, etc.
Static Electricity.—This is a term employed to define electricity
produced by friction. It is properly employed in the sense of a static charge
which shows itself by the attraction or repulsion between charged bodies.
When static electricity is discharged, it causes more or less of a current,
which shows itself by the passage of sparks or a brush discharge; by a
peculiar prickling sensation; by an unusual smell due to its chemical effects;
by heating the air or other substances in its path; and sometimes in other
ways.
Current Electricity.—This may be defined as the quantity of electricity
which passes through a conductor in a given time—or, electricity in the act
of being discharged, or electricity in motion.
An electric current manifests itself by heating the wire or conductor, by
causing a magnetic field around the conductor and by causing chemical
changes in a liquid through which it may pass.
Note.—Statics is that branch of mechanics which treats of the forces which keep bodies
at rest or in equilibrium. Dynamics treats of bodies in motion. Hence static electricity is
electricity at rest. The earth’s great store of electricity is at rest or in equilibrium.

Radiated electricity is electricity in vibration. Where the current
oscillates or vibrates back and forth with extreme rapidity, it takes the form
of waves which are similar to waves of light.
Positive Electricity.—This term expresses the condition of the point of an
electrified body having the higher energy from which it flows to a lower
level. The sign which denotes this phase of electric excitement is +; all
electricity is either positive or,-, negative.

Negative Electricity.—This is the reverse condition to the above and is
expressed by the sign or symbol-. These two terms are used in the same
sense as hot and cold.
Atmospheric electricity is the free electricity of the air which is almost
always present in the atmosphere. Its exact cause is unknown. The
phenomena of atmospheric electricity are of two kinds; there are the well-
known manifestations of thunderstorms; and there are the phenomena of
continual slight electrification in the air, best observed when the weather is
fine; the aurora constitutes a third branch of the subject.
Dynamic Electricity.—This term is used to define current electricity to
distinguish it from static electricity. This is the electricity produced by the
dynamo.
Frictional electricity is that produced by the friction of one substance
against another.
Resinous Electricity.—This is a term formerly used, in place of negative
electricity. The phrase originated in the well known fact that a certain
(negative) kind of electricity was produced by rubbing rosin.
Vitreous electricity is a term, formerly used, to describe that kind of
electricity (positive) produced by rubbing glass.
Magneto-electricity is electricity in the form of currents flowing along
wires; it is electricity derived from the motion of magnets—hence the
name.
Voltaic Electricity.—This is electricity produced by the action of the
voltaic cell or battery.
Electricity itself is the same thing, or phase of energy, by whatever source
it is produced, and the foregoing definitions are given only as a matter of
convenience.

ELECTRO-MOTIVE FORCE.

The term is employed to denote that which moves or tends to move
electricity from one place to another. For brevity it is written E. M. F.; it is
the result of the difference of potential, and proportional to it. Just as in
water pipes, a difference of level produces a pressure, and the pressure
produces a flow so soon as the tap is turned on, so difference of potential
produces electro-motive force, and electro-motive force sets up a current so
soon as a circuit is completed for the electricity to flow through. Electro-
motive force, therefore, may often be conveniently expressed as a
difference of potential, and vice versa; but the reader must not forget this
distinction.
In ordinary acceptance among engineers and practical working
electricians, electro-motive force is considered as pressure and it is
measured in units called volts. The usual standard for testing and
comparison is a special form voltaic cell, called the Clark cell. This is made
with great care and composed of pure chemicals.
The term positive expresses the condition of the point having the higher
electric energy or pressure, and, negative, the lower relative condition of the
other point, and the current is forced through the circuit by the (E. M. F.)
electric pressure at the generator, just as a current of steam is impelled
through pipes by the generating pressure at the steam-boiler.
Care must be taken not to confuse electro-motive force with electric force
or electric energy, when matter is moved by a magnet, we speak rightly of
magnetic force; when electricity moves matter, we may speak of electric
force. But, E. M. F. is quite a different thing, not “force” at all, for it acts
not on matter but on electricity, and tends to move it.

THE DYNAMO, OR GENERATOR.

The word dynamo, meaning power, is one transferred from the Greek to
the English language, hence the primary meaning of the term signifying the
electric generator is, the electric power machine.
The word generator is derived from a word meaning birth giving, hence
also the dynamo is the machine generating or giving birth to electricity.

Fig. 217.—See page 251.

Again, the dynamo is a machine driven by power, generally steam or
water power, and converting the mechanical energy expended in driving it,
into electrical energy of the current form.
To summarize, the dynamo-electric generator or the dynamo-electric
machine, proper, consists of five principal parts, viz:
1. The armature or revolving portion.

2. The field magnets, which produce the magnetic field in which the
armature turns.
3. The pole-pieces.
4. The commutator or collector.
5. The collecting-brushes that rest on the commutator cylinder and take
off the current of electricity generated by the machine.
Fig. 218 shows a dynamo of the early Edison type—the names of the
principal parts are given in the note below, as well as those of the other
parts of the machine.

Fig. 218.

This is a two-pole machine, direct current; the figure is introduced to
show the “parts” only—as this dynamo has been largely superseded by
others of the four pole type.
Note.—A, Magnet yoke; B, Magnet and field piece; C, Pole piece; D, Zinc field piece;
E, Armature; F, Commutator; I, Quadrant; JJ, Brushes; K, Adjusting handle for the brushes;
L, Switch pivot; M, Pilot lamp receptacle; N, Negative lug; O, Switch lever; P, Positive
lug; Q, Positive terminal; R, Negative terminal; S, Negative rod; T, Pole piece; UU,
Bearings; X, Slides for belt tightener; VVV, Driving pulley; Y, Connecting blocks, one on
each side of machine.

An electric motor is a machine for converting electrical energy into
mechanical energy; in other words it produces mechanical power when
supplied with an electric current; a certain amount of energy must be
expended in driving it; the intake of the machine is the term used in
defining the energy expended in driving it; the amount of power it delivers
to the machinery is denominated its out-put.
The difference between the out-put to the intake is the real efficiency of
the machine; it is well known that the total efficiency of an electric
distribution system, which may include several machines, usually ranges
from 75 to 80 per cent., at full load, and should not under ordinary
circumstances fall off more than say 5 per cent. at one-third to half load; the
efficiency of motors varies with their size, while a one horse-power motor
will, perhaps, have an efficiency of 60 per cent., a 100 horse-power may
easily have an efficiency of 90 per cent. and the larger sizes even more.
The general and growing application of electric power to the driving of
all kinds of machinery including pumps makes the question of motor
driving one of the most important in the power field. For many purposes, a
single speed is sufficient, but for others, it is imperative that the speed
should be variable; and for still others, though not absolutely necessary, a
speed adjustment is very desirable.
While the direct-current motor has been in this field so long that its
properties are well known and its possibilities fully developed, in the
operation of motors located in the immediate neighborhood of the generator
the alternating-current motor has marked advantages where a large area of

territory has to be covered and the conditions are nearly uniform, that is to
say—
Where the current has to be transmitted a long distance and the load is
approximately constant, the alternating system is preferred, as it can be
operated with small main lines or conductors. This effects a saving in
copper, over the direct system which requires larger conductors.

Fig. 219.

Fig. 220.

Fig. 217, on page 247, shows a four-pole generator designed to run by a
belt or directly connected to an engine. The five parts named, as the
principal parts of a dynamo, are all shown in the figure. The machine is
arranged ready to be bolted to the floor.
Fig. 219 on the opposite page is the armature which is made up of coils
of insulated wire, the free ends of which, see Fig. 220, are united to the
arms of the commutator bars. When the armature is finished, as shown, the
wire forms an unbroken circuit.

Fig. 221.

Fig. 221 is intended to represent another form of armature, but the
principle upon which it operates, is the same, as the other shown. A A,
represents the wire coils of the armature, B, is the shaft with its journals, C,
is the commutator. All commutators both for generators and for motor
armatures are insulated by mica between the bars.

Fig. 222.

Fig. 222 shows a woven wire brush. The brushes on the dynamo, page
247, are made of carbon.

Fig. 223.

Fig. 223 shows an alternating induction motor. Induction is a property by
virtue of which an electric current is transferred from one conducting line to
another without any metallic connection; it is that influence by which a
strong current flowing through a conductor controls or affects a weaker
current flowing through another conductor in its immediate neighborhood,
—the strong current remaining unaffected.

Fig. 224.

Fig. 224 exhibits the armature for the above alternator; it is familiarly
called a “squirrel cage armature” on account of its resemblance to the wheel
in a squirrel’s cage.
Its peculiar construction enables it to run without producing any sparks;
this feature renders it safe to run where there are explosive gases which
might be ignited by an electric spark. In the machine the bearings are cast
solid with the end shields, thus assuring perfect alignment when properly
turned. Another feature is the automatic self adjusting bearings which are
lubricated mechanically by rings resting upon the shaft. These rings were
formerly a failure, but by the use of mineral oils are now a success.

This machine is one of the simplest designs of alternating motors, the
example, Fig. 223, is one developing one hundred horse-power.
Fig. 225 shows a
revolving field with
“spider.” In this
construction of
generators or motors
the field revolves in
place of the armatures,
the first object of this
design is to reduce the
high rotative speed; it
is also claimed to have
a better electrical
efficiency.
The field spider
consists of an extra
heavy cast iron pulley
which is keyed to the
shaft; the low speed at
which it runs permits
the employment of
bolts to secure the field
Fig. 225. coils and laminated
pole pieces to the rim
of the spider, as shown in the engraving. With this construction each
individual pole piece can be removed and replaced independent of the
others.
The laminated pole piece, one of which is shown in detail in Figs. 226-
229, takes its name from the fact that it is built up of a large number of
layers of soft sheet iron, which it has been demonstrated give a better
electrical efficiency than a solid iron. Soft iron is the most magnetic of all
metals and is better suited for pole pieces than steel.
It should be understood that each individual pole piece is insulated from
the others as well as from the spider. The pieces of sheet iron are stamped

out—like washers and are cut apart and the ends united so as to form a
continuous coil, like a coil of wire and each coil is isolated; mica is used
between the layers.

Figs. 226-229.

Fig. 230 is designed to illustrate the front of a continuous current two
wire switchboard with circuit breakers; these are made up usually of marble
or slate so that they will not burn; the Insurance Underwriters require a non-
combustible material at this place, as well as hangers, and insulators used
for conductors.
The Switches shown in the middle of the board, are enlarged in Fig. 232,
and are used for closing the connections with the generators and lines
running to various parts of the field to be lighted or furnished with power.
The switch handles are made usually of wood or hard rubber; the blades
are of copper. The connections are soldered into the sockets shown upon the
ends of the screws which project beyond the back of the switch-board.
The upper row of figures as shown in Fig. 230 and enlarged in the
engraving, 231, are circuit-breakers. The use of these is analogous to that of
the safety-valve upon a steam boiler, so that when the pressure in the circuit
exceeds that at which it is set the “breaker” opens the circuit and thus
prevents damage.

Fig. 230.

In this case, the main contact is formed by means of a laminated brush
while the final stroke is made on carbon, the motion of this breaker is by
means of a toggle-joint which so multiplies the power applied that it does
not require much of an effort to close it; this device maintains the same
speed in operating the breakers when the circuit-breaker is tripped.
A Rheostat is a device for controlling the amount of electricity in a
conductor—by the insertion of coils of wire in a box—which may be

successively switched in or out of the main circuit by means of a lever and
button-switch. The best place to install a rheostat is on a wall or post, as the
resistance transforms a portion of the electric energy into heat, which heat
must be dispersed into the atmosphere.
A transformer is an induction coil employed usually for lowering electric
pressure, but it may also be used for raising the same, in which case it is
sometimes called a booster. A compensator is a transformer which works
automatically.
Ammeters record
the quantity of
current flowing
through the circuit,
in amperes.
Voltmeters record the
pressure or strength
of the current in
volts.
An Ampere is an
electric current
which would pass
through a circuit Fig. 232.
whose resistance is
Fig. 231. one ohm under an electro-motive force of one volt. A
Volt is an electro-motive force of sufficient strength to
cause a current of one ampere to flow against a resistance of one ohm.
The ampere is the unit for calculations relating to the quantity or volume
of a current; the volt is the unit for calculating the pressure or strength of
the current.
The action of the electric current in producing rotation in an electric
motor is really quite simple. While many electrical problems are
comparatively complicated, the principal elements in the operation of
electric motors may be readily understood. The fundamental fact in this
connection is the relation between an electric current and a magnet.

If a piece of round bar iron be surrounded by a coil through which an
electric current passes, it becomes a magnet. In Fig. 233 the passage of a
current through the coil of wire around the iron bar in either direction,
renders the iron a magnet, with all its well-known properties. It will attract
iron, and the space surrounding it becomes magnetic. Iron filings will
arrange themselves in the direction shown by the dotted lines in the figure.
One end of the magnet is the North or positive + pole and the other the
South or negative - pole.
If a wire, such as CD, be moved past either pole of the magnet, there will
be a tendency for current to flow in the wire either from C to D or D to C,
according to the character of the pole past which it is moved, and to the
direction of the movement. If the ends of the wire CD are joined by a
conductor, so that there is a complete circuit, a current of electricity will
flow through this circuit.
This circuit may be a simple wire, as shown by the line CEFD, or it may
be the wire coils on machines enabling the current to produce mechanical
work, or it may be electric lamps producing light. The indispensable feature
is that there shall be a complete unbroken circuit from C to D for the current
to flow, no matter how complicated or how long this circuit may be.
This description of a dynamo and motor carries with it all of the
elementary theory of electric generators and motors that is necessary for an
attendant to know in order to take reasonably intelligent care of electric
machines. Further useful knowledge must be acquired by studying the
different types of electric motors and dynamos. All these other types of
direct current machines have the same elementary theory, although their
construction may be quite different.
By suitable illustrations the operation of the electric motor as applied to
pumps will be easily understood; its application to other machines is the
same in theory and practice.
“Why an electric motor revolves” is a question well worth careful, and, if
necessary, long study.

Fig. 233.

The reason why there is a tendency for an electric current to flow in the
wire CD when it is moved in the vicinity of a magnet is not fully known.
There are several theories, all more or less complicated, and depending
upon pure assumptions as to the nature of an electric current. For practical
purposes it matters little what the reason is, the fact that current flows when
there ts an electric pressure in a closed circuit, is the important thing, and it
serves all useful purposes to know that current does flow, and that its
direction and amount are always the same under similar circumstances.
There are many facts in mechanics that are accepted and used practically,
about which little is known as to their fundamental and primary causes, and
this fact about motors and dynamos is, therefore, only one of many which
all must accept without a full and complete explanation.
The intensity of the electric pressure, or electro-motive force, depends
upon the velocity of revolution of the wire sections in the armature and
upon the strength of the magnets, and the quantity of current depends upon
the electro-motive force and upon the amount of the resistance in the
circuit. Other things being equal, the current, flowing through a long small
wire, or greater resistance, will be less than through a short, thick wire, or a
less resistance.
Having seen that when a wire is moved in the vicinity of a magnet an
electric pressure is produced which will cause a current to flow in a closed
circuit, one can easily conceive of many ways in which, by combining

magnets and wires so that there will be a relative motion between them, a
current of electricity may be generated. In order to cause a continuous flow
the relative motion must be continuous; and if the current is to be uniform
the motion must be uniform.

Fig. 234.

Two electro-magnets are shown in Fig. 234, in which the North pole of
one magnet is near the South pole of the other, and the magnetic field
between the two lies in the approximately straight lines between the two
magnets, as indicated by the dotted lines. If the wire CD be moved across
this field and its ends be joined, as by the metallic circuit CEFD, a current
will flow in this circuit. The wire CD may be made to revolve around the
wire EF, passing in front of one pole and then in front of the other pole, as
in Fig. 235. The current in the circuit will pass in one direction when the
wire is passing one pole, and in the other direction when it is passing the
other pole. The connection between this elementary arrangement and the
dynamo is easily recognized. In the dynamo a magnetic field is produced by
electric magnets, called “pole pieces,” and a considerable number of wires
similar to the wire CD are placed upon an armature so that they revolve in
front of these poles. Each individual wire produces current first in one
direction and then in another direction, as explained above; but if there be
many wires there will always be the same number in front of the North, or
positive pole, and the same number in front of the South, or negative pole,
so that the total or resultant action is practically uniform, and may be made
to produce a continuous current. Such a machine is the common direct
current dynamo, or motor.

Fig. 235.

A dynamo transforms mechanical into electrical energy, and a motor
transforms electrical into mechanical energy. The two operations are
reversible, and may be effected in the same machine; a dynamo may be
used as a motor, or a motor may become a dynamo.
A dynamo is a motor when it is driven by a current of electricity, and it is
a dynamo when it is driven by mechanical power and produces an electric
current. If a motor be driven by an engine, it can deliver a current of
electricity which is able to operate other motors or electrical apparatus or
lights. A simple form of electric machine is shown in Fig. 236, which is a
general form of the electric motor. In this there are two projections of steel,
H and G, which are made electro-magnets by the current flowing through
the wires wound around them from any source of electricity, such as a
battery at I and J. These magnets have poles facing toward an armature, K,
on a shaft. The poles G and H are called the “salient” poles; the poles M and
P are called the “consequent” poles. The magnetic flow or field is shown by
the dotted lines. On the periphery of the armature are wires in the slots
shown. As this armature revolves, there will be a tendency for electricity to
flow through the wires.

Fig. 236.

In order to distribute a current of electricity through these wires it is
necessary to make a complete circuit. As each of the wires in the slots
passes in front of a pole, a pressure or electro-motive force will be
generated, and its direction will depend upon whether the pole is a North or
a South pole, i.e., + or -.
Note.—In the above illustrations I and J represent the ordinary electric battery; in
electrical literature such marks always indicate a battery.

The pressure or electro-motive force generated in the wires moving in
front of the North, or positive field poles, will be in one direction, while that
of those in front of the South, or negative field poles, will be in the opposite
direction. Therefore, if two such wires be connected together at one end of
the armature, the free terminals of the wires at the other end of the armature

will have the sum of the electro-motive forces generated in the two wires.
The wires so connected can be considered as a turn of a single wire instead
of two separate wires, and this turn may be connected in series with other
turns, so that the resulting electro-motive force is the sum of that in all the
turns and all the wires so connected. It is customary to connect the coils of
an armature so that the electro motive force given is that obtained from half
the coils in series. The other half of the coils is connected in parallel with
the first half, so that the currents flowing in the two halves will unite to give
a current in the external circuit equal to twice the current in the two
armature circuits or paths.
It is evident that, as the armature revolves, wires which were in front of
the positive pole will pass in front of the negative, and that in order to
maintain the electro-motive force it will be necessary to change the
connections from the armature winding to the external circuit in such a way
that all the wires between the two points of connection will have their
electro-motive forces in the proper direction. The connection to the
armature must therefore be made not at a definite point in the armature
itself, but at a definite point with reference to the field magnets, so that all
the wires between two points or contacts shall always sustain the same
relation to the field magnets.
For this purpose a device known as a “commutator” is provided. The
commutator is made up of a number of segments, as shown at A, in Fig.
237, which are connected to the armature winding. On the commutator, rest
sliding contacts, or brushes, which bear on the segments and are joined to
an external circuit, making a continuous path through which current may
flow. As the commutator revolves, the different segments come under the
brushes, so that the relative position of the armature wires between the
brushes is dependent on the position of the brushes. The armature wires
which connect the brushes are those sustaining the desired definite position
to the field magnets, so that the currents from the armature at all times flow
properly into the external circuit, although individual armature wires carry
currents first in one direction and then in the other direction, depending on
the character of the pole in front of which they may be moving.

Fig. 237.

On two-pole machines there are two brush-holders, each containing one
or more brushes. On the four-pole machine there may be either two or four
brush-holders, and on a six-pole machine, either two, four, or six brush-
holders.
A single path of the current through the commutator and armature
winding is shown by the arrows on Fig. 237. The brushes B and C are
placed on the top side of the commutator to make them more accessible,
and this shows a peculiar but simple armature winding.
For the sake of simplicity, the batteries I and J, of Fig. 236, are not used
on common forms of generators or motors, but the current that flows from
the armature through the commutator is made to flow through the electro-
magnets either in whole or in part. If all of the armature current flows

around the electro-magnets or fields of the machine, it is a “series”
machine; if only a part of the current is used in this way, it is a “shunt”
machine; that is, some of the current is “shunted” through the fields.
Sometimes both the shunt and series windings are used, and in that case the
machine is called a “compound wound” machine. Such a machine has a
large wire through which the main current passes, and a fine wire through
which the shunted current flows. Fig. 237 shows how the commutator and
the fields are connected, and how the current flows from the wires in the
armature through the commutator in a series machine.
If the current delivered by a dynamo does not flow in the desired
direction, it can be reversed by shifting the wires in the binding posts or by
throwing a switch. If the motor does not revolve in the desired direction, it
can be made to do so by reversing the connections to the armature or field-
coils; so that, without knowing which way a current of electricity is to be
generated, any practical man can make a motor revolve in a proper direction
by simply changing its connections.
It is natural that a machine which gives out electric energy when driven
by an external power, should, when electric energy is delivered to it, reverse
its action and give out mechanical power and do work.
Perhaps the simplest way to explain the cause of the movement of an
electric motor, when supplied with a current, is to compare its action to the
well-known attraction of unlike poles or magnets and the repulsion of like
poles. Unlike poles are North and South; like poles are two North or two
South. In all motors a current through the field causes a North or South pole
to be maintained, and a current through the armature and brushes causes an
opposite polarity. These constantly-maintained unlike poles attract each
other and pull the armature around on its axis.
It has been explained that if a motor be driven by a belt an electro-motive
force is produced and the machine acts as a dynamo. It is also a fact that an
electro-motive force is produced whether the power for driving the machine
is received from a belt or from the electric current,—that is, whether the
machine be driven as a dynamo or as a motor. In a dynamo, however, the
current follows the direction in which the electro-motive force is acting. In
a motor, the electro-motive force produced has a direction opposed to that
of the flow of current. This may be illustrated by the following experiment.

Two similar machines are driven independently at 600 revolutions and
give an electro-motive force of 100 volts. Similar terminals of the two
machines are connected together; no current flows between the machines,
because the two pressures are the same and are in opposite directions. If
now the belt be thrown off from one machine, its speed will begin to fall;
this will lower its electro-motive force below that of the other machine or
dynamo, but will not change the direction of the force. There will now be a
difference of pressure in favor of the machine which is driven, and it will
deliver a current through the other machine and run it as a motor. The speed
of the motor will continue to fall until the difference in pressure or electro-
motive force between the two machines is only sufficient to cause the flow
of enough current to keep the motor running against whatever frictional
resistance, and other resistance there may be. The electro-motive force
generated in the motor, which is against, or counter to that of the current in
the circuit, is called the “counter electro-motive force.”
In order to determine how fast a motor will run without doing work under
any given pressure, it is not necessary to know anything about the dynamo
that furnishes the pressure. The pressure alone is sufficient to determine the
speed of the motor. For instance, if a motor will give a pressure of 500 volts
when running free at 100 revolutions, it will always run at about 100
revolutions when not doing work on an electric circuit where the pressure is
500 volts.

MAGNETIC NEEDLE.

The figure on page 242 shows a magnetic compass needle. This is used to
test the direction of an electric current flowing through a wire or cable
conductor. The plus sign, +, is the positive and the minus, -, sign is the
negative end or pole. A continuous current always flows from the positive to
the negative end or pole, hence the north end or pole, N, is the positive end
of the needle and the south pole, S, is the south pole of the needle.
When one of these devices is held in close proximity to a conductor of
electricity it immediately assumes a parallel position to the conductor and
indicates the direction in which the current is flowing. The long, upper
arrow, as shown in the figure, tells the direction of the flow. A small pocket
compass may be used in place of this device and is often carried in the

pocket of electricians for the purpose of indicating the direction of the
current.

PRESSURE IS NECESSARY TO PRODUCE AN ELECTRIC
CURRENT.

It should be understood that an electric dynamo or battery does not
generate electricity, for if it were only the quantity of electricity that is
desired, there would be no use for machines, as the earth may be regarded
as a vast reservoir of electricity, of infinite quantity. But electricity in
quantity without pressure is useless, as in the case of air or water, we can
get no power without pressure, a flow of current.
As much air or water must flow into the pump or blower at one end, as
flows out at the other. So it is with the dynamo; for proof that the current is
not generated in the machine, we can measure the current flowing out
through one wire, and in through the other—it will be found to be precisely
the same. As in mechanics a pressure is necessary to produce a current of
air, so in electrical phenomena an electro-motive force is necessary to
produce a current of electricity. A current in either case can not exist
without a pressure to produce it.

ELECTRIC PUMPING MACHINERY.

Since the conditions surrounding pumping plants are so widely different,
it is impossible to treat every practical application in detail, hence, the space
allotted to this subject has been used in the preceding succinct and plain
discussion of the principles upon which electric power is applied to the
operation of pumps.
The following are some of the advantages claimed for electric pumping
machinery:
“Economy in operation and maintenance is the first and most vital
consideration that demands the attention in the installation of pumping
machinery. In respect to economy, the electric system has many important
advantages. It is saving in the transmission of power, and thus enables a
pumping installation to be situated at a considerable distance from the

source of power where the first cost and maintenance expense of other
systems would be almost prohibitive.
“The economy in space required is also worthy of consideration. The
driving mechanism of a modern electric pumping outfit occupies a small
amount of room and the space required for wiring is negligible. In case of
accident, any mechanical injury to wires can be quickly and easily repaired
—thus the economy in time and expenditure for repairs. There is no large
loss by condensation. The only loss sustained with the electric system in the
transmission of power is a small loss due to line resistance, increasing
directly with the amount of water being pumped and ceasing entirely when
the pump is not in operation.”
A well designed electric pump will give an efficiency of from 75 to 80
per cent.; and, as the transmission loss depends upon the weight of copper
in the transmission line it can be made as low as the cost of power, and, 2,
the investment in copper will warrant.

DIRECTIONS FOR INSTALLATION.

1. It is important to locate the electric pump where it will be dry and
clean and where it will be thoroughly accessible for proper care.
2. No pipes should be allowed to pass above the electric motor where
liquids are likely to drip upon it.
3. The suction or supply pipe must be as short and straight as possible
and must be air tight, as air entering the pump through the suction reduces
its capacity or prevents it from working altogether.
4. A tight foot valve and a strainer should invariably be used on the
bottom end of the suction pipe when the water is to be lifted from 8 ft. to 10
ft. below the pump. Where the lift is excessive or for any reason the supply
be limited, an air chamber placed on the suction pipe near the pump will
prove beneficial in preventing slamming of the valves.
5. Provision should be made for draining both pumps and pipes in cold
weather by a proper application of frost cocks.
6. If the electric pump is kept dry, clean and well oiled, it will prove the
most desirable and least expensive apparatus to be had for the service.

7. Ascertain the nature of electric current to be used. Direct or
alternating? Voltage? (If alternating, note phase and number of alternations.)
8. Also record any unusual or peculiar circumstances connected with the
installation or operation of the apparatus; and if so, what?

DOMESTIC ELECTRIC PUMPS.

Fig. 238.

Fig. 239.

In many places the pressure on the mains is insufficient to raise the water
to the upper floors or through improperly designed systems of piping the
pressure may be so diminished as to make the flow extremely weak or the
difficulty in securing proper water supply may be due to inconvenient

location with reference to water mains. The automatic electric house tank
pumping plant has been designed and perfected to meet these conditions;
the electric plant is connected to some power or lighting circuit and
provided with an automatic attachment requiring no more care than can be
given by any casual attendant. Such an installation avoids the smoke, ashes,
dust and objectionable odors that accompany steam or gas plants.
The accompanying diagram shows the general arrangement of the
automatic electric house system used with a tank in the upper part of the
building and the pump in the basement or cellar. The operation is as
follows:
When water is being delivered to the tank, the float rises until the upper
knob makes forcible contact with the switch lever, opening the switch and
stopping the pump. When water is withdrawn from the tank, the float falls
until the lower knob makes contact with the switch lever, which again
closes the switch and starts the pump. The supply of water is thus
maintained within the tank without the aid of an attendant. The
accompanying illustration, Fig. 238, shows a Worthington house tank pump
of 500 gallons per hour capacity belted to a General Electric direct current
motor, the pump and motor being mounted on the same base.
Table of Capacity.
Maximum
Feet 1 H.P. Feet 2 H.P.
Diameter Length Revolutions Gallons Water Gallons
Will Pump Will Pump
of Plungers of Stroke per Minute per Minute Pressure per Hour
Against Against
in Lbs.
2 4 45 9.8 150 500 175 300
23⁄4 4 45 18.5 75 1,000 80 175
3 4 45 21.8 60 1,200 70 140
33⁄4 4 45 34.4 40 1,800 50 100

The above useful table is inserted to show the capacities, revolutions, size
of plungers, etc., in these electrically driven pumps, the automatic feature of
which is truly admirable.
It must be remembered that the number of combinations between small
electric motors and proportionate pumps for water, gas, air, etc., afford an
endless field for the exercise of engineering skill.

ELECTRIC MOTOR AND AIR PUMP.

Fig. 240 is intended to show the application of the electric motor to a
triplex pump of small size, the plungers being 31⁄8 inches in diameter. The
Stroke is 47⁄8 inches which gives a capacity of 108 cubic inches per
revolution, with a pressure of 50 lbs. to the square inch. The pumps require
about one-half horse power applied at the motor.

Fig. 240.

The high speed of the motor is reduced by two belt pulleys and two chain
wheels. These pumps may be worked independently to produce pressure or
vacuum as desired by a separate pipe for each pump.

MOTOR AND CENTRIFUGAL PUMP.

Fig. 241 is intended to show the application of the electric motor to a
centrifugal pump; these two machines are mounted on one bed plate,
directly connected by a flange coupling between them. The motor shown, is
almost identical with the machine illustrated, Fig. 217, and described on
page 251. The pump is so arranged that the discharge can be turned in any
direction desired. Wherever electric power is available and the centrifugal
pump is the form best adapted to the work, this combination presents
advantages over a steam engine operated by a plain slide valve such as is
generally used.

Fig. 241.

DIRECT DRIVEN MOTOR PUMP.

Fig. 242 shows a double pump driven directly, without gears or belt, from
the shaft of an electric motor. The pump crossheads are connected directly
to cranks at each end of the motor shaft. The cranks are set at right angles
and each pump is double acting, or has two plungers connected by outside

rods and with outside packed stuffing-boxes, so that this portion of the
pump is always accessible.
The plungers are 31⁄2 inches diameter and 51⁄2 inches stroke. The pump
and motor are mounted upon a rigid box girder frame: this unit is self-
contained and occupies a relatively small floor space.
Electric Drive for Fire Pumps. The importance of instantly operating fire
extinguishing apparatus can scarcely be exaggerated. The largest
conflagrations are but little flames at the beginning, and if caught at the
critical moment they make no record of destruction; for such service the
electric current is the ideal agent. A notable installation of electric-driven
pumps for fire service is in the Marshall Field store, Chicago, a building
occupying an entire city block. The outfit consists of a Laidlaw-Dunn-
Gordon duplex Underwriter pump connected by single reduction gearing to
a waterproof electric motor.

Fig. 242.

The pump cylinders, 8 × 12 inches, have a computed capacity of 700
gallons per minute at 140 pounds water pressure. The pump, besides its
other special features, is claimed to be rust proof throughout so that it will
not get out of ready running condition.

Fig. 243.

ELECTRIC-MINING PUMPS.

The electric system has especial conveniences for mine pumping because
of its adaptability to long transmissions of power; electric power can be
transmitted to almost any distance, and the pumps can be supplied with
either direct or alternating current motors. A mining outfit can be easily
divided into a number of parts, to facilitate lowering into a mine, after
which the assembling of the parts is a simple operation.
Stationary pumps for mine use are made in two classes: first, vertical
pumps having cylinders in a vertical position in which the over all height is
comparatively great and the horizontal dimensions as small as possible;
second, horizontal pumps with cylinders in a horizontal position and having
for cross dimensions the over all length. The class of pump to be selected,
of course, depends upon the limitations of the location. In either case, the
motor used for driving the pump is mounted on an extension of the pump
base, making a self-contained and compact outfit.

Engraving, Fig. 243, represents a Quintuplex pump used principally in
mining operations, or wherever large quantities of water are to be delivered
under high pressure in the shortest possible space of time. The pump here
shown was designed to deliver 225 gallons of water per minute under a
head of 1,200 feet. It has five plungers 4 inches in diameter each and having
a uniform stroke of 12 inches.
These pumps driven by electric motors it is said represent the most
economical method of transmitting power, as compared with the best
designs of steam pumps. An efficiency of 80 per cent. is claimed for these
pumps.
Note.—It is interesting to know that in one of the largest electric pumping installations
which has ever been made for mining work, the power is carried 2,500 feet underground at
a potential of 3,500 volts and then transformed into 220 volts at the motors. No trouble has
thus far resulted from the high voltage or any other cause; in regard to danger from
underground electric pumps, it can be stated that accidents due to the use of electricity in
such installations are almost unknown. Induction motors are arranged to operate without
moving contacts. They are therefore free from sparks and can be used in mines where the
presence of gases compels the use of safety lamps.

Fig. 244 exhibits an electric induction motor operating a 51⁄2 × 8 portable
track pump.
Portability is an important feature in all pumps for mine use; and, as track
pumps may be put into service immediately at any point on a system of
tracks, they meet this requirement better than pumps of any other form.
Such an outfit can be hauled to any point in the mine and there operated
from some convenient circuit such, for instance, as the circuit supplying
power to mine locomotives.

Fig. 244.

The pump and motor shown in Fig. 244 are mounted on an iron truck, no
wood whatever being used in construction, so that adjustment cannot be
affected by moisture and an easy running and durable pump is assured. The
pumps are made as compact and strong as possible for mine service, which
is usually exceptionally rough and continuous. They are of the horizontal
type which is best adapted for low passageways and are designed so as to
afford easy access to all parts. The pumps are single acting and the plungers
are provided with outside stuffing-boxes, which can be packed, and being in
sight, any leakage can be quickly detected. Access to all valves is made
easy by the removal of one large hand-hole cover on the valve chest.

THE STEAM

PUMP

Fig. 245.
G.KIRKHAM

THE STEAM PUMP.
The illustration, Fig. 245, on the opposite page represents the first
practical steam pump ever made; on pages 67-69 will be found an
interesting account of it. The water end is single acting; the steam end is, of
necessity, double acting to produce the reciprocating motion. From this
original design has been evolved the piston valve as well as many other
designs of valve motion for pumps.
Having already taken up in some detail the construction of “the parts of
the pump” and the necessary appliances connected with its use, it now
remains to consider the means by which the steam power generated is made
available and the mechanism by which the energy is transformed from
pressure into pumping power.
It may be well to consider at some length the “Steam end” of the pump.
This consists primarily of cylinders, together with their connections; these
constitute the muscular system of the pump. The muscular or operating end
is separate and distinct from the water end so far as construction is
concerned but in operation the two are closely allied. It is therefore
necessary as well as convenient to unite them in one equipment and thus
enable the propelling mechanism to furnish a constant source of power.
So far as the elastic force of steam itself is concerned its history dates
back to a period two hundred years B. C., when, as described by Hero, the
force generated by steam was utilized for actuating certain devices
constructed rather for curiosity than for any benefit which might be derived
from their use. Very little advance was made in the construction of practical
devices until the latter part of the eighteenth century when James Watt by
his improvements placed the stationary engine on an operative basis and
gave to the world what has proved to be the greatest invention of all time.
The first stationary steam engines were used for pumping water and were
of the single acting type, in which the steam was admitted at one end of the
cylinder, the opposite end being open to the atmosphere. The steam acting
on the piston forced it to the limit of its stroke when the supply was cut off.
The steam then condensed in the cylinder, forming a partial vacuum, and

the force of the atmosphere upon the opposite side of the piston forced it
back, causing it to complete its stroke before another supply of steam was
admitted. This was a slow process, wasteful of steam and attended with
many other inconveniences.
An improvement on this device was made in an engine built by Watt in
1774. This was a single acting engine but the condenser was separated from
the cylinder. The valves were so arranged as to admit live steam into the
upper end of the cylinder on the top of the piston and at the same time open
the lower end of the cylinder to the condenser. The steam followed the
piston in its downward stroke in which action it was aided by the partial
vacuum formed in the condenser. At the completion of the downward stroke
the valves were changed so as to close the ports to the steam supply and the
condenser, and at the same time open a communication between the two
ends of the cylinder equalizing the pressure above and below the piston.
The weight of the pump rod on the beam or lever connection overbalanced
the weight of the piston and caused it to complete the return stroke.
In 1782 the double acting steam engine was patented by Watt. This was a
device in which the live steam acted on each side of the piston alternately,
the opposite side of the cylinder being in communication with the
condenser. The same patent covered the method of applying the principle of
expansion of steam in the cylinder; a non-condensing engine was also
described.
Note.—This invention was of great historical importance as it covered all the essential
detail of modern practice in steam engine building and constituted the fundamental
principle of all steam engines.
Improvements have been made in form and construction, necessitated by new
adaptations which have been constantly developed. The requirements for higher speed,
increased pressure which implies greater power, and the constant desire for greater
economy in fuel have produced a variety of changes in detail but have not altered the
fundamental idea.

When the steam after being utilized in the cylinder makes its exit directly
to the open air, the engine is called single expansion for the reason that the
action of the steam takes place in one cylinder during a single stroke, and
what expansion takes place must be during one half of a revolution. When
the steam from one cylinder instead of exhausting into the open air, is
passed to a second cylinder, of larger area, and by expanding exerts a
pressure on a second piston to aid in the completion of the revolution, the

engine is called double expansion or compound, because the steam instead
of completing its work in a single operation is afforded a double
opportunity for expansion and an increased range of action. In the single
cylinder the temperature of the walls is reduced in each revolution to
correspond with that of the steam at the exhaust pressure.
This temperature must be restored by incoming steam at the beginning of
a new stroke which means a reduction of power. With a double cylinder
owing to the greater range of expansion, a higher temperature can be
maintained in the first cylinder and a large amount of initial condensation is
prevented. A still greater use of expansion may be obtained by the
introduction of a condenser which allows the final exhaust to be carried
below the atmospheric pressure to the extent of the vacuum formed. In
stationary and marine practice triple and quadruple expansion engines are
common. These are used in large units to give the greatest possible
economy in fuel.
Properties of Steam.—Before taking up in detail the valve and other
mechanism of the steam pump it may not be out of place to consider briefly
the action of steam and its expansive properties. Heat is identical with
mechanical force and the one can be converted into the other. Aside from
the means used in converting or developing the action a certain quantity of
heat always produces a certain quantity of work.

Fig. 246.

The temperature of steam at atmospheric pressure (14.7 lbs. absolute) is
212° Fahr. As the pressure increases the temperature rises, but is always the
same for a given pressure. The sensible heat required to raise the
temperature of water from 32° to 212° is 180° and the heat absorbed by the
water or latent heat at 212° is 996° making the total amount of heat
expended 1176°. As the temperature rises the latent heat decreases in nearly
the same proportion as the sensible heat increases. This number may
therefore be taken as a constant to express the unit of heat in one pound of

steam from 32° up to the temperature at which evaporation takes place.
Then 1176 × 772 = 907,872 pounds raised one foot which represents the
mechanical equivalent or maximum theoretical duty of the quantity of heat
contained in one pound of steam.
One cubic inch of water if converted into steam at the pressure of the
atmosphere (14.7 pounds) will occupy the space of 1642 cubic inches or
nearly one cubic foot. As the pressure increases the volume is relatively
diminished and if the same quantity of water is converted into steam say at
200 pounds pressure it will occupy a space of only 133 cubic inches.
Assuming that no loss occurred by condensation, if released at this pressure
it would expand and again occupy its relative volume at atmospheric
pressure.
This is illustrated by the accompanying diagram, Fig. 246, showing a
cylinder with an internal capacity of 1642 cubic inches provided with a
movable piston. A quantity of steam representing that formed from one
cubic inch of water is forced into it, supposing the weight on the piston to
be 200 lbs. per square inch, this weight will be raised until the space under
the piston occupied by the steam will be 133 cubic inches. If the supply is
now cut off (assuming that no condensation takes place) the piston will
remain at this place supporting its load. If the load on the piston is
diminished the volume of steam will expand and the piston will be
correspondingly raised in the cylinder. This action will be continued until
all the load is removed and only the weight of the atmosphere remains. The
volume of steam under the piston will then be 1642 cubic inches. It will
therefore be seen that the same quantity of steam has exerted a lifting
pressure upon the piston due to its relative volume commencing at 200
pounds per square inch and gradually decreasing until the pressure of the
atmosphere is reached.
The English unit of heat is that which is required to raise the temperature
of one pound of water one degree Fahrenheit and is known as the British
Thermal Unit, or B. T. U. Dr. Joule demonstrated by an ingenious device,
Fig. 247, in which a weight operated a paddle wheel agitating water in a
closed vessel, that it required 772 foot pounds to raise the temperature of
one cubic foot of water one degree, or, on the other hand, it was deduced
that one unit of heat was capable of raising 772 pounds one foot high. The

mechanical equivalent of heat is therefore accepted as 772 foot pounds for
one B. T. U. based on Joule’s experiment.A
The theoretical efficiency
of the use of steam by
expansion can never be
realized, owing to losses
occasioned by condensation,
caused by contact with the
cooler walls of the cylinder,
the unavoidable friction of
the working parts, and from
the fact that a certain portion
of the pressure must be
utilized to create a draft for
the fire. All these losses must
Fig. 247. be taken into consideration in
calculating the work actually
done.
From the foregoing it will be readily understood that if the steam is
allowed to exhaust from the cylinders at or near the pressure at which it is
admitted the work which it might have accomplished by expansion will be
lost. This means not only a loss of the steam but of a part of the fuel used to
generate it.
It is therefore advisable to get all the work out of the steam that is
possible and the nearer to atmospheric pressure the exhaust can be brought
the greater will be the economy.

FOOTNOTE:
A Note.—This unit has been recently changed to 778.

USEFUL DEFINITIONS RELATING TO STEAM.

Steam is water in a gaseous state; the gas or vapor of water; it liquifies
under a pressure of 14·7 and temperature of 212° F.