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FARM IMPLEMENTS

AND

FARM MACHINERY,

AND THE

Principles of their Construction and Use:

WITH

SIMPLE AND PRACTICAL EXPLANATIONS

OF THE

Lj\.w^s of MiOTionv ^ivr> fouck

AS APPLIED

ON THE FARM.

With SSr Illustrations.
BY

JOHN J. THOMAS.

NEW YORK:
ORANGE JUDD AND COMPANY,

245 BROADWAY.

Entered according to Act of Congress, in the year 1869, by

JOHN J. THOMAS,

In the Clerk's Office of the District Court of the United States for the Southern
DlBtrict of New York.

/a-thd^

/

PREFACE.

A small treatise, — the basis of the present work, — was
originally published in the Transactions of the lN"ew York
State Agricultural Society for 1850, under the title of
"Agricultural Dynamics," or the Science of Farm
Forces. A revised and greatly enlarged edition, adapted
to general use, was afterwards issued in book form, with
the name of " Farm Implements." Since the appearance
of the earlier editions, great and rapid improvements have
been made in farm machinery of nearly every kind ; and
the aim of the work in its present form is to supply, so
far as its limits will admit, the information eagerly sought
by cultivators in relation to all that has proved of value.

Another principal object has been to present in a simple
and intelligible manner, the leading principles of Mechan-
ical Science, applied directly in the farmer's daily routine,
— that he may know the reasons of success and failure,
and not be guided by random guessing. The first portion
of the book is chiefly devoted to a practical explanation
of these principles.

Union Springs, N". Y„ 1869.

CONTENTS,

PAIIT L— MECPIANICS.
CHAPTER I.
Introduction.— Value of Farm Macliiner}- — Importance of a

Kuowledge of Mechanical Principles 7-10

CHAPTER 11.
General Principles of Mechanics. — Inertia, Experiments and
Examples — Inertia of Moving Bodies, or Momentum — Fast
Riding— The Tiger's Leap— Pile Engines— Fly-wheel— Esti-
mating the Quantity of Momentum— Compound Motion —
Various Examples— Centrifugal Force .- 10-22

CHAPTER III.
Attraction. — Gravitation — Velocity of Falling Bodies — Resist-
ance of the Air— Coin and Feather— Galileo's Famous Experi-
ment—Cohesion-Soils — Strength of Materials— Capillary
Attraction — The Earth a Desert without it— The Ascent of
Sap — Centre of Gravity — Experiments — Upsetting Loads —
Shouldering Bags— Rocking Bodies 22-42

CHAPTER IV.

Simple Machines, or Mechanical Powers.— Law of Virtual
Velocities — The Lever — Many Examples of Levers — Esti-
mating the Power of Levers — Three-horse Whiffle-tre.e —
Compound Levers — Weighing Machines — Stump Pullers —
A Wild Theory— Wheel and Axle— Examples— Band and
Cog-work— The PuUej^— Packer's Stone Lifter— The Inclin-
ed Plane— Crooked Roads— Power of Locomotives— Good
and Bad Roads— The Wedge— The Screw — Knee-joint Pow-
er— Lever Washing Machine — Cheese Presses — Rolling Mills

—Straw Cutters 42-74

CHAPTER V.

Application of Mechanical Principles in the Structure of
Implements and Machines— Various Examples— Calculating
the Strength of Parts 75-81

CHAPTER VI.
Friction.— How to ascertain its Amount— Friction on Roads-
Resistance of Mud— The Results of the Dynamometer —
Width of Wheels— Velocity— Size of Wheels on Roads-
Friction Wheels— Lubricating Substances— Friction neces-
sary to Existence 81-93

CHAPTER VII.
Principles of Draught- Applied to Wagons— To Plows— Com-
bined Draught of Animals— Whiffle-trees for Three Horses—
4

CONTENTS. V

Potter's do.— Wier's Single-tree— The Dynamometer— Self-
registering do. — Waterman's do. — Dynamometer for Rotary
Motion 93-108

CHAPTER VIII.
ArrLTCATiON OF Labor.— Power of Horses— Of Men— Best Way

to Apply Strength 108-113

CHAPTER IX.
Models of Machines. — Common Blunders— Works of Creation

Free from Mistakes 113-115

CHAPTER X.
Construction and Use of Farm Implements and Machines
— Implements of Tillage. — Importance of Simplicity —
Plows— Rude Specimens— Cast-iron nnd Steel do.— Charac-
ter of a Good Plow— The Cutting Edge— Mould-board-
Easy Running Plows— Crested Furrow Slices— Lapping and
Flat Furrows— How to Plow Well— Fast and Slow Plowing
—The Double Michigan— The Subsoil Plow— The Paring
Plow— Gang Plow— Ditching Plow — Mole Plow— Coulters
— Weed Hook and Chain — Pulverizers — Harrows — Gcd-
des' Harrows — Scotch do. — Moi-gan Harrow — Norwegian
do.— Shares' do.— Cultivators— Holbrook's—Alden's— Gar-
rett's Horse-hoe— Two-horse Cultivators — Sulky do. — Com-
stock's Spader— Clod Crushers — Roller 115-152

CHAPTER XL
Sowing Maciiines— Wheat Drills — Biekfordand Huffman's do. —
Seymour's Broadcast Sower— Corn Planters— Truc's Po-
tato Planter— Hand Drills .153-157

CHAPTER XII.
Machines for Haying and Harvesting. — Mowing and Reap-
ing Machines — Cutter-bar — Combined Machines — Self
Rakers— Johnson's do. — Marsh's and Kirby's do. — Dropper
— Binders— Marsh's Harvester— Durability and Selection of
Machines— Hay Teddeis— Bullard's do. — American do. —
Horse Rakes— Revolving do.— Sulky Revolvers— Warner's
do. — Spring Tooth Rakes — HoUingsworth's do. — Hay
Sweep — Horse Forks— Cladding's do. — Palmer's, Myers'
Beardsley's, Raymond's — Harpoon Forks — Hay Carriers —
Hicks' do. — Building Stacks — Palmer's Hay Stacker — Ray-
mond's Hay Stacker — Dederick's Hay Press — Beater do. —
Hay Loaders 158-186

CHAPTER XIIL
Thrashing, Grinding, and Preparing Products. — Value of
Thrashing Machines — Endless Chain Power — How to
Measure Power of— Churning by Tread Power— Pitt's Ele-

TI CONTENTS.

vator — Corn Shellcrs — Bnrralls', Richards' — Root Washer
— Root Slicers — Farm Mills, Allen's, Forsman's — Emery
Cotton Gin 186-197

PART IL-MACHIKERY IN CONNECTION WITH WATER
CHAPTER I.

IItdrostatics. — Upward Pressure — Measuring Pressure — Cal-
culatin.i? Strength of Tubes, ete. — Artesian Wells— Determ-
ining Pressure in Vessels— A Puzzle Explahied—Hydro-
Btatic Bellows— Press— Specific Gravities— Table of do. —
Weight and Bulk of a Ton of Different Substances 198-210

CHAPTER II.
Hydraulics. — Velocity of Water — Discharge of Water through
Pipes — Velocity in Ditches — Leveling Ditches — Archime-
dean Screw-pumps — For Cisterns — Non-freezing do. — For
Deep Wells — Drive Pumps — Chain Pumps — Rotary do. —
Suction and Forcing Pump— Turbine Water Wheels— The
Water Ram— Water Engines for Gardens— Flash Wheel —
Nature of Waves — Size of do. — Preventing Inroads by do.
— Cisterns — To Determine Contents of 211-238

PART III.-MACIIINERY IN CONNECTION WITH AIR.

CHAPTER I.
Pressure of Air. — Weight of the Atmosphere— Hand Fastened

by Air — Barometer — Measuring Heights — Syphon 239-245

CHAPTER II.
Motion of Air.— Winds— Wind-mills, how Used— Brown's do.
— Causes of Wind — Chimney Currents — Construction of
Chimneys — To Cure Smoky do. — Chimney C:»i)s — Ventila-
tion 245-259

PART lY.— HEAT.
CHAPTER I.
Conducting Power— Expansion, Great Force of— Experiments
•with— Steam Engine — do., for Farms — Steam Plows—

Latent Heat— Green and Dry Wood 2G0-27G

CHAPTER IL
Radiation.— Several Examples in Domestic Economy — Dew and

Frost— Frost in Valleys— Sites for Fruit Orchards 276-280

APPENDIX.

Apparatus for Experiments 281-283

Discharge of Water through Pipes 284

Velocity of Water in Pipes 284

Rule for Discharire of Water 285-286

Velocity of Water in Tile Drains 286

Glossary 287-296

FARM IMPLEMENTS

AND

FARM MACHINERY.

PART I.

MECHANICS.

CHAPTER I.

INTRODUCTION.

No farm can be well furnished vvithout a large number
of machines and implements. Scarcely any labor is per-
formed without their assistance, from the simple opera-
tions of hoeing and spading, to the more complex work
of turning the sod and driving the thrashing-machine.
The more j)erfect this machinery, and the better fitted to
its work, the greater will be the gain derived by the farm-
er from its use. It becomes, therefore, a matter of vital
importance to be able to construct the best, or to select
the best already constructed, and to apply the forces re-
quired for the use of such machines to the greatest possi-
ble advantage.
7

8 MECHANICS.

Nothing shows the advancement of modern agriculturo
in a more striking light than the rapid improvement in
farm implements. It has enabled the farmer within the
last fifty years to effect several times the w^ork with an
equal force of horses and men. Plows turn up the soil
deeper, more evenly and perfectly, and with greater ease
of draught; hoes and spades have become lighter and
more efficient ; grain, instead of being beaten out by the
slow and laborious work of the flail, is now showered in
torrents from the thrashing-machine ; horse-rakes accom-
plish singly the work of many men using the old hand-
rake ; horse-forks convey hay to the barn or stack with
ease and rapidity ; twelve acres of ripe grain are neatly
cut in one day Avith a two-horse reaper; grain drills and
planting machines, avoiding the tiresome drudgery of hand
labor, distribute the seed for the future crop with even-
ness and precision.

The owner of a seventy-thousand-acre farm in Illinois
carries on nearly all his work by labor-saving machinery.
He drives posts by horse-power ; breaks his ground with
Comstock's rotary spader; mows, rakes, loads, unloads,
and stacks his hay by horse-power; cultivates his corn
with two-horse, seated or sulky cultivators; ditches low
ground, sows and plants by machinery; so that his labor-
ers ride in the performance of their tasks without exliaust-
incr their strenorth with needless walking: over extended
fields.

The great value of improved farm machinery to the
country at large has been lately proved by the introduc-
tion of the reaper. Careful estimate determined that the
number of reaping machines introduced throughout the
country up to the beginning of the great rebellion, per-
formed an amount of labor wliile working in harvest
nearly equal to a million of men with hand implements.
The reaper thus filled the void caused by the demand on
workingmen for the army. An earlier occurrence of that

VALUE OF FARM MACHINERY. 9

war must therefore have resulted in the general ruin of
the grain interest, and prevented the annual shipment of
the millions during that gigantic contest, which so greatly
surprised the commercial savans of Europe.

The implements and machines which every farmer must
have who does his work well are numerous and often
costly. A farm of one hundred acres requires the aid of
nearly all the following; two or more good plows, a
shovel-plow, a small plow, a subsoiler, a single and two-
horse cultivator, a seed-planter, a grain-drill, a roller, a
harrow, a fanning-inill, a straw-cutter, a root-slicer, a farm
wagon with hay-rack, an ox-cart, a horse-cart, wheel-bar-
row, sled, shovels, spades, hoes, hay-forks and manure-
forks, hand-rakes and horse-rakes, scythes and grain-
cradle, grain-shovel, maul and wedges, pick, axes, wood-
saw, hay-knife, apple-ladders, and many other smaller con-
veniences. The capital for furnishing the farms in the
Union has been computed to amount to more than five
hundred millions of dollars, and as much more is estimat-
ed to be yearly paid for the labor of men and horses
throughout the country at large. To increase the effect-
ive force of labor only one-fifth would, therefore, add an-
nually one hundred millions in the aggregate to the profits
of farming.

A knowledge of the science of mechanics is not so well
understood among all classes of people as it should be. A
loss often occurs from the want of a correct knowledge
of mechanical principles. The strength of laborers is
badly applied by the use of unsuitable tools, and that of
teams is partly lost by being ill adjusted to the best line
of draught. We may perhaps see but few instances of
so great a blunder as the ignorant teamster committed
who fastened his smaller horse to the shorter end of the
whifile-tree, to balance the large horse at the longer end ;
yet instances are not uncommon where operations are per-
formed to almost as great a disadvantage, and which, to
1*

XO MECHANICS.

a person well versed in the science of mechanics, would
appear nearly as absurd.

It is well worth while to look at the achievements made
through a knowledge of meclianical principles. Compare
the condition of barbarous and savage tribes with that of
modem civilized nations. The former, scattered in com-
fortless hovels, subsist by precarious hunting, or on scanty
crops raised on patches of ground by means of the rudest
tools. The latter are blessed with smooth, cultivated fields,
green meadows, and golden harvests. Commerce with
its hum of business, extending through populous cities,
and along a hundred far-stretching lines of rail-ways, scat-
ters comforts and luxuries to millions of homes ; while
ships for foreign commerce thread every channel and
whiten every sea. The contrast exhibits the difference
between ignorance on the one hand, and the successful
application of scientific principles on the other. It is our
present object to point out to the farmer the advantages
which would result from a wide extension, through all
classes, of this knowledge, that the opportunities may be
continually increased for general improvement.

CHAPTER n.

GENERAL PRINCIPLES OF MECHANICS.

Having briefly pointed out some of the advantages to
the farmer of understanding the principles of the ma-
chines he constantly uses, we now proceed to an examina-
tion of these principles. It will be most convenient to
begin with the simpler truths of the science, proceeding,
as we advance, to their apj^lication in the construction of
machines.

INERTIA. EXPERIMENTS AND EXAMPLES.

11

INERTIA.

An important quality of all material bodies is inertia.
This term expresses their passive state — that is, that no
body (not having life), when at rest, can move itself, nor,
when in motion, can stop itself. A stone has not power
to commence rolling of its own accord ; a carriage can not
travel on the road without being drawn ; a train of cars
never commences gliding upon the rails without the power
of the locomotive.

On the contrary, a body, when once set in motion, will
continue in motion perpetually, unless stopped by some-
thing else. A cannon ball rolled upon the ground moves
on until its force is gradually overcome by the resistance
of the rough earth. If a polished metallic globe were driven
swiftly on a level and polished metallic j)lane, it would
continue in motion a long time and
travel to a great distance ; but still
the extremely minute roughness of
the surfaces, with the resistance of the
air, would continually diminish its
speed until finally stopped. A wheel
made to spin on its axis revolves un-
til the friction at the axis and the
impeding force of the air bring it to
rest. But if the air is first removed,
:uum. \)j means of an air-pump, the mo-
tion will continue much longer. Under a glass receiver,
thus exhausted, a top has been made to spin for hours,
and a pendulum to vibrate for a day. The resistance of
the air may be easily perceived by first striking the edge
and then the broad side of a large piece of pasteboard
against the air of a room. It is further shown by means
of an interesting experiment Avith the air-pump. Two
fan-wheels, made of sheet tin, one, cr, striking the air
with its edges, and the other, 5, with its broad faces (fig.

Fansrevoli

vmg iti a vaci

12 MECHANICS.

1), are set in motion ali'ke; b is soon brought to rest,
■while a continues revolving a long time. If now they are
placed under the receiver of an air-pump, the air exhaust-
ed, and motion given to them alike by the rack-work c?,
they will both continue in motion during the same period.

There is no machinery made by man free from the
checking influence of friction and the air; and for this
reason, no artificial means have ever devised a perpetual
motion by mechanical force. But we are not without a
proof that motion will continue without ceasing when
nothing operates against it. The revolutions of the planets
in their orbits furnish a sublime instance ; where removed
from all obstructions, these vast globes wheel around in
their immense orbits, through successive centuries, and
with unerring regularity, preserving undiminished the
mighty force given them when first launched into the re-
gions of space.

To set any body in motion, a force is requisite, and the

heavier the body, the greater must be the force. A small

stone is more easily thrown by the hand than a cannon

ball ; speed is more readily given to a skiflf than to a large

and heavy vessel : but the same force

Fig. 2. 1 .,-,-, . . .

which sets a body in motion is re-
0 quired to stop it. Thus a wheel or a
grindstone, made to revolve rapidly,
would need as great an effort of the
arm to stop it suddenly as to give it
, , , , sudden motion. An unusual exertion

Inertia Apparatus.

of the team is necessary in starting a
loaded wagon; but when once on its way, it would
require the same effort of the horses to stop it as to hack
it when at rest.

The force of inertia is finely exhibited by means of a
little instrument called the inertia apparatus (fig. 2). A
marble or small ball is ])laced on a card, c, resting on a
concave stand. A spring snap is then made to strike the

INERTIA. — EXPERIMENTS AND EXAMPLES. 13

card, throwing it to a distance, but leaving the hall upon
the hollow end of the stand. The same experiment may
be easily performed by placing a very small apple or other
solid on a card, the whole resting on a common sand-box,
or even the hollow of the hand. A sud- pj^ 3.

den snap with the finger w^U throw the
card away, while the apple will drop into
the cavity. The following experiment is
still more striking: Procure a thread
just strong enough to bear three pounds,
and hang upon it a weight of two pounds
and a half Another half pound would
break it. Now tie another thread, strong
enough to bear one pound, to the lower ^ ''

hook of the weight. If the lower thread ^

be pulled gradually, the -upper thread
will of course break ; but if it be pulled
with a jerT<, the lower thread will break.
If the jerk be very sudden, the lower string will break,
even it be considerably stronger than the upper, the in-
ertia of the weight requiring a great force to overcome it
suddenly. The threads used in this experiment may be
easily had of any desired strength by taking the finest
sewing cotton, and doubling to any desired extent.

This experiment shows the reason why a horse, Avhen
lie suddenly starts with a loaded wagon, is in danger of
breaking the harness ; and why a heavier weight may be
lifted with a windlass or pulley having a weak rope, if the
strain is gradual and not sudden. For the same reason,
glass vessels full of water are sometimes broken when
hastily lifted by the handle. When a bullet is fired through
a pane of glass, the inertia retains the surrounding glass
in its place during the moment the ball is passing, and a
round hole only is made; while a body moving more
slowly, and pressing the glass for a longer space of time,
fractures the whole pane.

14 MECHAXICS.

INERTIA OF MOVING BODIES, OR MOMENTUM.

Momentum is the inertia of a moving hocly. When a
force is applied to a heavy body, its motion is at first slow ;
but the little momentum it thus acquires, added to the ap-
plied force, increases the velocity. This increase of velocity
is of course attended with increased momentum, which
again, added to the acting force, still further quickens the
speed. For this reason, when a steam-boat leaves the pier,
and its paddle-wheels commence tearing through the wa-
ter, the motion, at first slow, is constantly accelerated un-
til the increasing resistance of the water becomes equal
to the strength of the engine and the momentum.* Were
it not for the momentum of moving bodies (inertia exist-
ing), no speed ever could be given to any heavy body, as
a carriage, boat, or train of cars.

The chief danger in fast riding, or fast traveling of any
kind, is from the momentum given to the traveler. If a
rail-way passenger should step from a car when in full mo-
tion, he would strike the earth with the same velocity as
that of the train ; or if the train at thirty miles an hour
should be instantly stopped, the passengers would be
pitched forward with a swiftness equal to thirty miles an
hour. When a horse suddenly stops, the momentum of
the rider tends to throw him over the horse's head. When
a wagon strikes an obstruction, the driver falls forward.
A case in court was once decided against the plaintiff, who
claimed that the defendant had driven ao^ainst his wao:on
with such force as to throw the plaintiff to a great distance;
but the fact was shown that by such momentum he him-
self must have been driving furiously, and not the defend-
ant, and he lost his suit.

* In ordinary practice, this is not strictly correct, as, friction yaXW make
gonic differonco. This inlluencc will be more particularly considered on
a subsequent paj^c. Its omission here docs not at all alter ihQ principle
under consideration.

MOMENTUM. EXAMPLES.

15

An Eastern traveler once succeeded in saving his life by
a ready knowledge of this principle. He was closely pur-
sued by a tiger, and when near a precipice, watching his
Fig. 4. opportunity, he threw his coat and

hat on a bush, and jumped one
side, when the animal, leaping swift-
ly on the concealed bush, was car-
ried by momentum over the prec-
ipice.

As a large or heavy body pos-
sesses greater momentum than a
small or light one, so any body
moving with great speed possesses
more than one moving slowly ; for
instance, the momentum of a rifle
ball is so great as to carry it through
a thick plank, while, if thrown slow-
ly, it would scarcely indent it.

This property of bodies is applied
with great advantage to many
practical purposes. The momentum
of the hammer drives the nail into
the wood ; for the mere pressure
of its weight would not do it, if it
were a hundred times as heavy.
Wedges are driven by employing
the same kind of j^ower.

On a larger scale, the pile-engine
operates in a similar manner. The
ram or weight, h (fig. 4), is slowly
lifted by means of a pulley and
wheel-work, worked by the handles or cranks, h ^, until
the arms of the tongs which hold the ram are compressed
in the cheeks, i ?, when it suddenly falls with prodigious
force on the pile or post to be driven. In this way long
posts of great size are forced into the mud of swamps and

Tile Engine.

IG

MECHANICS.

Fig. 5.

river bottoms, where other means would fail. When a
steam-engine is used for lifting the ram, the work is more
rapidly performed.

An interesting example of the use and efficiency of
momentum is furnished by the water-ram^ a machine for
raising Avater, described on a subsequent page.

Tlic fly-wheel^ a large and heavy wheel used to regulate
the motion of machinery, derives its value from the power
of inertia, or momentum, which prevents the machine
from stopping suddenly when it meets with any unusual
obstruction. In the common thrashing-machine, it has
been found that a heavy cylinder, by acting as a fiy-wheel,
renders the motion steadier, and less liable to become im-
peded by large sheaves of grain. An ignorance of this
principle has sometimes proved a serious inconvenience.
A farmer, liaving occasion to raise a large quantity of
water, erected a liorse-pump ; but at every stroke of the

pump the animal was sud-
denly thrown loosely for-
ward, and again jerked back-
ward, as the piston fell ligM-
ly and rose lieavily. A ny-
wheel attached to the ma-
chinery would have prevent-
ed this unpleasant jerking,
and have enabled the horse,
in consequence, to accom-
l)lish more work. In the pile-driving engine, where a great
weight is suddenly thrown loose from a height, the horses
would be pitched forward when suddenly relieved of this
load but for the regulation of a fly-wheel, the motion of
which is not quickly changed, neither from fast to slow nor
irom slow to fast.

Wliere there is a rapid succession of forces required in
practice, the fly-wheel is usually of great advantage.
Hence its use in all revolvuig straw-cutters, where the

Straw-cutter xvithjly-whcd.

IXERTIA. THE FLY-WHEEL.

17

knives make quickly-repented strokes (fig. 5). More re-
cently it lias been applied to the dasher-churn (fig. 6),
where the rapid upright strokes are so well known to be
very fatiguing for the amount of force applied.

By thus regulating motion, the fly-wheel frequently
enables an irregular force to accomplish work which other-
wise it could not perform. Thus a man may exert a force
equal to raising a hundred pounds, Fig. 6.

yet, when he turns a crank, there /^/-^-^^'-v^a
is one part of the revolution where // /Tri^l^
he works to great disadvantage,
and where his utmost force will
not balance forty pounds. Hence,
if the work is hea\ y, he may not
be able to turn the crank, nor to
do any work at all. If, however,
a fly-wheel be applied, by gather-
ing force at the most favorable
part of the turning, it carries the
crank throus^h the other part. ^, .,„,,.

V . Ckum with a fly-wheeL for equal-

An error is sometimes commit- i^ing the motion.

ted by supposing the fly-wheel actually creates power, for
as much force is required to give it momentum as it
afterward imparts to the machine ; it consequently only
accumulates and regulates power.

On rough roads, the force of inertia causes a severe
strain to a loaded wagon when it strikes a stone. The
horses are chafed, the wagon and harness endangered, and
the load jarred from its place. This inconvenience is
avoided in part by placing the box upon springs, which, by
yielding to the blow, gradually lessen the effects of the
shock. For carts and slowly moving lumber-wagons
springs are useful, but more so as the velocity and
momentum increase. Even on so smooth a surface as a
rail-road, it w^as found by experiments made some years
ago, that when the machinery of a locomotive was placed

18 MECHANICS.

upon springs, it would endure the wear and tear of use
four times as long as without them.

For this reason, a ton of stone, brick, or of sand, is harder
for a team than a ton of wool or hay, which possesses con-
siderable elasticity.

ESTIMATING THE QUANTITY OP MOMENTUM.

The quantity of momentum is estimated by the velocity
and weight of the body taken together. Thus a ball of
two pounds weight moves with twice the force of a one-
pound ball, the speed being equal ; a ten-pound ball with
ten times the force, and so on. A body moving at the
rate of two feet per second possesses twice the momentum
of another of equal size with a velocity of only one foot
per second. A musket ball, weighing one ounce, flying
with fifty times the speed of a cannon ball, weighing fifty
ounces, would strike any object with equal force ; or, if
they should meet each other from opposite directions, the
momentum of both would be mutually destroyed, and
they would drop to the earth.

Where the mass is very great, even if the motion is
slow, the momentum is enormous. A large ship floating
near a pier wall may approach it with so small a velocity
as to be scarcely perceptible, and yet the force would be
enough to crush a small boat. When great weight and
speed are combined, as in a rail-way locomotive, the force
is almost irresistible. This circumstance often insures the
safety of the passengers ; for as nothing is capable of
instantly overcoming so powerful a momentum, when
accidents occur the speed is more gradually slackened,
and the passengers are not pitched suddenly forward. A
light wagon, rapidly driven, possessing but little compara-
tive force, is more suddenly arrested, and the danger is
greater.

When two bodies meet from opposite directions, each

COMPOUND MOTIOX. 19

sustains a shock equal to the united forces of both. Two
men accidentally coming in contact, even if walking
moderately, receive each a severe blow; that is, if each
were walking three miles an hour, the shock would be the
same as if one at rest Avere struck by the other with a
velocity of six miles an hour. This principle accounts for
the destructive effects of two ships running foul of each
other at sea, or of the collision of two opposite trains on
a rail-road.

The preceding principles show that a sledge, maul, or
axe will always strike more effective blows when made
heavier, if not rendered unwieldy.

COMPOUXD MOTION.

It often happens that two or more forces act on the
same body at the same time. If they all act in the same
direction, the effect will be equal to the sum of the forces
taken together ; but if they act in opposite directions, the
forces will tend to destroy each other. If two equal
forces act in contrary directions, they will be completely
neutralized, and no motion will be produced. Thus, as
an example of these forces — a bird flying at the rate of
forty miles an hour, with a wind blowing forty miles an
hour, will be driven onward by these two combined forces
eighty miles an hour ; but if it undertake to fly against
such a wind, it will not advance at all, but remain station-
ary. A similar result will take place if a steam-boat,
liaving a speed of ten miles an hour, should first run
down a river with a current of equal volocity, and then
upward against the current ; in the first case it would
move twenty miles an hour, and in the latter it would not
move at all.

Where forces act neither in the same nor in opposite
directions, but obliquely, the result is found in the follow-

20 MECHANICS.

ing manner: If a ball, placed at the point a (fig. 7), be
struck by two dilTcrent forces at the same moment, in the
direction shown by the two ar-
rows, and if one force be just suf-
ficient to carry it from a to c,
and the other to carry it from a
to J, then it will move inter-
mediate bet-ween the two, in the
direction of the diagonal of the
parallelogram a d, and to a dis-
tance just equal to tlic length of this diagonal or cross-
diameter.

"When the forces act very nearly togetlier, the parallelo-
gram of the forces will bo very narrow and quite long,
with a long diagonal Fip. 8.

(fig. 8) ; but if they act

on nearly opposite sides ^^ ^'^~~---^~^___^^ . • '

of the ball, they will

very nearly neutralize each other, and the diagonal or re-
sult -will be very short, showing that the motion given to
the ball will be very small (fig. 9).

These examples show the importance of having teams
attached to a plow or to a wagon very nearly in a straight
line with the draught, or else a part of the force Avill be
Fig. 9. lost ; and also the impor-

^^■^^"~*- -*-^ tance, when several animals

are drawing together, of
their working as nearly as
possible in the same straight line. For, the more such
forces deviate from a right line, the more they will tend
to destroy or neutralize each other.

A familiar example of the result of two oblique forces
is furnished when a boat is rowed across a river. If the
river has no current, the boat wall pass directly from bank
to bank perpendicularly ; but if tliere is a current, its track
will form a diagonal, and it will strike the opposite bank

CENTRIFUGAL FORCE.

21

lower down, according to the rapidity of the stream and
the slowness of the boat.

Another instance is afforded when a ferry-boat is
anchored, by means of a long rope, to a point some dis-
tance above (fig. 10) ; the boat, being turned obliquely,
will pass from one bank to the other by the force of the
current. Here the water tends to carry the boat down-
Fig. 10. ward, while the
force of the rope
acts upward; the
boat passes be-
tween the two
from bank to
bank. The ascent of a kite is precisely similar, the wind
and the string being counteracting forces. When a vessel
sails under a side wind, the resistance of the keel against
the water, and the force of the wind against the sail, act
in different directions, and produce a motion of the vessel
between them.

CENTRIFUGAL FORCE.

All bodies, when in motion, have a tendency to move
forward in a straight line. A stone thrown into the air is
gradually bent from this straight course into a curve by
the attraction of the earth. When a ball is shot from a
gun, the force being greater, it flies in a longer and
straighter curve. A familiar example also occurs, while
driving a wagon rapidly, in attempting to turn suddenly
to the right or left ; the tendency of the load to move
straight on will sometimes cause its overthrow. An
observance of this principle would prevent the error which
some commit by making sharp turns or angles in ditches
and water-courses ; the onward tendency of the water
drives it against the bank, checks its course, and wears
away the earth. By giving the ditch a curve, the water

22 MECHAXICS.

is but slightly impeded, and a much larger quantity will
escape through a channel of any given size.

When a grindstone is turned rapidly, the water upon
its surfiice is thrown off by this tendency to move in
straight lines. In the same way, a weight fastened to a
cord, whirled by the hand, will keep the cord stretched
during the revolution. A cup of water, attached to a
cord, may be swung over the head without spilling, the
water being held by centrifugal force. The same principle
causes a stone, when it leaves a sling, to fly off in a line.
This tendency to fly off from a revolving centre is called
centrifugal force — the word centrifugal meaning flying
from the centre. Large grindstones, driven with great
velocity by machinery, are sometimes split asunder by
centrifugal force.

The most sublime examples of this force occur in the
motion of the earth and planets, which will be more fully
explained in a future page.

CHAPTER m.

ATTRACTION.
GRAVITATION.

The earth, as is well known, is a mass of matter in the
foi-m of a globe, the diameter being upward of 7900 miles.
From its enormous size and the small portion seen from
one point, the surface appears flat, except where broken
into mountains and valleys.

The tendency which all bodies possess of falling toward
the earth is owing to the attractive force which this great
mass of matter exerts upon them. This kind of attrac-

GRAVITATION. TELOCITY OF FALLING BODIES.

23

tiou is called gravitation. The force with which a body-
is thus drawn is the iceight of that body.

When a stone is dropped from the hand, its velocity is
at first slow, but continues to increase till it strikes the
earth ; hence, the further it falls the harder it will strike.
This accelerated motion is precisely similar to that of a
steam-boat when it first leaves the wharf; the force of
gravity may be compared to the driving power of the
engine, and the quickened velocity of the falling stone
to the increased headway of the boat.

All bodies, whether large or small, fall equally fast, un-
less they are so light as to be borne up in part by the
resistance of the air. In the first second of time they fall
16 feet; in the second, 3 times 16, or 48 feet ; in the third
second, 5 times 16, or 80 feet, and so on. Or, if the whole
distance fallen be taken together, they fall 16 feet in one
second, 4 times 16 in two seconds, 9 times 16 in three
seconds, and so forth. In other words, the whole distance
is equal to the square of the time. This is plainly ex-
hibited in the followinsr table :

Secouds, from beginning
to fall.

1

2

3

4

5

6

Whole height fallen in

feet.

16

4X16
or 64.

9X16
or 144.

16X16
or 256.

25X16
or 400.

36X16
or5T6.

Space fallen in each sec-
ond in feet.

16

3X16
or 48.

5X16
or 80.

7X16
or 112.

9X16
or 144.

11X16
or 176.

A stone or other body will fall 1 foot in a fourth of a
second, 3 feet the next fourth, 5 feet the third fourth, and
7 feet the last fourth ; which is the same as 4 feet in half
a second, 9 feet in three-fourths of a second, and 16 feet
for the whole second.

The depth of an empty well, or the height of a preci-
pice, may be nearly ascertained by observing the time
required for the fall of a stone to the bottom. The time
may be measured by a stop-watch, or, in its absence, a
pendulum may be made by fastening a pebble to a cord,
which will swing from the hand in regular vibrations of

24 MECHANICS.

an exact second each if the cord be Sd^ inches long, or of
half a second each if it be about 9f inches long.

The velocity increases simply as the time, that is, the
speed in falling is twice as great in two seconds as in one ;
three times as great in three seconds ; four times as great
in four seconds, and so forth. A stone will fall four times
as far in two as in one second, while its velocity will be
doubled ; nine times as far in three seconds, while its
velocity will be tripled, etc.

If a stone is thrown upward, its motion continues
gradually to decrease, at the same rate as it increases in
falling ; hence the same time is required to reach its
highest point, as to fall from that point back to the earth.
Therefore the velocity with which it is first projected up-
ward is equal to the velocity which it attains at the
moment of striking the ground. There is an exception,
however, to this general rule. In a vacuum it w^ould be
perfectly correct, but in ordinary practice the resistance
of the air tends to diminish the velocity while ascending,
and still further to retard it while descending. For this
reason, it will fall with less speed than it first arose. For
heavy bodies and small distances, this exception would be
imperceptible ; but with small bodies falling from great
heights, the difference will be considerable.

The velocity of a stone after falling one second, or six-
teen feet, is at the rate of thirty-two feet per second;
hence, if thrown upward at that rate, it will rise just six-
teen feet high. After falling three seconds, the rate is
ninety-six feet ; and hence, if projected upward at ninety-
six feet per second, it will rise nine times sixteen feet, or
one hundred and forty-four feet high. And so of other
heights.

Were it not for the resistance of the air, a feather would
fall as swiftly as a leaden ball. This is conclusively shown
by an interesting experiment. A tall glass jar (fig. 11),
open at the bottom, is covered with a brass cap, fitting it

VELOCITY OP FALLING BODIES.

25

Fig. n.

!

air-tight. Through this cap passes an air-tight wire, Avhich,
by turning, opens a small pair of pincers. Within these
are placed a feather and a half dollar, and the air is then
thoroughly drawn from the receiver by means of an air-
pump. The Avire is turned, and the feather and coin both
drop at once, and strike the bottom at the same moment.

There are many examples showing the accelerated
motion and increased force of falling
bodies. When a large stone rolls down
a mountain, it first moves slowdy, but
afterwards bounds with rapidity, sweep-'
ing before it all smaller obstacles. Hail-
stones, although small, acquire such veloc-
i-ty as to break windows ; and but for
the resistance of the air, they w^ould be
much more destructive. The blow of a
sledge-hammer is more severe as it is lifted
to a greater height. Newton was first
led to the examination of the laws of
gravity by observing, when sitting under
an apple-tree, that the fruit struck his
hand with greatest severity when it fell
from the top of the tree.

It is not an unusual error to suppose
that a large body will fall more rapidly
than a small one. Some can scarcely be-
lieve that a fifty-six pound weight will Feather a^ coin fallmg

not drop Avith a greater velocity than a """^'^ '" " vacuum.
small nail, not remembering that a proportionately
greater force is required to overcome the inertia and
set the larger body in motion. This error existed for
many centuries, from the time of Aristotle until Galileo
first questioned its correctness. The celebrated ex-
periment which established the truth on this subject,
and led to the discovery of the laws of falling bodies
just explained, and which fomicd an era in modern
2

26 MECHANICS.

philosophy, was performed from the top of the leaning
tower of Pisa. Galileo was a philosophical teacher, and,
being a man who thought for himself, soon discovered, by
reasoning, the errors tliat had been received without a
doubt for more than twenty centuries. All the learning
of the age and the wisdom of the universities were against
him, and in favor of this time-honored error, the truth of
which no one had ever thought of submitting to experi-
ment. The hour of trial arrived, when he, an obscure
young man, 'stood nearly alone on one side, while the
multitude, with all the j)Ower and confessed knowledge
of the age, were on the other.

Tiie balls to be employed were carefully weighed and
scrutinized to detect deception, and the parties were satis-
fied. The one ball was exactly twice the weight of the
other. The followers of Aristotle maintained that when
the balls were dropped from the top of the tower, the
heavy one would reach the ground in exactly half the
time employed by the lighter ball. Galileo asserted that
the weights of the balls would not affect their velocities,
and that the times of descent would be equal. The balls
were conveyed to the summit of the lofty tower — the
crowd assembled round the base — the signal was given —
the balls were dropped at the same instant, and swiftly
descending, at the same moment struck the earth. Again
and again the experiment was repeated with unifoim
results. Galileo's triumph was complete — not a shadow
of doubt remained; but, instead of receiving the con-
gratulations of honest conviction, private interest, the loss
of place, and the mortification of confessing false teach-
ing, proved too strong for the candor of his adversaries.
They clung to their former opinions with the tenacity of
despair, and he was driven from Pisa.*

♦Mitcbell's Lectures.

COHESION. — EXAMPLES. 27

conEsioN.

The attraction of gravitation, as we have just seen, takes
place between bodies at a greater or less distance from
each other. There is another kind of attraction, acting
only when the parts of substances are in actual contact ;
this is called cohesion. It is this which holds the parts of
a body together and prevents it from falling to pieces. It
maybe^shown by taking two pieces of lead, and, after
having made upon them two smoothly-shaven surfaces
with a knife, pressing them firmly together ^vith a twist-
ino- motion (fig. 14). The asperities of the surfaces are
thus pushed down, and iho Fig- ^

particles are brought into
close contact, so that cohc- \Jii

sion immediately takes plaCO cohesive attraction m two lead balls,

between them, and some force will be required to draw
them asunder.* Two pieces of melted wax adhere to-
gether in the same w^ay. Melted pitch or other similar
substance, smeared thinly over the polished surfaces of
metal or glass, also causes cohesion to take place between
them. Smooth iron plates, two inches in diameter, have
been made to stick together so firmly with hot grease as
to require, when cold, a weight of half a ton to draw
them apart. Plates of brass of the same size, cemented
by means of pitch, required 1400 pounds. On this prin-
ciple depends the efficacy of those substances which are
used for cementing broken vessels.

The most perfect artificial polish which can be given to
hard metals is still so rough as to prevent the faces from

* That this is not atmospheric pressure, like that -which holds two
panes of wet glass together, is shown by the fact that it requires nearly
as great a force to separate them when they are placed under the exhaust-
ed receiver of an air-pump. Besides this, atmospheric pressure is much
■weaker than this force, with so small a surface.

28 MECUAIS'ICS.

coming into close contact; hence they must be either
melted, or softened like iron when it is welded.

The different degrees of cohesion which take place
between the particles of various soils, to reunite them
after they have been crumbled asunder, occasion the main
difference between light and heavy soils. When a light
soil becomes soaked with water, the particles adhere in a
very slight degree ; and hence, when it becomes dry again,
it is easily worked mellow. But if it be of a clayey
nature, too much moisture softens it like melted wax:
the particles are thus brought into close contact, and
strong adhesion takes place ; hence the hardness and diffi-
culty of working such soils when again dried. This ad-
hesion is lessened by applying sand, chip-dirt, straw, yard-
manure, or by burning the earth, but more especially by
thorough draining, which, preventing the clay from be-
coming so moist and soft, lessens the adhesion of its
parts.

Different substances are hard, soft, brittle, or elastic,
according to the different degrees or modes of action in
the attraction of cohesion.

STRENGTH OF MATERIALS.

It is a matter of great utility in the construction of
machinery to determine the different degrees of cohesion
possessed by different substances; or, in other words, to
ascertain their strength. This is done by forming them
into rods of equal size, and applying weights to their
lower extremities sufficient to break them, by drawing
them asunder. The amount of weight shows their rela-
tive degrees of strength. The following table gives the
weights required to break the different substances, each
being formed into a rod one quarter of an inch square :

STEENGTU OF MATERIALS. 29

Woods.

Ash, toughest 1000 lbs.

Beech .-.. 718 "

Box 1250 "

Cedar 712 "

Chestnut 656 "

Elm 837 "

Locust 1280 "

Maple 656 "

0!ik, white 718 "

Pine, white 550 "

" pitch 750 "

Poplar 437 "

Walnut.. 487 "

Jiletals.

Steel, best 9370 lbs.

*' soft 7500 "

Iron, wire 6440 "

" best bar 4690 "

" common bar.. 3750 "

" inferior bar 1880 "

" cast 1150 to 3100 "

Copper, wire 3800 "

" cast 2030 "

Brass 2800 "

Platina wire 3300 "

Silver, cast 2500 "

Gold, cast 1250 "

Tin 310 "

Zinc, cast 160 «

" sheet 1000 "

Lead, cast 55 "

" milled 207 "

From these tables we may ascertain the strength of
chains, rods, etc., when made of different metals, and of
timbers, bars, levers, swing-trees, and farm implements,
when made of woods. "Wood which will bear a very-
heavy weight for a minute or two, will break with two-
thirds of the weight when left upon it for a long time.
This explains the reason that store-house and barn timbers
sometimes give way under lieavy loads of grain, which
have appeared at first to stand with firmness.

30 itECHANICS.

Although the preceding table gives the strength of wood
drawn lengthwise, yet the comparative results are not
greatly different when the force is applied in a transverse
or side direction, so as to break in the usual way.

The following table shows the results of several experi-
ments with pieces of wood one foot in length, one inch
square, with the weight suspended from one end, breaking
them sidewise.

White oak, seasoned, broke with 340 lbs.

Chestnut, " " 170 "

Whitepine, " " 135 "

Yellow pine, " " 150 "

Ash, " " 175 "

Hickory, " « 270 "

A rod of good iron is about ten times as strong as the
best hemp rope of the same size. The best iron wire is
nearly twenty times as strong as a hemp cord. Hence the
enormous strength of the wire cables, several inches in di-
ameter, which are employed for the support of suspension
bridges.

A rope one inch in diameter will bear about 5000 lbs.,
but in practice should not be subjected to more than half
this strain, or about one ton. The strength increases or
diminishes according to the size of the cross-section of the
rope ; thus a cord half an inch in diameter will support
one quarter as much as an inch, and a quarter-inch cord a
sixteenth as much. A knowledge of the strength of
ropes, as used by farmers in windlasses, pulleys, drawing
loads, etc., would sometimes prevent serious accidents.
The following table may therefore be useful :

Diameter of rope or Pounds borne Breaking

cord in inches. with safety. weight.

One-eighth 31 lbs. 78 lbs.

One-fourth 125 " 814 "

One-luilf 500 " 1250 "

One 2000 " 5000 "

One and a quarter 3000 " 7500 "

Oneandahalf 4500 " 12,500 "

STRENGTH OF MATERIALS. 31

Tliese results Avill vary about one-fourth with the quaV
ity of common hemp. Manilla is about one-half as strong
as the best hemp. The latter stretches one-fifth to one-
seventh before breaking.

Wood is about seven to twenty times stronger when
taken lengthwise with the fibres than when a side force is
e:xerted, so as to split it. The splitting of timber or wood
for fuel is, however, accomplished with a comparatively
small power by the use of wedges, the force of heavy
blows, and the leverage of the two parts.

The attraction of cohesion is very weak in liquids ; it is
sufficient, however, to give a round or spherical shape to
very small portions or single drops, and to furnish a
beautiful illustration, on a minute scale, of the same prin-
ciple which gives a rounded form to the surface of the
sea. In one ctise, cohesion, by drawing toward a common
centre, foims the minute globule of dew upon the blade
of grass ; in the other, gravitation, acting in like manner,
but at vast distances, gives the mighty rotundity to the
rolling waters of the ocean.

CAPILLARY ATTRACTION.

Capillary attraction is a species of cohesion ; it takes
place only between solids and liquids. It is this which
holds the moisture on the surface of a wet body, and which
prevents the water from running instantly out of a wet
cloth or sponge. By touching the lower extremity of a
lump of sugar to the surface of water in a vessel, capillary
attraction will cause the water to rise among its granules
and moisten the whole lump. It may be very distinctly
shown by placing the end of a fine glass tube into water;
the water will rise in it above the level of the surrounding
surface. If the bore of the tube be the twelfth of an inch

32

MECHANICS.

in diameter (a, fig. 15,) it will rise a quarter of an inch;
if but the twenty-fifth of an inch in bore, as b, it will rise
half an inch ; but if only a fiftieth of an inch, the water
will rise an inch. This ascent of the liquid is caused by
the attraction of the inner surface of the tube, until the
weight of the column becomes equal to the force of the
attraction. Capillary attraction may be also exhibited by

Fig. 10

-, .„ ^, ,. , , capillarij attraction hettveen two panes of

Capillary attraction m tubes. "*" ■' glass.

two small plates of glass, placed with their edges in wa-
ter, in contact on one side, and a little open at the
other side, as in fig. 16. As the faces of the plates ap-
proach each other, the water rises higher, forming the
curve, a.

Capillary attraction performs many important offices
in nature. Tlie moisture of the soil depends greatly upon
its action. If the soil is composed of coarse sand or grav-
el, the interstices are large, and, like the larger glass tube,
will not retain the rain which falls upon it. Such soils
are, therefore, easily worked in wet weather, but become
too dry in seasons of drought ; but when the texture is
finer, and especially if a due proportion of clay be mixed
with the sand, the interstices become exceedingly small,
and retain a full sufficiency of moisture. If, however,
there is too much clay, the soil is apt to become close and
compact, ancj the water can not enter until it is broken up

EARTH A DESERT WITHOUT CAPILLARY ATTRACTIOX. 33

or pulverized. It is for this reason that subsoil plowing
becomes so eminently beneficial, by deepening the mellow
portion, and thus affording a larger reservoir, which acts
like a sponge in holding the excess of falling rains, until
wanted in the dry season. For the same reason, a well-
cultivated soil is found to preserve its moisture much bet-
ter durino^ the heat of summer than a hardened and nesr-
lected surface.

If capillary attraction should cease to exist, the earth
would soon become a barren and uninhabitable waste.
The moisture of rains could not be retained by the parti-
cles of the soil, but would immediately sink p■^„ 17
far down into the earth, leaving the surface
at all times as dry and unproductive as a
desert ; vegetation would cease ; brooks and
rivers would lose the gradual supplies wdiich
the earth affords them through this influence,
and become dried up ; and all j^lants and all
animals die for want of drink and nourish-
ment. Thus tlie very existence of the whole
human race evidently depends on a law, ap-

.. .^ , ,.,. , Apparatus ex-

parently msignmcant to the unthinkmg, but plaining the

... , . . T ... rising o/sap.

pomtmg the observing mmd to a strikmg
proof of the creative design which planned all the works
of nature, and fitted them with the utmost exactness for
the life and comfort of man.

ASCENT OF SAP.

The follow^ing interesting experiments serve to explain
the cause of the ascent of sap in plants and trees ;

Take a small bladder, or bag made of any similar sub-
stance, and fasten it tightly on a tube open at both ends
(fig. 17) ; then fill them with alcohol up to the point C,
and immerse the bladder into a vessel of water. The al-
cohol will immediately rise slowly in the tube, and if not
2*

34 MECHANICS.

more than two or three feet high, will run over the top.
This is owing to the capillary attraction in the minute
pores of the bladder, drawing the Avater within it faster
than the same attraction draws the alcohol outward. One
liquid will thus intrude itself into another with great
force. A bladder filled with alcohol, with its neck tightly-
tied, will soon burst if plunged under water. If a blad-
der is filled with gum-water, and then immersed as before,
the water will find its way w^ithin against a very heavy
pressure.

In this manner sap ascends through the minute tubes in
the body of trees. The sap is thickened like gum-water
when it reaches the leaves, and a fresh supply, therefore,
enters through the pores in the spongelets of the roots by
capillary attraction, and, rising through the stem, keeps
up a constant supply for the wants of the growing tree.

CENTRE OF GRAVITY.

The centre of gravity is that point in every hard sub-
stance or body, on every side of which the difiierent parts
exactly balance each other. If the body be a globe or
Fig. la round ball, the centre of

gravity will be exactly at the
g /^— centre of the globe ; if it be
a rod of equal size, it will be
at the middle of the rod. If
a stone or any other sub-
stance rest on a point directly under the centre of gravity,
it will remain balanced on this point ; but if the point be
not under the centre of gravity, the stone will fall toward
the heaviest side.

Some curious experiments are performed by an ingenious
management of the centre of gravity. A light cylinder
of cork or pasteboard contains a concealed piece of lead,
g (fig. 18). The lead, being heavier than the rest, will

4

CENTRE OF GRAVITY. EXRERIMENTS.

35

Body singularly balanced by
lead kiiobs.

cause the cylinder to roll up an inclined plane, when
placed as shown by the lower figure on the preceding en-
graving, until it makes half a revolu-
tion and reaches the place of the up-
per figure, when it will remain sta-
tionary. If a curved body, as shown
in fig. 19, be loaded heavily at its
ends, it will rest on the stand, and
present a singular appearance by not
falling, the centre of gravity lying
between the two heavy portions on
the end of the stand. A light stick
of some length may be made to stand
on the end of the finger, by sticking
in two penknives, so as to bring the
centre of gravity as low as the finger-end (fig. 20).
If any body, of whatever shape, be suspended by a
hook or loop at its top, it will
necessarily hang so that the
centre of gravity shall be di-
rectly under the hook. In this
way the centre in any substance,
no matter how irregular its shape
may be, is ascertained. Sup-
j)Ose, for instance, we have the
irregular plate or board shown
in the annexed Fig. 21.

figure (fig. 21) :
first hang it by

the hook a, andtf^ ^-....^f,

the centre of
gravity will be
somewhere in
the dotted line a b. Then hang it by the hook c, and it
will be somewhere in the line c d. Now the point e, where
they croiis each other, is the only point in both, conse-

Fig. 20.

Centre of gravity maintained by tv'o
penknives.

36 MECHANICS.

quently this is the centre sought. If the mass or body,
instead of being flat like a board, be shapeless like a stone
or lump of chalk, holes bored from different suspending
points directly downward will all cross each other exactly
at the centre of gravity.

LINE OF DIRECTION.

An imaginary line from the centre of gravity perpendic-
ularly downward to where the body rests is called the
line of direction.

Kow in any solid body whatever, whether it be a wall,
a stack of grain, or a loaded Avagoii, the line of direction
must fall within the base or part resting upon the ground,

Fig. 22. Fig. 23. ^^ ^^ ^^'^^^ immediately be

thrown over by its own
weight. A heavily and even-
ly loaded wngon on a level
road will be perfectly safe, be-
cause the line of direction falls

Centre of sravity on l^dmd inclined equally bctWCeU thc Avliecls,

'°''"^'' as shown in fig. 22, by the

dotted line, c, being the centre. But if it pass a steep side-
hill road, throwing this line outside the wheels, as in fig. 23,
it must be instantly overturned. If, however, instead of
the high load represented in thc figure, it be some very
heavy material, as brick or sand, so as not to be higher
than the square box, the centre will be much lower down,
or at J, and thus, the line falling within the wheels, the
load wi41 be safe from upsetting, unless the upper wheel
pass over a stone, or the lower wheel sink into a rut.
The centre of gravity of a large load may be nearly ascer-
tained by measuring with a rod ; and it may sometimes
happen that by measuring the sideling slope of a road, all
of which may be done in a few minutes, a teamster may
save himself from a comfortless upsetting, and perhaps

CENTRE CF GUAVITY. LOADIXG WAGONS. 37

heavy loss. Again, a load may be temporarily placed so
much toward one side, while passing a sideling road, as
to throw the line of direction considerably more up hill
than usual, and save the load, which may be adjusted
again as soon as the dangerous point is passed. This
principle also shows the reason why it is safer to place only
light bundles of merchandise on the top of a stage-coach,
while all heavier articles are to be down near the wheels ;
and why a sleigh will be less likely to upset in a snow-
drift, if all the passengers will sit or lie on the bottom.
When it becomes necessary ^.^ ^^ ^.^ ^^

to build very large loads
of hay, straw, wool, or
other light substances, the
"reach," or the long con-
necting-bar of the wagon,
must be made longer, so as

to increase the length of the centre 0/ gravity of an even and one-sided

load ; for, by doubling the '°'"^'

length, two tons may be piled upon the wagon with as

much security from upsetting as one ton only on a short

wagon.

Where, however, a high load can not be avoided, great
care must be taken to have it evenly placed. If, for in-
stance, the load of hay represented by lig. 24 be skillfully
built, the line of direction will fall equally distant within
each wheel ; but a slight misplacement, as in fig. 25, will
so alter this line as to render it dangerous to drive except
on a very even road.

Thus eveiy one who drives a wagon should understand
the laws of nature sufficiently to know how to arrange
the load he carries. It is true that experience and good
judgment alone will be sufficient in many cases; but no
person can fail to judge better, with the reasons clearly,
accurately, distinctly before his eyes, than by loose con-
jecture and random guessing.

38

MECHANICS.

Every faimer who erects a wall or building, every team-
ster who drives a heavy load, or even he who only carries a
heavy weight upon his shoulder, may learn something use-
ful by understanding the laws of gravity.

It is familiar to every one, that a body resting upon a
broad base is more difficult to upset than when the base

Fig. 26.

A ^'

/ \ '

V I

is narrow. For instance, the square
block (fig. 26) is less easily thrown
over than the tall and narrow block
of equal weight, because, in turning
the square block over its lower edge,
- the centre of gravity must be lifted
up considerably in the curve shown
by the dotted line c / but with a tall,
narrow block, this curve being almost
on a level, very little lifting is re-
quired. Hence the reason that a high load on a wagon is
so much more easily overturned than a low one.

Of all forms, a pyramid stands the most firmly on its
base. The centre of gravity, c (fig. 26), being so near the
broad bottom, it must be elevated in a very steep curve
to throw the line of direction beyond the base. For this
reason, a stone wall, or the dam for a stream, will stand
better when broad at bottom and tapering to a narrow top
than if of equal thickness throughout.

When a globe or round ball is placed upon a smooth
floor, it rests on a single point. If the Fig. 27.

floor be level^ the line of direction will
fall exactly at this resting-point (fig.
27). To move the ball, the centre will
move precisely on a level, without be-
ing raised at all. This is the reason
that a ball, a cylinder, or a wheel is rolled forward so
much more easily than a flat-sided or irregular body. In
all these cases, the line of direction, although constantly

CENTRE OF GRAVITY. — EXAMPLES.

39

chans^ing its place, still continues to fall on the very point
on wliich the round body rests.

But if the level floor is exchanged for a slope or inclin-
ed plane (fig. 28), the line of direc- Fig 28.
tion no longer falls at the touching-
point, but on the side from it down-
ward ; the ball will therefore, by its
mere weight, commence rolling, and
continne to do so until it reaches the
bottom of the slope.

Wheel-carriages owe their comparative ease of draught
to the fact that the centre of gravity in the load is moved
forward by the rolling of the wheels, on a level, or paral-
lel with the surface of the road, just in the same way that
the round ball rolls so easily. Each Avheel supporting its
part of the load at the hub, the same rule applies to each
as to a ball or cylinder alone. Hence, on a level road, the
line of direction falls precisely where the wheels rest on
the ground, but if the road ascend or descend, it falls else-
where ; this explains the reason Avhy it will run by its own
weight down a slope.

Whenever a stone or other obstruction occurs in a road,
Fi2. 2(«. it becomes requisite to raise the

centre by the force of the team-
and by means of oblique motion,
so as to throw the wheel over it,
as shown by fig.
29. One of the
reasons thus
becomes very
plain why a
large wheel will
run with more ease on a rough road than a smaller one ;
the larger one mounting any stone or obstruction without
lifting the load so much out of a level or direct line, as
sh6wn by the dotted lines in the annexed figures, (figs. 29

Fig. 30.

40

MECHANICS.

A firmly- set fruit-ladder.

and 30). Another reason is, the large wheel does not

sink into the smaller cavities in the road.

A self-supporting frait-ladder (fig. 31) (the centre of

gravity, when in use, being at or near the top) must have

its legs more widely
^'s- ^- F'g- 32. spread, to be secure from

falling, than if the centre
were lower down. Hence
such a position, as in fig.
32, would be unsafe.

The support of the
human body, in standing
and walking, exhibits
some interesting exam-
ples in relation to this
subject. A child can not learn to walk until he acquires
skill enough to keep his feet always in the line of direc-
tion. When he fails to do this, he topples over toward
the side where the line falls outside his feet. A man stand-
ing with his heels touching the wash-board of a room can
not possibly stoop over without falling, because, when he
bends, the line of direction falls forward
of his toes, the wall against which he
stands preventing the movement of his
body backward to preserve the balance.

In walking, the centre rises and falls
slightly at each step, as shown by the
waved line in fig. 33. If it were not
for the bending of the knee-joints, this
exercise would be much more laborious,
as it would then become needful to
throw the centre into an upward curve at every step.
For this reason, a wooden leg is more imperfect than the
natural one (fig. 34). Hence the reason why walking on
crutches is laborious and fatiguing, because at every on-

Fig. 33.

CENTRE OF GRAVITY. EXAMPLES.

41

ward step tlie body must be thrown upward in a curve,
like a wagon mounting repeated obstructions.

When a load is carried on the shoulder, it should be so
placed tliat the line of direction may pass directly through
Fig. 35. Fig. 36. the slioulder or back down to the

feet, fig. 35. An unskillful person
will sometimes place a bag of grain
as shown in fig. 36. The line falling
outside his feet, he is compelled to
draw downward with great force on
the other end of the bag. A man who
carrier a heavy pole on his shoulder should see that the
centre is directly over his shoulder, otherwise he will be
compelled to bear down upon the lighter end, and thus
add in an equal degree to the weight upon his body.

o<, rest

upon its side

Fig. 3T. ■

If an elliptical or oval body, fi
a, rolling it in either direction elevates
the centre, c, because it is nearest the
side on which the body rests. If,
when raised, it be suffered to fall, its
momentum carries it beyond the
point of rest, and thus it continues
rocking until the force is spent. The
course of the centre during these mo-
tions is shown by the curved dotted
line, G. If it be placed upon end, as in fig. 38, then any
motion toward either side brings the centre of gravity
nearer the touching-point, that is,
causes it to descend, and the body
consequently falls over on its side.
This may be easily illustrated with
an Qg^^ which will lie at rest upon its
side, but falls when set on either end.
The rockers of chairs, cradles,
and cribs, are formed on the princi-
ple just explained. If so made that the centre of gravity

Fig. 38.

42

MECHAXICS.

of the chair or cradle is nearer the middle of the rocker
than to the ends, the rocking motion will take place ; and
when the distance from the centre of gravity to the ends
of the rockers is but little greater

Fi-. 39.

Fiir. 40.

than the distance to the middle, c,
as in fig. 39, the motion will be
slow and gentle ; but if this differ-
ence be greater, as in fig. 40, it will
be rapid. When the centre is high,
the rockers must have less curvature
than where it is low and near the floor. If the centre of
gravity be nearer the ends than to the middle, the chair
will immediately be overturned. This principle should
be well understood in the construction of every thing
which moves bv rockin<T.

CHAPTER ly.

SIMPLE MACHINES, OR MECHANICAL POWERS.

ADVANl'AGES OF MACHINES.

The moving forces which are applied to various useful
purj)oses commonly require some change in velocity,
direction, or mode of acting, before they accomplish the
desired end. For example, a running stream of water has
a motion in one direction only ; by the use of machinery,
we change this to an alternating motion, as in the saw of
the saw-mill, or to a rotatory or whirling motion, as in the
stones of a grist-mill. The direct or straightforward
power of a yoke of oxen is made, by the employment of
the plow, to produce a side-motion to the sod, as well as
to turn it through half a circle. The thrashing-machine

SrMOPLE MACHINES, OR MECHANICAI. POWERS. 43

converts the slowly-acting pace of horses to the swift hum
of the spiked cylinder.

Any instrnment used for thus changing o^ modifying
motion is called a machine^ whether it be simple or com-
plex in its structure. Thus even a crow-bar^ used in lifting
stones from the earth, by diminishing the motion given by
the hand and increasing its power, may be strictly termed
a machine; while a harrow^ which neither alters the
course nor changes the velocity of the force applied, may
with more propriety be regarded as simply an implement
or tool. In common language, however, these distinctions
are not accurately observed, and a machine is usually con-
sidered to be any instrument consisting of different mov-
ing parts.

All machines, however complex, may be resolved into
two simple parts, or powers. These are,

1. The Lever;

2. The Inclined Plane.

The wheel and axle^ and the pulley are modified ap-
plications of the lever ; and the wedge and the screw of
the INCLINED PLANE, as wiU be shown on the following
pages. These six are usually termed the mechaiiical
powers. As they really do ntjt possess any power in
themselves, but only regulate power, the term "simple
machines " may be regarded as most correct.

THE LAW OF VIRTUAL VELOCITIES.

Before proceeding to the simple machines, it may be
well to explain a very important truth, which should be
considered as lying at the foundation of all mechanical
philosophy, and which renders plain and simple many things
^vhich would otherwise seem strange or contradictory.
This is, that the force required to lift any given body is
always in proportion to the weight of that body, taken

44 MECHAXICS.

together with the height to be raised. For instance, it
requires twice the force to raise two pounds as to raise
one pound, three times the force to raise three pounds,
and so forth. Also, twice as great a force is needed to
elevate any weight two feet as one foot, or three times as
great for three feet, and so on. Again, combining these
together, four times as great a force is required to raise
two pounds to a height of two feet as to raise one pound
only one foot ; eight times as great for four feet, and so
on. This holds true, no matter by what kind of ma-
chinery it is accomplished. Xow this may all seem very
simple, but it serves to explain many difficult questions in
relation to the real power possessed by all machines.

Take another example. Suppose that one wishes to
raise a weight of 1000 pounds to a height of one foot. If
his strength is equal to only 100 pounds, the weight
would be ten times too heavy for him. He might, there-
fore, divide it into ten equal parts of 100 pounds each.
Raising each part separately the required height of one
foot would be the same as raising one of them ten feet
high. The weight is lessened ten times, but the distance
is increased ten times. But there are some bodies, as, for
example, blocks of stone or sticks of timber, which can not
well be divided into parts in actual practice. He there-
fore resorts to a machine or mechanical power, through
which the same result is accomplished by raising the
whole weight in one mass with his single strength ; but in
this case as well as the other, the moving force which he
applies must pass through ten times the space 6f the
weight. We airive, therefore, at the general rule, that the
distance moved by the weight is as much less than that
moved by the power as the power is less than the weight.
This rule is termed by some writers the " rule of virtual
velocities ^^"^ virtual meaning not apparent or actual, but
according to the real effect, because the increase in
the velocity of the power makes up for increase in the size

THE LEVER.

45

of weight. This rule will be better understood after con-
sidering its application to the different simple machines.

The simplest of all machines is the lever. It consists of
a rod or bar, one end resting upon a prop or fulcrum^ F
(fig. 41), near which is the weight, W, moved by the
liand at P. The stone may weigh 1000 pounds; yet, if it
is ten times as near the fulcrum as the man's hand is, a
force of 100 pounds will lift it ; but it will be moved only
a tenth part as high as the hand has been moved, as shown

Fis41.

(lie second Und.

by the dotted lines. By placing the stone still nearer the
fulcrum, still less will be the power required to raise it,
but then the distance elevated would be also still less. By
sufficiently increasing the disproportion between the two
parts of the lever, the strength of a child merely might
be made to move more than many horses could draw.

These performances of the lever often excite astonisli-
ment at what appears to be out of the common course of
things ; yet, when examined by the principles of mechan-
ics, instead of appearing matters of astonishment, they are
found to be only the natural and necessary results of the
laws of force. In the case of the lever just described, it is
often incorrectly supposed that the power itself sustains
tlie weight. But this is not the case ; nearly the whole
of it rests upon the fulcrum. We often see proofs of this
error in common practice, where fulcrums or props entirely
insufficient to uphold the enormous weight to be raised
are attempted to be used. If the weight, for instance, be
ten times as near the fulcrum as to the power, then nine-
tenths of the weight rests upon the fulcrum, and the re-

46 MECHAXICS.

maining tenth only is sustained by the lifting power.
The lever only allows the power to expend itself through
a longer distance, and thus, by concentrating itself at the
weight, to elevate the latter through the shorter distance,
according to the rule of virtual velocities already ex-
plained.

The fulcrum may be placed between the weight and the
Eig. 42. power, as in fig. 42,

1 f!"^ ^'^ ^^^^ power may be

a:r;Hw-iTrirr-

Lever of t/ie first kind.

placed between the
fulcrum and the
weight, as in fig. 43,
the same principle of virtual velocities applying in all cases.

Where the fulcrum is between the power and the
weight, as in fig. 42, it is called a lever of the first kind.

Where the weight is between the fulcrum and the
power, as in fig. 41, it constitutes a lever of the second
kind.

Where the power is between the fulcrum and the
weight, as in fig. 43, it is termed a lever of the third
kind,

1. Many examples occur in pi'actice of levers of the first
kind. A crow-bar, used to raise stones from the earth, is
an instance of this sort :
BO IS a handspike ot

any kind used in the ^ M B^

same way. A hammer ^

'' . Lever of (he third kind.

for drawmg a nail

operates as a lever of the first kind, the heel being the ful-
crum, the nail the weight, and the hand the power ; the
distance through which the handle i>asses being several
times greater than that of the claws, the force exerted on
the nail is increased in like proportion. A pair of scissors
consists of two levers, the rivet being the fulcrum ; and in
using them, as every one has observed, a greater cutting
force is exerted near the rivets than toward the points.

THE J.EVEl^ EXAMPLES. 47

This is owing to the power "being expended through a
greater distance near the points, according to the rule al-
ready explained. Pincers, nippers, and other similar in-
struments are also double levers of the first kind.

A common steelyard is another example, the sliding
weight becoming gradually more efiective as it is moved
further from the fulcrum or hook supporting the instru-
ment. The brake or handle of a pump is a lever of this
class, the pump-rod and piston being the weight.

The common balance is still another, the two arms being

exactly equal, so that one weight will always balance the

Fi„. 44, other, and on this its usefulness

|f| -^^ and accuracy entirely depend.

The most sensitive balances have

light beams with long arms, and

the turning-point of hardened

steel or agate, in the form of a

mm

ii'HriihHi;iiiiwi'i-ijiiiiiiiiii!i!g thin wedge, on which the balance

turns almost without friction. Small balances have been
BO skillfully constructed as to turn with one-thousandth
part of a grain.

2. Levers of the second kind are less numerous, but not
uncommon. A handspike used for rolling a log is an ex-
ample. A wheel-barrow is a leverof the second kind, the
fulcrum being the point where the wheel rests on the
ground, and the weight the centre of gravity of the load.
Hence, less exertion of strength is required in the arm
when the load is placed near the wheel, excej)t where the
ground is soft or muddy, when it is found advantageous
to place the load so that the arm shall sustain a consider-
able portion, to prevent the wheel sinking into the soil.
A two-wheeled cart is a similar example ; and, for the same
reason, when the ground is soft, the load should be placed
forward toward the horse or oxen ; on the other hand, on
a smooth and hard, or on a plank road, the load should be

48

MECriAXICS.

Fifr. 45.

more nearly balanced. An observance of this rule would
often save a great deal of needless waste of strength.

A sack-barrow, used in barns and mills for conveying
heavy bags of grain from one part of the floor to another,

and in warehouses
for boxes, is a lever
nearly intermediate
between the first and
second kind, the
weight usually rest-
ing very nearly over
the fulcrum or
wheels. When the
bag of grain is
thrown forward of
the w^heels, it be-
comes a lever of the
first kind ; w^hen
back of the wheels,
it is a lever of the
second kind. As it
is used only on hard
and smooth floors,
and not, like the wheel-barrow, on soft earth, the more
nearly the load is placed directly over the wheels, the
more easily they will run.

3. In a lever of the third kind, the weight being further
from the fulcrum than the power, it is only used where
great power is of secondary importance Avhen com-
pared with rapidity and dispatch. A hand-hoe is of this
class, the left hand acting as the fulcrum, the right hand
as the power, and the resistance overcome by the blade
of the hoe as the weight. A hand-rake is similar, as well
as a fork used for pitching hay. Tongs are double levers
of this kind, as also the shears used in sheaririig sheep.
The limbs of animals, generally, are levers of the third

Sack-bcaroiv.

ESTIMATING THE POWEH OF LEVERS. 49

kind. The joint of the bone is the fulcrum; the strong
muscle or tendon attached to the bone near the joint is
the power ; and the weight of the limb, with whatever re-
sistance it overcomes, is the weight. A great advantage
results from this contrivance, because a slight contraction
of the muscle gives a swift motion to the limb, so import-
ant in walking and running, and in the use of the arms.

ESTIMATING THE POWEK OF LEVERS.

The power of any lever is easily calculated by measuring

the length of its two arms, that is, the two parts into

Fig. 46. Avhich it is divided by

.----'^' the weight, fulcrum,

f • X^^^-"^"' ^^^ lever of the first kind,

^ :"-'''' if the weight and

Lever of the first Und. p^^^^j, ^^ equally dis-

tant from the fulcrum, they will move through equal dis-
tances, and nothing will be gained ; that is, a power of
100 pounds Avill lift a weight of 100 pounds only. If the
power be twice as far as the weight, its force will be
doubled ; if three times, it will be tripled ; and so forth.
In a lever of the second kind, if the weight be equidistant
between the fulcrum Fig. 47,

and power, the power ^p'---r--__
will move through i T~*"~~~~~~--;rr-.^

twice the distance of I | ''^ -^^— ^fc^'^^

the weight, and the ^

power of the instru- ^''' ""^ "'' '"^""^ ^'^"^'

ment will therefore be doubled ; if twice as far, it will be
tripled, and so on, as shown in the annexed figures. The
same mode of reasoning will explain precisely to what
extent the force is diminished in levers of the third kind.

These rules will show in what manner a load borne on
a pole is to be placed between two persons carrying it,

50

MECHANICS.

F\^. 48,

If equidistant between them, each will sustain a like por-
tion. If the load be twice as near to one as to the other,
the shorter end will receive double the weight of the
longer. For the same reason, when three horses are

worked abreast, the two
horses placed together
should have only half
the length of arm of the
main whiffle-tree as the
single horse, fig. 48.
The farmer who has a
team of two horses un-
like in strength, may
thus easily know how to
adjust the arms of the
whiffle'-tree so as to correspond with the strength of each.
If, for instance, one of the horses possesses a strength as
much greater than the other as four is to three, then the
weaker horse should be attached to the arm of the whiffle-
tree made as much longer than the other arm as four is
to three.

In all the preceding estimates, the influence of the
weight of the lever has not been taken into consideration.
In a lever of the first kind, if the thickness of the two
arms be so adjusted that it will remain balanced on the
fulcrum, its weight
will have no other
effect than to in- ^-^^^^^i::::::;:^--^^
crease the pressure

on the fulcrum ; but F^

if it be of equal
size throughout, its longer arm, being the heavier, will
add to its power. Tlie amount thus added will be equal
to the excess in the weight of this arm, applied so far
along as the centre of gravity of this excess. If, for ex-
ample, a piece of scantling twelve feet long, a b, fig. 49,

Fiff. 49.

COMBINATION OF LEVEES. 51

be used as a lever to lift the corner of a building, then
the two portions, a c, c d^ will mutually balance each
other. If these be each a foot in length, the weight of
ten feet will be left to bear down the lever. The centre
of gravity of this portion will be at e, six feet from the
fulcrum, and it will consequently exert a force under the
building equal to six times its own w^eight. If the scant-
ling weigh five pounds to the foot, or fifty pounds for the
excess, this force will be equal to three hundred pounds.

In the lever of the second kind, its weight operates
against the moving power. If it be of equal size through-
out, this will be equal to just one-half the weight of the
lever, the other half being supported by the fulcrum.

With the lever of the third kind, the rule applied to the
first must be exactly reversed.

COMBINATION OP LEVEES.

A great power may be attained without the inconven-
ience of resorting to a very long lever, by means of a com-
pj„ 5Q hination of levers. In fig.

: y 50, the small weisrht P, act-

fe-;. ; /^^ ji\(^ ing as a moving power, ex-

^ ^ erts a three-fold force on the

next lever ; this, in its turn, acts in the same degree on the
third, which again increases the power three times. Con-
sequently, the moving power, P, acts upon the weight,
W, in a twenty-seven-fold degree, the former passing
through a space twenty-seven times as great as the latter.

A combination of levers like this is employed in self-
regulating stoves. It is in this case, however, used to
multiply instead of to diminish motion. The expansion
of a metallic rod by heat the hundredth part of an inch
acts on a set of iron levers, and the motion is increased,
by the time it reaches the draught-valve, to about one
hundred times.

52

MECHANICS.

Fiir. 51.

A more compact arrangement of compound levers is
shown in fig. 51, where the power, P, acts on the lever

A, exerting a force on the
lever B five times as great as
the power. B acts on the
lever C with a force increased
three times, and this, again,
on the weight, W, with a
four-fold force. Multiplying
5, 3, and 4 together, the prod-
uct is 60 ; hence a force of
one 230und at P wnll support
GO pounds at W. By gradu-
ating (or marking into
f^ \ notches) the lever C, so that

Compound levers. the distance is measured as

the weight is moved along it, a compact and powerful
steelyard for weighing is formed.

WEIGHING MACHIXE.

A valuable combination of levers is made in the con-
struction of the weighing machine., used for weighing cat-
tle, wagons loaded with hay, and other heavy articles.

Weighing Machine.

The wagon rests on the platform A (fig. 52,) and this
platform rests on two levers at W, W, which presses their
other ends both on a central point, and this again bears on

THE WEIGHING MACHINE.

53

the lever D, the other end of which is connected by means
of an upright rod with tlie steelyard at F.

There are two important points gained in this combina-
tion. In the first place, the
levers multiply the power so
much that a few pounds'
weight will balance a heavy
load of hay weighing a ton
or more ; and, in the next,
the load resting on both the
levers, communicates the
same force of weight to the
central point, from whatever
part of the platform it hap-
pens to stand on : for if it
presses hardest on one lever,
Portable Platform Scale. it bears lighter, at a cor-

responding rate, on the other. In practice, there are

Fig. &4.

Large Platform Scale.

always two pairs, or four levers, which proceed from each

54

MECHAXICS.

corner of the platform, and rest on one point at the centre.
We have taken the two only, to simplify the explanation.
A powerful stump-extracting machine, allowing a suc-
cession of efforts in the use of the lever, is exhibited by-
fig. 55. The lever, «, should be a strong stick of timber,
furnished with three massive iron hooks, secured by bolts
Fig. 55. passing through, as

represented in the
figure. Small or
truck wheels are
placed at each end
of the lever, merely
for the purpose of
moving it easily over
the ground. The
stump, 5, used as a
fulcrum, has the
chain passing round
near its base, while
another chain passes
over the top of the
stump, c, to be toin
out. A horse is at-
tached to the lever
Lever Stim]) MAchine. at </, and, moving tO

e, draws the other end of the lever backward, and loosens
tlie stump ; while in this position, another chain is made
to connect g to A, and the horse is turned about, and draws
the lever backward to ?*, which still further increases the
loosening ; a few repetitions of this alternating process
tear out the stump. Very strong chains are requisite for
this purpose. Large stumps may require an additional
horse or a yoke of oxen. Where the stumps are remote
from each other, iron rods with hooks may be used to
connect the chains.

The power which may be given to this and to all other

A WILD THEORY.

65

Ficr. 56.

modes of using the lever, as we have already seen, depends
on the difference between the lengths of its two arms. A
yoke of oxen, drawing with a force of 500 pounds on the
long arm of a lever 25 feet long, will exert a force on the
short arm of six inches equal to 50 times 500 pounds, or
25,000 pounds, on the stump.

It was after an examination of the great power which
may be given to the lever by increasing this difference
that Archimedes exultingly exclaimed, " Give me but a
fulcrum whereon to place my
lever, and I will move the earth !"
Admitting the theoretical truth of
this exclamation, and supposing
there could be a lever which he
might have used for this purpose,
its practical impossibility may be
quickly understood by computing
the whole bulk of the globe ; for
such is its enormous size and cu-
bical contents, that Archimedes
must have moved forward his
lever with the strength of a hun-
dred pounds and the swiftness
of a cannon ball for eight hundred million years to have
moved the earth the thousandth part of an inch !

WHEEL AXD AXLE.

In treating of the lever, it was shown to be capable of
exerting a force through a small distance only. Hence,
if a heavy body were required to be elevated to any con-
siderable height, it would be necessary to accomplish it
by a succession of efforts. This inconvenience is removed
by a constant and unremitted action of the lever in the
form of the wheel and axle.

Let the weight, lo (fig. 56,) be suspended by a cord

56

MECHANICS.

from the end of the lever, a &, and a wheel attached to
the lever, so that this cord may wind upon it as the
weight is elevated; then let the power be applied at the
other end by means of a cord, and a larger wheel be at-
tached, so that this cord too may wind upon the larger
wheel. These two wheels (fastened together so as to
form one), as they are made to revolve on their axis, will
now constitute, in a manner, a succession of levers, acting
through an indefinite distance according to the length of
the cords. The levers here successively acting are of the
" first kind," and the axis of the wheel is the fulcrum.
This arrangement constitutes in substance the wheel and
axle / and its power, like that of the simple lever, depends
on the comparative velocity of the weight and the moving
force. If, for example, the larger wheel is four times the
circumference of the smaller, a force of one hundred applied
to the outer cord will raise a weight of four hundred
pounds.

one view the power ex-
erted through the
wheel and axle, where
a small weight of C
pounds will wind up
(or balance) other
weights separately,
weighing 8, 12, or 2i
l^ounds, as the difier-
ence increases between
the size of the wheel

TT%«e; and axle, shmvinq the heavier weight far ^^^ ^^ *'^® ^^^^» ^^'
less motion. cording to the rule of

virtual velocities already explained.

The thickness of the rope has not been taken into con-
sideration. This is very small when compared with the
diameter of the outer wheel, but often considerable when
compared with that of the inner. To be strictly accurate,

The annexed figure exhibits

Fig. 57.

WHEEL AND AXLE. EXAMPLES. 57

therefore, the force must be considered as acting at the
centre of the rope ; hence the diameter of the rope must
be added to the diameter of the wheel.

There are various forms of the wheel and axle. In the
common windlass, motion is given to the axle by means of
a winch, which is a lever like the handle of a grindstone.
The windlass used in digging wells has usually four pro-
jecting levers or arms. The wheel used in steering a ves-
sel is furnished with pins in the circumference, to Avhich
the hand is applied in turning it. In the capstan (for
weighing anchor) the axis is vertical, and horizontal levers
are applied around it, so that several men may work at
once. The power of all these forms is easily calculated
by the rule of virtual velocities — that is, that the velocity
with which the power moves is as many times greater
than the velocity of tlie weight, as the weight exceeds the
power. A simple and convenient rule for computing in
numbers the power of wheel-work is the following : Multi-
ply all the numbers together which express either the cir-
cumferences or diameters of the large wheels, and then
multiply together all the numbers which express the diam-
eters di the smaller wheels or pinions; divide the greater
number by the less, and the quotient will be the power
sought.

BAND AND COG WHEELS

Where great power is required, several wheels and
axles may be combined in a man- rig. 50.

ner corresponding with that of the
compound system of levers already
explained. In this case the axis of
one wheel acts on the circumference
of the next, producing a continued
slower motion, and increasing the
power in a corresponding degree. Combined cog-ivJieels.
The wheels arc made thus to act by means of cogs or teeth,
3*

58

MECHANICS.

or of bands (fig. 59). In ordinary practice, however, com-
bined wheels are made use of to multiply motion instead
of to diminish it, familiar instances of which occur in the
grist-mill and thrashing machine.

In connecting a system of wheels, the cord or strap
may be used where great force is not required, the friction
round the circumference being sufficient to prevent slip-
ping. Bands are chiefly useful where motion is to be
transmitted to a distance ; as, for example, from a horse-
power without a bam to a thrashing-machine within it.
]Fig. 60. Liability nf sliding is some-

times useful, by preventing
the machinery from breaking
when a sudden obstruction
occurs. Where the force is
great, the necessary tension or
tightness of the cord produces
too great a friction at the
axle. In such cases, cogs or
teeth must be resorted to.
The term teeth is usually
applied when they are formed
of the same piece as the
wheel, as in the case of cast-
iron wheels. Co[/s are teeth
formed separately and inserted into the wheel, as with
wooden wheels. Pinions are the small wheels, or, more
properly, teeth set on axles.

Form of cogs— a, badly formed ,
&, iwoiier foi-m.

FOEM OF TEETH OR COGS.

The form of the teeth has a great influence on the
amount of friction among wheel-work. Badly formed
teeth are represented by the wheel-work at a, in the an-
nexed figure, consisting of square projecting pins. When
these teeth first come into contact with each other, they

FORM OF TEETH OR COGS 59

act ohliquely together, and thus a part of their force is lost,
and they continue scraping together with a large amount
of friction so long as they remain in contact. These
effects are avoided by giving to them the curved form,
represented by h. Here, instead of pressing each other
obliquely, they act at right angles, that is, not obliquely,
and instead of scraping, they roll over each other with
ease. These curves are as- £]£. 6i.

certained by mathemat- ^-^ — ~y<'\~^^'^^ ""^-^

ical calculation, which "/"'"---,/ ^j( V''"' ^

cannot be here given; ' /\ /j\ /\ '

it may be enough to state -'""^^ "^B — ^B- * "

in contact shall always ,^ j ^^"^^^^

work at right angles to I

each other. For ordi- Mode of giving the best form U) cogs.

nary practical purposes, however, they may be made
as shown in the annexed figure (fig. 61), by striking
circles whose diameters shall embrace just three teeth.
The points of the teeth thus formed are removed, leaving
a blunt extremity, according to the figure.

There are a few other rules that should always be ob-
served in constructing wheel-work, in order that the
wheels mny run easily together, without jerking oi* rat-
tling, the most important of which are the following :

1. The teeth must be of uniform size and distance from
each other, through the whole circumference of the wheel.

2. Any tooth must begin to act at the same instant
that the preceding tooth ceases to touch its corresponding
tooth on the other wheel.

3. There must be sufficient space between the teeth not
only to admit those of the other wheel, but to allow a cer-
tain degree of play, which should be equal to at least one-
tenth of the thickness of the teeth.

4. The pinions should not be very small, unless the

60

MECHANICS.

f

wheels they act on are quite large. In a i^inion that has
only eight teeth, each tooth begins to act before it reaches
the line of the centres, and it is not disengaged as soon as
the next one begins to act. A pinion of ten teeth will
not operate perfectly if working in a wheel of less than 72
teeth. Pinions of less than six teeth should never be
used.

5, To give strength to the teeth of wheels, make the
wheels themselves thicker, which increases the breadth of
the teeth.

6. Wheel-work is often defective when not made of
uniform material, in consequence of the relative number

Fig. 62. of teeth working together not being such as
to equalize the wear of all alike. If the
number of teeth on a wheel is divided with-
out a remainder by the nuniber of the pinion,
then the same teeth will repeatedly engage
each other, and they will often wear uneven-
Bevei-wiieeis. \j^ The number should be so arranged that
every tooth of the pinion may work in succession into the
teeth of the wheel. This is best eifected by first taking a
number for the wheel that will be evenly fi-. 63.

divided by the number on the pinion, and
then adding one more tooth to the wheel.
This will effect a continual change, so
that no two shall be engaged Avith each
other twice until all the rest have been
gone through wdth. This odd tooth is
called the hunting-cog.

Cog-wheels arc most usually made
vv^ith the teeth on the outside or cir- rmversGijoint.
cumference of the wheel ; these are termed spur-wheek.
If the teeth are set on one side of the wheels, they are
termed crown-wheels. When they are made so as to work
together obliquely, they are called bevel-wheels, ns in fig. 02.
Where the obliquity i^ email, ihc motion may be com-

THE PULLET.

61

muiiicated by means of the universal joint, as shown in
fig. 63. This is commonly used in the thrasking-machine,
where there is a slight change in the direction of motion
between the horse-power and the thrasher.

THE PULLEY.

Fi£. 64,

///////////////

Pulley doubling tJie
foice.

Let a cord fixed at one end pass round a movable
grooved wheel, and be grasped by the
hand at the other end: then, in lifting
any weight attached to the wheel, by
drawing up the cord, the hand will move
with twice the velocity of the weight.
It will, therefore, exert double the degree
of force. This operates Fig. 65.
precisely as a succession of
levers of the second kind,
the fixed cord being the
fulcrum, and the cord drawn
up by the hand, the power.
It thus constitutes one of the simplest kinds
of the pulley, fig. 64.

The wheel is called a sheave / the term
pulley is applied to the block and sheave ;
and a combination of sheaves, blocks, and
ropes is called a tackle.

There are various combinations of single
pulleys for increasing power, the most com-
mon of which, and least liable to become
deranged by the cord being thrown off the
wheels, is shown in fig. 65. In this and in
all similarly constructed pulleys, the weight p^n^f six-fold
is as many times greater than the power as power.
the number of cords which support the lower block. If
there be six cords, as in the figure, the weight will be six
limes the power.

62

MECHANICS.

MllllllUllllllHllllllillilllili

Where a cord is passed over a single fixed M'heel, as in
fig. 66, or over two or more wheels, no power is gained,
the moving force being the same in
iliiiHiiii'Hliilliilllliiiii!/ velocity as the weight. Such pulleys
are sometimes, however, of use by
altering the direction of the force.
The latter is applied with advantage
to unloading or pitching hay by
means of a horse-power, saving much
time and labor, as explained on a
future page.

Among the many applications of
the pulley, one is shown in the ac-
companying figure (fig. 67) rep-
resenting Packer's Stone Lifter^ for
raising large boulders from the soil,
PuUey witJi m increase of Weighing from One to four and five
power. tons, and afterwards placing them in

walls. It is also employed for tearing out small or partly
decayed stumps.

The usefulness of tho pulley depends mainly upon its
lightness and port- Fig. ot.

able form, and the
facility with which,
it may be made
to operate in al-
most any situation.
Hence it is much
used in building,
and is extensively
applied in the rig-
ging of ships. In Poc/r^r'^ stone UfUr.
the computation of its power there is a large drawback,
not taken into account in the preceding calculation, which
mateiially lessens its advantage; this is the friction of
the wheels and blocks and the stiffness of the cordage,

THE INCLINED PLANE. 63

which are often so great that two-thirds of the power
is lost.

THE INCLINED PLANE.

The inclined plane or slope possesses a power which is
estimated by the proportion which its lengtli bears to the
height. If, for example, the plane be twice as long as the
perpendicular height, then in rolling the body a up the
inclined plane (fig. 68), it will move through twice the
distance required to lift it directly from h to c. Therefore
only one-half the strength else required need be exerted for
this purpose. The same reasoning
will apply to any other proportion
between the height and length ;
that is, the more gradual or less
steep the slope becomes, the greater
will be the advantage gained. A familiar example occurs
in lifting a loaded barrel into a wagon : the longer the
plank used in rolling it, the less is the exertion needed.

A body, in rolling freely down an inclined plane, acquires
the same velocity that it would attain if dropped peri)en-
dicularly from a height equal to the perpendicular height
of t^e plane. Thus, if an inclined plane on a plank road
be 100 yards long and 16 feet high, a freely running
wagon, left to descend of its own accord, will move 32
feet per second by the time it reaches the bottom, that
being the velocity of a stone falling 16 feet. Or, a rail-
car on an inclined plane 145 feet high will attain a speed
of 96 feet per second, or more than 65 miles an hour, at
the foot of the plane, which is equal to the velocity of a
stone falling three seconds, or 145 feet.

ASCENT IN EOADS.

All roads.not perfectly level maybe regarded as inclined
planes. By the application of the preceding rule, we

64 MECHANICS.

may discover precisely how much strength is lost in draw-
ing heavy wagons up hill. If the load and wagon weigh
a ton, and the road rise one foot in height to every five
feet of distance, then the increased strength required to
draw the load will be one-fifth of its weight, or equal to
400 pounds. If it rise only one foot in twenty, then the
increase in power needed to ascend this plane will be only
100 pounds. The great importance of preserving, as
nearly as practicable, a perfect level is obvious.

There are many roads made in this country, rising over
and descending hills, which might bo made nearly level by
deviating a little to the right or to the left. Suppose, for
example, that a road be required to connect the two points

Fiff. 69.

fez-Jj^f

a and h (fig. 69), three miles apart, but separated by a
lofty hill midway between them, and one mile in diameter.
Passing half a mile on either side would entirely avoid
the hill, and the road thus curved would be only one
hundred and forty-eight yards, or one-twelfth of a mile
longer. The same steep hill is ascended perhaps fifty to
five hundred times a year by a hundred different farmers,
expending an amount of strength, in the aggregate,
sufficient to elevate ten thousand tons annually to this
height, as a calculation will at once show — more than
enough for all the increased expense of making the road
level.

It is interesting and important to examine how much
further it is expedient to carry a road through a circuitous
level course than over a hill. To ascertain this point, we
must take into view the resistance occasioned by the rough
surface or soft material of the road. Roads vary greatly

THE RESISTANCE OF ROADS. 65

in this particular, but the following may be considered as
about a fair average. In drawing a ton w^eight (including
wagon) on freely running wheels, on a perfect level, the
strength exerted will be found about equal to the follow-

ing

On a hard, smooth plank road 40 pounds.

On a good Macadam road 60 "

On a common ^ood liard road 100 "

On a soft road about 200 "

Now let us compare this resistance to the resistance of
drawing up hill. First, for the plank road — forty pounds
is one-fiftieth of a ton ; therefore a rise of one foot in fifty
of lengtl^ will increase the draught equal to the resistance
of the road. Hence the road might be increased fifty feet
in length to avoid an ascent of one foot ; or, at the same
rate, it might be increased a mile in length to avoid an
ascent of one hundred and five feet. But in this estimate
the increase in cost of making the longer road is not taken
into account. If making and keeping in repair be equal
to three hundred dollars yearly per mile, and one hundred
teams pass over it daily, at a cost for 'traveling of four
cents each per mile, being four dollars daily, or twelve
hundred dollars per annum, then the cost of making and
repair would be one quarter of the expense of traveling
over it. Therefore the mile should be diminished one
quarter in length to make these two sources of expense
counterbalance each other. Hence a road with this
amount of travel should, with a reference to public
accommodation, be made three-fourths of a mile longer
to avoid a hill of one hundred and five feet. This
estimate applies to loaded teams only. For light car-
riages the advantages of the level road would not be so
great. One-half to five-eighths of a mile would, there-
fore, be a fair estimate for all kinds of traveling taken
together.

66 MECHANICS.

The following table shows the rise in a mile of road for

different ascents :

For a rise

of 1 foot in 10, the

road ascer

ids 528 feet per

do.

do.

13,

do.

406

do.

do.

do.

15,

do.

352

do.

do.

do.

20,

do.

264

do.

do.

do.

25,

do.

211

do.

do.

do.

30,

do.

176

do.

do.

do.

35,

do.

151

do.

do.

do.

40,

do.

132

do.

do.

do.

45,

do.

117

do.

do.

do.

50,

do.

106

do.

do.

do.

100,

do.

53

do.

do.

do.

125,

do.

42

do.

The same kind of reasoning applied to a common good
road will show that it will be profitable for the public to
travel about half that distance to avoid a hill of one
hundred and five feet. In this case the whole yearly
cost of the road, including interest on the land, and the
cost of repairs, would not usually be more than a tenth
part of the same cost for plank, or would not exceed thirty
dollars.

On rail-roads, where the resistance is only about one-
fifth part of the resistance of plank roads, the dispropor-
tion between the draught on a level and up an ascent be-
comes many times greater. Thus, if a single engine move
three hundred and fifty tons on a level, then two engines
will be required for an ascent of only twenty feet per
mile, four engines for fifty feet per mile, and six engines
for eighty feet per mile.

Such estimates as these merit the attention of the
farmer in laying out his own private farm roads. It may
be worthy of considerable effort to avoid a hill of ten or
twenty feet, wliich must be passed over a hundred times
yearly with loads of manure, grain, hay, and wood. The
greatly increased resistance of soft materials, also, is too
rarely taken into account. A few loads of gravel, well
applied, would often prevent ten times the labor in plow-

FOR^t AND MATERIALS FOR ROADS. 67

ing through deep ruts, to say nothing of the breaking
of harness and wagons by the excessive exertions of the
team.

F0R3I AND MATERIALS FOR ROADS.

The depth of the mud in common roacls is often un-
necessarily great, in consequence of heaping together
with the plow and scraper the soft top-soil for the raised

Section of badly formed road.
carriage-way. When heavy rains fall, this forms a deep
bed of mud, into which the wheels Avork their way, and
cause extreme labor to the team. A much better way is
to scrape oft' and cart away into the fields adjoining all
the soft, rich, upper surface, and then to form the harder
subsoil into a slightly rounded carriage-way, with a ditch
on each side. Such roads as this have a very hard and
firm foundation, and they have been found not to cut up

Fig. 71.

Section of weU formed road.
into ruts, nor to form much mud, even in the wettest sea-
sons. On this hard foundation six inches of gravel will
endure longer and form a better surface than twelve
inches on a raised " turnpike" of soft soil and mud.

It frequently hap^^ens that the form of the surface in-
creases the quantity of mud in a road, by not allowing
the water to flow off freely. The earth is heaped up in a
high ridge, but having little slope on the top (fig. 70),
where the water lodges, and ruts are formed, the only dry
portions being on the brink of the ditches, where the
water can escape. Instead of this form, there should be a
gradual inclination from the centre to the ditches, as
shown in fig. 71. This inclination should not exceed 1

bo MECHANICS.

foot in 20. On hill-sides the sloj^e should all be toward
the liigher ground, as in fig. 72.

Hard and durable roads are made on the plan of Telford.
Their foundation is rounded stones, placed upright, with
the smaller or sharper ends upward. The smaller stones

cf road for hiU-sides.

are placed near the sides, and the larger at the centre,
thus giving to the road a convex form. The spaces
are then filled in with small broken stone, and the whole
covered with the same material or with gravel. The
pressure of wagons crowds it compactly between the
stones, and forms a very hard mass.

IMPORTANCE OF GOOD KOxVDS.

The principles of road-making should bo better under-
stood by the community at large. Farmers are deeply
interested in good roads. Nearness to market, and facili-
ties for all other kinds of communication, are worth a
great deal, often materially afiecting the price of land
and its products. The difference between traveling ten
miles through deep mud, at tAVO miles j^er hour, with half
a load, and traveling ten miles over a fine road, at five
miles per liour, with a full load, should not be forgotten.

" In the absence of such facilities," says Gillespie, " the
richest productions of nature waste on the spot of their
growth. The luxuriant crops of our western prairies are
sometimes left to decay on the ground, because there are
no rapid and easy means of conveying them to market.
The rich mines in the northern part of the State of New

GOOD AND BAD EOADS. 69

York are comparatively valueless, because the roads among
the mountains are so few and so bad, that the expense of
the transportation of the metal would exceed its value.
So, too, in Spain it has been known, after a succession of
abundant harvests, that the wheat has actually been
allowed to rot, because it wo-uld not repay the cost of
carriage." Again, " When the Spanish government re-
quired a supply of grain to be transferred from Old Castile
to Madrid, 30,000 horses and mules were necessary for the
transportation of four hundred and eighty tons of wheat.
Upon a broken-stone road of the best sort, one-hundredth
of that number could easily have done the work." He
furth"er adds, in speaking of the improvements in roads
made by Marshal Wade, in the Scottish Highlands, *' His
military road is said to have done more for the civilization
of the Highlands than the preceding efforts of all the
British monarchs. But the later roads, under the more
scientific direction of Telford, produced a change in the
state of the people which is probably unparalleled in the
history of any country for the same space of time. Large
crops of wheat now cover former wastes ; farmers' houses
and herds of cattle are now seen where was previously a
desert ; estates have increased seven-fold in value and
annual returns; and the country has been advanced at
least one hundred years."

THE WEDGE.

The wedge is a double inclined plane, the power being
applied at the back to urge it forward. It becomes more
and more powerful as it is made more acute ; but, on ac-
count of the enormous amount of friction, its exact power
can not be very accurately estimated. It is nearly always
urged by successive blows of a heavy body, the momentum
of which imparts to it great force.

All cutting and piercing instruments, as knives, scissors,

70

MECHANICS.

chisels, pins, needles, and awls, are wedges. The degree
of acuteness must be varied according to circumstances ;
knives, for instance, which act merely by pressure, may be
made with a much sharper angle than axes, which strike
a severe blow. For cutting very hard substances, as iron,
the edge must be formed with a still more obtuse angle.

The utility of the wedge depends on the friction of its
surfaces. In driving an iron wedge into a frozen or icy
stick of wood, as every chopper has observed, the want
of sufficient friction causes it immediately to recoil, unless
it be i^reviously heated in the fire. The efficacy of nails
depends entirely on the friction against their wedge-like
faces.

THE SCREV7"

The screw may be regarded as nothing more than an
inclined plane winding round the surface of a
cylinder (fig. 74), This may be easily under-
stood by cutting a piece of paper in such a
form that its edge, a h (fig. 75), may represent
the inclined plane ; then, beginning at the wider
end, and wrapping it about the cylindrical piece
of wood, c, the upper edge of the paper will
represent the thread of the screw.
Although the friction attending the use of the screw is

considerable, and without it it would not retain its place,

yet the slope of its in-
clined thread being so

gradual, it possesses

great power. This power

is multiplied to a still

greater degree by the

lever #iich is usually employed to drive it, a (fig. 76).

If, forj*example, a screw be ten inches in circumference,

and its thread ll^lf an inch apart, it exerts a force twenty

Fi«. 75.

THE SCREW.

71

times as great as the moving power. If it be moved
by a lever twenty times as long as the diameter of the
Fig. 76. screw, here is another increase of twenty

times in force. Multiplying 20 by 20
gives 400, the whole amount gained by
this combination, and by which a man
applying one hundred pounds in force
could exert a pressure equal to twenty
tons. About one-third or one-fourth of
this should, however, be deducted for
friction.

When the screw is combined with the
wheel and axle (fig. 77), it is capable of exerting great
power, which may be readily calculated by multiplying
the power of the screw and its lever into the power of
the wheel and axle.

Hi

rillllllll!IIIIIIIIHIHillllil!llllllllllllllll

Screw and lever
combined.

THE KNEE-JOIXT POWER.

Fig. 78.

The Jcnee-jomt or toggle-joint is usually regarded as a com-
pound lever, and consists of two rods connected by a turn-
ing joint, as represented in fig. 78. The outer end of one of
Fig_ 77_ the levers is fixed to

a solid beam, and the
other connected with
a movable block.
When the joint a is
forced in the direc-
tion indicated by the
arrow, it produces a
powerful pressure
upon the movable
block, which in-
creases as the lever approaches a straight line. This is
easily understood by the rule of virtual velocities, for the
force moves with a velocity many times greater than the

Screw, lever, and wJied
conMned'.

Knee-joint pjwer.

72

3IECIIAXICS.

power given to the block, and this relative difference in-
creases as the joint is made straighter.

This power is made use of in the lever printing-press,
where the greatest force is given just as the pressure is
completed. Another example occurs in the Lever Wash-
ing-machine (fig. 79), which is worked "by the alternating
motion of the handle, A, pressing a swinging board, per-

Fi-. 79.

Lever Washing-viachiiic.

forated with holes, with great force against the clothes
next to one side of the water-box. Like the printing-
press, this machine exerts the greatest jDOwer just as the
motion of the lever is completed, and at the time it is
most needed. The same principle is exhibited in KendalVs
Cheese-press (fig. 80), where the lever and the wheel and
axle are combined with the two knee-joints, one on each
side of the press, drawing down a cross-beam upon the
cheese with a greatly multiplied power.

Dick'' 8 Cheese-press (fig. 83), operates on a similar
piincii>Ie. Figs. 81-2 show the structure of its

working

l.EVEU WASHIXG-MACIIIXE.

Fis. 80.

73

Kendall's Cheese-press.

part, the dotted lines indicating the position of the lever,
Avhich is inserted into a roller or axle, and, by turning,
drives the movable iron blocks asunder, and raises the
cheese against the broad screw-head above, as shown in
lis:. 82. In fio". 81, the raised lever shows that the blocks

Fig. 83. Fi^. 81.

arc at first near togetlier, but are
crowded asunder as the lever is press-
ed downward. This cheese-press is
made of cast-iron, and has great
power; to try it, weights were in-
creased upon the lever, until the iron
frame broke with a force equal to six-
teen tons.

The power exerted by a rolling-
mill, where bars of iron are flattened
in their passage between two strong
rollers, is precisely like that of the knee-joint, Tlje only
4

74

Dick's cast-iron Cheese-press.

difference is, that the rollers, which may be considered as a
constant succession of levers coming into play as they re-
volve, are both fixed, and consequently the bar has to yield
between them (fig. 84). Tlie Fig. 84.

greatest power is exerted just
as the bar receives the last
pressure from the rollers. The
most powerful and rapidly-
working sjtraw-cutters are those
which draw the straw or hay
between two rollers, one of
which is furnished with knives
set around it parallel with its
axis, and cutting on the oilier, which is covered with un-
tanned ox-hide (fig. 85).

Principle of the knee-joint in the
rolling-milL

STRAW CUTTERS.

Pig. 85.

75

Hide Boiler Straw Cutter.

CHAPTER V.

APPI^ICATION OF MECHANICAL PRINCIPLES IN THE

STRUCTURE OF SIMPLE IMPLEMENTS AND

PARTS OF MACHINES.

In contriving the more difficult and complex machines,
the principles of mechanics must be closely studied, to
give every part just that degree of strength required, and
to render their operation as perfect as possible. But in
making the more common and simple implements of the
farmer, mere guess-work too often becomes the only guide.
Yet it is highly useful to apply scientific knowledge even
in the shaping of a hoe handle dr a plow-beam.

The simplest tool, if constantly used, should be formed
with a view to the best application of strength. The
laborer who makes with a common hoe two thousand

76 "^ MECHANICS.

strokes an hour, should not wield a needless ounce. If
any part is heavier than necessary, even to the amount of
half an ounce only, he must repeatedly and continually
lift this half ounce, so that the whole strength thus spent
would be equal, in a day, to twelve hundred and fifty
pounds, which ought to be exerted in stirring the soil and
destroying weeds. Or, take another instance: A farm
wagon usually weighs nearly half a' ton; many might be

Fi-. 8G.

I ^ ^-^^

Hadly-fornieO.fork handle.

reduced fifty pounds in weight by proportioning every
part exactly to the strength required. How much, then,
should we gain here? Every farmer who drives a wagon
with its needless fifty pounds, on an average of only five
miles a day, draws an unnecessary weight every year
equal to the conveyance of a heavy wagon-load to a dis-
tance of forty miles.

Now a knowledge of mechanical science will often ena-
ble the farmer, when he selects and buys his implements,
to judge correctly whether every part is properly adapted
to the required strength. We shall suppose, for instance,
that he intends to purchase a common pitchfork. He
finds them differently formed, although all are made of the

Fig. 87.
O'

Badly -formed fork handle.

best materials. The handles of some are of equal size
throughout. Some are smaller near the fork, as in fig. 86,
and others are larger at the same place, as in fig. 87.
Now, if he understands the principle of the lever, he
knows that both of these are wrongly made, for the right
hand placed at a is the fulcrum, where the greatest
strength is needed, and thei'cfore the one represented by
fig. 88 is both stronger and lighter than the others.

PRINCIPLES IX THE STRUCTURE OF IMPLEMENTS. 77

Again, lioe handles^ not needing much strength, chiefly
require lightness and convenience for grasping. Hence,
in selecting from two such as are represented in the annex-
ed figures, the one should be chosen which is lightest near

Fig. 88.

Wdl-formed fork handle.

the blade, nearly all the motion being in that direction,
because the upper end is the centre of motion. The right
liand, at «, acting partly as the fulcrum, the hoe handle
should be slightly enlarged at that place. Fig. 89 rep-
resents a well-formed handle ; fig. 90, a clumsy one. Rake
handles should be made largest at the middle, or where
the right hand presses. Rake-heads should be much
larger at the centre, and tapering to the ends, where the
stress is least, the two parts operating as two distinct lev-

Fis:. 89.

a

Well-formed hoc handle.

ers, acting from the middle. Wood horse-rakes might be
made considerably lighter than they usually are by ob-
serving the same principles. The greatest strength requir-
ed ioY plow-beams is at the junction with the mould-board,
and the least near the forward end, or furthest from the
fulcrum or centre of motion.

Now it may be tliat the fivrmcr who has had much ex-
perience may be able to judge of all these things without

Fig. 90.

o

Badly-formed hce handle.

a knowledge of the science. But this scientific knowledge
would serve to strengthen his experience, and enable him
to judge more accurately and understandingly by showing
him the reasons ; and in many cases, where 7iew imple-
ments were introduced, he might be enabled to form a

78

MECHANICS.

good judgment before he had incurred all the ex2->ense and
losses of unsuccessful trials.

Even so simple a form as that of an ox-yoke is often
made unnecessarily heavy. Fig. 91 represents one that is
faulty in this respect, by having been cut from a piece of

Fi- 91.

timber as wide as the dotted lines a c / and being thus
weakened, it requires to be correspondingly large. Fig.
92 is equally strong, much lighter, and is easily made from
a stick of timber only as wide as a h in the former figure.
In the heavier machines, it is necessary to know the de-
gree of taper in the diftercnt pnrts with accuracy. A
thorough knowledge of science is needed to calculate this

Pig. 92.

with precision, but a supei'ficial idea may be given by cuts.
If a bar of wood, formed as in a (fig. 93), be fixed in a
wall of masonry, it will possess as nmch strength to sup-
port a weight hung on the end as if it were the same size
throughout, as h. The' first is equally strong witli the
second, and much ligliter.--' The same form doubled must

* The simple style of this work precludes an explanation of the mode
of caleulution for determinini:: tlie exact form. Where the stick tapers
only on one side, it is a common parabola ; if on all sides, a cubic
parabola.

VARIOUS EXAMPLES.

7-9

be given if the bar is supported at the middle, with a
weight at each end, or with the weight at the middle,
supported at each end, as c. This form, therefore, is a
proper one for many parts of implements, as the bars of
whiffle-trees, the rounds of ladders, string-pieces of bridges,
and any cross-beams for supporting weights. The proper
form for rake-teeth and fence-posts, the pressure being
nearly alike on all parts, is nearly that of a long wedge,
or with a straight and uniform taper. Therefore a fence-
l^ost of equal size throughout contains nearly twice as
much timber as is needed for strength only.

The form of these parts must, however, be modified to
suit circumstances ; as whifiie-trees must be large enough

Fi-. 93.

P^^S^S5^

at the ends to receive the iron hooks, wagon-tongues for
ironing at the end, and spade handles for the easy grasp
of the hand.

The axle-trees of wagons must be made not only strong
in the middle, or at centre of pressure, but also at the en-
trance of the hub; because the wheels, when thrown side-
wise in a rut, or on a sideling road, operate as levers at
that point, a and h (fig. 94), show the manner in which
the axles of carts may be rendered lighter without lessen-
ing the strength, a being the common form, and b the im-
proved one.

80

MECHANICS.

Sometimes several forces act at once on different parts.
For example, the spokes of wagon-wheels require strength
at the hub for stiffening the wheel ; they must be strong
in the middle to prevent bending, and large enough at

Fig. 94.

a ^

the outer ends, where they are soonest weakened by de-
cay. Hence there should be nearly a uniform taper,
slightly larger at the middle, and with an enlargement at
the outer end, as c (fig. 94).

A very useful rule in practice, in giving strength to
structures, is this : The strength of every square beam or
stick to support a weight increases exactly as the width
increases, and also exactly as the square of the depth in-
creases. For example, a stick of timber eight inches wide
and four inches deep (that is, four inches thick), is exactly
twice as strong as another only four inches wide, and with
the same depth. It is twice as wide, and consequently
twice as strong; that is, its strength increases just as the
width increases, according to the rule given. But where
one stick of timber is twice as deep^ the width being the
same, it is four times stronger ; if three times as deep, it
is 7iine times stronger, and so on. Its strength increases
as the square of the depth, as already stated. The same
rule will show that a board an inch thick and twelve inch-
es wide will be twelve times as strong when edgewise as
when lying flat. Hence the increase in strength given to
whifile-trees, fence-posts, joists, rafters, and string-pieces
to farm-bridges, by making them narrow and deep.

CALCULATING THE STRENGTH OF PARTS. 81

Again, the strength of a round stick increases as the cube
of the diameter increases ; that is, a round piece of wood
three inches in diameter is eight times as strong as one an
inch and a lialf in diameter, and twenty-seven times as
strong as one an inch in diameter. This rule shows that
a fork handle an inch and a half in diameter at the middle
is as much stronger than one an inch and a quarter in
diameter, as seven is greater than four. Now this rule
would enable the farmer to ascertain this without break-
ing half a dozen fork handles in trying the experiment,
and it would enable the manufacturer to know, "without

Fig. 95.

the labor of trying many experiments, that if he makes a
fork handle an inch and a half at the middle, tapering a
quarter of an inch toward the ends, it will enable the
w^orkman to lift with it nearly twice as much hay as with
one an inch and a quarter only through its whole length.
A mode of adding strength to light bars of wood, by
means of braces, is shown in fig. 95, representing light
whiffle-trees, stiffened by iron rods in a simple manner.
The same method is sometimes adopted to advantage in
making light fruit ladders, and for other purposes.

CHAPTER VI.

FRICTION.

The subject of friction has been postponed, or merely

alluded to, to prevent the confusion of considering too

many things at once. As it has an important influence on

the action of machines, it is worthy of careful investigation.

4*

82 MECHAXICS.

I

It is familiar to most persons, that when two surfaces
slide over each other while pressing together, the minute
unevenness or roughness of their surfaces causes some ob-
struction, and more or less force is required. This resist-
ance is known as f notion.

ROLLING FEICTION.

The term is also applied to the resistance of one body
rolling over another. This may be observed in various
degrees by rolling an ivory ball successively over a carpet,
a smooth floor, and a sheet of ice ; the same force which
would impel it only a few feet on the carpet would cause
it to move as many yards on a bare floor, and a still
greater distance on the ice. The two extremes may be
seen by the force required to draw a carnage on a deep
sandy or loose-gravel road, and on a rail-road.

NATUEE OF FEICTION.

If two stiff bristle brushes be pressed with their faces
together, they become mutually interlocked, so that it
will be quite difficult to give them a sliding motion. This
may be considered as an extreme case of friction, and
serves to show its nature. In two pieces of coarse, rough
sandstone, or of roughly-sawed wood, asperities interlock
in the same way, but less in degree ; a diminished force is
consequently required in moving the two surfaces against
each other. On smoothly planed wood the friction is still
less; and on polished glass, where the unevenness can not
be detected without the aid of a powerful magnifying
glass, it is reduced still further in degree.

ESTIMATING THE AMOUNT OF FRICTION.

In order to determine the exact amount of friction be-
tween different substances, the following simple and in-

TO ASCERTAIN THE AMOUNT OF FRICTION. 83

genioiis contrivance is adopted : An inclined plane, a h
(fig. 96), is so formed that it may be raised to any desired
height by means of the arc of a circle and a screw. Lay
a flat surface of the substance we wish to examine upon
this inclined plane, and another smaller piece or block of
the same substance upon this surface ; then raise the plane
until it becomes just steep enough for the block to slide
down by its weight. ISTow, by measuring the degree of
slope, we know at once the amount of friction. Suppose,
for example, the two surfaces be smoothly-planed wood:
it will be found that the plane must be elevated about
half as high as its length ; therefore we know, by the

Fig. 90.

properties of the inclined i)lane, heretofore explained, that
it requires a force equal to one-half the weight of the
wooden block to slide it over a smooth Avooden surface.
Some kinds of wood have more friction than others, but
this is about the average.*

From the result of this experiment we may learn that
to slide any object of wood across a floor requires an
amount of strength equal to one-half the weight of the
object. A heavy box, for instance, weighing two hundred
pounds, can not be moved without a force equal to one
hundred pounds. It also shows the impropriety of placing

* These experiments may be made with tolerable accuracy, by hook-
ing a spring-balance into any object of known weight, and then observ-
ing the comparative force as measured by the balance, to draw it over a
perfectly level surface.

84 MECHANICS.

a heavy load upon a sled in winter for crossing a bare
wooden bridge or a dry barn floor, the friction between
cast-iron sleigh-shoes and rough sanded plank being nearly
equal to one-third of the whole weight.* Hence a load
of one ton (including the sled) would require a draught
equal to more than six hundred pounds, which is too much
for an ordinary single team. On bare unfrozen ground the
friction would be still greater. On a plank bridge, with
runners wholly of wood, it would be equal to half the
load. All these facts may be readily proved by actually
placing the sled on slopes of plank and of earth, and by
observing the degree of steepness required for sliding
down by its own weight.

In a similar way, we are enabled easily to ascertain the
force required to draw a wagon upon any kind of level
surface. Suppose, for example, that we w^ish to determine
the precise amount of force for a wagon weighing, with
its load, one ton, on a plank road. Select some slight de-
scent, Mhere the wagon will barely run with its own
weight. Ascertain by a level just what the degree of de-
scent is ; then divide the weight of the wagon by the de-
gree of the slope, and we shall have the force sought for.
To make this rule plainer by an example : It will be found
that a good, newly-laid plank track, if it possess a de-
scent of only one foot in fifty feet distance, will be suflS-
cient to give motion to an easy-running wagon ; therefore
we know that the strength required to draw it on a level
will be only one-fiftieth part of a ton, or forty pounds.

The resistance oflTered to the motion of a wagon by a
Macadam road, by a common dry road, and by one with
six inches of mud, may be readily determined in the same
way by selecting proper slopes for the experiment. If by
such trials as these the farmer ascertains the fact that a

* On clean hard wood, with polished metallic shoes, the friction
would be much less, or a fourth or fifth.

EESULTS "WITH THE DTNAMOMETEE. 85

few inches of mud are sufficient to retard his wagon so
much that it will not run of its own weight down a slope
of one foot in four (and few common roads are ever
steeper), then he may know that a force equal to one-fourth
the whole weight of his wagon and load will be required
to draw it on a level over a similar road — that is, the
enormous force of five hundred pounds will be needed for
one ton, of which many wagons will constitute nearly one-
half. Hence he can not fail to see the great importance,
for the sake of economy, and humanity to his team, of
providing roads, whether public or private, of the hardest
and best materials.

- EESULTS WITH THE DYXAMOMETEE.

Another mode of determining the resistance of roads is
by means of the Dynamometer.^ It resembles a spring-
balance^ and one end is fastened to the wagon and the
other end connected with the horses. The force applied
is measured on a graduated scale, in the same way that
the weight of any substance is measured with the spring-
balance. A more particular description of this instrument
will be given hereafter.

Careful experiments have been made with the dynamom-
eter to ascertain accurately the resistance of various kinds
of roads. The following are some of the results :

On a new gravel road, a horse will draw eight times as
much as the force applied ; that is, if he exerts a force
equal to one hundred and twenty-five pounds, he will
draw half a ton on such a road, including the weight of
the wagon, the road being perfectly level.

On a common road of sand and gravel, sixteen times as
much, or one ton.

On the best hard-earth road, twenty-five times as much,
or one and a half tons.

* From two Greek worda, dunamiSy power, and metreo, to measure.

86 MECHANICS.

On a common broken-stone road, twenty-five to thirty-
six times as much, or one and a half to two and a quarter
tons.

On the best broken-stone road, fifty to sixty-seven times
as much, or three to four tons.

On a common plank-road, clean, fifty times as much, or
three tons.

On a common plank-road, covered tliinly with sand or
earth, thirty to thirty-five times as much, or about two
tons.

On the smoothest oak plank-road, seventy to one hund-
red times as much, or four and a half to six tons.

On a highly-finished stone track-way, one hundred and
seventy times as much, or ten and a half tons.

On the best rail-road, two hundred and eighty times as
much, or seventeen and a half tons.

The firmness of surface given to a broken-stone road by
a paved foundation was found to lessen the resistance
about one-third.

On a broken-stone rond it was found that a horse could
draw only about two-tliirds as much when it was moist
or dusty as when it was dry and smooth; and when
muddy, not one-half as much. "When the nmd was thick,
only about one quarter as much.

The character of the vehicle has an influence on the
draught. Thus, a cart, a part of the load of which is sup-
ported by the horse, usually requires only about two-thirds
the force of liorizontnl draught needed for wagons and
carriages. On rough roads the resistance is shghtly
diminished by springs.

On soft roads, as earth, sand, or gravel, the number of
pounds draught is but little affected by the speed; that is,
the resistance is no greater in driving on a trot than on a
walk ; but on hard roads it becomes greater as the velocity
increases. Thus a carriage on a dry pavement requires
one-half greater force when the horses are on a trot than

WIDTH 03' WHEELS. 87

on a walk ; but on a mudcly road the difference between
the two rates of speed is only about one-sixth. On a rail-
road, where a draught of ten pounds will draw a ton ten
miles an hour, the resistance increases so much at a high
degree of speed as to require a force of fifty pounds per
ton at sixty miles an hour — that is, it would require five
tiimes as much actual power to draw a train one hundred
miles at the latter rate as at the former ; but as the speed
is six times as great, the actual force during a given time
would be five times six, or thirty times as great.

WIDTH OF WHEELS.

Wheels with wide tire run more easily than narrow tire,
on soft roads ; on hard, smooth roads, there is no sensible
difference. Wide tire is most advantageous on gravel and
new broken-stone roads, both by causing the vehicles to
run more easily, and by improving the surface. For the
latter reason, the New York turnpike law allows six-inch
wheels to pass at half price, and twelve-inch wheels to pass
free of toll. Wheels with broad tire on a farm would pass
over clods, and not sink between them; or would only
press the surface of new meadows, without cutting the
turf. But where the ground becomes muddy, the mud
closes on botli sides of the rim, and loads the wheels. On
clayey soils, narrow tire unfits the roads for broad wheels.
For these reasons, broad wheels are decidedly objection-
able for clayey or soft soils, and they are chiefly to be
recommended for broken-stone roads, and gravelly, or dry,
sandy localities. They are also much better for the wheels
of sowing or drilling machines, which only pass over
mellowed surfaces.

• The larger the wheels are made, the more easily they
run ; thus a wheel six feet in diameter meets with only
half the resistance of a wheel three feet in diameter.

A flat piece of wood, sliding on one of its broad sur-

88 MECHANICS.

faces, is subject to the same amount of friction as when
sliding upon its edge. Hence the friction is the same,
provided the pressure be the same, whether the surface be
small or large.* Or, in other words, if the surfaces are
the same, a double pressure produces a double amount of
friction ; a triple pressure, a triple amount, and so on.

A narrow sleigh-shoe usually runs with least force, for
two reasons : first, its forward part cuts with less resist-
ance through the snow ; and, secondly, less force is re-
quired to pack the narrow track of snow beneath it. The
only instance in which a wide sleigh-sboe would be best, is
where a crust exists that would bear it up, and through
which a narrow one would cut and sink down.

VELOCITY.

Friction is entirely independent of velocity ; that is, if
a force of ten pounds is required to turn a carriage wheel,
this force will be ten pounds, whether the carriage is
driven one or five miles per hour. Of course, it will re-
quire fiA^e times as much force to draw five miles per hour,
because five times the distance is gone over ; but, measured
by a dynamometer or spring-balance, the pressure would
be the same. In precisely the same way, the weight of a
stone remains the same, whether lifted slowly or quickly.
If the friction of the wheels of a wagon on their axles be
equal to ten pounds, driving the horse fast or slowly will
not inciease or diminish it. But fast driving will require
more strength, for the same reason that a man would need
more strength to carry a bag of wheat up two flights of
stairs than one, in one minute of time.

FKICTION AT THE AXLE.

A carriage wheel, or any other wheel revolving on an

* Generally speaking, this is very nearly correct ; but when the pres-
sure is intense, the friction is slightly less on tlie smaller surface.

SIZE OF WHEELS CX ROADS.

89

axle, will run more easily as the axle is made smaller.
This is not owing to the rubbing surfaces being less in
size, as some mistakenly suppose, for it has just been
shown that this makes very little or no difference, pro-
vided the pressure is the same; but it is owing to the
• leverage of the wheel on the friction at the axis ; and the
smaller the axle, the greater is this leverage ; for, if the

Fig. 97.

axle, a (fig. 97), be six
inches in circumference,
and the wheel, h c, be
ten feet in circumference,
then the outer part of
the wheel will move
twenty times further
than the part next the
axle. Therefore, accord-
ing to the rule of virtual
velocities (already ex-
plained,) one ounce of
force at the rim of the
wheel will overcome twenty ounces of friction at the
axle ; or if the axle were twice as large, then, according
to the same rule, it would require two ounces to over-
come,the same friction acting between larger surfaces.

For this reason, large wheels in wheel-work for multi-
plying motion, if not made too heavy, run with less force
than smaller ones, the power acting upon a larger lever.
Plorse-powers for thrashing-machines, consisting chiefly of
a large, light crown-wheel, well stiffened by brace-work,
have been found to run with remarkable case; a good
example of which exists in what is known as Talpin^s
horse-power, when made in the best manner.

FKICTION- WHEELS.

On the preceding principle, friction-wheels or friction-
roUers are constructed, for lessening as much as possible

90

MECirA>;ics.

Friction-wheels.

the friction of axles in certain cases. By this contrivance,
the axle, a (fig. 98), instead of revolving in a simple hole
or cavity, rests on or Letween the edges
of tvv^o other wheels. As the axle re-
volves, the edges turn with it, and the
rubbing of surfaces is only at the axles
of these two w^heels. If, therefore, these
axles be twenty times smaller than the wheels, the friction
will be only one-twentieth the amount without them.
This contrivance has Tig. 90.

been strongly recom-
mended and con-
siderably used for
the cranks of grind-
stones (fig. 99), but
it was not found to
answer the intended
purpose so well as
w^as expected, for
the very plain reason '"-■'
that, in using a
grindstone, nearly all the friction is at the circumference,
or between the stone and the tool, w^hich friction-wheels
could not, of course, remove.

Grindstone on Friction-ivheels.

LUBllICATING SUBSTANCES.

Lubricating substances, as oil, lard, and tallow, applied
to rubbing surfaces, greatly lesson the amount of friction,
partly by filling the minute cavities, and partly by sepa-
rating the surfaces. In ordinary cases, or where the
machinery is simple, those substances are best for this
purpose which keep their places best. Finely-powdered
black-lead, mixed with lard, is for this reason better for
greasing carriage wheels than some other applications.
Drying oils, as linseed, soon become stiff by drying, and

LUBEICxlTIXG SUBSTANCES. 91

are of little service. Olive oil, on the contrary, and some
animal oils, which scarcely dry at all, are generally pre-
ferred. To obtain the full benefit of oil, the application
must be frequent.

According to the experiments made with great care by
Morin, at Paris, the friction of wooden surfaces on wooden
surfaces is from one quarter to one-half the force applied;
and the friction of metals on metals, one-fifth to one-
seventh — varying in both cases with the kinds used.
Wood on wood was diminished by Inrd to about one-fifth
to one-seventh of Avhat it was before ; and the friction of
metal on metal was diminished to about half what it was
before ; that is, the friction became about the same in both
cases after the lard was applied.

To lessen the friction of wooden surfaces, lard is better
than tallow by about one-eiglith or one-seventh; and tal-
low is better than dry soap about as two is to one. For
iron on wood, tallow is better than dry soap about as five
is to two. For cast-iron on cast-iron, polished, the friction
with the diflferent lubricating substances is as follows :

Water 31

Soap 20

Tallow 10

Lard 7

Olive oil 6

Lard and black-k-ad 5

AYhen bronze rubs on wrought iron, the fi'iction with
lard and black-lead is rather more than with tallow, and
about one-fifth more than with olive oil. With steel on
bronze, the fiiction with tallow and with olive oil is about
one-seventh less than with lard and black-lead.

As a general rule, there is least friction with lard when
hard wood rubs on hardwood ; with oil, when metal rubs
on wood, or metal on metal — being about the same in
each of all these instances.

In simple cases, as with carts and wagons, where the

92 MECHANICS.

friction at the axle is but a small portion of tlie resistance,*
a slight variation in tlie effects in the lubricating sub-
stance is of less importance than retaining its place. In
more complex machinery, as horse-powers for thrashing-
machines, friction becomes a large item, unless the parts
are kept well lubricated with the best materials.

Leather and hemp bands, when used on drums for
wheel-work, should possess as much friction as possible, to
prevent slipping, thus avoiding the necessity of tightening
them so much as to increase the friction of the axles.
Wood with a rough surface has one-half more friction
than when worn smooth ; hence moistening and rasping
small drums may be useful. Facing with buff leather or
with coarse thick cloth also accomplishes a useful purpose.
It often happens that wetting or oiling bands will prevent
slipping, by keeping their surfaces soft, and causing them
to fit more closely the rough surface of the drum.

ADVANTAGES OF FRICTION.

Although friction is often a serious inconvenience, or
loss, in lessening the force of machines, there are many
instances in which it performs important offices in nature
and in works of art. " Were there no friction, all bodies
on the surface of the earth would be clashing against each
other; rivers would dash with an unbounded velocity, and
we should see little besides collision and motion. At
present, whenever a body acquires a great velocity, it soon
loses it by friction against the surface of the earth. The
friction of water against the surfaces it runs over soon
reduces the rapid torrent to a gentle stream ; the fury of

* If the friction at the axle be one-twelfth of the force, and the diam-
eter of the wheels ten times as great as the diameter of the axle, the
friction at the axles will be reduced to one-twelfth of a tenth, or one
hundred and twentieth x>art of the force, according to the law of virtual
velocities as applied to the wheel and axle.

FRICTION NECESSARY TO EXISTENCE. 93

the tempest is lessened by tlie friction of the air on the
face of the earth, and the violence of the ocean is subdued
by the attrition of its own waters.

" Its offices in the works of art are equally important.
Our garments owe their strength to friction, and the
strength of ropes depends on the same cause ; for they are
made of short fibres pressed together by twisting, causing
a sufficient degree of friction to prevent the sliding of
the fibres. Witliout friction, the short fibres of cotton
could never have been made into such an infinite variety
of forms as they have received from the hands of ingenious
workmen." * Deprived of this retaining force, the parts
of stone walls, piles of wood and lumber, and the loads
of carts and wagons, as well as the wheels themselves,
would slide without restraint, as if their surfaces were of
the most icy smoothness, and walking without support
would be impossible.

The tractive power of locomotives depends on the fric-
tion between the wheels and iron rails, which is equal to
about one-fiftli of the weight of the engine ; tliat is, a
locomotive weighing twenty-five tons will draw with a
force of five tons, without producing slipping of the
wheels.

CHAPTER VII.

PRINCIPLES OF DRAUGHT.

An examination of the nature or laws of friction enables
us to ascertain the best line of draught for teams when
attached to wagons and cari-iages. If there were no fric-
tion whatever upon the road, the best direction for the

♦Encyclopaedia Americana.

94 MECHANICS.

traces would be parallel with its surface, that is, on a level ;
but as there is always some friction, the line of draught
should be a little rising, so as to tend to lessen the pressure
of the wheels on the road.

Now this upward direction of the draught should
always he exactly of such a slope, that if the same slope
were given to the road, the vjagon would Just descend by
its weight. The more rough or muddy the road is, the
steeper should be this line of drauglit or direction of the
traces." On a good common road it would be much less,
and on a plank-road but slightly varied from a horizontal
direction. On a rail-road the line should be about level.
On good sleighing, some of the strength of the team is
commonly lost by too steep a line of draught.

The reason of this rule may be understood by the fol-
lowing explanation : Let the obstruction, «, in the annexed
Fig. 100. figure (fig. 100) represent the friction the

wheel constantly meets with in rolling
over a common road. To overcome this
friction, the wheel must rise in the di-
rection of the dotted line. Tiierefore, if
^ the force is made to pull in this direction,
i^,--— sisss^^j^"- it will act more advantageously than in
any other, because this is the course in which the centre of
the wheel must move. Now if a downward slope were
given to the road at this obstruction, the wheel and the
obstruction would both be brought on a level, and the
wheel would move with the slightest degree of force.

It will be imderstood from the j^receding rule that a sled
running on bare ground should be drawn by traces bearing
upward in a large degree. The same remark will apply to
the i)low, Avhicli slides upon the ground in a similar way,
with the pressure of the turning sod as a load. Hence

* Provided the wheels are not made smaller for this i)urpose, iucrcasing
their resistance.

PRINCIPLES OF DRAUGHT APPLIED TO PLOWS. 95

the reason that a great saving of strength results from the
use of short traces iu plowing. An experiment was tried
for the purpose of testing this reasoning ; first, with traces
of such length that the horses' shoulders were about ten
feet from the point of the plow ; and secondly, with the
distance increased to about fifteen feet. With the short
traces a strength was required equal to 2^ cwt., but with
the long traces it amounted to o^- cwt.

But the draught-traces may be made too short. When
this is the case, the ^*- ^o^-

plow is necessarily .-^'' '

thrown too much upon ^^?==^. ,.--''' i

its point, to keep it '*'""'^^^^=^-''' i

from flying out of the n^c=^. __...._ i

ground, by wliich means it vforks badly in turning the fur-
row. In addition to this evil, the plowman is compelled to
bear down heavily, adding to the friction of the sole on
the bottom of the furrow, and greatly increasing his labor.

The line of draught should be so adjusted that the plow
may press equally all along on its sole or bottom, which
will cause it to run evenly and with a steady motion.

Fig. m.

Line of draiiiht for the plmo.

This end will be eff*ected by giving the traces or draught-
chain just such a length that the share of the plow (or
centre of resistance), tlie clevis, and the point of draught
at the horses' shoulders (or the ring of the ox-yoke) shall
all form a straight line. This is shown in the annexed
figure, where A is the place of the ox-ring or of the for-
ward extremity of the traces (fig. 101).

The centre of resistance will vary with the depth of

90 MECHANICS.

plowing. When the furrow is shallow (as shown by the
lines G H, fig. 102), tlie centre of resistance will be at A,
requiring the team to be fastened to the lower side of the
clevis, C ; but when the depth is greater (as shown by F
H), the centre of resistance will be at B, requiring a
higher attachment to the clevis ; the point of draught, E,
remaining the same in both cases.

So great is the difference between an awkward and skill-
ful adjustment of the draught to the plow, that some
workmen with a poor implement have succeeded better
than others with the best; and plows of second quality
have sometimes, for this reason, been preferred to those
of the most perfect construction.

C0:srBIXED DKAUGIIT OF ANIMALS.

When several animals are combined together, it is of
great importance that they should be exactly matched in
gait. Much force is -Fig- 103.

often wasted when fc=e==i «fc
they draw unsteadily
or unevenly. It is
more difficult to di-
vide the draught equally among several animals when
placed one before the other, than when arrayed abreast, for
some may hang back, and others do more than their share,
unless a skillful driver is always on the watch. It also hap-
pens, when tlms arranged, that the forward horses draw hori-
zontally, while the hindmost one draws in a slopitig line,
and the line of draught between them thus being crooked,
more or less force is lost. This may be, however, remedied
in part by placing the taller animals forward, and the
smaller behind.

For these reasons, when only three horses are used, they
should always be placed abreast. The force required for
each may b3 rendered exactly equal by the whiffle-trees

COMBINED DRAUGHT OP ANIMALS.

97

usually employed for this purpose, and represented in fig.
103, where two horses are attaclied to the shorter end, and

k.

Fig. 104.

t

Whipplc-tree for three horses.

the third to the longer end of the common bar. Another
ingenious but more complex arrangement is shown by fig.
104, where also the ^. .„.

central horse has
only half the two
others, by being at-
tached to the longer
ends of the inter-
mediate bars. An-
other, and a more
perfect contrivance,
is Patterns Tkree-
horse Clevis, re-
presented by fig. 105. It consists of two wlieels to-
gether, one twice the diameter of the other, and each
having a groove in which a chain runs. The chains
are fastened to the respective wheels, so that the
single horse draws on the larger wheel, against the two
horses on the smaller. With common w^hiffle-trees, the
relative draught of each horse is maintained only Avhen
they draw evenly ; with Potter's there is no variation at
any time. It is made by E. M. Potter, Kalamazoo, Mich.
Fig. lOG represents the mode of attaching four horses in
draught, their force being equalized by passing the chain
round the wheel in the pulley-block, a, security being pro-
vided that the liindmost pair shall not encroach on the

98

MECHANICS.
Fig. 106.

forward pair, by connecting the end of the chain at the
same time to the plow.

avier's single-tbee.

This is used exclusively for plowing in orchards, and is
worthy of notice here. The leather traces are hooked at

the rear of the wooden
bar, and, passing around
the ends, prevent the
possibility of being
caught in the bark of the
trees. The teamster may
therefore drive as closely as he chooses without danger of
injury. For this reason he is able to turn over the Avholo
surface without leaving an unplowed strip along the row.

CONSTRUCTION AND USE OF THE DYNAMOMETER.

The dynamometer, or force-measurer, has been already
briefly alluded to, but a more particular description will
be useful. In the construction and selection of all ma-
chines and implements that require much power in their
use, the dynamometer is indispensable, although at present
but little known. As an example of its utility, the farmer
may wish to choose between two plows which, so far as
he can perceive, may do their work equally well ; but
this instrument, when applied, may show that the team

THE DYNAMOMETER.

99

must draw with a force equal to 400 pounds in mov-
ing one.of them through the soil, while 300 pounds would be
sufficient for the other. He would, therefore, select the one
of easiest draught, and by doing so would save the labor of
one day in four to his team, or twenty-five days in a hund-
red, which would be worth many times the cost of the
trial. The same advantage might be derived in the selec-
tion of harrows, cultivators, horse-rakes, straw-cutters, and
all other implements drawn by horses or worked by men.
Again, the farmer may be in doubt in choosing between
two thrashing-machines, which in other respects may work
equally fast and well ; but the dynamometer may show
that one requires a severer exertion from the team, and
consequently is less valuable for use.

The operation of this instrument may be readily under-

Dynamometer, or Force-measurer.

Stood by fig. 108, where b represents the dynamometer,

Fig. 109.

Elliptic Dynamometer.

made precisely similar to a large and stiif spring balance,

100

MECH^VKICS.

with one hook attached to the plow and the other to the
whiffle-tree. The amount of force required to draw the plow
is accurately measured on the scale by the index or pointer,«.

Sometimes the motion of this index is multiplied, or
made greater and more easily seen, by means of a cog-
wheel and rack-work ; but this renders the instrument, at
the same time, more complex.

Another form of this instrument is slioAvn in fig. 109,

Fig. 110.

Elliptic D'jnamometer, in compact form : S S, spring; F, cross-lever for moving

index.

where tlie ends of the oval spring, Q Q, are attached to
the plow and draught. The harder the force exerted by
the team, the closer together will the sides of tliis spring
be brought, causing the rod, E, to press against the index
or pointer, and showing the precise degree of force on the
circular scale.

An improvement, by rendering the instrument more
compact, is shown in fig. 110, where S S is the spring, and
directly over it is the graduated scale.

SELF-EECOKDING DYNAMOMETER.

101

An inconvenience occurs in the use of the instruments
now described from the rapid vibration of the index, re-
sulting from the quick changes in the force, partly from
inequalities in the soil, and partly from the unsteady mo-
tion of the horses. The vibration is sometimes so great
that the index can hardly be seen, rendering-it difficult to
measure the average force. This inconvenience has been
removed, in a great degree, by attaching to one end of
the index, E (fig. 110), a piston working in a cylinder filled
with oil, C ; this piston has a small hole through it, through
which the oil passes from one side to the other as the
draught varies, but not fast enough to allow any sudden
motion.

SELF-EECOKDIXG DYNAMOMETEE.

A less simple but more perfect instrument is the Self-
recording Dynamometer^ which marks accurately all the

Fijr. 111.

27>>i

TT"

_^_

■"—

A

,J

, h

»r

„rll J

I'll III

A -^^

'lllliii

jiMiM

840

L_^_ .J

illllil

liilii'

nil

220

,1^1 Jl!,, II

.'''''■•iri|r,;

200

m

•!

,l!i

iilf!

lAfl

■m

ill

11

II

160

ip—

140l

,.0

100

80

60

'

40

20

The markings of the Self-recording Dynamometer.

vibrations on a slip of paper while the plow is in opera-
tion. A pencil is fixed to the index, and presses, by means
of a spring, against the paper, thus giving a true register

102 jtEcnAJNics.

of the force exerted. To prevent the pencil from con-
stantly marking on the same line, the paper is made to
move slowly in a side direction, so that all the vibrations
are shown, as represented in fig. Ill, and they may be ac-
curately examined and read off at leism-e, a and h repre-
senting the forces of two different plows, drawn through
a single furrow across the field. The motion of the paper
is effected by being j^Iaced on two rollers, one of which
unwinds it from the other. This roller is made to turn by
Fig. 112. means of a wheel running on

the ground, which gives mo-
tion to the roller through an
endless chain, working a cog-
wheel by means of an endless
screw. The cylindiical dyn-

Self-recording Bynamometcr. amomctcr, showU in fig. 112,

is used for this purpose, lengthwise upon which the two
rollers are placed for holding the paper. With this in-
strument a permanent register might be made of the
force required for different plows, with an accuracy not
liable to dispute.

All difficulties have been completely overcome by the
recent invention of IT. Waterman, of Hudson, N. Y. His
dynamometer was used with entire success at the Auburn
reaper trial in 18G0, and at the trial of plows at Utica, in
18G7, under the Committee of the N. Y. State Agricul-
tural Society. A full description of all the parts would
require too much space for the character of this work; the
following is a brief explanation of the mode of its opera-
tion :

This dynamometer is furnished with a spiral spring,
like those we have already described, working a piston in
a cylinder of water. To this, two dial plates are added

waterman's dynamometek. 103

one of which shows, by a slowly revolving index, the ex-
act distance which the horses have traveled, without
looking at in for a distance of more than five miles.
The other dial plate gives a perfectly accurate record of
the whole force expended from the commencement of the
experiment to its termination. In other words, it takes
all the different and varying forces, and adds them accu-
rately in one aggregate or whole, seen at a glance on the
dial plate under the eye.

We shall attempt a brief description of the modes by
which the indexes on these two dial plates are moved.

The mode by which the distance traveled is recorded
will be easily understood. A wheel one yard in circum-
ference runs on the ground and communicates its
motion by a cord, to a wheel attached to the dyna-
mometer. T'nis, by means of an endless screw
and cog-w^ork, moves the index slowly around the
face, and thus records the distance traveled. There
are two parts of this portion of the apparatus, which
deserve a description. One is the w^heel around
which the cord passes in connection Avith the wheel
which runs on the ground. It is very important that
the exact number of the revolutions of tliis wheel should be
maintained, as compared with those of the ground wheel.
This is regulated as follows : The groove in this wheel is
made by screwing together two beveled edged wheels, as
shown in the annexed section, fig. 113. By placing thin pa-
per between these two wheels, the width of the groove
may be varied with the utmost accuracy, and the cord
consequently let further in towards the centre. The other
part which we desire to notice, although not original in
this dynamometer, is the manner in which the index is car-
ried around the face of the dial plate. There are two
cog-wheels on the same axis, one with a hundred cogs,
and the other with ninety-nine — both fitting into the same
pinion. Consequently, when one has made the entire rev-

104

MECHANICS.

olution, tlie other has fallen one cog behind, and a hund-
red revolutions are required for the index, placed upon
one of them, to come around again so as to coincide witli
its first position.

The endless screw attaclied to the band- wheel already no-
ticed moves one cog at every yard advanced, and the in-
dex passing around in a hundred revolutions, it is obvious
that it will show 10,000 yards, or more than five miles.

We sliall now attempt to describe thatpart of the ma-
chine which furnishes an accurate record of the force. In
doing this, we omit most of the details and vary some of
the parts, in order to make the explanation simpler and
clearer, the object being merely to explain the principle.
The band- wheel a, fig. 114, (shown also in fig. 113,) re-
volves once for every yard of onward movement, as already

stated. In doing
so, it causes the
arm d c, to vi-
brate backwards
and forwards, on
a pin at d ; the
connecting rod b
c being set near
the circumference
of the wheel Z>, this vibrating movement is shown by the
dotted lines at f and i. The slide A moves on this vibra-
ting rod, by being connected with the spiral spring already
described, which indicates the force of the draught ; the
stronger the draught, the further this slide is moved toward
c. When there is no draught at all, the rod e remains at
the pivot c?, and has no motion; but as the slide A
is moved successively along the arm, this rod e is
thrust backwards and forwards, more or less, accord-

to the force of the draught.

This thrusting move-

ment
force

turns the ratchet wheel g faster or slower as this
varies. A self-recordino: index is connected with

waterman's dynamometer. 105

this wheel by an arrangement similar to that already de-
scribed for registering the distance.

This explanation shows the principle of the self-regis-
tering attachment, but in one respect it must be varied in
order to be entirely accurate. The ratchet wheel must
necessarily permit some play of the click or pawl, which
would soon lead to serious error. This is wholly prevent-
ed by facing the wheel with India rubber, and causing
the pawls to press this India rubber surface. *

It will be observed that a movement of this wheel is
made at every revolution of the band-wheel, or once in
every yard ; and in traveling a hundred yards, a hundred
such movements are made. Every one of these may be
different in amount from the others, yet the whole sum
will be accurately measured.

It is absolutely essential that every part be finished with
perfect workmanship, so that there may be no play or
rattling of the teeth, producing loss of motion. Its
measurements have been entirely satisfactory, although its
records must necessarily vary with the condition of the
cutting edge of plows, with the running order of mow-
ing machines, the temper or sharpness of the knives, and
the skill of the manager or driver.

A more general use of the dynamometer would doubt-
less result in important advantage to farmers as well as
plow-makers. The trials which have been made, both in
this country and in Europe, have proved that a great dif-
ference exists in plows, as to ease of draught, — some
ploAVS requiring a force more than fifty per cent greater
than others, to turn a furrow of equal width and depth.
Hence the farmer who employs the plow which runs most
freely may accomplish as much by the use of two horses,
as another can do by using one of hard draught by em-
ploying three horses.

R*

106

MECHAXICS.

DYITAMOMETEE FOR ROTARY MOTION.

All these dynamometers apply only to simple, onwar^
draught, as in plowing, drawing wagons, harrowing, etc.
There is another, represented in fig. 115, of very ingenious
but complex construction, which shows the force required,
in working any rotary machine, such as thrashers, straw-,
cutters, and mills, and showing, at the same time, the ve^
locity, and recording the number of revolutions made.

The whole machine is supported by a cast-iron framer

Fi-. 115.

jyynamomctcrfor measuring the force and velocity of thrashing-machines.

work, on four small wheels with ilanges, like the wheels of
rail-cars, that it may be conveniently run up on a temporary
rail-way to the thrashing or other machine to be tried.

The band-wheel /, on the shaft e, is connected with the
machine under trial, and the force is supposed, in this in-
stance, to be applied by hand to the handle a, on the fly-
wheel.

DYNAMOMETER FOR ROTARY MOTION. 107

When the fly-wheel is turned in the direction shown by
the arrow, it causes the two cog-wheels to revolve, and
moves the band in the direction shown by the other aiTow.
Now, whatever force is required to turn the wheel /*, con-
nected with the machine under trial, must be overcome by
a corresponding force applied to the handle a, because
the wheel-work is so adjusted that this handle moves with
the same velocity as the band on the band-wheels.

The wheel /", being connected by the band to the wheel
d^ which is on the same axis or shaft as the cog-wheel /,
the resistance of the machine under trial tends to keep
the cog-wheel / from turning, until enough force is ap-
plied to the handle «, to set the cog-wheel ^ in motion.
Now the greater the resistance, the greater will be the
power needed at the handle. This power, therefore, is
measured accurately in the following manner :

The axle g^ of the cog-wheel ^, rests at its further end
in an oblong hole or mortise, which allows it liberty to play,
or rattle up and down within narrow limits. This same
axle, ^, passes through a hole in the lever i so that when
it rattles up and down, it carries this lever up and down
with it. The other part of the lever turns on the shaft
h of the other cog-wheel.

Now when the man at the fly-wheel applies his force to
the handle <z, the resistance of the machine under trial
causes the cog-wheel I to refuse to turn ; consequently,
his force, instead of turning it, lifts it up in the mortise,
and raises the lever with it. As he increases his force
against the handle, let weights be hung on the lever, until,
at the very moment that the wheel begins to revolve, the
weights shall be just heavy enough to keep the lever down
in the mortise. This weight, therefore, will measure the
exact force needed to turn the machine : the greater the
resistance of the machine, the greater must be the weight.

There is another weight, J, used to balance the lever
and cog-wheel I, while the machine is at rest, or before

108 MECHANICS.

the force is applied to it, so that the weight at m shall rep-
resent the force truly. The weight m is, of course, to be
multiplied by the power it exerts on the lever ^, which
should be graduated like the bar of a steelyard.

There are a few other parts of this dynamometer not
yet described. One is the cylinder o, filled with oil, in
which a perforated piston works, preventing the rapid
vibration of the lever ^, as the force varies, precisely
similar to the cylinder of oil described in fig. 110, p. 100.
Another part is the pendulum p, with the wheel r, which
measures the time.

The use of this instrument has been already attended
with some important results in detecting the great amount
of friction existing in some thrashing-machines of high
reputation, which has been found to amount, in certain
cases, to more than one-half of the whole power applied.
It is only by detecting so great a waste that we are ena-
bled to take measures for its prevention.

CHAPTER VIII.

APPLICATIOX OF LABOR.

Most of the moving powers applied by the farmer to
accomplish labor are the exertions of animal strength. A
principal object of the preceding pages is to point out how
this strength can be applied in the most economical
manner, and to aid in the substitution of cheap horse-
power for more costly human labor. It will doubtless
contribute to the end to exhibit the relative efficiency of
each, as well as the results of strength differently applied.

The amount of work which any machine is capable of
perfoi-ming is denoted by comparing this amount with

POWER OF HOESES. 109

the power of a single horse ; hence the common expres-
sions of twenty, or fifty, or a hundred horse-power
engines. The strength of difierent horses varies greatly,
but the expression, as commonly understood, indicates a
force equivalent to raising or pressing with a force equal
to 150 pounds 20 miles a day, at the rate of two and a
half miles an hour. This is the same as 33,000 pounds
raised one foot in one minute. The results of numerous
experiments in different places give the actual power of
the average of horses at somewhat less than this ; and
there is no doubt that, for most of the farm-horses of this
country, the result would be considerably less. The
power of a strong English draught-horse has been ascer-
tained to be about 143 pounds for 22 miles a day, at 2|
miles an hour. Many American horses are scarcely more
than lialf as strong. The strength of a man, working at
the best advantage, is estimated at fine-fifth that of a
horse.

As the speed of a horse increases, his strength of draught
diminishes very rapidly, till at last he can move only his
own weight. This is owing to three reasons : first, the
load moves over a greater space in a given time, and if,
for instance, the speed be doubled, liaLf the load only can
be carried with the same quantity of power, according to
the law of virtual velocities ; secondly, the horse has to
carry the full weight of his body, whatever his speed may
be, and the force expended for this purpose alone must,
therefore, be doubled as the speed is doubled ; thirdly, a
very quick and unaccustomed motion of the muscles is in
itself more fatiguing than the ordinary or natural velocity.

The following table show^ the amount of labor a horse
of average strength is capable of performing in a day at
different degrees of speed, on canals, rail-roads, and on
turnpikes. The force of draught is estimated at about 83
pounds. This is considerably less than the horse-power
used ill estimating the force of machinery, but it is as much

110 MECHANICS.

as an ordinary horse can exert without being improperly
fatigued with continued service :

Velocity Duration of the Work accomplisJiedfor one day, in tons, drawn
per hour. day's work. one mile.

Miles. Hours. On a canal. On a rail-road, dn a tiu-npike.

21 1 2 llMa 520 115 14

3 8 243 a 12
SMa 59|io 153 82 10

4 41] 2 102 72 9

5 29lio 52 57 7.2

6 ' 2 30 48 6

7 IM2 19 41 5.1 >

8 11 U 12.8 36 4.5

9 ■= 3|k 9 32 4
10 3|^ 6.6 28.8 3.6

From the preceding table it will be seen that a liorse, at
a modei:ate walk, will do more than four times as much
work on a canal as on a rail-road ; but the resistance of
the water increases as the square of the velocity, and
therefore when the speed reaches five miles an hour, the
rail-road has the advantage of the canaL On the rail-
road and turnpike the resistance is about the same,
whether the speed be great or little, the chief loss with
fast driving resulting from the increased difficulty with
which the horse carries forward his own body, which
weighs from 800 to 1200 pounds. The table also shows
that when it becomes necessary to drive rapidly with a
load, it should be continued but for a very short space of
time ; for a horse becomes as much fatigued in an hour,
when drawing hard at ten miles an hour, as in twelve
hours at two and a half miles an hour ; because when a
boat is driven through the water, to double its velocity
not only requires that twice ^e amount of water should
be moved or displaced in a given time, but it must be
moved with twice the velocity, thus requiring a four-fold
force.

The muscular formation of a horse is such that he will
exert a considerably greater force when working horizon-

POWER OF MEN. Ill

tally than up a steej), inclined plane. On a level, a horse
is as strong as five men, but up a steep hill he is less strong
than three; for three men, carrying each 100 pounds, will
ascend faster than a horse with 300 pounds. Hence the
obvious waste of power in placing horses on steeply
inclined tread-wheels or aprons. The better mode is to
allow them to exert their force more nearly horizontally,
by being attached to a fixed portion of the machine. For
the same reason, the common opinion is erroneous that a
horse can draw with less fatigue on an undulating than on
a level road, by the alternations of ascent and descent
calling difierent muscles into play, and relieving each in
turn ; for the same muscles are alike exerted on a level
and on an ascent, only in the latter case the fatigue is
much greater than the counterbalancing relief. Any per-
son may convince himself of the truth on. this subject by
first using a loaded wheel-barrow or hand-cart for one day
on a level, and for the next up and down a hill; bearing
in mind, at the same time, that the human body is better
fitted for climbing and descending than that of a horse.

A draught-horse can draw 1600 pounds 23 miles in a
day, on a good common road, the weight of the carriage
included. On the best plank-road he will draw more
than twice as much.

A man of ordinary strength exerts a force of 30 pounds
for 10 hours a day, with a velocity of 2|- feet per second.
He travels, without a load, on level ground, during 8^
hours a day, at the rate of 3.7 miles an hour, 31J miles a
day. He can carry 111 pounds 11 miles a day. He can
carry in a wheel-barrow 150 pounds 10 miles a day.

Well-constructed machines for saving human labor by
means of horse-labor, when encumbered with little fric-
tion, will be found to do about five times as much work
for each horse as where the same work is performed by
an equal number of men. For example : an active man
will saw twice each stick of a cord of wood in a day.

112 MECHANICS.

Six horses, with a circular saw, driven by means of a good
horse-power, will saw five times six, or thirty cords, work-
ing the same length of time. In this case the loss by
friction is about equnl to the additional force required for
attendance on the machine.

Again : a man will cut with a cradle two acres of wheat
in a day. A two-horse reaper should therefore cut, at the
same rate, ten times two, or twenty acres. This has not
yet been accomplished. We may hence infer that the
machinery for reaping has been less perfected than for
sawing wood. It should, however, be remembered, that
great force is exerted, and for many hours in a day, in
cutting wheat with a cradle, and tlierefore less than
twenty acres a day may be regarded as the medium
attainment of good reaping-macliines when they shall
become perfected.

Applying the same mode of estimate, a horse-cultivator
Avill do the work of five men with hoes, and a two-horse
plow the work of ten men with spades. A horse-rake
accomplishes more than five men, because human force is
not strongly exerted with the hand-rake.

In using difierent tools, the degree of force or pressure -
applied to them varies greatly with the mode in wliich the
muscles are exerted. The following table gives the results
of experiments with human strength, variously applied,
for a short period :

Force of the hands Force of the tool

on the tool. on the object.

With a drawing-knife 100 lbs. 100 lbs.

" a large auj^er, botli hands 100 " about 800 "

" a serew-driver, one band 84 " 250 "

" a bench-vice handle 72 " about 1000 "

" a windlass, with one hand 60 " 180 to 700 "

" a hand-saw 36 " 36 "

" a brace-bit, revolving 16 " 150 to 700 "

Twisting with thumb and fingers, but-
ton-screw, or small screw-driver 14 " 14 to 70 "

The force given in the last column will, of course, vary

BEST WAY TO APPLY STRENGTH. 113

with the degree of leyerage applied; for example, the
arms of an auger, when of a given length, act with a
greater increase of power with a small size than with a
large one. This degree of power may be calculated for
an auger of any size, by considering the arms as a lever,
the centre screw the fulcrum, and the cutting-blade as the
weight to be moved. The same mode of estimate will
apply to the vice-handle, the windlass, and the brace-bit.
Every one is aware that a heavy weight, as a pail of
water, is easily lifted when the arm is extended downward,
but with extreme difficulty when thrown out horizontally.
In the latter case, the pail acts with a powerful leverage
on the elbow and shoulder-joint. For this reason, all
kinds of hand labor, with the arms pulling toward or
pushing directly from the shoulders, are most easily per-
formed, while a motion sidewise or at right angles to the
arm is fas less effective. Hence great strength is applied
in rowing a boat or in using a drawing-knife, and but little
strength in turning a brace-bit or working a dasher-churn.
Hence, too, the reason that, in turning a grindstone, the
pulling and thrusting part of the motion is more powerful
than that through the other parts of the revolution.
This also explains why two men, working at right
angles to each other on a windlass, can raise seventy
pounds more easily than one man can raise thirty
pounds alone. This principle should be well understood
in the construction or selection of all kinds of machines
for hand labor.

CHAPTER IX.

MODELS OP MACniXES.

Serious errors might often be avoided, and sometimes
gross impositions prevented, by understanding the differ-
ence between the working of a mere model, on a miniature

114 MECHANICS.

scale, and the working of the full-sized machine. It is a
common and mistaken opinion that a well-constructed
model presents a perfect representation of the strength
and mode of operation of the machine itself.

When we enlarge the size of any thing, the strength of
each part is increased according to the square of the
diameter of that part ; that is, if the diameter is twice as
great, then the strength will be four times as great ; if the
diameter is increased three times, then the strength will
be nine times, and so on. But the vieight increases at a
still greater rate than the strength, or according to the
cube of the diameter. Thus, if the diameter be doubled
(the shape being similar), the weight will be eight times
greater ; if it be tripled, the weight will be twenty-seven
times greater. Hence, the larger any part or machine is
made, the less able it becomes to support the still greater
increasing weight. If a model is made one-tenth the real
size intended, then its different parts, when enlarged to
full size, become one hundred times stronger, but they are
a thousand times heavier, and so are all the weights or
parts it has to sustain. All its parts would move ten
times faster, which, added to their thousand-fold weight,
would increase their inertia and momentum ten thousand
times. For this reason, a model will often work perfectly
when made on a small scale ; but when enlarged, the parts
become so much heavier, and their momentum so vastly
greater, from the longer sweep of motion, as to fail entirely
of success, or to become soon racked to pieces.

This same piinciple is illustrated in every part of the
works of creation. The large species of spiders spin
thicker webs, in comparison with their own diameter,
than those spun by the smaller ones. Enlarge a gnat
until its whole weight be equal to that of the eagle, and,
great as that enlargement would be, its wing will scarcely
have attained the thickness of writing-paper, and, instead
of supporting the weight of the animal, would bend down

I

WORKS OF CREATION FREE FROM MISTAKES. 115

from its own weight. The larger sj)iders rarely have legs
so slender in form as the smaller ones ; the form of the
Shetland pony is quite different from that of the large
cart-horse ; and the cart-horse has a slenderer form than
the elephant.

The common flea will leap two hundred times the length
of its own body, and the remark has been sometimes made
that a man equally agile, with his present size, would
vault over the highest city-steeple, or across a river as
wide as the Hudson at Albany. Now, if the flea were
increased in size to that of a man, it would become a
hundred thousand times stronger, but thirty million times
heavier; that is, its weight would become three hundred
times greater than its corresponding strength. Hence we
may infer that the enlarged flea would be no more agile
than a man ; or that, if a man were proportionately
reduced to the size of a flea, he could leap to as great a
distance.

All this serves to illustrate in a striking manner the
great difference in the working of models and of machines.

CHAPTER X.

CONSTRUCTION AND TISE OF FARM IMPLEMENTS AND MA-
CHINES IMPLEMENTS FOR TILLAGE.

The application of mechanical princij)les in the struc-
ture of the simpler parts of implements and machines has
been already treated of. It remains to examine more
particularly those machines chiefly important to the farmer,
and to show the application of these principles in their
use and operation. ,

116 MECHANICS.

Farm implements and machines for working the soil
should be, as far as possible, simple and not complex, be-
cause they mostly meet with an irregular resistance, con-
sisting of hard and soft soil and stones variously mixed
together. A locomotive is made up of many parts ; but
having a smooth surface to traverse, the machinery works
uniformly and uninjured ; but if in its progress it met
with formidable obstructions and uneven resistance, it
would be soon racked and beaten to pieces. Hence the
long-continued and uniform success of the simple plow ;
as well as the failure of complex digging machines, unless
worked exclusively in soils free from stone. A complex
machine, that meets with an occasional severe obstruction,
receives a blow like that of a sledge ; and when this is
repeated frequently, the probability is that some part will
be bent, twisted, knocked out of place, or broken. If the
machine be light, the chances are in its favor; but if
heavy, its momentum is sucli that it can scarcely escape
severe injury. If composed of many distincL parts, the
derangement or breakage of one of these is sufficient to
retard or put a stop to its working, and men and teams
must stand idle till the mischief is repaired.

Hence, after the trial of the multitude of implements
and machines, we fall back on those of the most simple
form, other things being equal. The crow-bar has been
employed from time immemorial, and it will not be likely
to go out of use in our day. For simplicity nothing ex-
ceeds it. Spades, hoes, forks, etc., are of a similar char-
acter. The plow, although made up of parts, becomes a
single tiling when all are bolted and screwed together.
For this reason, with its moderate weight, it moves
through the soil with little difficulty — turning aside from
obstructions, on account of its wedge form, when it can-
not remove them. The harrow, although composed of
many pieces, becomes a fixed solid frame, moving on
through the soil as a single piece. So with the simpler

IMPOETAXCE OF SIMPLICITY IX MACHINES. 117

cultivators. Contrast these with the ditching machine
(Pratt's) considerably used some years ago, but ending
in entire failure. It Avas ingeniously constructed and
-well-made, and when new and every part uninjured,
worked admirably in some soils. But it was made
up of many parts, and weighed nearly half a ton. These
two facts fixed its doom. A complex machine, weighing
half a ton, moving three to five feet per second, could not
strike a large stone without a formidable jar ; and con-
tinued repetitions of such blows bent and deranged the
working parts. After using a while, these bent portions
retarded its working ; it must be frequently stopped, the
horses become badly fatigued, and all the machines were
finally thrown aside. This is a single example of what
must always occur with the use of heavy complex machinery
working in the soil. Mowing and reaping machines may
seem to be exceptions. But mowers and reapers do not
work in the soil or among stones ; but operate on a soft,
uniform, slightly resisting substance, made of the small
stems of plants. Every farmer knows what becomes of
them when they are repeatedly driven against obstruc-
tions by careless teamsters.

There is another formidable objection to complex ma-
chines— this is, their cost. Even with some of proved
value, the expense is a serious item with moderate farm-
ers. Mowers and reapers, $130; grain drills, $80 or 890;
thrashing machines, $100 to $400 ; horse rakes, $45 ; hay
tedders, $80 to $100 ; iron rollers, $50 to $100; and even
some of the efficient ncAV potato diggers are offered for
not less than $100. Placing all these sums, and many
others for necessary tools together, the whole will be
found a large outlay — more economical by far, it is
true, than doing without them; but greater simplicity
and consequent cheapness, as well as durability, would
facilitate progress in agricultural improvement. A single
machine, Comstock's spader, is offered at $250 — ^twenty

118 MECIIAXTCS.

times the price of the best cast-iron plow, and ten times
that of the most finished steel plow. And yet it is ap-
plicable only to land free from stone.

The object of these remarks is to caution farmers againlst
investing money in Fig. 116.

newly invented con-
trivances of high
promise at first,
which are liable to
the objection point-
ed out ; and also in- ^^ooloo Flow.
ventors and manufacturers themselves against engaging in
enterprises having at hand golden promises, but with
failure in the distance.

PLOWS.

The simplest plow, used probably in the earlier ages of
the world, and found at the present day only among de-
graded nations, is the crooked limb of a tree, with a pro-
jecting point for tearing the surface of the earth. The
above figure represents an improvement on the first rude
implement, and is found at tlie present day in Northern

Fig. 117.

Moorish Plow.

India. Fig. 116 shows the Kooloo plow, consisting wholly
of wood, except the iron point. Fig. 117 exhibits the
implement now used in Morocco, which resembles the
India plows, with the addition of a rude piece of tim-
ber as a mould-board. Both these perform very imperfect

PLOWS.

119

work, and have remained with little change for centuries,
the owners not enjoying the benefit of agricultural read-

Fijr. 118.

ing and intelligence. Fig. 118 is a step in advance, and
represents a plow still used in some parts of Europe. In
the less improved joortions of Germany, the Baden plow,

Fi-. IIQ

Fijr. 120.

Baden Plmv.
represented by Fig. 119, is employed, and does not differ
greatly from the "bull plow" commonly used in this
country at the beginning of the
present century. Great im-
provement has been made within
the past fifty years, among others
by the ingenuity and labors of
Jethro Wood, and more recently
by a great number of inventors
and manufacturers in different
parts of the country. Wood
introduced the cast-iron plow
into general and successful use, ^^^^"^ ^'"^^"^^ ''^■
by cheapening its construction and perfecting its form,

120

MECIIAXieS.

and others liave made important improvements, including
the steel mould-board now largely employed at the West.
Cast-iron plows have been generally used throughout
the Eastern States ; but for tlie peculiar soil of the West,
it has been found absolutely necessary to use steel plows
exclusively ; and for the purpose of keeping them at all

Moline Plow.

times sharp for cutting the vegetable fibre and separating
the parts of the soil readily, the practice is common to
carry a large file or rasp for this purpose. These steel
plows are made of plate previously rolled. They are be-
coming partially introduced also at the East, although in
hard and gravelly soils the cast-iron mould-board is pre-
ferred by many, and Fig. 123.
regarded as even
more durable. The
steel plate plow is
lighter than the cast-
iron, but is more
expensive. The ac-
companying figure
(Fig. 121,) represents the celebrated "Moline plow," made
by Deere & Co., of Moline, III, one of the best and most
extensively introduced among the Western steel imple-
ments; and Fig. 122 shows an excellent one of Eastern
manufacture, made by Woodruff, Allen &; Co., of Auburn,

)\ 00'/ nni <( \i < a s Htce' Plow.

CUARACTEE OF A GOOD PLOW. 121

N. Y. Good steel plows cost about double those made
of cast-iron.

CHAEACTEE OP A GOOD PLOW.

Every good plow should possess two important quali-
ties. The first relates to its working. It should be easily-
drawn through the soil, and run with unifonn depth and
steadiness. The second refers to the character of the work
when completed. The inversion of the sod, especially if
encumbered with vegetable growth, should be complete
and perfect ; and the mass of earth thus inverted should
be left as thoroughly pulverized as practicable, instead of
being laid over in a solid, unmoved mass. This is of the
greatest importance on heavy soils, and is highly useful
on those of a lighter character, except, it may be, clear sand
or the lightest gravels. The harrow, at best, is an imper-
fect loosener ; it pulverizes the surface, but its weight, and
that of the team, press down the mass below. Whatever
loosening, therefore, can be accomplished in plowing is a
gain of vital importance.

THE CUniXG EDGE.

The point and cutting edge of the plow perform the first
work in separating the furrow-slice from the land. It is
important that this edge should not only do the work well,
but with the greatest possible ease to the team. The force
required to perfonn this cutting is greater than many sup-
pose. The gardener who thrusts his sharp spade into the
hard earth uses more force than afterwards in lifting and
inverting the spit. We may hence infer that a large part
of the power of the team is expended in severing the fur-
row-sljce. This inference has been proved correct by the
use of the dynamometer, in connection with carefully con-
flucted experiments, which have §hpwn the force usually
6

122

MECHANICS.

expended for cutting off the side and bottom of the furrow-
slice, in firm soils, to exceed all tho rest of the force re-
quired to draw the plow. The point or share should
therefore be kept sharp, and form as acute an angle as
practicable, as shown in Fig. 123. Some plows which other-
Fig. 123. Fig. 124. Fig. 125.

wise work well are hard to draw because the edge, being
made too thick or obtuse, raises the earth abruptly.
Fig. 124.

Where stones or other obstructions exist in the soil, it is
important that the line of the cutting edge form an acute
angle with the land-side, or, Fig. 120. Fig. 127.

in other words, that it form a
sharp wedge, (Fig. 125.) It
will then crowd these obstruc-
tions aside, and pass them
with greater ease than when formed more
obtuse, as shown in Fig. 126, for tho same
reason that a sharp boat moves more freely
through the water than one whicli is blunt
or obtuse. The gardener or ditcher proves

this advantage when he thrusts a sharp-
pointed shovel. Fig. 127, more easily through
stony or gravelly soil, than one with a square
edge. (Fig. 128.)

But when the soil is free from stones, or
obstructions, or is filled with small roots
which the plow should cut off, as in the
"Western prairies, the sharpness of the edge
is more important than its form ; and hence
the reason that the use of the rasp or file becomes ueces-

THE CUTTING EDGE. 123

sary in the field, to keep a sharp cutting edge at all times
on tlie share.

Note.— It Las been shown in the Report of the Trial of Plows at Utica,
that so far as yet determined by experiment in England, about thirty-five
per cent of the whole required draught is expended in overcoming the
friction of the implement on its bottom and sides, about fifty-five for
cutting the furrow-slice, and only about ten per cent for turning the
sod. Hence the exclusive attention formerly given to forming the
mould-board, as a means of reducing the draught, should have been
directed more to lessening the force tequired for cutting the hard soil.

These experiments, however, do not appear to have been entirely
satisfactor}', especially for the light plows of this country; and it may
be interesting to test their accuracy by calculation. The average weight
of hard earth is about 125 lbs. per cubic foot ; and the average draught
of plows at the trial near Albany- in 1850 was about 400 lbs. for a furrow-
slice a foot wide and six inches deep. If a team in turning such sod
moves two miles an hour, it raises a slice three feet long, equal to a
cubic foot and a half (weighing 187 lbs.,) six inches each second — which
would be the same as raising 31 lbs. three feet per second, which is the
velocity of the plow. The mere force required to turn the sod, not esti-
mating friction, would therefore be only one-thirteenth of the 400 lbs. of
draught force. But the friction of dry earth on smooth iron is never
less than one-half its weight; and if the earth is slightly plastic, its
friction often is equal to, and sometimes exceeds, its weight. Taking
the smallest amount, the friction on the mould-board would be equal to
half the weight of the portion of sod resting on the mould-board, or
about 31 lbs. This increased weight would also add equally to the fric-
tion of the sole of the plow, or 31 lbs. more— making the whole friction
62 lbs. ; which added to the weight of the sod would amount to 93 lbs.
— or more than one-fifth of the whole draught.

To ascertain the amount of friction, suppose the plow weighs 100 lbs.
Half its weight would be 50 lbs., the friction on the sole of the plow.
The friction of the sides would vary greatly with plows, being very
small with those having a perfect centre-drauglit, or with no tendency
to press against the land on the left. The whole friction and force for
lifting the sod would therefore be about 150 lbs. ; leaving 250 lbs. as the
force for cutting the slice. A very easy running plow would leave a
much smaller force — some as low as 200 lbs.

This estimate is liable to great variation. A wet and clayey soil would
double the friction ; a very hard piece of ground would add much to
the force required for cutting the slice ; if loose, the force would be com-
paratively small ; or if quite moist, this force would be also much dira-
ished ; while the great diflference in the draught of plows would vary the
results still farther. The estimate, however, for soil dry enough to be
friable, and of medium tenacity, is probably not far from correct, for
plowing in this country — showing that most of the force required is for

124

MECHANICS.

the act of cutting, and indicating the importance of giving special at-
tention to the cutting edge.

THE MOIJLD-BOAED.

A prominent difference between good and bad plows
results from the form of the mould-board. To un-
derstand the best form, it must be observed that the slice
is first cut by the forward edge of the plow, and then one
side is gradually raised until it is turned completely over,
or bottom side up. To do this, the mould-board must
combine the two properties of the wedge and the screw.

The position of the furrow-slice, from the time it is first
cut until completely inverted, may be represented by
placing a leather strap flat upon a table, and then, while

Fig. 129.

holding one end, turning over the other, so as to bring
that also flat upon the table, as in Fig. 129.

Now, if the sole object were merely to invert the sod,
the mould-board might have just such a shape as to fit
the furrow-slice while in the act
of turning over, or resemble pre-
cisely the twist of this leather strap.
All the parts of this screw will be
found to fit a straight-edge, if
measured across at right angles, as indicated by the dot-
ted lines in Fig. 130.

But there are two objections to this form in practice.
The first is that the sod is laid over smoothly and un-
broken, and without being at all pulverized. On heavy and
hard soils this is a serious fault. The other objection is
that the sod is elevated as rapidly at the first movement,
when its weight is considerable, as just before falling,
when its pressure on the mould-board is slight. These diffi-
culties are in part removed by giving the mould-board a

THE MOULD-BOAED. 125

shorter twist towards its rear. This form is distinctly-
shown in the figure of Holbrook's Stubble Plow, on
a future page ; and it contributes largely to that crumbling
movement of the sod, so important for effecting pulveriza-
tion.

The mould-board of a plow is capable of an almost infi-
nite variety of forms, and the multitude of inventors have
each adoi^ted a different one. Some have made their
selections by repeated random trials ; while others, among
whom Thomas Jefferson was the first, devised a series of
straight lines, mathematically arranged, by which uniform-
ity was given to the shape. The limits of this work pre-
clude a full explanation. Many modifications in com-
bining lines have been adopted, the most successful of
which is that of Ex-Governor Holbrook, of Vermont,
whose plows made according to these rules have perform-
ed admirably. It is less essential that farmers generally
should understand these mathematical principles, provided
they find a plow that will do good work ; because, as al-
ready shown, the form of the mould-board has compara-
tively little to do with the required draught of the team.
It will be readily understood, however,
that more force will be needed for draw-
ing a short or blunt plow, like Fig. 131,
than one in the form of a longer wedge,
as in fig. 132, the latter, like a sharp
boat in water, moving more easily. Care
must be taken, however, that this slender wedge be not
too long, else the friction of the sod on the extended sur-
face may overbalance the advantage. j,.^, ^^^^
The cutting part of the plow may be
improperly formed like the square end
of a chisel, and the sod may slide back-
ward on a rise, with a very slight turn,
until elevated to a considerable height before inversion ; this
must require more force of the team, and make the plow hard

126

MECHANICS.

to hold, on account of the side pressure. Tlie character of
this kind of plow may be quickly perceived by simply ex-
amining the mould-board after use ; the scratches, instead
of passing around horizontally, as they should do, are seen
to shoot upward across the face and disappear at the top.

Instead of this form, the point should be long and acute,
and the mould-board so shaped as to begin to raise the
Fig. 133. left side of the sod

the moment it is cut,
and before the right
side is yet reached
by the cutting edge.
This turning motion
being continued, the
iMbrooTc's shibhie Plow, or Deep TUier. gQ(j |g inverted bv be-
ing scarcely lifted from its bed; and the pressure which
turns it being opposite to the pressure of the land-side, an
equilibrium of these two pressures is maintained, and the
plowman is not compelled to bear constantly to the right
to keep the plow in its place.

There is, however, an exception, in deep or trench plow-
ing, where it becomes necessary to throw the earth from
the bottom of a furrow to the top of the inverted sod. A
plow of this kind is represented in Fig. 133, which shows
Holbrook's deep tiller for stubble land, capable of jilowing
Fi?. i?A. a furrow a foot deep, and

elevating the earth, which
passes lengthwise over the
mould-board. A similar
Crested Furrow-dicer. f^^m must bo adopted for

the rear mould-board of the Double Michigan Plow, so
that the lower earth of the furrow may be thrown on
the sod inverted by the first or skim-plow.

The share should also be so placed as to cut the slice
at equal thicknesses on both sides. Some plows are made

CRESTED FUBEOW SLICES.

127

Fig. 135.

60 as to cut deepest on the land-side, forming a sort of saw-
teeth section to the unmoved earth below, and leaving
what is termed crested or acute ridges at the top. (Fig,
134.) Such plowing requires as much force in cutting the
slice, and nearly
as much in turn-
ing it over, as
when level fur-
rows are made,
and should there-
fore be avoided.
The same result
is DToduced when ■^'^ straight Cutter^ Laying Lapped Furrows.

the plow is improperly gauged, and the plowman is com-
pelled to press the handles to the left, to keep it from
running too much to land.

On heavy or clay soils, it is sometimes desirable to place
inverted sod in an inclined or lapping position, in order to
give more exposure to the crumbling action of the weath-
er, and to effect better drainage beneath. Fig. 135 is a
section of these lapped furrows. In order to be equally in-
clined on both sides, their thickness must be precisely two-
thirds their breadth ; that is, if the plow runs eight inches
deep, the slices should be twelve
inches Avide. This mode of plow-
ing is controlled by the position
of the cutter, which should be
very nearly upright, as shown in
Fig. 135. It has been justly re-
marked that the cutter to a plow
(Fig. 136,) is almost as important
as the rudder to a ship, and if
its position be altered, as shown in The Cutter.

Fig. 137, so as to cut under the sod, the furrows will cease
to be lapped and will lie flat. This position is desirable
in light or loose soils where exposure to the action of the

128

MECHANICS.

air is not desirable, and where it becomes more important

to bury com-
pletely all veg-
etable growt'l*
on the surface.
If furrows arc
cut wider in
proportion to
their depth,
The Inclined Cutter, Laying Flat Furrows. thev will be

more likely to be laid flat. For example, if the plowing
is six inches deep, and the furrows are a foot wide, the
sod will generally dispose itself in a horizontal or flat
position, and this result will be the more certainly secured
by giving the form to the cutter already described. Lap-
ping the furrows is the common practice in England, but
is less necessary for this country, Avhere the moisture of
rains dries more quickly, and the severer frosts eflect a
ready pulverization; and especially is the practice less
needed in thoroughly drained land.

The Committee for the trial of implements, appointed
by the New York Stats Agricultural Society, enumerated
the following desirable qualities in plows, which every
farmer may find useful to examine when he is about to
purchase. 1. Pulverizing power. 2. Non-liability to
choke in stubble. 3. Lightness of draught, considered in
connection with pulverizing power. 4. Ease of holding.
5. Durability. 6. Cheapness. 7. Excellence of mechani-
cal work. 8. Excellence of material. 9. Thorough inver-
sion and burial of weeds. 10. Even distribution of wear.
11. Regularity or trueness of turning and carrying the
furrow-slice in sod.

OPERATIOX OF TLOWING.

The expert plowman so adjusts his implement that it
will *cut a furrow of just such width and thickness as

V
OPERATION OF PLOWING. 129

may be done with the least draught to the team, and the
least exertion to himself. " To secure this end," says
Todd, " the team is hitched as close to the plow as it can
be and not have the whiffle-trees hit their heels in turn-
ing at the corners. As the length of the traces is in-
creased, in plowing, the draught increases. IN'ow put the
connecting ring, or link, or dial clevis, at the end of the
beam, in the lowest notch ; and if it will not run deep
enough, raise it another notch at a time until it will run
just deep enough. Now alter the clevis from right to
left, or from left to right, as may be necessary, until the
plow will cut a furroAV-slice just wide enough to turn it
over well. If the plow crowds the furrow-slice without
turning it over, it shows that the furrow-slice is too nar-
row for its deptli; and the plow must be adjusted to cut
a wider slice. On the contrary, if the plowman is obliged
to constantly push the furrow-slice over with his foot, if
the ground he is plowing be very smooth and even, it
shows that there is an imperfection or fault somewhere.
Sometimes by adjusting a plow to run an inch deeper, it
will do very bad w^ork. And sometimes it is necessary to
adjust it to cut a little wider, or a little narrower, before
it wdll cut the furrow-slice as well as it ought to be cut.
When a good plow is correctly adjusted, it will glide
along, where there are no obstructions, without being
held, for many rods. "When a plow is constantly inclined
to fall over either way, and the plowman must hold it up
all the while, to keep it erect, there is either an imperfec-
tion in the construction of the plow, or it is not adjusted
correctly. When a plow " tips up behind^"* and does not
keep down flat on its sole, or when it seems to run all on
the point, either the point is too blunt, or is worn off" too
much on the under side, or there is not " dip enough " —
pitching of the plow downwards — to the point. Some-
times I have found that a plow could not be adjusted by
the clevis so correctly as all the parts were arranged ; and
6*

130 MECHANICS.

that by shortening the traces or draught chain, or giving
them a little more length, it would run like another plow.
When a plow is adjusted to run just right, as the point
wears off it is necessary many times to give a little more
length to the draught chains, or to adjust it with the
clevis to run a little deeper. It is sometimes impossible
to adjust a plow to run just right with the style of clevis
which is on the end of the beam. The arrangement ought
always to be such that the draught can be adjusted half
an inch at a time, either up or down, or to the right or
left. Then if the beam of the plow stands as it should, so
that the most correct line of draught will cut the end of
the heam^ it can be most correctly adjusted in a few
seconds.

" To make a plow run deeper, raise the connecting point
at the end of the beam one or more notches higher in the
clevis ; or lengthen the draught chains. To make it run
more shallow, lower the draught a notch or more in the
clervis ; ov shorten the draught chains ; or, which should
never be done, shorten the back-bands or hip-straps of the
harness. To make a plow take a wider furrow-slice, carry
the connecting point one or more notches in the clevis to
the right hand. A notch or two to the left hand will
make a plow cut a narrower furrow-slice. Or, which is
seldom allowable, a plow may be made to run more shal-
low by putting the gauge-wheel lower, so as to raise the
end of the beam. And a plow may be made to cut a nar-
rower furrow-slice by carrying the handles to the left
hand, or wider by carrying and holding them to the right,
beyond an erect position ; neither of which is allowable,
except for a temporary purpose."

FAST AND SLOW PLOAVING.

It has already been shown in the chapter on Friction,
that the resistance is scarcely increased by velocity, when
one body slides over another. The same rule, nearly, ap-

FAST AND SLOW PLOWING. 131

pears to apply to force required for cutting the earth,
And as the friction of the plow and the force exerted m
cutting the earth have been found to be the greater
part of the whole draught, repeated experiments by the
dynamometer have proved that but little increased resist-
ance, as an average, occurs when a plow is drawn with in-
creased velocity ; the only additional power being that of
doing more work in a given time. For example, if a force
of 400 lbs. be required to draw a plow, whether at two or
at four miles an hour, then twice as much power only is
needed to plow an hour at four miles, as at two miles per
hour. In other words, no more actual force in amount is
necessary in most instances for a team to plow an acre in
four hours at the faster speed than in eight hours at the
slower. Hence the importance on the score of economy
in time, of employing horses that have a naturally rapid
gait, provided they possess full strength to overcome the
required draught with ease. Fast plowing, however, is
better adapted to stubble land than sod.

THE DOUBLE MICHIGAN PLOW.

The Double Michigan, called also the sod and subsoil
plow, possesses some important advantages. The forward
or skim plow pares off a sod a few inches in thickness,
and inverts it into the bottom of the previous furrow.
The second or main plow follows, and throws up the lower
soil, completely burying the inverted sod and giving a
loose, mellow surface to the field. This forms an excellent
preparation for all crops, particularly carrots and other
roots, which grow best in a deep, loose bed of earth ; and
where a portion of the subsoil improves the top-soil by be-
ing mixed with it, a permanent advantage results. A
greater depth may be attained by the use of this double
plow than with one having a single mould-board, in sod
ground, because the inversion will be complete even if the

132 MECHANICS.

width of the furrow is only one-half the depth. But with
a single plow, the width must be considerably greater than
the depth, or the ^. ,„

-. .-.,,, Fi-. 138.

sod will be thrown
on its side or edge

and cannot be in-
verted. There is

one disadvantao^e,

, .1 DmUe Michigan Plow.

however, in the

use of the double plow. A greater force is required
to make two cuts in the soil, one above the other, than
one cut with a single share.* For this reason more
force must be used to plow a field to a given depth, say
one foot, with the double than with the single plow. But
the single plow, in order to reach this depth, would re-
quire to be so large and to turn so wide a furrow that no
ordinary amount of team could be had to do the work.
And in addition to this difficulty the inverted surface would
not be so well pulverized as by the use of the double
plow.

THE SIDE-HILL PLOW.

Side-hill or Swivel plows are well known, and are so
constructed as to throw the furrow-slice down hill, which-
ever way the team may be passing. The mould-board is
turned to the right and left alternately for this purpose,
the right-hand horse walking in the furrow in one direc-
tion, and the left-hand horse in the other. This plow is
sometinies used for level land when it becomes desirable
to avoid dead furrows and ridges, "without plowing around
the field. Fig. 139 represents the SA^ivcl j^low manufac-

* This result has been proved by the use of the dynamometer; Avhich
has also shown that a greater amount of earth, in cubie leet, may be
turned over with a deep-rtinning plow than with a shallow one, as there
is less foree expended in cutting the slice wlien compared with the whole
bulk — provided the soil is nearly uniform in hardness at different depths.

THE SIDE-HILL PLOAV.

133

Fig. 130.
Holbrook's Patent Swivel

tured by F. F. Ilolbrook & Co., Boston, one of the best
in use, and particu-
larly valuable for its
thorough pulveriza-
tion of the soil. One-
half of the double
mould-board shown
in the cut is used for
throwing the furrow iiommk's ^ide-Mi Plow.

to the right, and the other half to ihu left — the change
being effected by passing it under the plow with a single
movement and hooking it in place.

THE SUBSOIL PLOW.

When the common two-horse plow alone is used by
farmers, it pulverizes the soil only a few inches in depth,

Fiff. 140.

Subsoil plowing in the furrow of a common plow.

and its own weight and the tread of the horses on the
bottom of the furrow gradually form a hard crust at that
depth, through which the roots of plants and the moisture
of rains do not easily penetrate. Hence the roots have
only a few inches of good soil on the surface of the earth
for their support and nourishment ; and when heavy rains
fall, the shallow bed of mellow earth is soaked and injured
by surplus water. Again, in time of drought, this shal-
low bed of moisture is soon evaporated, and the plants
suffer in consequence.

But, on the other hand, when the soil is made deep, it
absorbs, like a sponge, all the rains that fall, and gradually
gives off the moisture as it is wanted during hot and dry
seasons. For this reason, deep soils are not so easily in-

134 MECHANICS.

jured by excessive wetness, or by extreme drought, as
shallow ones. In addition to this advantage, they allow
a deeper range for the roots in search of nourishment.

Soils are deepened by trench-plowing and by subsoiling.
In trench-plowing, the common plow with a mould-board
is made to enter the earth to an unusual depth, and to
throw up a portion of the subsoil, covering with it the
top-soil which is thrown under. A subsoil plow, on the
contrary, only loosens the subsoil, but does not lift it to
the surface.

The Double Michigan Plow, just described, is strictly a
trench-plow, and is one of the best implements for this
purpose.

When the subsoil is of such a character that its mixture
with the surface tends to render the whole richer, trench-
plowing is best ; but when of a more sterile character, it
should be only loosened with the subsoil plow, and more
cautiously intermixed with the richer portion above.

It often happens that the subsoil plow is very useful in
loosening the soil for the purpose of allowing the trench-
plow to run more freely through it.

The operation of the subsoil plow is shown in fig. 140.

In using the subsoil plow the less the earth is raised,
provided it is well broken to pieces, the easier will be the
draught. The part which moves under the soil and per-
forms this loosening is of course in the form of a wedge.
If the subsoil is dry, hard, and not adhesive, a long and
acute wedge will run most easily ; but if the subsoil is
stony, a shorter wedge will succeed better. For general
purposes it should therefore be of medium length.

Different modes of connecting this wedge to the beam
above have been adopted, each possessing its peculiar ad-
vantages. Fig. 141 represents a subsoil plow with a
single, broad, upright shank, cutting like a wedge, with

THE SUBSOIL PLOW.

135

double edges as well as double i^oints, and capable of be-
Fig- 141. ing reversed when

it becomes w^orn.
In light or grav-
elly soils this jdIow
runs well ; but
where the earth
is adhesive and
rather moist, the
shank in pressing the

Broad-shank SubsoUer.
friction of the two faces of

this

Fiir. 142.

Subsoil plow.

compact soil apart becomes enormous, amounting in some
cases to more than triple the force required to loosen
■Pis,u3, the soil below.

This plow is there-
fore not to be rec-
ommended for
general use. The
objection is in a
great measure ob-
viated in the plow
shown in fig. 142,
where, the forward portion of the broad plate is made
thicker than the rest. The friction is still further less-
ened by employing two narrow shanks, as in fig. 143.

Another improvement for lessening friction might be
made by using narrow bars of iron or steel, braced and

Two-shanked SvbsoUer.

136 MECHANICS.

connected as shown in fig. 144. The ditching plow,
exhibited in fig. 147, is similar in the construction of
Fig. 144. this part, and it

has been found
to work well
for subfioiling,
particularly in
stony land. If
the subsoil hap-

Brace-shank SubsoUer. pens tO be filled

with roots, the interstices in these plows sometimes become
choked — a difiiculty, however, which rarely occurs. In
such cases it may be better to employ the plow represented
by fig. 141.

New subsoil plows have been lately constructed at the
West, by which the operations of both plows are perform-
ed at once. A saving is thus made in the expense of the
implement and in the labor of one man. In one, known
as the Nichols' plow, a flat, triangular blade runs a few
inches below the common plow ; in Wlieatley's, a narrow
blade bent like the letter U beneath the plow performs
the work.

The benefit of subsoiling will last three or four years ;
but it is of great importance that land be well under-
drained, for if the earth becomes heavily soaked with wa-
ter, it settles down into one compact mass, and the advant-
ages of the operation are lost.

THE PARIMG TLOW

consists merely of a flat blade, whicli runs beneath the
surface, shaving off the roots, but not moving the soil (fig.
145). A shield, shown in the cut, is placed beneath the
beam, to regulate the depth of the cutting blade. It is
used in cutting turf for burning, and for destroying this-
tles and other deep-rooted weeds. When made light for
a single horse, it is sometimes used advantageously for

THE GA^'(i PLOW-

IS?

cutting the grass and weeds between rows of badly tilled
corn. A two-horse paring plow has been constructed, in
which the depth of cutting is accurately regulated by
wheels placed on an axle, like those of a cart. The cast-

Fisr. 145.

Paring plow.

iron blade, which cuts about three feet Avidc, is raised or
depressed by means of screws passing through the axle.
Its chief utility is in destroying grass and weeds before
the sowing of broadcast crops.

THE GANG PLOW

consists of three or four small mould-boards placed side
by side (fig. 146), and is used for shallow plowing, or for

Fi^. 146.

Gang plow.

burying manure or seed on inverted sod, without disturb-

138 MSCIIAXICS.

ing tlie turf beneath. In those of the best construction,
the depth is regulated by wheels, and the breadth of the
furrows by turning the cross-beam more or less obliquely,
by means of a fixed contrivance for this purpose. The
gang plow is liable to become impeded or clogged by
stubble, coarse manure, or weeds, and has not come into
extensive use.

DITCHITSTG PLOWS.

In most localities where tile drains are made, two-thirds
of the labor of cutting is loosening the earth with the
pick, before shoveling it out. By means of the ditching
plow this laborious work is performed by horses. One
span, with a good plow made for this purpose, will loosen
the subsoil fast enough for eight or ten men shoveling,
and cutting about 100 rods 3 ft. deep in a day ; or an hour

or two each day with

Fi"'. 147

the plow will keep
two men at work.
If the subsoil is very
hard, this work
should be done early
in summer. The
implement is drawn
by two horses, at-
tached to the ends of a main whiffle-tree about seven feet
long, one walking on each side of the ditch. From one
to three times passing will loosen the subsoil five to eight
inches, which is then thrown out by narrow shovels, on
both sides, so that it may be easily returned after the tile
is laid, by means of a common plow drawn by the long
whiffle-tree before mentioned.

There are several modifications of the ditching plow, all
accomplishing the same end. The adjustable dltcliing
plow, (6g. 147,) admits of so great a change in the height

Adjustable Ditcldng Plow.

DITCHING PLOWS. 139

of the beam and handles, that it may be run down in the
bottom of a ditch to a depth of four feet. It is, perhaps,
the best implement of the kind for all purposes and soils.
The movable portion of the beam is attached to the fixed
beam by a stout loop and staple, and rises on a cast-iron
arc, which j)asses through it, as shown by the dotted lines.
The handles rise on a stiff, woode?i arc, (as tlie dotted lines
exhibit,) a piece of thick plank, shown in the small figure
on the right, being placed between the handles and fast-
ened to them, to render them more firm and steady. The
iron work, although light, is braced so as to impart great
strength and security. The point is screwed on separate-
ly, and is nearly the only i^art that wears by use.

This ditching plow may be used for common subsoiling,
the shortness of the share rendering it especially adapted
to stony land.

Several ditching machines have been constructed for
performing the entire operation of cutting the earth and
throwing it out, but nearly all of them are too complex
for common use. Except in land entirely free from stone,
some of their many parts are liable to become bent or in-
jured by use, and a very slight derangement of this kind
renders them partly or entirely useless. Any ditching
machine, therefore, to work well among stone, must be
simple atid strong, so as to withstand the frequent shocks
met with in overcoming obstructions in the soil.

. MOLE PLOW.

The Mole Plow has a wooden beam, sheathed with iron
on the lower side, which moves close to the ground, be-
low which a thin, broad coulter extends downward, and
to the lower end of this coulter a sharp iron cylinder is
attached. This moves horizontally, point foremost, through
the soil, producing a hollow channel beneath the plow for
the escape of the water, the only trace on the surface be-

140 3rECHAXIC3.

ing a nar^o^y slit left by the coulter. It is dragged for-
ward by means of a chain and capstan worked by a horse,
the machine itself being fixed with strong iron anchors.
This mode of draining is only adapted to clay soil, free
from stone, and although cheaply performed, has been little
used since the introduction of tile-draining.

APPENDAGES TO THE PLOW.

Wheel Coulters. — In soils free from stones and coarse
gravel, and especially on the Western prairies, wheel
coulters are found to answer a good purpose, cutting
through the turf and roots of grass Avith great ease, and
making a smoother slice than the common cutter. But
where stones and other obstructions exist, it is necessary
to use the simpler, single blade coulter. A good repre-
sentation of the wheel coulter is seen on the figure of the
Moline Plow, on an early page of this chapter.

Weed-Hook and Ciiaix. — In turninor under larore
weeds, grass, or other tall vegetable growth, two modes
are adopted. One is Fig. 143.

the use of the weed
hook represented in
the annexed cut ;
and the other is that
of a chain. The
w^eed-hook has been
long known, and is
made in various Weeci-hook.

forms. Sometimes it is bent in the form of a bow
with the lower point projecting forward, as in the upper
figure; another form is like that shown in the lower cut,
pointing backwards. This is less liable to be caught by
obstructions. The weed-hook operates on the principle
of bending the tall growth forward and prostrate, so that
the turning sod completely buries it. The same object is

WEED-HOOK AND CHAIX. 141

attained by the use of a heavy chain ; and different modes
are used for attaching it to the plow. One of the sim-
plest is to fasten one end to the right-hand portion of the
main whiffle-tree, and the other to the right handle. In
another mode, the chain forms a loop. All these modes
of burying vegetable growth are important in turning
under clover and other green crops.

The weeddiook is usually made of round rod-iron, stiff
enough to perform its work, and to possess some spring
when it meets with obstructions. Those not accustomed
to its use may adjust its position by bending it, until it
performs satisfactorily. It is secured to the plow-beam
by placing the forward end in a small groove cut lengtli-
wise in the under side of the beam, passing a band over
it, and wedging until properly secured. Lighter and mo^e
perfect weed-hooks may be made of steel rod, similar to
that used for rake teeth ; they will bend back on meet-
ing obstructions, and spring again into position. Such
weed-hooks should be made and sold with the other ap-
pendages of plows, now that the inversion. of green clover
for manure has become an essential part of good forming.
Sometimes the weed-hook is made to extend at right
angles to the plow-beam, curving outwards and down-
wards. This form requires greater stiffness, and small bar-
iron is usad.

No plow will cover weeds or other growth two or three
feet high ; but by the use of this hook, the whole is laid
completely under the surface.

Regulating Wheel. — It has long been a question witli
plow men whether the wheel under the beam for regula-
ting depth is really a disadvantage or a benefit. It is fully
shown in the able Report by J. Stanton Gould, of the Trial
of Plows at Utica, drawn from accurate experiments, that
the wheel not only gives better plowing with moderate
skill, but that it slightly lessens the draught. Uniformity
in the depth of the slice is preserved, without constant

142 MECHANICS.

vigilance on the part of the attendant ; and this imifonn-
ity, by preventing uneven running, lessens the aggregate
amount of draught. It is, however, quite important that
the wlieel sustain little or no pressure ; for as soon as the
beam bears upon it, the line of draught becomes crooked
at the expense of the team. These facts were established
by careful experiments with the dynamometer.

PULVEEIZEKS.

Tlie fine f)ulverization of the earth, for the ready ex-
tension of the roots of plants, for the action of air on the
soil, for the retention of moisture, and for the thorough in-
termixture of manure, is of great importance to the farmer.
It is but partially accomplished by the plow, which crum-
bles the soil only so far as may be done by the act of
turning it over. Henee additional implements are needed
for this purpose, among which are the harrov:, the cuUioa-
tor, and the clod-crusher.

HARROWS.

The Brfish-harroio, the original and rudest form of the
implement, and still used for covering grass seed, as often
made, is a poor implement. The
most projecting limbs are cut partly
off, that all may lie flat, but it often
happens that the projecting angles of
^the larger branches plow into the

ground and make deep furrows. This
Brush-harrow. . , t i ^ t i

may be prevented by a careiul selec-
tion of the small tree which forms the brush, or still better
by constructing a simple rough plank frame, so that any
quantity of short brush may be placed between two pieces
of plank, to admit the tops of the brush to incline down-
wards and backwards, being lield in place by a few spikes
or bolts. Fior. 149.

I

GEDDES AND SCOTCH HARROWS.

143

The Geddes Harrow is one of the best in use for rough or
uneven land. The teeth being situated considerably back
of the point of draught, its motion is even and steady,
and easy for the team. In conse-
quence of its wedge-form, it passes
obstructions more readily. The
center or draught-rod forms a set
of hinges, by which it becomes
adapted to uneven ground, or by
which it may be easily lifted to
discharge weeds, roots, or other
obstructions. Or it may be doubled
back, and carried easily in a wagon.
The accompanying figure (fig. 150)
Geddes Hanoiv. renders its construction intelligible,

without further description. To prevent its
rising in the middle, as it has been found to do
when the draught traces are as short as easy

Fin:. 151.

draught requires, the chain is attached to the
bar on each side, as shown in fig. 151.

The Square Harrow admits of a larger number of teeth,
and when made in the best form, effects thorougli pulveri-
zation on smooth land, free from obstructions. A modifi-
cation known as the Scotch
harrow, represented in fig.
152, has forty teeth, inserted
in such a manner that each
tootli forms a separate track,
as shown by the dotted lines.
The hinges, as in all square
harrows, enable it to fit a
rolling or uneven surface,
and it may be folded for
carrying in a cart or wagon. scotch or square harrow.

For the fine pulverization of a smooth surface, a still
srreater number of teeth has been found to answer an

144 MECHANICS.

excellent purpose, leaving the soil almost as smooth as a
garden bed. Tough and sound timber, only two inches
square, is used for the frame, and the teeth are five-
eighths of an inch square.

The Morgan Harrow is an improvement of the Scotch
implement, slots being made in the hinges, so that each of
the two portions is capable of jDlaying freely up and
down, as the surface varies, and rendering the rear teeth
less liable to follow in the track of the preceding. The
draught-iron is made to slide on an iron arc, so that the
lines formed by the teeth are controlled at pleasure. It
is converted into a broadcast cultivator by inserting flat
teeth, the flat portion below being the same in width as
above, and pointing slightly forwards. These teeth pul-
verize the soil deejjly and thoroughly. They are success-
fully used for digging potatoes, operating like a large
number of potato-hooks, drawn by horses.

The Norwegian Harrow (fig. 153) is a new machine for

Fig. 153.

Norwegian Harrow, kept from clog^nf* by hoo cylinders of teeth
playing into each other.

pulverizing the soil, which performs the work in a very
perfect manner, by turning up, instead of packing down,
the earth. Two rows of star-shaped tines play into each
other, and produce a complete self-cleaning action, pre-
venting clogging even in quite adhesive soils. Its com-

I

shares' harrotv^. 145

plex character and cost have prevented its coming into
more general use.

Shares' Harrow (fig. 154) is the most perfect of all im-
plements for pulverizing the freshly inverted surface of
sward land, to a depth two or three times as great as the
common harrow can effect. The teeth being sharp, flat
Fig. 154. blades, cut with great ef-

ficiency ; and as they slope
Uke a sled-runner, they pass
over the sod, and instead of
tearing it up like the com-
mon harrow or gang-plow,
Shares' Harrow. ^hey tend to keep it down,

and in its place, while the upper surface of the sod is
sliced up and torn into a fine, mellow soil. The price of
Shares' harrow is about $20, but if furnished with steel
teeth, as it should be, it would cost more.

CULTIVATORS.

The Cultivator or Horse-hoe is used for loosening and
pulverizing the soil among drilled crops, and for cutting
and destroying weeds. A usual form is shown in fig. 155,
which represents _ Fi^r. 153.

Ilolbrook's, one
of the best of its
kind. The wlieel
in front regulates
the deptli ; the
sides may be ex-
panded or con-
tracted sufficient-
IV to vary the Hdtrrook's Horse-hoe or OulUvator.

width from fifteen to thu-ty-six inches ; they are reversible,
so that the soil may be thrown from or towards the row ;
«|nd the frame is high enough to prevent clogging with

T

146 MECHAiaCS.

weeds, stubble, or manure. Various forms of teetli are
used, according to the nature of the work, and they aro
made of steel or cast-iron. The steel teeth, represented
in fig. 152, are well adapted for cultivating the rows of
Indian com and other hoed crops, where the soil is al-

Fi^. 15G.

Claw-toothed cultivator for bard grfmnd.

ready moderately mellow. For harder soils, the teeth
should be in the form of claws, as shown in fig. 156, their
sharp, wedge-form points penetrating and loosening the
earth with comparative ease. An efficient cultivator is
made by using both kinds of teeth in the same implement,
placing the claws forward for breaking the hard earth, and
the broader teeth behind for stirring it.

Steel plates, with sharp or " duck-feet " edges screwed
at the lower ex- Fig. 15t.

tremitics of the
teeth, (fig. 157)
are useful for par-
ing or cutting the
roots of weeds;
and formed like
the mould-board of a plow, they are used for throwing the
mellow earth toward the row, or, when reversed, from it.

Alden's Thill Cultivator is furnished with fixed thills,
extending backwards from the handles. The whole im-
plement thus runs with remarkable steadiness and great
efficiency, and the driver, by bearing on the handles,

GAERETr S HOKSE-HOE.

147

readily increases the depth of the teeth, or by bearing to
the right or left, guides it in the row. It is not capable
of being expanded and contracted in width.

Garretfs Horse-hoe, an English invention, is a modifi-
cation of the cultivator, and is used for cultivating car-
rots and other root-crops in drills, cleaning eight or ten
rows at once. It is furnished with sharp, horizontal
blades, which run beneath the surface, and shave off and
destroy all the weeds within an inch of the rows of young
plants. These rows, having been planted by means of a
drilling-machine, are straight, and perfectly parallel, and
the operator has only to watch 07%e row, and guide the
blades for that row, the apparatus being so contrived
that the blades for the other rows shall run at the same
distance from them.

Fig. 158 represents an end view of this implement. It
exhibits the apparatus by which the length of the axle is

Fis. 15S.

Garretfs Horse-hoe — End view,

altered to suit all kinds of planting ; by which each hoe
is kept independent of the others, so as to suit the ine-
qualities of the ground, and by which they can be set any
width, from seven inchei^- to thirty. It shows the oblique
angle at which then- run — this obliquity being easily al-

148 MECHANICS.

tered to any desired degree : this is effected by a move-
ment of the upper handle, represented in the figure. By
the lower handle, the whole is accurately guided. It is
said that two men, one to lead the horse, and the other to
guide the implement, will dress ten acres of root-crops in
a single day, and that it has proved eminently a labor-
saving machine. It can be used only on smooth land,
free from stone.

TWO-IIORSE CULTIVATORS

are made to run on two wheels, and the depth of the
teeth is regulated by raising or lowering the frame-work
that holds them. They have been much used for pulver-
izing the surface of inverted sod, and fitting it for the re-
ception of seed, but are likely to be superseded for this
purpose by Shares' harrow. Modified so as to pass the
two spaces between three rows of corn, they are known
as double culti'vators, and have now come into use for cul-
tivating large fields, and are generally adopted for this
purpose at the West. They accomplish twice the work
of the single cultivator. They are of two kinds : those
called the sulky cultivators, being furnished with a seat
on which the driver rides, and the walking cultivators,
without seat, the attendant walking behind. The former
will accomplish more work in a day, with less fatigue to
the driver ; the walWng cultivators are better suited to
rough, or sidling ground, and are cheaper. Many manu-
facturers make them of different forms, both at the West
and in some of the more eastern States. The best sulky
cultivators cost about 175.

This new machine, which has been used to some extent
in the broad fields of the West, forks up the soil by means
of a series of revolving teeth. It is drawn by two or
four horses, accqrding to its size and the strength of the

I

comstock's rotary spader. 149

animals, the driver riding on a seat. Sometimes two ma-
chines are attached -together, and both are driven by one
man. It is used only on land free from sod, such as com,
or other stubble, and is not adapted to land containing
stones or rocks.

Its advantages are the following : Greater ease of
draught, when compared with the plow, the chief source
of friction being the thrusting of tlie teeth into the soil,
while the friction of the plow at the mould-board is usu-
ally equal to at least half the weight of the moving sod,
added to half the entire weight of both plow and sod, on
the sole in the bottom of the furrow, while more force is
required to cut with the edge of the share than with the
points of the rotary spader. Hence it is found to do
twic/C or three times as much work with the same team as
a plow. It does not form a hard crust in the bottom of
the furrow, like the plow ; and it leaves friable soils pul-
verized ready for planting, without the use of the harrow.

There are some serious drawbacks to the general intro-
duction of this machine. Its cost exceeds ten times that
of a good steel plow, while its complexity renders it more
liable to strain or breakage, except in uniform and stone-
less soils. It cannot be used in wet seasons, and pulver-
izes such land only as is previously free from grass. It
may, however, prove valuable on extensive farms.

CLOD-CRUSHERS.

In clayey soils, clods are often formed in abundance
during the process of cultivation. These become very
hard in diy weather, and prevent the proper extension of
the fine roots of plants in search of nourishment, and also
the intermixture of manure with the soil, without which
it has been found that two-thirds, or even three-fourths, of
the value of manure is lost to growing crops.

Different modes of pulverizing the clods have been

150

MECHANICS.

adopted. Tho simplest is the " drag-rollei'^'' represented
in fig. 159. It is made of a log, or portion of a hollow
tree, into which a common two-horse wagon tongue has
been fitted, by which it is dragged, over the ground with-
out rolling, grinding to powder, in its progress, every clod
over which it passes. The greater the diameter of the

log, the less will
be the liability of
its clogging by
gathering the
clods before it.
It may also be
^^^^^"""^'"'■- made of a half

log, with the round side downward. Fig. 160 represents
a similar imple- Fig. i go.

ment for one
horse ; this is used
for working be-
tween the rows
of corn in cloddy

OTOnnd One-horse Clod-crusher.

The use of these simple implements, by reducing rough

Fis. IGl.

fields to a condi-
tion as mellow as
ashes, has,in some
instances, been
the means of
doubling the crop.
It is necessary
that the soil be
dry when they
are used, to pre-
vent its packing
together.

CrosskiWs Clod-crusher. ^

CrossMVs Clod-crusher, first used in England, is a
more powerful and more costly implement (fig. 161). It

CLOD-CRUSHERS, 151

consists of about two dozen circular cast-iron disks,
placed loosely upon an axle, so as to revolve separately.
Their outer circumference is formed into teeth, which
crush and grind up the clods as they roll over the surface
of the field. Every alternate disk has a larger hole for
the axle, which causes it to rise and fall while turning
over, and thus prevent the disks from clogging. Fig. 162
represents this implement, as modified and manufactured
in this country. It is used only where heavy clay soils
prevail.

This clod-crusher can bo used only where the ground
and the clods have become quite dry. Even then it packs

Fig. 162.

American Clod-crusher.
the soil, and if followed by a harrow, with scarifier teeth,
to loosen it again, it would j^rove an advantage. It is
only in certain seasons that it is most successfully em-
ployed, or when quite dry weather follows a wet spring.
As thorough tile-draining is generally adopted, it becomes
less necessary.

The best clod-crushers are sold for about $125.

THE ROLLER.

This implement, now in general use, is employed for
pressing in grass seed after sowing, for smoothing the sur-
face of new meadows early in spring, and for other similar

152 MECHANICS.

purposes. On light soils, it is most valuable, and may be
used at nearly all times with safety. Heavy or clay soils
will be crusted and injured if rolled while wet. The

Fig. 1G3.

Meld Boiler.

roller was formerly made of a single i:)iece, or of a log of
wood dressed to a true cylinder ; but this scraped the
earth when turned to the right or left. A great improve-
ment was made by cutting the single roller into two
parts; and a still greater, by employing cast-iron, in sev-
eral sections, as shown in fig. 163. The cost of cast
rollers is about $85 to $100.

CHAPTER XL

PLANTING AND SOWING-MACHINES.

Sowing-machines, for wheat and other grains, possess
great advantages over hand-sowing. All the seed being
deposited by them at a nearly uniform depth, and com-
pletely covered with earth, it vegetates and grows evenly,
and the plants are uniformly strong and vigorous. A
less quantity of seed is required, and the crop is heavier.

W'HEAT DRILLS.

Several excellent grain drills are now manufactured and
sold in this country, having much similarity in external
appeai'ance. One of the best and most widely knowD

SOWING-MACHINES.

153

Fijj. 1&4.

is made by Biclcford <h Huffman^ of Macedon, N. Y. It
is represented in
the accompany-
ing cut, showing
eight dropping
tubes. The mode
by which the
grain is dis-
charged from the
hopper down
these tubes is ex-
hibited in section in fig. 165 ; <? being the interior of the
liopi^er, hh a revolving wheel, the projecting rims of which

form the bottom of the seed-holder ;

the axle at a causes this wheel to

revolve, and the small projections on

the interior of the

rim carry the seed

to c, where it drops

through an opening

in the plate which

forms the side of the

seed-holder. The

rapidity of discharge is perfectly con-
trolled by wheel-work, which causes the
axle a to revolve slowly or fast at pleasure. The
seed-holder is divided into two parts by the wheel
a h, as shown by cross section in figure 166 ; one
part, d, containing wheat, barley, and other medium-
sized grains, and the -pig. 167.
other, c, for com, peas,
and the larger seeds.
This figure shows the
opening in the side-

Crosssecfion of Seed-
Jwlder.

Cross-section of Dis-
charger.

r^

^

Sliding EeversMe Bottom of Hopper.

Ti'

plates, through which the grain is discharged. As these
two divisions must be used on separate occasions, the

154 MECHANICS.

openings between them and the hopper are opened and
closed at pleasure by a slidhig bottom, with a single
movement of the hand. This sliding bottom is shown in
fig. 167, and forms hoppers with sloping sides, down
which the grain passes freely.

The ends of the tubes, which are shod with steel, are
made to pass any desired depth into the mellowed soil,
and depositing the seed, it is immediately covered by the
falling earth, as the drill passes. This drill is furnished
with an attachment for sowing plaster, guano, or any
other concentrated manure, and also with a grass-seed
sower.

A great improvement has been made in the mode al-
ready described, of discharging the seed ; fonnerly, seed-
drills generally were furnished with a revolving cylinder,
in the surface of which small cavities were made, for car-
rying off ^d dropping measured portions of the grain ;
these often broke or crushed the seed, and were liable to
derangement. Others were furnished with circular, re-
volving brushes, for pressing the seed through holes in
the bottom of the hopper ; but this contrivance was im-
perfect) and the brushes were liable to wear out. In the
discharging apparatus of the drill just described, the
seeds are never crushed, and the whole being substantially
made of cast-iron, it may be run a lifetime. The best
grain drills are sold for $80 or 890.

setmoub's broadcast sower

is an excellent machine for sowing plaster, ashes, guano,
salt, or any other concentrated fertilizer, as well as com-
mon grain and grass seed. The disagreeable, and even
dangerous, as well as heavy and laborious work of sow-
ing these manures by hand renders such a machine de-
sirable on every farm. It is drawn by one horse, sows

CORN PLANTERS. 155

ten feet wide, and the operator rides in a seat. Seymour's
Plaster Sower sows these fertilizers, whether wet or dry.
These machines are sold at about 870.

CORX PLANTERS.

Among the best one-horse corn planters, which make
one drill at a time, are Emery's, Harrington's, and Bil-
lings'. The last-named is represented in the annexed cut.
It drops in hills, eleven inches apart in the row, or, if de-
Fig. IGS. sired, twenty-two

inches, the perfora-
tions in the slides,
regulating the

number of grains.
It is so constructed
as to drop any
desired amount of

Billings' Corn Planter. plaster, guanO, Or

other concentrated manure, without coming in contact with
the seed. This, and other one-horse drills, arc well adapted
to planting fields of considerable size, for cultivating in
rows but one way. On a larger scale, two-horse drills
are employed. Wheat drills are often used for this pur-
pose, employing only two of the tubes. Another class of
corn planters, for planting in hills, the rows running both
ways, consist of hollow tubes, Avhich contain the seed,
and which, by striking or pressing on the soil, drop and
cover a hill at one stroke.

true's potato planter.

For field culture, this implement has proved an import-
ant saver of hand labor. It is drawn by one horse, and
cuts, drops, and covers the potatoes at one operation. It
is usually employed on ground wliich has been plowed

156 MECHANICS.

and harrowed only, the driver forming the drills by the
eye, as the planting proceeds. Straighter rows may be
made by first marking the land with a good corn-marker,
and thien employing a small boy to ride, directing him to
keep the horse on the line. The driver has then only to

Fig. IGO.

True's Potato Planter.

watch the working of the machine before him. If the
ground is rough, or rather dry, it is better to furrow the
land previously with a single horse, running the planter
in these furrows.

For using this machine successfully, the seed potatoes
must be previously assorted, so that those of nearly equal
size may be used at a time. It is common to assort them
into two sizes, which may be done in winter, or on rainy
days. Each potato passes the throat of the hopper sin-
gly ; and if one in a bushel happens to be too large, it
will choke the opening. After passing the hopper, each
potato is sliced into pieces of the desired size, which
then, one by one, drop down the hollow coulter, and are
buried. The throat of the hopper is readily contracted
or expanded, and adapted to any assorted size of seed.
One man, with a liorse, will plant several acres in a day,
and if the ground be in good order, with nearly or quite

HAND DKILLS AND SEED SOWEKS.

157

as mucli accuracy as by hand, and with more uniformity
of depth.

HAND DRILLS, OE SEED SOWEKS.

These are great savers of labor for sowing the seeds of
ruta-bagas, carrots, Fi=- 1~0-

field beets, and
other farm root
crops, besides peas
and beans. One
of the best in use
is Harrington's,
represented by fig.
170, and made by
F. F. Ilolbroolc &

Co., Boston. The Ilarriyigton's Hand Seed Sower.

side chains mark the rows, and it makes its own drill,

drops, and covers
the seed with ac-
curacy, at one
operation. It is
readily changed,
to the hand culti-
vator, by remov-
ing the dropper,
and attaching the

Harrington's Hand Cultivator. cultivator teeth,

shown in fig. 171. It then becomes a convenient imple-
ment for running between the rows, in small fields.

158

MECHANICS.

CHAPTER XIL
MACHINES FOR HAYING AND HARVESTING.

MOWIXG AND REAPING MACHINES.

The cutting part of the mowers and reapers made at
the present day consists of a serrated blade, as shown by

Fiir. 172.

Knives.

fingers, shown

I >^

I I

CutUi'-bur.

Fi?. 171.

fig. 172, Avhich passes througli narrow slits in each of the

forming, when thus united,
the cutting ap-
paratus, as ex-
hibited in the an-
nexed figure, of
'Wood''s Mow big-
machine (figure
174). When the
machine is used, the motion of the wheels on which it
runs is multiplied by
means of the cog-
wheels, imparting
quick vibrations, end-
wise, to this blade,
shearing off tlie grass
smoothly as it ad-
vances through the
meadow, like a large
number of scissors
in exceedingly rapid
motion.

WoocTs Mmver,

The finger-bar, the most important part, nov/ adopted

MOWERS AND KEAPEES.

159

in all mowing and reaping machines, was invented by
Henry Ogle, of Alnwick, England, in 1822, and his machine
was put in successful operation, after much experimenting,
by T. & J. Brown, of that place. But so strong was the prej-
udice of the working people against labor-saving machine-
ry, that they threatened to kill the manufacturers if they
persevered ; and the enterprise for a time was given up.*
The limits of this work permit >only a brief notice of
some of the chief Fig. its.

points in mow-
ers and realtors ;
and a few ma-
chines are refer-
red to, out of a
largo number of I3
kinds, which are '^M
made in the dif-
ferent States,
and which have
proved them- The Kirby Machine as a Mower.

selves worthy of the confidence of farmers.

riff. iTG. The operation of

mowing is shown in
fig. 175, which rep-
resents the Kirby
mower, one of the
best single - wheel
machines, cutting a
swath five feet
wide, as fast as the
horses advance.
Buckeye Mower with Fdded Bar, Various contriv-

ances are adopted for lifting or folding the cutter-bar when
the machine is not in operation, or in passing from one field

* Woodcroft.

160

MECHANICS.

to another. A neat and convenient form is used in the
Buckeye Mower, represented in the accompanying cut,
(fig. 176) where the bar is folded over in front of the
driver's feet.
In the mowing-machine, the cutting apparatus is nar-
row, causing the
newly cut grass to
fall evenly behind it,
covering the whole
surface of the
ground. The reap-
ing-machine is simi-
lar in construction,
with the addition of
a platform for hold-

Kirby Eeaper, with Hand Bake. jj^o- the ffrain aS it

falls, as shown in the annexed figure of the Kirby machine,
changed to a reaper (fig. 177).

This figure represents the reel, which is attached to,
and is worked by the machine, causing the grain, as it is
cut, to drop smoothly Fig. its.

upon the platform.
When a sufficient
quantity has collected
there, it is swept off
by the hand rake, and
is afterwards bound in
a sheaf. The annexed
cut exhibits the Cayu-
ga Chief, (an excellent Cayuga CJikf— Combined Moioer and Reaper.
two-wheeled machine) as a reaper, in which the opera-
tion of hand-raking is distinctly represented.

SELF-EAKING KEAPEES.

Mowing-machines need but one man for their man-
agement, who merely drives the horses that draw it.

SELP-RAKIKG EEAPEES. 161

Reapers, as usually made, require another man besides the
driver, to rake off the bunches of cut grain, which is se-
vere labor. Various self-raking contrivances have been
used to obviate this labor, several of which have been
made to do excellent work, and are coming into general
use.

One of the first successful self-raking attachments to
the reaper was that used by Seymour & Morgan, of
Brockport, N. Y. It was one of the kind which sweeps
across the platform, in the arc of a circle, delivering the
gavel at the side of the machine. The ordinary reel is
used with this class of rakes. An objection to them is,
that the grain is seized for throwing off at a point behind
the cutters. Owen Dorsey introduced an improvement in
the form of what are termed reel-rakes, which strike the
grain forward of the cutters. A series of sweeps or
beaters were employed, combined with one or more rakes,
the gavel being delivered from the platform at each cir-
cuit of the rake. At first, the horizontal motion of these

arms prevented the
driver from riding
on the machine. An
improvement was ef-
fected, so that the
arms and rakes, after
passing the platform,
were made to rise to
^ a nearly vertical posi-

mx. X-.* cv7^ 7 tion, thus passing the

The Kirby Self-raker. ' ^ ^

driver freely. The

accompanying engraving, (fig. 179) representing the self-
raker used on the Kirby machine, shows the position of
the arms when in motion — one of them serving as a rake
at each revolution. There are several modifications of
this class of brakes, made by different inventors. MarsfCs
machine consists of beaters and rakes combined, and de-

162

MECHANICS.

livers one or more gavels at each revolution, according to
the number of rakes used at a time, Johnson's rake is
furnished with rake-heads for each of the arms, which are
60 arranged as to dip low into the grain forward of the
cutters, and afterwards to rise in j^assing over the plat-
form. To discharge the grain, the driver uses a latch-
cord and lever, so that the path in which the rake travels
is changed by opening a switch or gate, permitting one of
the rakes to pass low enough to sweep the platform. The
Cayuga Chief, Buckeye, Hubbard, and other reapers, use
this self-raker. The Kirhy machine employs a self-raking
attachment of its own, already represented in fig. 179.
Two or three of the arms, or beaters, at the option of the
driver, bring the grain on the platform ; the other one or
two carry the rake-head. The driver may throw off a
gavel, or two gavels, at each revolution; or the rake may
be made to run continuously, at regular intervals, without
attention on the part of the driver. The arms, or rakes,
are so made as to be adjustable to the height of the grain.
Tlie Dropper is a simple contrivance, (represented in
the annexed en-
graving) consist-
ing of a light plat-
form, which holds
the grain until the
gavel is large
enough, when it
suddenly drops
and discharges it.
It is much used at
the West, and, al-
though hardly so perfect as some self-rakers, is preferred
by many farmers, the gavels being delivered behind the
machine, and thus keeping the binders up to their work,
in clearing the way for the next passage of the reaper.

Fig. 180.

Cayuga Chief with Dropper.

M^VRSn's HARVESTER. 163

BINDERS.

Several machines for binding grain have been invented,
possessing considerable merit, but so far they do not ap-
pear to be adapted to general introduction.

Marshes Harvester, much used at the West, is so con-
structed, that two men may readily bind as fast as the
harvester does its work. The binders stand on a small

platform, furnished
with a guard or rail,
and the grain, as fast
as it is cut, is carried
up by an endless
apron to a platform,
where each man alter-
nately makes his
band, and receives
and binds his sheaf.
As they expend no
The Marsh HarcesUr. time in stooping, or

in passing from gavel to gavel, they are enabled to work
^v-ith ease and rapidity. The weight is only that of one
man more than on a h arid-raker.

Headers are reaping-machines employed for cutting the
heads of wheat with a small portion of the straw, leaving
most of the straw standing. They are usually driven by
four horses, and arc thrust forward ahead of the team. A
two-horse wagon, in addition, is driven along side, to re-
ceive from an endless apron the heads, as they are cut by
the reaper. They are onTy used on the extensive fields of
the West, and a diiference of opinion prevails as to their
general value.

DURABILITY AND SELECTION.

Mowing and reaping-machines, being complex, or made
up of many parts, would soon be broken and destroyed,

-*<:.*

164 MECHANICS.

if the resistance tliey meet with were irregular ai.d full of
obstructions, like those which the plow encounters.
Standing grain and grass present a soft and uniform re-
sistance, and hence, well-made machines will last several
years without much repair. The Report of the Auburn
trial of mowers and reapers gives five years as the aver-
age " lifetime " of these machines. Much will depend on
the amount of work performed in a season ; an extensive
farmer states, that he usually cuts about five hundred
acres with each machine before it needs renewing. Much,
also, depends on the care which the machines receive ;
such as keeping them always well sheltered from the
weather, and tlioroughly cleaning every part, and care-
fully wiping the journals and bearings before they are laid
aside for the season.

In selecting mowers and reapers, there are several
points which the purchaser should carefully observe ; as,
for example — 1. Simplicity of construction. 2. Use of
best material for knives and other parts used in manufac-
ture. 3. Finish and perfection of gearing and running
parts. 4. Durability, as proved by use. 5. Ease of
draught. 6. Freedom from side draught. 7. Quality
of work. 8. Ease of management. 9. Convenience
and safety of driver. 10. Adaptation to uneven sur-
faces. A part of these points can be fully determined
only by thorough trial ; and it is always safest to
purchase of those manufacturers whose machines have
been long enough in general use to establish their char-
acter in these respects. Fortunately, there are many in
different parts of the country, -svho have secured a good
reputation, from whom machines, or parts for repairs, may
be obtained without sending long distances. The report
of the Auburn trial, in 1866, states, that out of twenty
different mowing-machines, which were tried on a rough
meadow, every one, with two exceptions, *' did good
woik, which would be acceptable to any farmer ; and the

HAY TEDDERS.

165

appearance of the ^iiole meadow, after it had been i*aked
over, was vastly better than the average hand mowing of
the best farmers in the State." Since that trial, a con-
tinued improvement in manufacture has been taking place,
and the machines are becoming more perfect.

The price of a good two-horse mowing-machine is
about $120 ; and of a combined mower and reaper, about
$170.

HAY TEDDIXG MACHTNIIS.

Machines for stirring up and turning the drying hay
have long since been known and used in England, and a
few were introduced into use in this country. But as
they were heavy and cumbersome, they never came into
common use. A

few

ms. 183.

years since, ^^

Bullard's Hay Ted-
der was invented,
and has been wide-
ly used. It scatters
and turns the hay
with great rapidi-
ty, and consists of
several forks, held ^^
nearly upright, but
worked by a com-
pound crank, so as
to scatter the hay

,T /. , 1 Bullard's Bay Tedder.

m the rear of the

machine. The close resemblance of the movement of
these forks to the energetic scratching of a hen presents
a ludicrous appearance to one who sees it for the first
time. The use of the tedder is found greatly to hasten
the drying process, especially on heavy meadows, and to
enable the farmer to secure his hay in so short a time as
frequently to avoid damaging storms.

166 MECHANICS.

A new machine, remarkable for its simplicity and per-
fection of working, is the American Hay Tedder, made
by the Ames Plow Company, of Boston. It is repre-
Fig, 183 sented in the

accompanying
cut. It is furnish-
ed with sixteen
forks, attached
to a light reel in
such a manner
that they re-
volve rapidly,

T!ie American Hay Tedder. . , i. j ■>

With a rotary,
continuous, and uniform motion. It never clogs, may be
easily backed, and readily passes over ordinary obstruc-
tions, without any attention on the part of the driver.

Hay tedders should be used on the meadow about
three times a day, which will enable the farmer to cut his
crop in the morning, and draw it in the same day ; giving
him, also, more uniformly dried, and better hay.

The price of hay tedders varies from 875 to $100.

•

nOESE IIAY-RAKES.

The simplest and original form of the horse-rake is
represented in fig. 184. It was made of a piece of strong
scantling, three inches square, tapering slightly toward
the ends, for the purpose of combining strength with
lightness, and in which were set horizontally about fif-
teen teeth, twenty-two inches long, and an inch by an
inch and three-fourths at the place of insertion, tapering
on the under side, with a slight upward turn at the
points, to prevent running into the ground. The two
outer teeth were cut oif to about one-third their first
length, and draught-ropcG attached. If these pieces were

HOKSE IIAY-EAKES.

167

too short, the teeth wore hard to guide ; if too long, the
rake was unloaded with difficulty. Handles served to guide

Ficr. 184.

Simple Horse-rake,

the teeth, to lift the rake from the ground in avoiding ob-
structions, and to empty the accumulated hay.

In using this rake, the teeth were run flat upon the
ground, passing under, and collecting the hay. When
full, the horse was stopped, the handles thrown forward,
the rake emptied and lifted over the windrow thus formed.
The windrows, as in other horse-rakes, were made at
right angles to the path of the rake, each load being de-
posited opposite the last heap formed, in previously cross-
ing the meadow. A few hours' practice enabled any one
to use this rake without difficulty ; the only skill required
was to keep the teeth under the hay, and above the
ground. «

In addition to raking, this implement was employed for
sweeping the hay from the windrow, and drawing it to the
stack. It was also useful for cleaning up the scattered
hay from tlie meadow, at the close of the work ; for rak-
ing grain-stubble, and for pulling and gathering peas. If
made of the toughest wood, and with the proper taper in
the main parts for lightness and strength, according to
the principles already pointed out in a previous chapter,
it was easily lifted, and its use not attended with severe
labor.

168

MECHANICS.

This simple liorse-rake has nearly gone out of use, and
yet, on account of its simplicity and cheapness, it is wor-
thy of being retained on small farms, and especially on
meadows with uneven siirfaces. The cost need not be
more than three or four dollars. From twelve to fifteen
acres could be raked with it in a day.

The Bevolving Horse-rahe (iig. 185) was next generally
adopted, possessing the great advantage of unloading

Fi<?, 185.

Revolving Horse-rake^

without lifting the rake or stopping the horse. It has a
double row of teeth, pointing each way, which are brought
alternately into use as the rake makes a semi-revolution
at each forming windrow, in its onward progress. They
are kept flat upon the ground by the pressure of the
square frame on their points, beneath the handles ; but as
soon as a load of hay has collected, ^he handles are
slightly raised, throwing this frame backwards, off the
points, and raising them enough for the forward row to
catch the earth. The continued motion of the horse
causes the teeth to rise and revolve, throwing the back-
ward teeth foremost, over the windrow. In this w^ay, each
set of teeth is alternately brought into operation. The
cost of this rake is from $7 to $10, and twenty acres
or more could be raked with it in a day.

A further improvement has been made in the revolving
rake, by attaching it to a sulky, on which the operator

KEYOLVIXG IIORSE-KAKES. 169

rides, enabling him to do a larger amount of work with
less fatigue. There arc several modifications, some of
F'^S'^' which place the rake

in front of the sulky-
wheels, and others,
in the rear. One of
the best and most
widely used is
*' Warner's Sulky
p Revolver," manu-
factured by Bly-
myer, Day & Co., of Mansfield, Ohio, and by otliers. It is
represented in the annexed cuts, fig. 186 showing it in
the operation of raking, and fig. 187, the same machine,
with the rake thrown Pj„ ^g^

upon the wheels, for
driving from field to
field. The head is
the same as the com-
mon revolving rake-
head — the. teeth be-
ing tipped with mal-
leable iron. The
rake is operated by
means of a lever, at-
tached to a journal at the centre of the rake-head. By
means of cams, stop, and spring, the lever and head are
entirely at the will of the operator. A slight pressure,
equal to seven or eight pounds, on a lever, causes the
rake to revolve ; and it is also readily elevated for back-
ing, or for passing obstructions.

An important advantage of this rake is, its gathering
the hay free from gravel and earth ; also its cheapness
recommends it — the price being about $35.

170

MECHANICS.

SPRING-TOOTH RAKE.

Fig. 188.

The original form of the spring-tooth rake is shown in
fig. 188. The teeth were made of stiff, elastic wire, on

the/)o//?^5 of which
the rake ran, and
not on the flat
sides, as in those
already described.
They bent in pass-
ing an obstruction,
and sprung back
again to their place.
Thisj-ake was un-
loaded by simply
lifting the liandles,
which was easily
done, the rake be-

Sprinj-tooth Horsc-rakc. ^^„ lirrht. and

about one-half the weight being sustained by the horse.

All the spring-tooth rakes made and used at the present
time are attached to wheels, and a seat is furnished for
the driver. There are many j^atented modifications, some
possessing advantages of greater simplicity, or ease of
management ; but all appear to be good and efficient
rakes, enabling the operator to gather about twenty-five
acres in a day.

Among the best of the spring-tooth rakes is that of
Hollingsworth, made by Wanzer & Cromwell, of Chicago,
and represented in the accompanying engraving. Each
tooth is separate, and may be readily replaced. As soon
as the rake is loaded with liay, the driver, by touching
the lever before him, drops it at the line of the windrow.
The cost is about $45,

THE HAT-SWEEP.

Fir?, isf).

171

Fi-. lOJ.

UoUtngswonh's Spring-tooth EaJce.
THE 11 AY-SWEEP.

Where the hay is secured in stacks, or in hay-barns
situated contiguous to the meadow, the use of the hay-
sweep, in connection with the horse-fork, would probably

enable two or three
men, and two boys,
with three horses, to
draw and pack away
thirty tons a day^ or
more. The hay -sweep,
invented many years
ago by W. R. Smith,

Hay-Sweep.

of Macedon, N. Y., is but little known. The accompanying
figures (190 and 191) exhibit its construction and use. It
is essentially a large, stout, coarse rake, with teeth pro-

/

173 ^ MECHANICS.

jecting both ways, like those of a common revolver ; a
horse is attached to each end, and a boy rides each horse.
A horse passes along each side of the windrow, and the two

Fiff. 191.

Hay-sweep in OperaMon.
thus draw this rake after them, scooping np the hay as
they go. When 500 pounds or more arc collected, they
draw it at once to the stack, or barn, and the horses turn-
ing about at each end, causing the gates to make half a
circle, draw the teeth backward from the heap of hay,
and go empty for another load — the teeth on opposite
sides being thus used alternately. To pitch easily, the
back of each load must be left so as to be pitched first.

The dimensions should be about as follows : — Main
scantling, below, 4 by 5 inches, 10 feet long ; the one
above it, same length, 3 by 4 inches ; these are three feet
apart, connected by seven upright bars, 1 by 2 inches, and 3
feet long. The teeth are flat, 1^ by 4 inches, 5 feet long,
or projecting 2.} feet each way ; they are made tapering
to the ends, so as to run easily under the windrow. A
gate, swinging half way round on very stout hinges, is
hung to each end of this rake, and to these gates the
horses are attached. Each gate consists of two pieces of
scantling, 3 inches square, and 3 feet long, united by two
bars of wood, 1 by 2 inches, and a third, at the bottom, 3
inches square, and tapering upwards, like a sled runner ;

HOKSE HAY-FOEKS.

173

tliesG runners project a few inches beyond the gate. The
whiffle-trees are fastened a little above the middle of the
gate, and should be raised or lowered so as to be exactly-
adjusted. This machine may be made for 86 or ST.

In using, not a moment is lost in loading or unloading.
"No person is needed in attendance, except tlie two small
boys that ride the horses. If the horses walk three miles
an hour, and travel a quarter of a mile for each load, they
will draw 12 loads, or three tons an hour, or thirty tons
in ten hours, leaving the men wholly occupied in raising
the hay from the ground, by means of another horse, with
the pitchfork.

It will be obvious, that this rapid mode of securing hay
will enable the farmer to elude showers and storms, which
might otherwise prove a great damage.

nOESE IIAT-FOEKS.

Every farmer who has ever pitched off from a wagon
in one day ten or twelve tons of hay
is aware that no labor on the farm
can be more fatiguing. Tlie horse-
fork, in its various forms, which, to a
considerable extent, has been brought
into use, has afforded great relief,
gevere labor being not only avoided,
but much greater expedition attained.
The effective force of a horse is, at
least, five times as great as that of a
stout man ; and if half an hour is
usually required for him to unload a
ton of hay, then only six minutes
would be necessary to accomplish the
same result with horse-power. Actual
experiment very nearly accords with
this estimate.

A simple form of the horse pitchfork was described in

Fiff. 192.

Original Ilorsefork.

174

MECHANICS.

the Albany Cultivator, in 1848, from wliich a subscriber
in Bradford County, Pa., made the first used in that re-
gion. Some years later, he stated that there were at least
two hundred in use. The preceding figure represents
this simple and original fork. A is the head, twenty-
eight inches long, and two and a half inches square, made
of strong wood. A G is the Imndle, five and a half feet

long, mortised
into the head,
with an iron
clasp or band of
hoop iron fitting
over the head,
and extending
six inches up the
handle, secured
by rivets. The
prongs of the
fork are made of
good steel, one-
half an inch
wide at the
head, twenty
inches long, and
eight inches
apart, with nuts to screw them up tight. Kivets are placed
on each side of the middle ones, to prevent the head from
Bplitting, The rope is attached to staples at the ends of
the head. The single rope D extends over a tackle-block, at-
tached to a rafter at the peak of the barn, about two feet
within the edge of the bay. The rope then passes down
to the bottom of the door-post, under another tackle-
block, and to the outside of the barn, where the working
horse is attached to it. A small rope or cord G is attached
to the end of the handle, by which it is kept level, as it
ascends over the mow. The cord is then slackened, and

Filching Hay through a JVindaw with Horse-power.

cladding's iiorse-fckk.

175

the hay tilts the fork, discharging its load. The horse is
then backed up, ready for another fork load, the only labor
of the workman being to drive the fork into the hay and
keep the cord steady. An important advantage is gained,
besides the saving of time ; for the man on the load, being
relieved from the severe labor of pitching, is fresh and
vigorous for throwing on another load in the field.

The length of the handle made it difficult to use this fork
under low roofs, and an improvement was made by Glad-
ding^ by which the head of the rake only Avas tilted,
leaving the handle in its horizontal position. A hinge-
joint is placed at the connection of the hca:! and handle,
so that, at any
moment, by a jerk
on the cord which
passes up a bore
in the handle, the
fork is dropped, as
shown in fig. 194,
and its load depos-
ited. This may be
done instantane-
ously, at the mo-
ment it happens to
be swung to the most favorable spot. Its weight causes the
head to fly back of its own accord, and resume its former
position, ready for another forkful. The rope suspending
the fork should be fastened to the highest portion of one
of the raftprs, over the mow, and a smooth board should
be placed, vertically, against the fiice of the mow, for the
hay to slide on as it ascends. By attaching this rope in
front of, and within a window, the hay is carried with
ease into the window, and thus lofls over sheds, carriage-
houses, etc., where the old horse-fork could not be used,
are filled by the use of Gladdinrfs improvement. This is
one of the best forks, adapted to all kinds of pitching,

Gladding" s Ilay-forTc.

176

MECHANICS.

and has unloaded a ton of hay in about three muiutes;
and over a beam twenty-two feet high, under a Ioav rafter,
in about nine minutes.

In using horse forks, as already stated, their operation
is much facilitated by providing a board slide, to be
placed vertically against the face of the mow, or bay, on
which the hay moves upward. In pitching into a win-
dow, the bottom of this board slide should be placed out
a few feet from the building, and the top should rest on
the base of the window. When convenient, the back
end of the wagon load should be placed towards the win-
dow. There is no limit to the height at Avhich the pitch-
ing may be easily performed — giving the use of the
horse-fork a great advantage over hand pitching; and
barns, with high j^osts, may be built for the storage of
hay.

Other forms have been adopted for pitching under roofs,
by using shorter handles. One of the best is Palmer's

Fi^. 195. Fi-^lOn.

Palmer's Fork.

Fork^ made by Wheeler & Co., Albany, and Palmer & Co.,

DOUBLE FORKS.

177.

Chicago, which is represented in the accompanying figures,
Fig. 197. Fig. 198. the light-hand one

showing its posi-
tion when ascend-
ing, loaded with
hay ; the left-hand,
with the knee-joint
brace contracted,
by jerking the cord
for emptying the
load. Still another,
known as Myers*
Elevator^ is shown
in fig. 197, in its

Myers' Hay Elevator. position Avhen lift-

ing the hay, and fig. 198, when dropping it. The head is
iron, and it is a strong and simple fork.

DOUBLE FORKS.

The double forks clasp the load of hay like the claws of
a bird. This class Fig. 199.

of forks may be
used for pitching
over a beam, with-
out a board facing.
They are better
adapted to pitch-
ing short straw,
especially those
w^hich like Ray- ,
mond's,have sever-
al teeth; but more
time is required for
thrusting in the
two forks than one.
One of the simplest is Beardsley's Hay Elevator, (fig. 199)
8*

•178

MECHANICS.

which sufficiently explains itself.

Fiff. 200.

nay7nond's Fori;.

77iond^s Elevator^ made by J. II.
Y., consists of two three-pronged
forks, connected together by a
hinge, (fig. 200) and is one of the
best double forks. Connected
with this fork is a ready con-
trivance for attaching it, in a
moment, to any rafter or beam.
The accompanying figure (fig.
201) represents the clamp by
which this attachment is effected,
and fig. 200 shows the elevator,
secured in position from two
points, with the forks opened,
Avhen dropping their load. It is
raised and lowered by the double'
ropes 2>assing over the two fixed
pulleys, and the one on the
elevator — the horse moving twice
as fast as the load is raised.
Thus attached to two beams, the

The *' Little Giant"
Fork resembles the
claws of a bird, and
has a fluted, tubu-
lar, cast head, the
single grasping-
tooth being double-
jointed, and per-
mitting it to enter
the grain freely.
On the movement
of the horse, it is
brought to its
place, grasping its
load firmly. JRay-
Chapman, Clayvillc, IST.

Fig. 201.

Grappling Irons and Jloisiing
Taskle.

load may be run hori-

HARPOOX FORKS.

179

zontally, as well as raised vertically, as more fully ex-
plained under the head of Stacking. By the single fasten-
"^g> (fig* 201) the fork is only raised vertically.

HAEPOON FORKS.

For pitching hay exclusively, or any material which
hangs well together, the harpoon forks do their work
more rapidly than any other, but they are not adapted to

Fig. 205.
Fig. 204.

Fig. 202,

Walker's Harjyoon Fork. Sprout's Fork.

short straw. Walker's harpoon, made by Wheeler,Melick
& Co., Albany, is a straight bar of metal, appearing al-
most as simple as a crow-bar, (fig. 202. Its point is driven
into the hay as far as desired, when a movement at the han-
dle is made, which turns up the point at right angles, (fig.
203,) enabling it to lift a large quantity of hay. A modifica-
tion has spurs, which are thrown out on opposite sides.
The combined fork and knife invented by Kniffen & Hai>

180 MECHANICS.

rington, of Worcester, Mass., is an excellent hay-knife,
when folded, as in fig. 205, and an efficient elevator, when
opened, as in fig. 204. It is well adapted to the use of
farmers who have nothing but hay to pitch, and plenty of
room for the elevator to swing in. At the Auburn trial,
this fork discharged a load of hay weighing twenty-three
hundred pounds, over a beam, in two minutes.

The prices of horse-forks, of different kinds, vary from
$10 to $20.

HAY CARRIERS.

An inconvenience results from the fixed position of a
hay-fork, preventing the hay from being distributed over
different parts of a broad bay, except so far as it may be
swung to the right or left, and the load dropped at a sig-
nal Several hands are sometimes required to spread this
hay evenly, as it is rapidly discharged by the horse-fork.
Another disadvantage is, the required narrowness of the
bay, which cannot well be more than twenty or twenty-
five feet wide. These objections are obviated, and the
hay carried fifty or a hundred feet horizontally, by means
of HicJc's Elevator and Carrier^ of which the following
clear and full description is given in the Report of the
Auburn Trial of Implements : — " It consists of a track,
made of 2 by 5-inch plank, fastened to the rafters a few
inches below the ridge of the barn by l|-inch square
strips and twelve-penny nails. Upon this track runs a
car ; a rope passes through it, and through a catch pulley
attached to a horse hay-fork, then back to the car ; the
other end passes back to the end of the barn, and returns
through pulley wheels to the bam floor, to which end a
horse is attached.

By a peculiar arrangement of the car, it is held in posi-
tion on the track, over the load to be unloaded, until a
forkful of hay is elevated to it, when it is liberated from

HAY CAKEIERS. 181

its position, and the fork made fast to the car in one oper-
ation, then it moves off on the track very easily, and any
distance you may choose to have it carried ; the operator,
by pulling a cord, trips the fork, and the horse, turning
around, walks or trots back to the place of starting ; the
car is pulled back to its jDosition by the trip cord, when
the fork descends for another load.

The fork comes back so easily and quickly that the
horse can be kept in motion continually, elevating from
300 to 400 pounds of hay, and carrying it forty to fifty
feet in a horizontal direction, and returning for another
load in less than a minute.

Its advantages over the old mode are :

1st. — The hay can be carried into the second, third, and
fourth bays from the wagon, as easily as into the first,
thus saving a large amount of labor in the mows.

2d. — The hay is elevated perpendicularly from the load,
thus obviating the friction caused by dragging the forkful
of hay over and against the beam ; also the danger of
tripping or breaking the fork as it is drawn over the beam.

Sd. — The car and fork return so easily, the fork drop-
ping in the middle of the load, ready to be thrust into the
hay immediately ; whereas, in the old method, it is very
hard work to get the fork back, if the hay has been car-
ried any distance.

Ath. — The horse turns around, and walks or trots back
to the place of starting, instead of backing, thus saving
much labor to both horse and driver.

5th. — The hay need be elevated only high enough to
clear the highest beam, when it can be carried horizon-
tally, until the mows are more than half full, when, by
shortening a rope, the fork can be made to pass along
only sixteen inches below the very peak of the barn.

6th. — It requires but very little force to carry the hay
horizontally, whereas, by the old methods, it requires
more force to carry it horizontally than to elevate it.

182 MECHANICS.

7^A. — By extending the track four feet beyond t'he end
of the building, hay can be elevated and carried into
long, low hovels, or cow barns, when no other arrange-
ment would work at all.

The car is small, and the track light and simple ; a
weight has been lifted of 1,080 pounds by it at one time,
with a i^air of mules."

By using a strong car, it may be employed for unload-
ing coal from a boat.

BuiLDixG Stacks. — Three long poles may be used for
this purpose, securely chained at the top, and spread in
the form of a tripod. The one to which the lower pulley
is attaclied should be set firmly into the ground, to pre-
vent displacement by the outward draught. Holes are
bored into the poles at convenient distances, and cross
Fi'^. 206. pieces secured to them, for holding

the board slide, and permitting it
to be gradually raised, as the stack
goes up. The hay may be pitched
from the ground as well as from a
load, without inconvenience, to any
height.

Instead of chaining the poles to-
gether, they may be firmly secured
by using two stout clevises, the
bolts of which are passed through

Mo^ of Couvlir^ themes. ^ j^^j ^^^^ ^^^ ^^^^

of the poles, (fig. 206).

Palmer's Hay Stacker, represented in fig. 207, has
been much used at the West, where large quantities of
hay are deposited out of doors. It first elevates the hay,
and then swings it around over the stack, dropping it
where desired. It does not drag the hay against the
side of the stack, requires no staking down to prevent
tipping, and is easily drawn on the sills as runners, to any
part of the farm. The horizontal motion of the crane is

PALMER'S HAT STACKER.

183

Fi-. 207.

effected as follows : — Two ropes are attached to the wbiffle-
tree, one, a strong one, to elevate the hay, running on the
pulleys at B, C, and D ; and the other, a smaller one, pass-
ing the swivel pulley at A, on the
end of the lever _S, extending frorj.
the foot of the upright shaft. This
cord then passes up and over a
pulley above the weight M The
weight is about four pounds, and is
attached to the end of the smaller
cord. At the same time that the
horse, in drawing, elevates the fork
with its load of hay, the weight
JEJ is raised until it strikes the pul-
ley, when the power
of the horse becomes
applied to the end of
the lever B, causing
it to revolve, and

swing the hay over ^^ -^^'^=^'=^'^^^tim^

the stack. As the Palmer's my stacker.

horse backs, the weight drops again to the ground,
taking up the slack rope from under the horse's feet, and
the weight of the fork causes the arm of the derrick to
revolve back over the load. The intended height for
raising the hay, before swinging, is regulated by length-
ening or shortening the smaller cord, as the arm will not
revolve until the weight strikes the pulley under the
head block. T. G. & M. W. Palmer, of Chicago, OAvn
this invention, and furnish the smaller parts of the ma-
chine, the heavier being easily made on the farms where
intended to be used. *

Fig. 208 shows the manner in which Eaymond's Ele-
vator is mounted for stack building. These poles need
not be so heavy as when three poles alone are used. They
are kept from being drawn over towards each other in

184 MECHANICS.

elevating heavy leads, by lashing the lower end of each
outer pole to a strong stake, driven into the ground
obliquely, by first making a hole with a crow-bar. It is
convenient to place the two pole tripods sufficiently dis-
tant from each other to give room for the stack, or rick,

Fig. 208.

ForTi on Poles for Building Stacks.

and to allow the wagon to pass within them. The eleva-
tor first lifts its load, and then carries it along the rope,
till the man on the load drops it by a jerk of the cord.
This apparatus is made by J. H. Chapman, of Clayville,
K Y.

HAY PRESSES.

Among the best Hay Presses in the country is the one
manufactured by L. & P. K. Dederick, Albany, and rep-
resented in the annexed engraving. It is worked by one
or two horses, operating with great force by means of
the arms on each side, which are connected with toggle-
joint levers, explained in .a former part of this work. The
hay is thrown in from the upper platform, and when re-
duced to compact bales, by means of the powerful force
which this press gives, is taken out at the lower. In order
to prevent the necessity of the horses running back at

dederick's hay press.

Fi<r. 200.

186

Dederick^s Hay Press.

the pressure of every bale, Dederick's patent capstan (fig.

210) is employed with this press. ^J"- 210.

The horse or horses, in passing

around, wind up the rope on a

horizontal wheel or drum. The

possibility of any accident by

slipping backwards is prevented

by the pawl or anchor, -E', at the ^^^.

end of the lever, When the ^'^

186 MECHANICS.

pressure is completed, the driver touclies the upright rod,
and detaches the wheel or drum, by which the rope is
drawn backwards, without stopping the horses, which,
continue to walk around the circle. 1

This capstan answers an admirable purpose in using]
the common horse hay-fork, by obviating the necessity of
backing up at every forkful.

The New York Beater Press Company, of Little Falls,
manufacture a press, working like a pile engine, and re-
ducing the hay to a degree of compactness nearly equal
to that of solid wood. These bales are well adapted to
long conveyance by land or shipment to foreign ports.

Hay Loaders. — Several of these, of different construc-
tion, have been tried to a limited extent, but, so far, the
experiments have been but partially successful, or the
machines have not proved themselves fully adapted to
general use. Their expense, when compared with the horse-
fork, and, to some degree, their cumbersome character,
have proved objections. They mostly require very smooth
meadows, are often difficult to work in the wind, and
those constructed on the endless-rake principle are found
to carry up small stones or gravel into barley, endangering
the thrashing machine. Further ingenuity and labor on
the part of inventors appear to be required, to place them
generally within the reach of farmers.

CHAPTER XIIL

THRASHING, GRINDING, AND PREPARING PRODUCTS.
THRASHING MACHINES.

The old mode of beating out grain with the hand flail,
(fig. 211,) has now nearly passed away, and thrashing
machines liave come into general use.

VALUE OF THRASHIXG MACIIIXES. 187

S. E. Todd makes the following statement relative to
the saving of labor effected by these machines : " I have
thrashed a great deal of grain of all kinds, with my own
Fig. 211 _^^ flail; and I have talked with

others who have been accustomed
to thrash their grain with flails,
and I have come to the conclusion
thr.t the following figures rep-
resent a fair average as to the
quantity of grain that an ordinary
laborer will be able to thrash and
clean in a day, viz. : Seven bushels
An Old Flail. ' o^ wheat, eighteen bushels of oats,
fifteen bushels of barley, eight bushels of rye, and twenty
bushels of buckwheat. In order to make this more intelligi-
ble, it Avill be necessary to double the number of bushels
that one man is able to thrash, as two men will be requir-
ed to clean the grain with a fanning mill.

"In order to labor economically and advantageously
with a thrashing machine, two horses, at least, and three
men are necessary. In most instances four or five men
w^ill be required, which will make a force equal to fifteen
men with flails. Such a gang of hands, and two good
horses, with such a thrasher and cleaner as Harder's, are
capable of thrashing and cleaning of the same kind of
grain to which allusion has been made, one hundred and
seventy bushels of wheat, three hundred and twenty-five
of oats, two hundred and twenty of barley, one hundred
and. eighty of rye, and two hundred and sixty of buck-
wheat. Some manufacturers of thrashing machines fix
the average day's work higher than these figures. In
some instances, I will acknowledge that a span of horses
and five men can do much more than the amount repre-
sented by the foregoing figures ; yet I am satisfied that in
the majority of instances they will not thrash and clean a
greater number of bushels than I have indicated. But,

188

MECHAXICS.

even at the low figures that I have recorded, such a ma-
chine as Ilarder's, or Palmer's Climax, or Wheeler, Melick
& Co.'s, will he found to be a great labor-saving machine
for thrashing all kinds of grain.

" There is one consideration that should not be over-
looked, in this estimate, which is the much greater amount
of labor performed, with far less fatigue. When one la-
borer can perform the work of two or more workmen with
less fatigue than has usually been required, a great point
is gained."

J. Stanton Gould, estimating from a large number of
statements that a saving of five per cent of the grain is
effected by using the machine, over thrashing by the flail,
computes the aggregate annual saving in the United. States
to be over eight million bushels of wheat, two million
of rye. eight million of oats, and. nearly a million of barley.

For farms of moderate size, the eyidless-chain powers
for driving thrashing machines are most convenient, being

Ficr. 212.

Endless-chain horse-power, driving a thrashing-machine.

compact or requiring but little room, easily conveyed from
one place to another, and readily applicable to sawing
wood, cutting straw, and to various other purposes. Fig.
212 represents a single horse-power, driving a small thrash-
ing machine, with a simple, horizontal separator and straw

TO MEASURE ENDLESS CHAIN POWER. 189

carrier; and fig. 213 shows a two-horse power, (Emery's,)
with the wheel-v^ork on which the en dless^ platform runs.
The power of these machines, and the amount of fric-
tion in running them, may be easily ascertained by the
rule, already given in a former part of this work, for de-
termining the power of the inclined plane ; for the only

Fis. 213.

Two-horse Tread Power.

difference between the endless chain and a common in-
clined plane is, that in one the plane is fixed, and the body
moves np its surface, and in the other the plane itself
moves downward, and the weight or animal upon it re-
mains stationary. The same principle applies in both cases.

First, to ascertain the friction, let the platform be placed
on a level, with the horse upon it ; then gradually raise
the end until the weight of the horse will just give it mo-
tion. This will show the precise amount of tlie friction ;
for if the end be elevated one-twentieth of its length,
then the friction is one-twentieth the w^eight of the horse
and platform.

Secondly, to determine the power, when the end is still
further raised, measure the difference between the height
thus given and the length of the platform. If, for in-
stance, the height of the inclination is one-eighth of its
length, and the horse is found to weigh eight hundred
pounds, then the power is one hundred pounds, or one-
eighth the weight of the horse.

190

MECHANICS.

Fisf. 214.

This rule will not, however, apply, when the draught
of the horse is added to its weight; for it usually happens
that the weight alone is not sufficient, without placing the
platform in too steep a position for the horse to work
comfortably. He is, therefore, attached to a whiffle-tree,
and to ascertain the joower requires the use of the dyna-
mometer, in connection with tlie preceding mode.

Great improvement has been made of late years in

the appendages of
thrashing machines.
The large number
of laborers formerly
employed in raking
and separating the
straw, and placing it
on the stack, is now
dispensed with, and
the whole done by
machinery, working
by the same power
that drives the
thrasher. Among the best and most widely known ma-
chinery for this purpose is that invented by H. A. Pitts,
and represented in a portable form by fig. 214. It sepa-
rates the grain, cleans it, and carries the straw by means
of the elevator, (shown folded in the cut,) to the top of
the highest stack.

The tread-power is successfully applied to churning, as
chown in the cut, (fig. 215.) The employment of a sheep,
of one of the larger breeds, has been found better and
more convenient than a dog, as it is heavier, more quiet,
less averse to the labor, and when the task is done, it is
turned into the yard or pasture, where it is readily found
next time.

The cost of horse-powers and thrashers combined, of
the different forms, varies from 8225 to $400.

Pitts' Thrasher and Straw Carrier.

CORN SHELLERS.
Fis. 215.

191

Churn worked bjj dog-poiver.

Corn Siiellers are made for both hand and horse-
power. One of the most convenient and compact hand
machines is JBurralVs, made of iron, furnished with a fly-
wheel to equalize Fi<x. 21G
velocity, and v/orked
by one person while
another feeds it, one
ear at a time. Or, one
person alone will turn
it mth one hand, while
the ears are dropped
in with the other.
Several other good
corn shellers are made
mostly of wood.

Fig. 217 represents
a sheller, mostly of
cast iron, driven by
horses, by means of
the band partly seen in the cut. The corn in the ear is
thrown into the hopper at one end, and is separated from

BurralTs Cahi SheUer.

192

MECHANICS.

the cob by rows of teeth revolving in a concave bed and

Fig. 217.

and ejecting

norse-power Com Sheller.
set spirally, thus carrying the cobs alon
them from the opposite end.

For shelling corn in large quantities, powerful machines
driven by horses or steam are required. An excellent
sheller for this i3urposo is made by Ulchards, of Chicago.
The corn is shoveled directly from the wagon or crib in-
to the hopper, and requires no extra feeders, or hands,
to keep the machine from choking. It is built wholly
Fig. 218. of iron, combining

strength and dura-
bility. The shellers
are made of different
sizes requiring from
two to twelve horse-
power. The former
will shell one bushel,
HicTiards' Corn SMUer. and the latter ten

bushels per minute. The cost varies from $175 to $475.
The following is a description of the vforking part.

The shelling cylinder is made of heavy rods of wrought
iron, placed equidistant, presenting a corrugated surface,
which cannot v/ear smooth. Within this, a revolving iron

eichard's corn siiellee. 19a

cylinder, with chilled teeth, thrashes the corn against the
surfaces of the rod cylinder. The teeth approach the
rods sufficiently close to keep every ear in rapid motion,
shelling one ear or one bushel with the same facility. A
regulator at the discharge end places the machine within
control of the operator. The spaces between the rods
allow the shelled corn to escape freely, thus lessening the
draught, relieving the cylinder from clogging and from all
liability to cut or grind the grain.

The cleaner consists of a cylindrical screen revolving
around the Avhole length of the sheller, and extending be-
yond it. A heavy fan blast passes directly through this
screen, and under it, subjecting the corn to two separate
cleanings, and delivering it in good condition for market.
The cleaned corn discharges upon either side desired, and
the cobs arc delivered with the dust at the end of the ma-
chine.

archimedea:n^ root-washer.

The spiral principle has been successfully applied in the
Archimedean BooUoasher^ (fig. 219.) The roots to be

Fig. 210.

CroskilVs Archimedean Root-washer.

washed are first delivered into a hopper, from which they
9

194

MECHANICS.

pass into an inclined cylinder made of strips of wood with
grate-like openings. The cylinder has two portions sepa-
rated by a partition, in the first of which they remain
while the handle is turned for washing them. As soon as
the washing is finished, the motion of the handle is re-
versed, which throws them into the other part, which has
a spiral partition, along which they pass until they drop
into a spout outside.

BOOT SLICERS.

These are mostly worked by hand. Out of a large
number of inventions for this purpose, two are here rep-
resented ; — Wellington's, made of iron, the knives being

Fi- 2-21.

Fip:. 220,

Wellington's Boot Cutter. Hoot Cutter of }\vod.

on a revolving cone within the hopper, and shown below
•the machine ; the other of wood, with the knives on the
face of an iron wheel, which forms one side of the hopper.
These two machines will cut roots at the rate of about a
bushel per minute.

TAHIOUS KINDS OP rAE:ir MILLS.

193

FAEM MILLS.

These are made of iron, and with bnrr-stones. The

former are cheaper, and answer a good purpose for grind-
ing feed for domestic animals. The latter may be also

used for grinding flour.

Figure 222 represents an iron farm mill manufactured

by R. H. Allen & Co., of New York. The grinding sur-
faces are of chilled iron,

so arranged as to be

self-sharpening, and to

last a long time without

repairs. When necessary,

new plates are readily

inserted. The mill is

driven by horse or other

power, the band from

which is seen in the cut.

It will grind from five to

ten bushels per hour,

varying with the fineness

of the meal and the

amount of driving pow- Allen's Horse MUl.

cr. A two-horse railway power may be used to advantage,
pj^ ^.^3 This mill is about three feet

square, four feet high, and
weighs three hundred pounds.
Several other iron mills of a
similar character are made by
difierent manufacturers, and
usually cost about $50.

Among the burr-stone farm
mills, one of the best, most
compact, and most substan-
tial, is JFor8ma?i's, of Chicago,

represented by fig. 223. It will be perceived from this

Forsmari's MUl.

19G

MECHANICS.

figure that tlie spindle is horizontal, and the face of the
stones vertical. The frame is of iron. The diameters of
the stones vary from sixteen to thirty inches, and the
weight from 400 to 1,500 lbs. The smaller size may be
run with a j^ower of one to four horses ; the larger, with
that of ten to thirty horses. Prices $150 to $375. The
manufacturers claim that it will grind from one and a
lialf to three bushels per hour, for each horse-power used
in driving it.

THE COTTON GIN.

Since the invention of the Cotton Gin by Eli "Whitney,
great improvements have been made, by which the cotton
is cleaned with great rapidity and in a perfect manner.

Fig. 2^.

Emertjs Cotton Gin—Sectwn.

The machine manufactured by II. L. Emery, of Albany,
is one of the best for this purpose. It is represented in
section in fig. 224. The hopper, at the right, is furnished
with what is termed a Ficker Boll Svpporte)\ which re-
volves within the hopper, in the direction shown by the
arrow, and prevents the cotton from becoming packed. It

emery's COTTOX GIN'.

197

is then taken by the teeth of the saw cylinder, which re-
duce the cotton to a fine condition. These teeth are
swept by the brush cylinder, which, running in the same
direction with the teeth, and slightly faster, carries the
cotton off from them. Fig. 225 represents the operation,
the seed escaping from the bottom of the hopper and the

Fijr. 225.

Emery's Cotton Gin, with Condenser.
cotton thrown to the rear into the condenser, which fin-
ishes the cleaning process and packs or condenses the lint
cotton within a limited space. The arrows shown in the
section indicate the direction of the revolutions of the
picker, saws, and brush cylinder, and also the course
which the cotton takes in passing through the gin and
condenser.

PART H.

MACHINERY IN CONNECTION WITH WATER.

GENERAL PRINCIPLES.

Hydrostatics * treats of the weight and pressure of
liquids when not in motion ; HYDRAFLics,f of liquids in
motion, as, conducting water through pipes, raising it by-
pumps, etc. ; and Hydrodyxamics J includes both, by-
treating of thefoi'ces of the liquids, whether at rest or in
motion.

CHAPTER I.

HYDROSTATICS.
UPWARD PRESSURE.

A remarkable property of liquids is their pressure in
all directions. If wo place a solid body, as a stone, in a
vessel, its weight will only press upon the bottom; but if
we pour in water, the water will not only press upon the
bottom, but against the sides. For, bore a hole in the
side, and the side pressure will drive out the water in a
stream ; or bore small holes in the sides and bottom of
a tight wooden box, stopping them with plugs ; then press
this box, empty, bottom downward, into water, allowing
none to run in at th6 top. Now draw one of the side
plugs, and the water will be immediately driven into the

* From two Greek words, hudor^ water, and statos^ standing, or at rest,
t From two Greek words, hudoi\ water, and auloa^ a pipe.
X From two Greek words, hiidor, water, dunamis, power.
198

UPWARD PEESSUKE OF LIQUIDS. 199

box by the pressure outside. If a bottom plug be drawn,
the water will immediately spout up into the box, show-
ing the pressure upward against th.e bottom. Hgnce the
pressure in all directions^ upward, sideways, and down-
ward, is proved.

The upward pressure of liquids may be shown by pour-
ing into one end of a tube, bent in the shape of the letter
U, enough water to partly fill it ; the upward pressure will
drive the water up the other side until the two sides are
level.

On this principle depends the art of conveying water
in pipes under ground, across valleys. The water will
rise as high on the opposite side the valley as the spring
which supplies it. The ancient Romans, who were unac-
quainted with the manufacture of strong cast-iron pipes,
conveyed water on lofty aqueducts of costly masonry,
built level across the valleys. Even at the present day,
it has been deemed safest to build level aqueducts for con-
veying great bodies of water, as in very large pipes the
*j)ressure would be enormous, and might result in violent
explosions.

If the valleys are deep, the pipes must be correspond-
ingly strong, because, the higher the head of water, the
greater is the pressure. For the same reason, dams and
large cisterns should be strongest at bottom. Reservoirs
made in the form of large tubs require the lower hoops to
be many times stronger or more numerous than the upper.

MEASUEEMENT OF PRESSURE AT DIFFERENT HEIGHTS.

The amount of pressure which any given height of wa-
ter exerts upon a surface below may be understood by
the following simple calculation :

If there be a tube one inch square (with a closed end),
half a pound of water poured into it will fill it to a height

200 MACHINERY IX COXNECTION WITH WATER.

of fourteen inches ;'^ one pound will fill it twenty-eight
Fig. 226. inches ; two pounds, fifty-six inches ;

^ibs. 56 in. ten pounds, twenty-three feet ; twenty
pounds, forty-six feet, and so on.
Now, as the side pressure is the same
as the pressure downward for the
i)iibs.j.2in. same head of water, the same column
will, of course, exert an equal pressure
on a square inch of the side of the
tube. Or, if the tube be bent, as
lib 28 ill. shown in the annexed figure (fig.

2:26), the pressure upward on the end
of the tube, at a, will be the same for
the various heights.
1/2 lb. 14 In. Now, as the pressure of a column

fifty feet high is about twenty-two
pounds on a square inch, the pressure
on the four sides is equal to eighty-
eight pounds for one inch in length.
Plence the reason that considerable
strength is required in tubes which
have much head of water, to prevent their being torn
open by its force.

DETERMINING THE STRENGTH OF PIPES.

The question may now arise, and it is a very important
one. How thick must be a lead tube of this size to prevent
danger of bursting with a head of fifty feet, or of any
other height? To answer it, let us turn to the table of
Ihe Strength of Materials in a former part of this work,
where we find that a bar of cast lead one-fourth of an
inch square will bear a weight of fifty-five pounds. If the

* This is nearly correct, for a cubic foot (or 1,738 cubic inches) of
water weiglis 63 lbs. Consequently, one pound will be 37.9 cubic inch-
es, and will fill the tube nearly 38 inches high.

CALCULATING THE STKEXGTH OF TUBES. 201

tube be only one-sixteenth of an inch thick, one inch of
one of its sides will possess an equal strength, that is,
will bear fifty-five pounds only, and the tube would conse-
quently burst with fifty feet head. If one-tenth of an
inch thick, the tube would just bear the j^ressure, and, to
be safe, should be about twice as thick, or one-fifth of an
inch. Half this thickness would be sufficient for twenty-
five feet of water, and would require to be doubled for
one hundred feet. A round tube, one inch in diameter,
having less surface to its sides, would be about one-third
stronger. A tube twice the diameter would need twice
the thickness ; or if less in diameter, a proportionate de-
crease in thickness might take place. If, instead of cast
lead, milled lead were used, the tube would be nearly four
times as strong, according to the table of the strength of
materials already referred to.

SPRINGS AXD ARTESIAX WELLS

result from the upward pressure of water. Rocks are
usually arranged in inclined layers (fig. 227), and when

Fig. 227.

d
h ^

rain falls upon the surface, as at c d, it sinks down in the
more porous parts between these layers, to c. If the lay-
ers happen to be broken in any place below, the water
finds its way up through the crevices by the pressure of
the head above, and forms springs. If there are no open-
ings through the rocks, deep borings are sometimes made
9*

202

MACHINERY IX COIfNECTIOX "WITH WATER.

artificially, through which the water is driven up to the
surface, as at a, forming what are termed Artesian Wells.
The head of water which supplies them may be many
miles distant, the place of discharge being on a lower
level. It has sometimes been found necessary to bore
more than a thousand feet downward before obtaining
water which ^vill flow out freely at the surface of the earth.

DETERMINIXG THE PRESSURE OX GIVEN SURFACES.

The pressure of liquids upon any given sui-face is always
exactly in proportion to the height, no matter what the
shape of the vessel may be. If,
for instance, the vessel a (fig.
228), be one inch in diameter,
and the vessel b be three inches
in diameter, the water being
equally high in both, the press-
ure on the whole bottom of b
will be nine times as great as on
the bottom of a ; or any one inch of the bottom of b will
receive as great a pressure as the bottom of cf. Again, if
the vessel c, broad at the top, be narrowed to only an
inch in diameter at bottom, the press-
ure upon that inch will still be the
same, most of the weight of its con-
tents resting ligainst the sides, d d.
If the vessel, A (fig. 229), be filled
with water to a height of fourteen
inches, the pressure will be half a
l^ound on every square inch of the
bottom, or upon every square inch
of the sides fourteen inches below the surface. If the
tube, C, be an inch square, the water will be driven into
it with a force of half a pound, and will press with that
force iigainst the one-inch surface of the stop-cock, C. If

Fiff. 229.

A PUZZLE EXPLAINED.

203

the tube, B, be noTV filled to an equal height, the same
force will be exerted against the other side. To prove
this, let the stop-cock be opened, when the two columns
of water will remain at an exact level.

If enough water be now j^oured into the tube, B, to fill
it to the top, it will immediately settle down on a level
with the water in A, raising the whole surface in the lat-
ter. This result has seemed strange to many, who can
not conceive how a small column of water can be made to
balance a large one, and it has been therefore termed the
Hydrostatic Paradox. But the difficulty entirely vanish-
es, and ceases to appear a paradox, when we remember
that the water in the larger vessel rises as much more
slowly than it descends in the smaller, as the large one
exceeds the smaller ; thus acting on the principle of vir-
tual velocities in precisely the same manner that a heavy
weight on the short end of a lever is upheld by a small
Aveight on the long end. The great mass of water is sup-
l^orted directly by the bottom of A, in the same way that
nearly all the weight on the lever is supported by the
fulcrum. A man who was seeking a solu-
tion to the absurd mechanical problem of
perpetual motion, and who supposed that
the large mass in A would overbalance the
small column in B, and drive it upward,
constructed a vessel in the form shown in
fig. 230, so that the small column, when
forced upward, "vvould flow back into the
larger vessel perpetually. He was, how-
ever, greatly surprised to see the fluid in
both divisions settle at the same level.

This principle may bo further explained by the following
experiment : AB (fig.231) represents the inside of a metallic
vessel, with a bottom, C, which sUdes up and down, water-
tight. If water be poured in to fill the lower or larger
part only, it will be found to press on the sliding bottom

Attempted Perpetual
Motion.

204

MACHINERY IN CONNECTION AVITH WATER.

Fig. 231.

A

B

H

B

^

B^=

IIIIF^ -"^iirniiiii 1

r

. u

r

with a force exactly equal to its own weight ; that is, if
there is a pound of water, it will press on the bottom with
a force equal to one pound. Now, if the bottom be pushed
upward, so as to drive the water into the
narrow part of the vessel, the pressure upon
the bottom becomes instantly much greater,
or equal to many pounds, the water being
the same in quantity, but with a much
higher head than before. Suppose the nar-
row part of the vessel is twenty times
smaller than the larger part, then, in pushing
the bottom up one inch, the water is driven
twenty inches upward in the tube. So then,
according to the rule of virtual velocities, it will require
twenty times the force, because it moves upward twenty
times faster.* This, then, is precisely similar to the in-
stance where a pound on the longer end of a steelyard
balances twenty pounds on the shorter ng. 032.

end. In this instance, the upper parts,
D D, of the vessel operate as the fulcrum
of a lever, and offer resistance to the slid-
ing part as soon as the water begins to
ascend the tube.

HYDROSTATIC BELLOWS.

This principle is shown in the Sy-
drcstatic Bellows (fig. 232), which con-
sists of two round pieces of board. Hydrostatic Bellows.

connected by a narrow strip of strong leather ; into it is
inserted a long, narrow tube, B, with a small funnel, e, at
the top. When water is poured into this tube, it will
raise a weight as much greater than the weight of the

W'

* The pressure will be as great upon the bottom as if the vessel con-
tinued a uuifurm size all the way up.

HYDROSTATIC PRESS. 205

water in the tube as the surface of the upper board ex-
ceeds the cross-section of the tube. Thus, if a pound of
water fills a tube half an inch in diameter, and the bellows
are two feet in diameter, then this pound will raise more
than two thousand pounds on the bellows (if it be strong
enough), because the surface of the bellows is more than
two thousand times greater.

In the same way, a strong, iron-bound hogshead may-
be burst with the weight of a single gallon of water by
pouring it into a long and narrow tube set upright in
the bung of the filled hogshead. If, for instance, the inner
surface of the hogshead be 20 square feet, or 2,880 square
inches, a tube of water 23 feet high will press with a force
of 10 pounds on every square inch, or equal to a force of
28,800 pounds, or 14 tons, on the whole surface.

HYDROSTATIC PRESS.

The Hydrostatic Press owes its extraordinary power to
a similar principle ; but, instead of a bellows, there is a
moving piston in a strong metallic cylinder; and instead
of being worked by the mere weight of the water, it is
driven into the cylinder by means of the lever of a pow-
erful forcing-pump. An instrument of this sort, possess-
ing enormous power, was used to elevate the great tubular
iron bridge in England. It was found necessary to make
the sides of the cylinder into which the water was driven
no less than eleven inches thick, of solid iron ; and so
great was the pressure given to the confined water, as
to have forced it up through a tube higher than the
summit of Mont Blanc. I'n the port of New York, ves-
sels of a thousand tons' burden have been lifted by the
hydrostatic press.

This machine has been applied in compressing hay, cot-
ton, and other bulky substances into a compact form, so
that they may occupy but little space, for conveyance to

20G

MACHINERY IX COXNECTIOX WITH WATER.

distant markets. The following figure (fig. 233) exhibits
the different parts of this powerful machine. A is a cis-
tern to supply water, which is raised by working the han-
dle, B, of the forcing-pump ; the water passes through the
valve, C, opening upward, and through the spring valve,

Fis. 233.

Hydrostatic Press.

D, opening toward the large cylinder, E. Being thus
driven into the space, E, it raises the piston, F, and exerts
a prodigious pressure upon the mass of hay or cotton, G.
The piston is lowered by turning the screw, H, which al-
lows the water to pass back into the cistern at I. In the
figure the hay or cotton is shown as visible to the sight,
in order to represent the whole more plainly ; but in prac-
tice it is thrown into a square box or chamber of strong
plank, of the size of the intended bundle. One side is

HYDROSTATIC PRESS. 207

hung upon stout hinges, and is opened for the removal of
the bale when the pressing is completed.

To estimate the power of this machine, divide the
square of the diameter of the piston, F, by the square of
the diameter of the piston of the forcing-pump, and multi-
ply the quotient by the power of the lever, B. For ex-
ample, suppose the piston, F, is 16 inches in diameter, and
the piston of the forcing-pump is 2 inches in diameter.
The square of 16 is 256 ; divide this by 4, the square
of 2, and the resuU will be 64. If the lever, B, increases
the power five times, the whole power of the machine will
be 320 ; that is, a force of one pound applied to the lever
will raise the large piston with a force equal to 320 pounds ;
or, if a force of 100 pounds be given to the lever, the
power will be 32,000 pounds, or 16 tons. Reducing the
diameter of the smaller piston to half an inch, and in-
creasing the force of the lever to twenty times, the whole
power exerted will be thirty-two times as great, or equal
to 960 tons. In ordinary practice, it is more convenient
and economical to reduce the diameter of the larger piston
to a few inches only, making the forcing-pump correspond-
ingly small, the power depending entirely on the dispro-
portion between them. Such presses may be worked rap-
idly by horse, water, or steam power.

One great advantage which the hydrostatic press pos-
sesses over those worked by screws results from the little
friction among liquids, nearly the only friction existing in
the whole machine being that of the two pistons, which is
comparatively small. Another is the smallness of the
compass within which the whole is comprised ; for a man
might, with one not larger than a tea-pot, standing before
him on a table, cut through a thick bar of iron with as
much ease as he could chip pasteboard with a pair of
shears.

208

MACHINERY IJf CONNECTION WITH WATER.

SPECIFIC GRAVITIES.

Fig. 2;M.

In connection with Hydrostatics, the subject of the
specific gravities of bodies is one of importance. The
si)ecific gravity of a substance is its comparative iceight
with some other substance, an equal bulk of each being
taken. Water is usually the standard for comparison.

To ascertain the specific gravity, weigh the body both
in and out of water, and observe
the difference; then divide the
whole weight by this difference, and
the quotient will be the specific
gravity sought. For example, if a
stone weighs 12 lbs. out of water
and 7 lbs. in water, divide 12 by
5, and the quotient is 2.4, which
shows that the stone is 2*1,^ times
heavier than water. Figure 234
shows the mode of weighing the
body in water, by suspending it be-
neath a balance on a hair or thread.

It was in a similar way that Archimedes is said to have
succeeded in detecting the suspected fraud in the manu-
facture of the golden crown of the ancient king of Syra-

Instrument for taking Specific
Gravities.

cuse. He first

weighed

It, and then found that it dis-

placed more water when plunged in a vessel just filled,
than a piece of pure gold, and also that it displaced less
than silver, whence he inferred the mixture of these two
metals.

When the specific gravity of a substance lighter than
water is to be ascertained, it is loaded down by a weight,
so as to sink in water, for which allowance is made in the
calculation. A very simple way to determine this in dif-
ferent kinds of wood is to form them into rods or sticks
of uniform size throughout, and then to observe what
portion of them sink when placed endwise in water.

TABLE OF SPECIFIC GRAVITIES.

209

A knowledge of the specific gravities of various sub-
stances becomes useful in many ways, among which is
ascertaining the weight of any structure, machine, or im-
plement, by knowing that of the material used in its man-
ufacture; determining the cost, by the pound, of such
material ; or knowing the bulk or size of any load for a
team. The latter may often be of great use in ordinary
practice, by enabling the teamster to calculate beforehand
the amount of load to give his horses, whether in timber,
plank, brick, lime, sand, or iron, without first subjecting
them to overstraining exertions in consequence of error in
random guessing.

Tables of specific gravities, for this purpose, and weights
of a cubic foot of different substances, are here given.

TABLE OF SPECIFIC GRAVITIES.

Metals.

Gold, pure 19.36

" standard 17.16

Mercury 13.58

Lead 11.35

Silver. 10.50

Copper 8.83

Iron 7.78

" cast 7.20

Steel 7.82

Brass, common 7.83

Tin 7.29

Zinc 6.86

Stones aiLcL Eartlis.

Brick 1.90

Chalk 3.25 to 2.66

Clay 1.93

Coal, anthracite, about 1.53

Coal, bituminous 1.37

Charcoal 44

Earth, loose, about 1.50

Flint 3.58

Granite, about 2.65

Gypsum 1.87 to 3.17

Limestone 3.38 to 3.17

Lime, quick 80

Marble 2.56 to 2.69

Peat.. . » 60 to 1.33

Salt, common 2.13

Sand 1.80

Slate 3.67

Woods — dry.

Green wood often loses one-third of its weight by seasoning, and
Bometimcs more. The same kind varies in compactness with soil,
growth, exposure, and age of the trees.

210

MACIIINEKY IN CONNECTION WITH WATER.

Apple 68 to .79

Ash, %vliite 72 to .84

Beech 73 to .85

Box 91 to 1.32

Cherry 71

Cork 24

Ehn 58 to .67

Hickory 84 to 1.00

Maple 65 to .75

Pine, yellow 55 to .66

Oak, English 93 to 1.17

" white 85

" live 94 to 1.12

Poplar, Lombardy 40

Pear 66

Plum 78

Sassafras 48

Walnut 67

Pine, white 47 to .56 | Willow,

.58

Beeswax 96

Butter 94

Honey 1.45

Lard 94

Milk 1.03

Oil, linseed 94

Miscellaneous.

Oil, whale

" turpentine.

87

Sea water 1.02

Suffir. 1.60

Tallow 93

Viue^ar 1.01 to 1.08

WeigJits of a Cubic Foot of various Snbsiaiices^ from which the B^dk of a
Load of one Ton may be easily calculated.

Cast Iron 450 pounds.

Water 62

White pine, seasoned, about 30

White oak, " " 52

Loose earth, about 95

Common soil, compact, about 124

Clay, about 135

Clay with stones, about 160

Brick, about 125

Bulk of a Ton of different Substances.

23 cubic feet of sand, 18 cubic feet of earth, or 17 cubic feet of clay,
make a ton. 18 cubic feet of gravel or earth before digging make 27
cubic feet when dug; or the bulk is increased as three to two. There-
fore, in filling a drain two feet deep above the tile or stones, the earth
should be heaped up a foot above the surface, to settle even with it,
when the earth is shoveled loosely in. A cubic foot of solid half-rotted
manure weighs about 56 lbs., requiring about 36 cubic feet to the ton. If
coarse or dry, more will be required. Hay varies much in specific grav-
ity with the kind, and the degree of pressure in the bay or stack ; but
good timothy hay, under medium pressure, requires about 500 cubic
feet to the ton ; clover, variable,— about one-half more.

VELOCITY OF AVATEK. 211

CHAPTER IL

HYDRAULICS.
VELOCITY OP FALLING WATEK.

Liquids in motion are subject to the same laws as solids
in motion. Falling water increases in velocity at the
same rate that the motion of falling solids is accelerated,
as already explained under the head o^ Gravitation. Thus
a perpendicular stream of water descends one foot in a
quarter of a second, four feet in half a second, nine
feet in three-fourths of a second, and sixteen feet in one
second. Like falling solids, the velocity at the end of
the first quarter will be eiglit feet per second ; at the end
of tlie second quarter, sixteen feet ; at the end of the third
quarter, twenty-four feet ; and at the end of the fourth
quarter, thirty-two feet per second.

Xow, if there be an orifice made in the side of a vessel
of water, the water will spout out with the same swiftness
as if it fell perpendicularly from an equal height, were it
not retarded a little by friction. For example, if the
head of water is one foot above the orifice, the velocity
would be at the rate of eight feet per second, but for fric-
tion, which reduces it to about five and a half feet. The
velocity for any other height of head may be easily found
by deducting the same proportionate rate from the veloc-
ity of a falling body. Thus, for example, if the head be
sixteen feet, the speed would be thirty-two feet (as shown
under Grcivitation)^ from which, deducting the friction,
the real velocity would be about twenty-two feet per
second.

It has been already shown that the velocity of a falling
body increases at the same rate as the increase in the time
of falling ; for instance, the speed is twice as great in two
seconds as in one ; three times as great in three seconds ;

212

MACHINERY IN CONNECTION WITH -WATER.

four times as great in four seconds, and so on. But the
distance fallen through increases as the square of the time ;
that is, it is four times as great in two seconds, nine times
as great in three seconds, sixteen times as great in four
seconds, etc. Thus we see that, in order to produce a
twofold velocity, a fourfold height is necessary, etc. So
also in the escape of water under a head : to double the
velocity of the stream, the head must be four times as
high ; to triple it, the head must be nine times as high, etc.

DISCHARGE OF WATER THROUGH ORIFICES AND PIPES.

The discharge of "wuter from a vessel is greatly influ-
enced by the nature of the orifice through which it flows.
Fiff. 235. Fig. 236. Fig. 237. If, foT example, a

ail '*'iii _ .Hiiiiiii^^^^^ ^'' ^^'*^'^

have a thin bottom
of tin, with a
smooth, circular
hole, we might natu-
rally suppose that
the discharge would
be as easy as it
could be made, and
that water would
pass as rapidly
through it as
through any orifice
of an equal size. But this is not the fact.
As the particles approach this orifice, their
motion throws them across, and they
partly obstruct the opening ; it will be
seen that they converge toward a point
just under the orifice, where the stream will be consider-
ably contracted (Fig. 235). If a short tube be inserted
into the hole (the head being the same), this crossing of

DISCHARGE OF WATER THROUGH PIPES. 213

particles will be partly prevented, and the liquid will flow
more rapidlj^ The greatest effect is produced when the
tube is twice as long as its diameter (fig. 236). If the
tube be enlarged at its upper and lower end, similar to the
form of the contracted stream of water in fig. 237, the
quantity discharged is greatly increased.

When water flows down an inclined plane, the same law
applies as to the motion of a solid body rolling down a
plane. The velocity increases as the square of the distance,
and is the same as the velocity of a body falling freely
downward from a height equal to the perpendicular height
of the plane. Unless the stream, however, is very large,
its speed is quickly diminished by the friction of its chan-
nel,* until this friction becomes as great as the descending
force, after which the motion becomes uniform. Hence
the reason that large streams, with an equal degree of de-
scent, flow so much moVe rapidly than small ones, the
gravitating force being so much greater that friction has
a less retarding effect upon them. ^

In pipes which wholly surround the flowing stream, the
friction becomes still greater, and the difficulty is only ob-
viated by making the pipe of larger dimensions than
would otherwise be necessary, so as to allow a free passage
of a sufficient quantity of water through the centre of the
tube, while a ring or hollow cylinder of water is nearly at
rest all around it. The tables in the Appendix exhibit
this decreased velocity in tubes of various sizes.

Lead pipes, for conveying the water of springs under-
ground, should commonly be three-fourths of an inch in
diameter. Five-eighths will answer where the distance U
short and the descent considerable. But with a half-inch
pipe, the friction of the sides is so great, compared with
the small force of the current, that but little water will
flow through it.

* Which increases as the square of the velocity.

214 MACHINERY IN CONNECTION WITH WATER.

VELOCITY OF WATER IN DITCHES.

It is often of great practical utility to know what
amount of water may be carried off in draining, or sup-
plied in irrigation, by channels of any given size and
descent. The following rule will apply to all cases, from
the plow-furrow to the mill-race, or even to the large
river, and may be used by any boy who understands
common arithmetic, and which is illustrated and made
plain by the example that follows the rule.

To ascertain the mean [or average) velocity of water in
a straight channel of equal size throughout :

Let /*=the fall in two miles in inches ;

Let c?=the hydraulic mean depth ;

Let v==the velocity in inches per second ;
then the rule is thus expressed : • t'=0.91 V/c?, or, in plain
words, the velocity is equal to the hydraulic mean depth,
multiplied by the fall, with the square root of this prod-
uct extracted, and then multiplied by 0.91.

The " hydraulic mean depth " is found by dividing the
cross-section of the channel by the perimeter^ or border.
The perimeter is the aggregate breadths of the sides and
bottom of the channel.

The rule will be rendered quite plain by an example.
Suppose a smooth furrow is cut six inches wide and four
inches deep, with perpendicular sides, and that it descends
one inch in a rod ; to find the quantity of water that will
flow through it. One inch fall in a rod is 320 inches in a
mile, or 640 in two miles. The perimeter in contact with
the water will be six inches on the bottom and four
inches in each side = 14 inches. The area of the cross-
section will be six times 4 = 24, which, divided by 14,
the perimeter, gives 1.7 = the hydraulic mean depth.
Then, by applying the preceding rule:

tj=9.91 4/ 640 X 1.7, or v=0.91 x33=«30 inches, is the ve-

LEVELING IXSTEUMENTS. 215

locity per second, winch would be about three gallons jDcr
second, or three hogsheads per mmute.

An open ditch, therefore, with smooth sides, conveying
a stream of this size, would carry off, in one hour, from
an acre of land, all the water w^hich might fall by half an
inch of rain, during the wet season ; for half an inch of
rain would be one hundred and eighty hogsheads per
acre, which would pass off in one hour ; or it would sup-
ply in one hour, by the process of irrigation, as much
water as a heavy shower of half an inch. Where the
descent is greater, the increased quantity may be readily
calculated by the rule given. The capacity of smooth-
sided underground channels may be determined in the
same way ; but if built of rough stones, great allowance
must be made, as they will retard the flow of water.

In common practice, too, even with straight, open
ditches, the velocity will be much diminished by the
rough sides.

LEVELENG I^'STRUMENTS.

The simplest mode of leveling^ or ascertaining the slope
for ditches, is to cut a few yards of the ditch, so that wa-
ter may stand in it, and then to set two sticks perpendicu-
larly, both rising to an equal height above the surface.

Simjile Method cf Taking Levels.

The sticks should be measured at equal distances from
the top downward, and marked, and then pressed into
the earth, till the water reaches the mark. The level may
then be determined with much accuracy by " sighting "
over the tops of these sticks. Fig. 238 exhibits this ar-
rangement. The shorter the sticks, and the longer the
piece of water, the less will be the liability to ovror.

216

MACHINERY IN CONNECTION WITH WATED.

A leveling instrument for general use, sujficiently ac-
curate for all common purposes, may be made in the fol-
lowing manner : — Pro-
cure a mason's or car-
penter's spirit-level, {a,
fig. 239) fasten it to the
upper side of a straight
bar of wood, and on the
ends of this bar secure
small, upright pieces of
tin plate, b, b, having
openings cut in the
centre. Horizontally
across these openings,
draw very fine wire,
which shall be exactly
at equal heights above
each end of the bar of wood, to adjust which, one should
be capable of sliding, and be screwed or wedged to its
place at pleasure. The bar is placed on a common com-
pass stafi", as shown in Fig. 240.
the cut, turning at the
ball and socket, below
the spirit level. A tripod
(fig. 240) is better, if it
can be had. A small
spirit-level should be se-
cured across the bar, so
that it may be adjusted
both ways. When the
bar is made perfectly
level, as shown by the air-bubble, by sighting through at
the two wires, the levelness or descent of the land may be
determined.

To ascertain whether these threads are both of equal
heights above the bar, let a mark be made where they in-

ARCHIMEDEAN SCREW. , 217

tersect some distant object ; then reverse the instrument,
or turn it end for end., and observe whether the threads
cross the same mark. If they do, the instrument is cor-
rect ; but if they do not, then one of the sights must be
raised or lowered imtil it becomes so.

In laying out canals and rail-roads, where extreme ac-
curacy is needed, the spirit-level^ attached to a telescope,
is used. So great is the perfection of this instrument,
that separate lines of levels have been run with it for six-
ty miles, without varying two-thirds of an inch for the
whole distance.

The use of a cheap and simple instrument to determine
the position an.d descent of ditches with ease and preci-
sion, before commencing with the spade, will save a vast
amount of the trouble and expense which those often
meet with vrhose only method is to " cut and tri/.^^

HYDRAULIC MACHINES.

ARCHIMEDEAN SCREW.

Machines for raising water are of frequent use on every
farm. One of the simplest contrivances, in principle, for
this purpose, is the Screw of Archimedes. It may be

Fi?. 341.

The Screw of Archimedes

easily made by winding a lead tube around a wooden
cylinder or rod (fig. 241), in the form of a screw. Wl^en
10

218

MACniNERT IN CONNECTION WITH WATER.

placed in an inclined position, with one end in water, and
made to revolve, the water resting at the lower side of
each turn of the screw is gradually carried from one end
to the other, and discharged at the upper extremity. Its
simplicity and small liability to get out of order render
the Archimedean screw sometimes useful where water is
to be raised from an open stream to a short distance, as
for irrigation, the motion being easily imparted to it by
means of a small water-wheel, driven by the stream.

PUMPS.

Great improvement has been made in tlie common
Tig. ais. pump for farms within a few years.

The best cast-iron pumps, made
almost wholly of this .metal, ex-
ceed in durability and ease of
working those formerly con-
structed of wood, and excel others
in cheapness. Fig. 242 exhibits
the working of the common pump,
the water first passing through
the fixed valve below, and then
through the one in the piston ;
both opening upward, it cannot
flow back without instantly shut-
ting them. The water is driven
up by the pressure of the at-
mosphere, explained in the next
chapter.

Fig. 243 is an iron cistern pump,
showing the mode of bolting it to
the floor or platform, and rep-
resenting, also, its neat and com-
pact form, occupying but little

Common Pump : b, lower or fixed • i • xi.

valve, G, piston with valve, a, SpaCC at ODC SlClC, Or lU tnC COmcr
opening upward: H d, piston,' r> i •- ■» xi, • j.

rod; F, spout, of a kitchen, over the cistern.

PUMPS.

219

Fig. 244.

Fig. 244 represents a cistern or well pump, so constructed
that the working parts are about 20 inches below the plat-
form, or base of the pump, and it is therefore well adapt-
ed for outdoor work. If the well
or cistern is kept covered tight,
the i3ump will not freeze below
the platform. It will succeed
in any well not over twenty feet
deep, and by means of its
various couplings may be made to
draw water in a horizontal or in-
clined position, provided the whole
height is not much over twenty feet.

Fi-. 213.

Cistern Fiunp.

Non-freezing Ptxmp.

An excellent deep-well pump, made bj Cowing & Co.,
of Seneca Falls, N. Y., is represented by fig. 245 ; the
working part, being placed at the bottom of the well, is
adapted to any depth of water, the rod working safely
within the pipe. The lower part of the cylinder is fur-
nished with a strainer, and is plugged at the bottom, to

220 MACniXERY IX CONNECTION AVITII AVATER.

Fig. 246. Fig. 2-45.

Drive rajiip.

prevent the ingress of sand and
mud. The connecting pipe between
the cylinder at the bottom and the
standard at the top is wrought or
galvanized iron. The pump,
course, needs bracing, to prevent
swin^cino^ when worked.

Drive Pumps. — Fig. 246 rep-
resents the new mode of making
wells, by simply driving into the
earth common iron gas-pipe, pointed
at the lower end, and perforated at
the sides, near the lower extremity,

DRIVE PUMPS.

221

for tlie ingress of vrater — thus obviating entirely tlic cost
and labor of digging wells. If driven through a subter-
ranean spring, a stratum of water, or a wet layer of sand or
gravel, it is obvious that the Avater will immediately flov/
through the perforations into the pipe ; and, by attaching a
good pump to the pipe and pumping for a time, all the par-
ticles of sand and fine gravel will be drawn out ; and the
cavity thus formed around the perforations will remain filled
with pure water. These tubes and pumps are admirably
adapted to localities where large beds of wet gravel exist
fifteen or twenty-five feet below ; and, in fact, to all soils
where large stones are not abundant. Where these occur,
the pipe must be withdrawn, and tried in a new place,
until success is attained.

In the Chain Piimp^ a partial cross-section of which is

Fig. 247.

Fig. 248.

Section. Botary Pump, for Barrels, etc.

here shown, (fig. 247), the chain is made to revolve rapid-
ly on the angular wheel by means of a winch attached to

222

MACHINERY IN CONNECTIOX WITH WATEE.

the upper one, and being furnished with a regular succes-
^^s-249. sion of metallic discs, which

nearly fit the bore in the tube,
a, the water is carried up in
large quantities. When the
motion is discontinued, the
water settles down again into
the well, and consequently
this pumj) is not liable to-
accident by freezing. By
sweeping rapidly through the
water, it preserves it in better
condition, and prevents stag-
nation. The fi-iction being
very small, it will last a long
time without wearing out.

Rotary Pumps. — A succes-
sion of cavities made in the
exterior of a short cylinder
receive the water from the
pum2>tube below, and force
it away into the elevating
tube. When driven fast, it
pumps with great rapidity.
It possesses this advantage
over the common pump, that
the motion being continuous,
no force is lost by repeatedly
checking the momentum. In
the figure on the preceding
page, the pump is represented
as inserted in a barrel of oil,
which is to be emptied into
the reservoir above, and is
Sucuu,. una io,ung-pump. worked by hand. Larger

rotary pumps are driven by horse and steam power.

TTTRBIN-E WATER-WHEELS.

223

Suction and Forcing-Pump. — The accompanying cut (fig.
249) represents a suction and forcing-pump combined in one,
for the purpose of drawing water from a well or cistern,
and forcing it to tanks in upper stories, or throwing water
into upper rooms in case of fire. By lengthening the rod,
the working parts may be placed at the bottom of a deep
well, and the whole used as a deep well pump.

TURBIXE WATER-WHEELS.

The large wooden wheels formerly used for the appli-
cation of water power to mills and other machinery are
rapidly giving place to iron Turbine wheels. Overshot
wheels, the best kind formerly employed, were turned by
the weight of the water, the whole of which was held in
the slowly descending buckets of the wheel. Turbine
wheels do not hold the water, but merely receive and im-
part the force of the rushing current, the water being
held by the flume above. Hence, a turbine wheel of
quite small size may impart to machinery nearly the
whole force of a powerful current of water.

Turbine wheels are placed in a horizontal position, with

vertical axes. Being
under water, they never
freeze ; and they are not
impeded by back-Avater
when a flood occurs.
There are two principal
kinds among those in
common use, — those,
like the Reynolds wheel,
which have a single
opening at the side,
Sectibn of Reynolds' Wheel. through which the Wa-

ter is admitted ; and such as the Leffel and Van de Water
wheels, into which the water is admitted through several
openings around them.

224

MACHINERY IN CONNECTION WITH WATER.

Fig. 251.

Fig. 250 is a section of the Reynolds wheel ; G^ the

gate for admitting the
water through the hori-
zontal shiite from the
flume ; A^ A, the circu-
lar passage for the water,
which is gradually di-
minished in volume as it
strikes tlie buckets or
blades, -B, J?, and escapes
through the bottom and
top of the wheel. The
arrows sliow the currents, and the curved dotted lines the
openings through which the Fig. 253.

water escapes — the curved
arrows exhibiting the re-
bounding of the current
against the blades, before
passing out through the is-
sues. Fig. 251 is an exterior
view of the wheel, showing
the gate for the admission
of the water ; and fig. 252
represents the shaft and

Fig. 254. Section of Van de Water W/ieel.

buckets separate.

Fig. 253 is a section of
the Yan de Water wheel,
G, G, G, G, being the
gates for admitting wa-
ter, and J?, B^ the buck-
ets ' — the arrows rep-
resenting the entering
currents. H shows, by
dotted lines, the position
Van de Water Wheel. of one of the gates when

closed. The water, after entering the buckets, passes out

TUBBIXE WATEK-WHEELS. 225

below, where the blades are curved backwards, to receive
all the force of the escaping water. Fig. 254 is a view of
this wheel, showing the admission gates, and the wheel at
the top, for opening and shutting the gates at one movement.

Tlie Reynolds wheel is placed under water, outside the
flume, and the current admitted at the side, as ah-eady
stated. The Van de Water wheel is placed within, and
on the bottom of the flume, in the floor of which a circu-
lar hole is cut, through which the water escapes. Both
are excellent Avheels, and are among those most exten-
sively manufactured in the country — the former by George
Tallcot, of New York, and the latter by the invemtor, II.
Van de Water, of Attica, IST. Y.

Turbine wheels, of the best construction, do not lose
more than one-seventh or one-eighth of the whole descend-
ing force of the water. Hence, the power of any stream
may be determined beforehand with much accuracy, if
the descent or head and the number of cubic feet of Ava-
ter per minute are known. It has been already shown in
this work, that a single horse-power is equal to lifting
33,000 lbs. one foot, per minute. This is equivalent to
raising 530' cubic feet of water to the same height, or 53
cubic feet, ten feet high. A stream, then, which falls 10
feet, and discharges 53 cubic feet in a minute, or nearly 1
per second, has an inherent force of one horse-power.
Add one-seventh, making it about 60 cubic feet, and we
have the size of a stream for one horse-power, at ten feet
fall. Twenty feet descent would double the power, forty,
quadruple it, and so on ; and a similar increase result
from employing a larger stream. As examples, a small
Avheel, seven or eight inches in diameter, will be sufficient
for such a purpose. One of this size, wdth 20 feet head,
and discharging 70 or 80 cubic feet of water per minute,
will possess about three horse-power ; and with forty feet
head, requiring over 100 cubic feet per minute, it will
have a power of eight or nine horses.
10*

226 MACHINERY IN CONNECTION WITH WATER.

The simple rule given in the second paragraph of the
present chapter, for determining the velocity of a current
of water spouting out under any given head, will enable
any one who understands arithmetic to calculate the
proper speed of a turbine wheel, which varies with the
head and the diameter of the wheel. It is found that the
buckets or blades should move with about two-thirds the ve-
locity of the current as it rushes from the flume ; hence,
as an example, under a head of 16 feet, which drives out
a stream about 22 feet per second, the exterior of the
turbine wheel should move about 14 or 15 feet per second.
If 1 fo#t in diameter, it should therefore revolve five
times per second ; or, if 2^ feet in diameter, only twice
per second. Other examples may be readily computed.

There are occasional opportunities for employing water
power for driving farm machinery — as thrashing ma-
chines, mills for grinding feed, corn shellers, wood saws,
straw cutters, etc., by bringing streams along hill-sides,
or over blufi*s; in w^hich cases, turbine wheels would be
cheaper than steam-engines, and require neither food nor
fuel. The water of small streams might be saved in dams
or ponds, giving a power of five or six horses for
one day in each week for grinding, thrashing, and other
purposes.

THE WATER-RAM.

One of the most ingenious and useful machines for ele-
vating water is the Water-ram. It might be employed
with great advantage on many farms, were its principle
and mode of action more generally understood. By means
of a small stream, with only a few feet fall, a current of
water may be driven to an elevation of 50 feet or more
above, and conveyed on a higher level to pasture-fields
for irrigation, to cattle-yards for supplying drink to
domestic animals, or to the kitchens of dwellings for cu-
linary purposes.

THE WATER-KAi^r.

227

Its power depends on the momentum of the stream.
Its principal parts are the reservoir, or air-chamber. A,
(fig. 255), the supply pipe, ^, and the discharge pipe, C.
The running stream rushes down the drive, or supply-
pipe, JB, and, striking the waste valve, D, closes it. The
stream being thus suddenly checked, its momentum opens
the valve, JEJ, upward, and drives the water into the reser-
voir, A, until the air within, being compressed into a
smaller space by its elasticity, bears down upon the water,
and again closes the valve, M The water in the supply-
pipe, JB, has, by this Fig. 255.
time, expended its mo-
mentum, and stopped
running ; therefore the
valve, J), drops open
again, and permits it to
escape. It recommences
running, until its force

again closes the waste

valve, D, and a second water-mm.

portion of water is driven into the reservoir as be-
fore, and so it repeatedly continues. The great force of
the compressed air in the reservoir drives the water up
the discharge-pipe, C, to any required height or distance.

The mere weight of the water will only cause it to rise
as high as the fountain head ; but like the momentum of
a hammer, which drives a nail into a solid beam, which a
hundred pounds would not do by pressure, the striking
force of the stream exerts great power.

The discharge pipe, (7, is usually half nn inch in diame-
ter, and the supply-pipe should not be less than an inch
and a fourth. A fall of three or four feet in the stream,
with not less than half a gallon of water per minute, with
a supply-pipe forty feet long, will elevate water to a
height as Grreat as the strene^th of common half-inch lead

228 MACHINERY IN CONNECTION WITH WATER.

pipe will boar.* The greater the height, in proportion to
tlie fall of the stream, the less will be the quantity of wa-
ter elevated, as compared with the quantity flowing in
the stream, or escaping from the waste valve.

H. L. Emery gives the following rule for determining
the quantity of water elevated from a stream : — ^Divide
the elevation to be overcome by the fall in the drive-pipe,
and the quotient will be the proportion of water, (passing
through the drive-pipe), which will be raised, — deducting,
also, for waste of powder and friction, say one-fourth the
amount. Thus, with 10 feet fall, and 100 feet elevation,
one-tenth of the water would be raised if there were no
friction or loss ; but, deducting, say one-fourth for these,
seven and a half gallons in each hundred gallons
would be raised, the rest escaping, or being required to
accomplish this result. Or, if the fall of the water in the
supply-pipe be 3 feet, and the elevation required in the
discharge-pipe be 15 feet, about one-seventh part of all
the water will be elevated to this height of 15 feet. But
if the desired height be 30 feet, then only about one-four-
teenth part of the water will be raised ; and so on in
about the same ratio for different heights. A gallon per
minute from the spring would elevate six barrels five
times as high as the fall, in twenty-four hours, and at the
same rate for larger streams. With a head of 8 or 10
feet, water may be driven up to a height of 100, or even
150 feet, provided the machine and pipes are strong
enough. The best result is obtained when the length of
the drive-pipe and the momentum it produces are just suf-
ficient to overcome the reaction caused by the closing of

* When water is raised to a considerable elevation by means of the
water-ram, the reservoir must possess great strength. If the height be
100 feet, the pressure, as shown on a former page, is about forty-four
pounds to tlie square inch. With an internal surface, therefore, of only
y square feet, the force exerted by the column of water, tending to
burst the reservoir, would be equal to more than twelve thousand
pounds.

THE water-ra:m. ,229

the waste vahe at each pulsation, and prevent the current
of water from being thrown backward or up the drive-
pipe ; hence, the greater the disproportion between the
fall and the required elevation, the longer or larger must
be the drive-pipe, in order to obtain sufficient momentum.
A descent of only a foot or two is sufficient to raise water
to moderate elevations, but the drive-pipe should be of
large bore. This pipe should always be very nearly
straiglit, so that the water, by having a free course, may
acquire sufficient momentum to compress the air in the
ram, and push the water up the discharge-pipe. Water
may be carried to a distance of a hundred rods or more,
but as there is some friction in so long a discharge-pipe,
a greater force is required than for short distances. The
discharge-pipe should, therefore, be larger, as the length
is increased. Half an inch diameter is a common size,
but long pipes may be five-eighths or three-fourths ; and,
when practicable, it is more economical to reach an eleva-
tion with a short and strong pipe, and to use a lighter
and weaker one for the upper part. A pit, lined with
brick or smooth stone, for placing the ram, protects it
from freezing ; and both pipes should be under ground
for tlie same reason. The supply or drive-pipe is usually
40 to 50 feet long; but where the fall is 8 or 10 feet, it
should be sixty or seventy feet.

Unlike a pump, there is no friction or rubbing of parts
in the water-ram, and, with clean water, it will act for
years without repairs, continuing through day and night
its constant and regular pulsations, unaltered and unob-
served. A small quantity of sand, or of dead grass or
other fibre, in the water, will be liable to obstruct the
valves, and render frequent attention necessary.

including those for extinguishing fires and for irrigating
gardens, are constructed on a principle quite similar to

230 MACIIINERY IX CONNECTION WITH WATER.

Fig. 256.

Fig. 257.

Garden-erujine.

that of the water-ram. In-
stead, however, of compress-
ing the air, as in the ram,
by the successive strokes of
a column of running water,
it is accomplished by mcniis
of a forcing-pump, driving
the water into the reservoir,
from which it is again ex-
pelled with great power, by
means of the elasticity of
the compressed air. Fig. 256
represents a garden-engine,
movable on wheels, which
may be used for watering
gardens, washing windows,
or as a small fire-engine. Fig
257 is another, of smaller g
size, foi" the same purposes,

and ill a neat and compact CvUndrical Garden-engine.

form, the working part being within the cylindiical case.

THE FLASH-WriEEi,, FOll KAISING WATER.

2S1

THE FLASH-WHEEL

is employed with great advantage where the quantity of
water is large, and is to be raised to a small height, as in
draining marshes and swamps. It is like an undershot
wheel with its motion reversed; in fig. 258 the ar-
rows show the direction of the current when driven up-
ward. It must, of course, be made to fit the channel
closely, without touching and causing friction. In its best
form, its paddles incline backward, so as to be nearly up-

Fig. 258.

Flash, or fen ivhcdfor raising water rapidly short distances.

right at the time the water is discharged from them into
the upper channel. It has been much used in Holland,
where it is driven by wind-mills, for draining the surface-
water off from embanked meadows. In England, it has
been driven by steam-engines ; and in one instance, an
eighty-horse-power engine, with ten bushels of coal, raised
9,840 tons of water six feet and seven inches high, in an
hour. This is equal to more than 29,000 lbs. raised one
foot per minute by each horse-power, showing that very
little force is lost by friction in the use of the flash-wheeU

232 MACHINERY IX CONXECTIOX WITH WATER.

WAVES.

NATURE OF WAVES.

An inverted syphon, or bent tube, like that shown in
fig. 259, may be used to exhibit the ^''^'- ~^'->-

principle on which depends the motion
of the waves of the sea. The action of
the waves on shores and banks, and the
inroads which they make upon farms
situated on the borders of lakes and
large rivers, present an interesting sub-
ject of inquiry.

If the bent tube (fig. 259) be nearly filled with water,
and the surface be driven down in one arm by blowing
suddenly into it, the liquid will rise in the other arm.
The increased weight or head of this raised column will
cause it to fall again, its momentum carrying it down below
a level, and driving the water up the other arm. The
surfaces will, therefore, continue to vibrate until the force
is spent. The rising and falling of waves depe'nd on a
'similar action. The wind, by blowing strongly on a por-
tion of the water of the lake or sea, causes a depression,
and produces a corresponding rise on the adjacent surface.
The raised portion then falls by its weight, with the add-
ed force of the wind upon it, until the vibrations increase
into large waves.

THE WATER NOT rROGRESSIVE.

The waves thus produced have a progressive motion
(for reasons to be presently shown), as every one has ob-
served. A curious optical deception attending this ad-
vancing motion has induced many to believe that the
water itself is rolling onward ; but this is not the fact.
The boat which floats upon the waves is not carried for-
ward with them ; they pass underneath, now lifting it on

WATEK OF WAVES NOT PKOGUESSIVE. 233

their summits, and no\v dropping it into the hollows
between. The same effect may be observed with the wa-
ter-fowl, which sits upon the surface. It often happens,
indeed, that tlie waves on a river roll in an opposite di-
rection to the current itself.

If a cloth be laid over a number of parallel rollers, so
far apart as to allow the cloth to fall between them, and a
progressive motion be then given to them, the cloth remain-
i.Mg stationary, a good representation of waves will bo
afforded, and the cloth will appear to advance ; or if a
strip of cloth be Inid on a floor, repeated jerks at one end
will produce a similar illusion.

It is only the form of the wave, and not the water
which composes it, which has the onward motion. Let
the dark line in fig. 260 represent the surface of the water.

Fig. 2G0.
A

B

A is tlie crest of one of the waves, and being higher than
the surface at B^ it has a tendency to fall, and B to rise.
But the momentum thus acquired carries these points so
far that they interchange levels. The same change takes
place with the other waves, and the dotted line shows the
newly formed surface as the water thus sinks in one place
and rises in another. The same process is again repeat-
ed, and each wave thus advances further on, and its pro-
gressive motion is continually kept up.

BREADTH AXD VELOCITY OF WAVES.

Each wave contains at any one moment particles in all
possible stages of their oscillation ; some rising, and some
falling ; some at the top, and some at the bottom ; and
the distance from any row of particles to the next row
that is in precisely the same stage of oscillation is called

234 MACHINERY IN CONNECTION WITH WATER.

breadth of the wave, that is, the distance from crest to
crest, or from hollow to hollow.

There is a striking similarity between the rising and
falling of waves and the vibrations of a pendulum, and it
is a very interesting and remarkable fact, that a wave al-
ways travels its own breadth in precisely the same time
that a pendulum, whose length is equal to that breadth,
performs one vibration. Thus, a pendulum 39-J inches
long beats once in each second, and a wave whose breadth
is Z^\ inches travels that breadth in one second. The"
length of a pendulum must be increased as the square of
the time for its vibrations ; that is, to beat but once in
two seconds, it must be four times as long as for one
second ; to beat once in three seconds, it must be nine
times as long, and so on. In the same way, waves which
travel their breadth in two seconds are four times as wide
as those traveling their breadth in one second ; and thus
their breadth, and consequently their speed, increases as
the square of the time. Large waves, therefore, roll on-
ward with far greater velocity than small ones. If only
thirty-nine inches wide, they move about two and a quar-
ter miles an hour, and pass once each second ; if

13 feet wide, tliey move 4)^ miles an hour, passing once in 2 seconds.

53 do. do, 9 do. do. 4 do.

209 do. do. 18 do. do. 8 do.

83G do. do. 36 do. do. 16 do.

Although the water itself does not advance where there
is much depth, yet when it reaches a shore or beach, the
hard and shallow bottom prevents it from falling or sub-
siding, and it then rolls onward with a real progressive
motion from the momentum it has acquired, breaks into
foam, and lashes the earth and rocks. The sea billows
are sometimes twenty-five feet in elevation,* and when
these advance upon a stranded ship on a lee shore, with

* No authentic measnreracnt gives the perpendicular height of waves
more tlian twenty-five feet.

rREYEXTING THE IXKOAD OF WAVES. 2oO

the speed of a locomotive, tlieir effects are in the highest
degree appalling; and iron bolts are snapped, and massive
timbers crashed beneath their violence,

PEEVENTIXG THE IXKOAD OF WAVES.

To prevent the inroads of lake waves npon land, the
remedies must vary with circumstances. The difficulty
would be small if the water always stood at the same
height. The greatest mischief is usually -done when they
rise over the beach of sand and gravel which they have
beaten for centuries. Wooden bulwarks soon decay.
Where loose stones can be had in large quantities, form-
ing sloping rip-rcfp walls, they may be cheapest ; but they
are not unfrequently placed too near lovr-water mark to
protect the banks. Substances Avhich offer a gradual im-
pediment to the waves are often quite effectual, though
not formidable in themselves. It is curious to observe how
so slender a plant as the bulrush, growing in water several
feet deep, will destroy the force of waves. If it grew
only near the shore, where the water has progressive mo-
tion, it would soon be dashed in heaps on the beach.
Parallel hedge-rows of the osier willow, protected by a
wooden barrier until well grown and established would,
in many cases, prove efficient.

Stones and timber bulwarks arc often made needlessly
Fig. 261. liable to injury by

being built nearly
perpendicular, and
the waves break
suddenly, and with
full force, like the
blows of a sledge against them. A better form is shown
in fig. 261, where a slope is first presented, to weaken their
force without imposing a full resistance, and their
strength is gradually spent as they rise in a curve. A

236 MACIIINEKY IX CONNECTION WITH WATEE.

move gradual sloj^e than the figure represents would be
still better. It is on this principle that the stability of the
world-renowned Eddystone light-house depends. The
base spreads out in every direction, like the trunk of a
tree at the roots; and although the spray is sometimes
dashed over its lofty summit by the violence of the storm,
it has stood unshaken on its rocky base far out in the sea,
against the billows and tempests, for nearly a century.

An instance occurred many years ago in England, where
the superiority of knowledge over power and capital
without it was strongly exemplified. The sea was mak-
ing enormous breaches on the Norfolk and Suffolk coast,
and inundated thousands of acres. The government com-
missioners endeavored to keep it out by strong w^alls of
masonry and breakwaters of timber, built at great ex-
pense ; but they were swept away by the fury of the bil-
lows as fast as they were erected. A skillful engineer
visited the place, and, with much difficulty, persuaded
them to adopt his simple plan. Observing the slope of
the beach on a neighboring shore, he directed that suc-
cessive rows of fagots or brush be deposited for retaining
the sand, which was carted from the hills, forming an em-
bankment with a slope similar to that of the natural
beach. Up this slope the waves rolled, and became grad-
ually spent as they ascended, till they entirely died away.
The breach was effectually stopped, and this simple struc-
ture has ever since resisted the most violent storms of
the German Ocean.

CONTENTS OF CISTERNS.

Connected with the subject of hydraulics is the collec-
tion and security of water falling upon roofs, in all cases
where a deficiency is felt by farmers in the drought of
summer. The amount which falls upon most farm-build-
ings is sufficient to furnish a plentiful supply to all the

CONTENTS OF CISTERNS. 237

clomestic animals of the farm when other supplies fail, if
cisterns large enough to hold it were only provided.
Generally speaking, none at all are connected with barns
and out-buildings, and even when they are furnished,
they are usually so small as to allow four-fifths of the
water to waste.

If all the rain that descends in the Northern States of
the Union should remain upon the surface, without sink-
ing in or running off, it would form, each year, a deptli
of about three feet. Every inch that falls upon a roof
yields two barrels for each space ten feet square; and
seventy-two barrels a year are yielded by three feet of
rain. A barn thirty by forty feet supplies annually
from its roof eight hundred and sixty-four barrels, or
enough for more than two barrels a day for every day in
the year. Many farmers have in all five times this
amount of roof, or enough for twelve barrels a day, year-
ly. If, however, this water were collected, and kept for
the dry season only, twenty or thirty barrels daily might
be used.

In order to prevent a waste of water on the one hand,
and to avoid the unnecessary expense of too large cisterns,
their contents should be determined beforehand by calcu-
lation.

RULE FOR DETERMINING THE CONTENTS.

A simple rule to determine the contents of a cistern,
circular in form, and of equal size at top and bottom, is
the following : — Find the depth and diameter in inches;
square the diameter, and multiply the square by the deci-
mal .0034, which will give the quantity in gallons* for one
inch in depth. Multiply this by the depth, and divide by

* This is the standard gallon of 231 cubic inches. The gallon of the
State of New York contains 221.181 cubic inches, or 6 pounds at its
maximum density.

238 MACmNERT IN CONNECTION WITPI WATEE.

31^, and the result will be the number of barrels the cis-
tern will hold.

For each foot in depth, the number of l^arrels answer-
ing to the different diameters are,

For 5 feet diameter 4.66 barrels.

6 " 6.71 "

7 " 9.13 "

8 «' 11.93 "

9 " 15.10 "

10 " 18.05 "

By the rule above given, the contents of barn-yard
cisterns and manure tanks may be easily calculated for any
size whatever.

The size of cisterns should vary according to their in-
tended use. If they are to furnish a daily supply of
water, they need not be so large as for keeping supplies
for summer only. The average depth of rain which falls
in this latitude, although varying considerably with season
and locality, rarely exceeds seven inches for two months.
The size of the cistern, therefore, in daily use, need never
exceed that of a body of w^ater on the whole roof of the
building, seven inches deep. To ascertain the amount of
this, multiply the length by the breadth of the building,
reduce this to inches, divide the product by 231, and the
quotient will be gallons for each inch of depth. Multiply-
ing by 7 will give the full amount for two months' rain
falling upon the roof. Divide by 31|^, and the quotient
will be barrels. This will be about fourteen barrels for
every surface of roof ten feet square when measured hori-
zontally. Therefore, a cistern for a barn 30 by 40 feet
should hold one hundred and sixty-eight barrels ; that is,
as large as one ten feet in diameter, and nine feet deep.
Such a cistern would supply, with only thirty inches of
rain yearly, no less than six hundred and thirty barrels,
or nearly two a day.

Cisterns intended only for drawing from in times of
drought, to hold all the water that may fall, should have
about three times the preceding capacity.

PART III.

MACHIKERY IN CONNECTION WITH AIR

CHAPTER I.

PRESSURE OF AIR.

Pneumatics treats of tlie me-
chanical properties of the air.

The actual weight of the air
may be correctly found by weigh-
ing a strong glass vessel furnished
with a stop-cock, a (fig. 262), after
the air lias been withdrawn from
it by means of an air-pump. Let
it be accurately balanced by
weights in the opposite scale;
then turn the stoj>cock and admit
the air, and it will immediately
descend, as shown in the figure.
The weight of the admitted air
may be ascertained by adding
weights until it is again balanced.

Fi?. S62.

Balance for Weighing Air.

HEIGHT AND WEIGHT OF THE ATMOSPHERE.

The atmosphere which covers the earth extends upward

to a height of about fifty or sixty miles. At the surface

of the earth the air is about eight hundred times lighter

than the water, and the higher we ascend, the rarer or

239

240 MACHINERY IN COXNECTIOX WITII AIR.

lighter it becomes, from the diminished pressure of the
weight above. At seven miles high, it is four times light-
er than at the surface ; at twenty-one miles, it is sixty-
four times lighter ; and at fifty miles, about twenty thou-
sand times lighter. At this height it ceases to refract the
rays of the sun so as to render it visible at the earth's sur-
face ; but if it decreases at the same rate upward, at a
hundred miles high it must be nearly a thousand million
limes rarer than at the earth.

If the atmosphere were uniformly of the same density,
with its present Aveight, it would reach only five miles
high. Although so much lighter than water, yet, from
its great height, it presses upon the surface of the earth
as heavily as a depth of thirty-three feet of water. This
is nearly equal to fifteen pounds on every square inch, or
more than two thousand pounds to the square foot. This
enormous weight would instantly crush us, did not air,
like liquids, press in every direction, so that the upward
exactly counterbalances the downward pressure, and the
air within the body counteracts that without.

The weight of the atmosphere is strikingly shown by
j7j„ 28.3 means of an air-

pump, which pumps
the air from a glass
vessel, placed mouth
downward upon the
brass plate of the
machine (fig. 263).
When the air is
pumped out, and the
upward or counter-
balancing air remov-
ed, so heavy is the
load upon the glass
^''■■^'"^- vessel, that a strong

man could scarcely remove it from the plate, although it

WEIGHT OP THE ATMOSPHEEE. 241

be no larger than a small tumbler. A glass jar with a
mouth six inches across would need a force equal to nearly
four hundred pounds to displace it. If Fig. 264.

there be a glass vessel open at both ends,
the hand placed on the top may be so
firmly held by the pressure that it can not
be removed until the air is again admit-
ted below (fig. 264). If a thin plate of
glass be placed on the top of this open The H^^^Tf^tcned
vessel, on j^umping out the air, the h -A-ir.

weight will suddenly crush it with a noise like the report
of a gun.

Some interesting instances occur in nature of the use
of atmospheric pressure. Flies walk on glass by means
of the pressure against the outside of their feet, the air
having been forced out beneath. In a similar way, some
kinds of fishes cling to the sides of rocks under water, so
as not to be swept off by the current. Dr. Shaw threw a
fish of this kind into a pail of water, and it fixed itself so
firmly to the bottom, that, by taking hold of the tail, he
lifted up the pail, water and all.

It is the pressure of the atmosphere upon water that
drives it up the barrel of a pump as soon as the air is
pumped out from the inside. Hence the reason that
pumps can never be made to draw water more than thirty-
three fe^t below the piston, a height corresponding to the
weight of the atmosphere. In practice they never draw
water even to this height, as a perfect vacuum can not be
made by pumping.

THE BAROMETER.

On the same principle the barometer is made. It con-
sists of a glass tube, nearly three feet long, open at one
end, and which is first filled with mercury, a liquid nearly
fourteen times heavier than water. The open end is then
U

242 MACHrN-EET i:n" conxectio:^" with aie.

placed downward in a cup of mercury. The weight of
the mercury in the tube causes it to descend until the
pressure of the atmosphere on the mercury in the cup
preserves an equilibrium, which takes place when the col-
umn in the tube has fallen to about two feet and a
n?. .Cu. i^aif j^igij^ ^i^Q upper part of the tube being left a
perfect vacuum, as no air can enter (fig. 265). Xow,
as the height of the column of mercury depends
alone upon the weight of the atmosphere, then,
whenever the air becomes lighter or heavier, as it
constantly does during the changes of the weather,
the rising or falling of the column indicates these
changes ; and, what is very important, it shows
the approaching changes of the weather several
^cleT" ^^^^^ before they actually take place. Hence
it becomes a valuable assistant in foretelling
the weather. When the mercury falls, showing that
the atmosphere is becoming lighter, it indicates the
approach of storms or rain ; when it rises, a settled or fair
sky follows. These are often foreshown before there is
any change in the appearance of the sky. For this rea-
son the barometer is sometimes called a weather-glass. It
is of the greatest value to navigators at sea. Long
voyages, wliicli formerly required a year, have been made
in eight months by means of the assistance afforded by
the barometer, admitting a full spread of canvas 'by night
as well as by day, from the certainty of its predictions.
On land its indications are not so certain, and at some
places less so than at others. Sometimes, and more com-
monly during autumn and winter, the sinking of the mer-
cury is followed only by wind instead of rain. There is,
however, no doubt that its use would be of much advant-
age in large farming establishments, more especially dur-
ing the precarious seasons of haying and harvesting.

The barometer is an instrument of great value in de-
termining with little labor, and with considerable accuracy,

THE BAROMETER.

243

the heights of mountains, hills, and the leading points of
an extensive district of country. In rising above the level
of the sea, the weight of the air above us becomes less ;
that is, the pressure of the air upon the barometer de-
creases, and the column of mercury gradually falls as we
ascend. To determine, therefore, the height of a mount-
ain, we have only to place one barometer at its foot while
another stands at the top, and then, by observing the
difference in the height of the mercury, we are enabled to
calculate the height of the mountain. The following ta-
ble shows how much the barometer falls at different alti-
tudes, thirty inches being taken for the sea-level :*

At 1,000 feet above the sea
2,000
3,000
4,000
5,000

1 mile "

2 "

3 "

4 "

5 "
10 "
15 ''
20 "

the column flills to 28.91 inches.

27.86 "

26.85 "

" 25.87 "

24.93 "

u 24.67 "

" 20.29 "

" 16.68 "

13.72 "

" 11.28 "

4.24 "

" " 1.60 "

" " 0.95 "

At the level of the sea, the barometer falls about one
hundredth of an inch for a rise of nine feet, or a little
more than the tenth of an inch for a rise of one hundred
feet. At a height of one mile it requires about eleven
feet rise to sink the mercury a hundredth of an inch.

In selecting land in mountainous districts of the coun-
.try, where degrees of frost increase with increased alti-
tudes, and' where the height of one portion above another
has an important relation to the cost of drawing loads up

* The mercury rarely stands as high as 30 inches at the level of the
sea, the mean height being about 29.5 inches. But tliis does not affect
the measurement of heights, which is determined, not by the actual
height, but by the difference in heights.

244

MACniXERY IN CONNECTION TVITH AIK.

and down liill, the barometer might become of much
practical value.

THE SYPHON.

The syphon operates on a principle quite similar to that
cf the pump ; but, instead of pumping out the air of the
tube through which the water rises, a vacuum is created
Fig. 26G. by the weight of a column of water, in

the following way : Fig. 26G represents a
syphon, which is nothing more than a
tube bent in the form of a letter U in-
verted. Nov/, if this be filled through-
out with water, and then placed with the
shorter arm in the vessel of water. A,
the weight of the column of water in the
longer arm, which is outside, will over-
balance the weight of the other column,
and will therefore run out in a stream. This tends to cause
a vacuum in the tube, which is instantly filled by the water
rushing up the shorter arm, being driven up by the press-
ure of the atmosphere. A stream will consequently con-
tinue running through the syphon until the vessel is
drained.

The syphon may sometimes be very usefully employed in
emptying pools or
ponds of water on
high ground, with-
out the trouble of
cutting a ditch for

this purpose. For ^^^^

instance, let a (fig. 267) represent a body of water which
it is desirable to drain ofi*; by placing the lead tube, h c,
so that the arm, c, may be lowest, and apjilying a pump
at this ai-m to withdraw the air and fill the syphon with
water, it will commence running, and continue until the

Fig. 2G7.

d

WINDS. 245

water has all been drawn off. Difficulties, however, some-
times occur. If the tube is small and very long, and the
descent is trifling, the friction of the water in the tube
may prevent success. Water iisually gives out small
quantities of air, which collects in the higher part of the-
syphon, and after a while fills it, causing the stream to
cease running ; but syphons for this purpose, when only a
few rods in length, with several feet descent, are usually
found to succeed well. If the discharging orifice is sev^
eral times smaller than the tube, it is frequently of material
use, by causing a slow and steady current through the
syphon.

CHAPTER II.

MOTION OF AIR.
WINDS.

Wind is air in motion. Its force depends on its speed.
When its motion is slow, it constitutes the soft, gentle
breeze. As the velocity increases, the force becomes
greater, and the strong gale sweeps around the arms of
the wind-mill with the strength of many horses, and huge
ships are driven swiftly through the waves by its press-
ure. By a still greater velocity of the air, its power be-
comes more irresistible, and solid buildings totter, and
forest trees are torn up by the roots in the track of the
tornado.

The force of wind increases directly as the square of
the velocity. Thus a wind blowing ten miles an hour ex-
erts a pressure four times as great as at five miles an hour,
and twenty-five times as great as at two miles an hour.

246

MACHIXERY IN" CONNECTION WITH AIR.

The following table exhibits the force of wind at different
degrees of velocity :

Description.
Hardly percei^tible.
Just perceptible.

Miles an
hour.

1

2

3

4

5

6

7
10
15
20
25
30
35
40
45
50
GO
80
100

Pressure in lbs. on
a,

squarefoot.

.005

.020 ]

.045 j

.080

,125

.180)

.320 i"

.500

1.125

2.000 ^

3.125 f

4.500

0.125

8.000 )

10.125 [

12.500

18.000

32.000

50.000

Lii^lit breeze.

Gentle, pleasant wind.

Pleasant, brisk wind.

Very brisk.

Stron.o;, hi^li wind.

Very high.

Storm or tempest.
Great storm.
Hurricane.

Tornado, tearing up trees, and sweeping off
buildings.

These forces may be observed at a time when the air is
still, by a forward motion equal to that of the wind. Thus
walking moderately gives the faint breeze against the
face ; riding in a wagon at six miles an hour causes the
sensation of a pleasant wind ; the deck of a steam-boat at
fifteen miles produces a brisk blow ; while an open rail-car
at forty miles an hour occasions a sweep of the air nearly
resembling a tempest.

The preceding table will enable any one to calculate
with considerable accuracy the amount of draught which
a horse must constantly overcome in traveling with a
covered carriage against the wind, adding, of course, the
speed of the horse to tlmt of the wind. For example,
suppose a horse with a covered carriage is driven against
what we tenn " a very brisk wind," blowing 24 miles an
hour, and pressing 3 lbs. on the square foot. The carriage
top offers a resisting surface four feet square, or with six-

»rOTION AGAES^ST THE WIND. 247

teen square feet. Three times sixteen, or 48 lbs., are con-
sequently required to be overcome with every onward
step of the horse. Kow, we have already seen, when
treating of '^ application of labor," that a horse traveling
three miles an hour for eight hours will overcome only 83
lbs. with ordinary working, which is not double the resist-
ance of the wind. Hence we perceive that more than
half the horse's strength is lost by driving against such a
current. At six miles an hour, all his strength, without
over-driving, would be expended in overcoming the force
of the wind, and the power required for moving the car-
riage would be so much excess of labor. For simplifying
the operation, the increased motion of the wind occasion-
ed by driving against it has not been taken into account.
Even with a small pressure, the loss in power is consid-
erable for an entire day. When, for example, the air is
perfectly still, traveling six miles an hour will cause a con-
stant resistance of 3 lbs. on the carriage, or one-fourteenth
of the power exerted for a full day's work. The same
speed against a " gentle wind " of six miles an hour, add-
ed, would increase the resistance fourfold, or equal to 12
lbs. ; more than one-fourth of the horse's strength at six
miles an hour through the day.

WIND-MILLS.

The power possessed by the sails of a wdnd-mill may be
nearly ascertained in the same Avay, the area of the sails
being known, and first deducting their average velocity.

In all wind-mills, it is important that the sails should
have the right degree of inclination to the direction of the
wind. If they were to remain motionless, the angle
would be different from that in practice. They should
more nearly face the Avind ; and as the ends of the sails
sweep around through a greater distance and faster, they
should pres-ent a flatter surface than the parts nearer the

248

MACHINERY IN CONNECTION WITH AIR.

centre. The sails should, therefore, have a twist, to give
them the most perfect form, so that the parts nearest the
centre may form an angle of about 68 degrees with the
wind, the middle about 72 degrees, and the tips about 83
degrees.

In order to produce the greatest effect, it is necessary to
give the sails a proper velocity as compared with the ve-
locity of the wind. If they were entirely unloaded, the ex-
tremities would move faster than the wind, in consequence
of its action on the other parts. The most useful effect is
produced Avhen the ends move about as fast as the wind,
or about two-thirds the velocity of the average surface.

The most useful wind is one that moves at the rate of
eight to twenty miles per hour, or with an average press-
ure of about one pound on a square foot. In large wind-
mills, the sails must be lessened when the wind is stronger

than this, to prevent the
arms from being broken ;
and if much stronger, it
is unsafe to spread any,
or to run them.

The force of wind may
be usefully applied by al-
most every farmer, as it
is a universal agent, pos-
sessing in this respect
great advantages over
water-power, of which
very few farms enjoy
the privilege.

Wind may be applied
to various purposes, such
as sawing wood by the
aid of a circular saw,
turning grindstones, and particularly in pumping water.
One of the simplest contrivances for pumping is represented

Wind-mill for pumping water on farms :
A, wind-mill; ]i,vane; \, pump-rod.

WIND-MILL FOR rUMPING WATER.

249

by fig. 268, where A is the circular wind-mill, with a number
of sails set obliquely to the direction of the wind, and al-
ways kept facing it by means of the vane, B. The crank of
the wind-mill, during its revolutions, Avorks the pump-rod, I,
and raises the water from the well beneath. In whatever di-
ns:. 260.

Bam surmounted ivith wind-mill for pumping wateTf
cutting straw, 6fC.

rection the Avind may blow, the pump will continue work-
ing. The pump-rod, to work steadily, must be immediately
under the iron rod on which the vane turns. If the di-
ameter of the wind-mill is four feet, it will set the pump
in motion even with a light breeze, and with a brisk wind
will perform the labor of a man. Such a machine will
pump the water needed by a herd of cattle, and it may be
placed on the top of a barn, with a covering, to which may
be given the architectural effect of a tower or cupola, as
shown in fig. 269.

A more compact machine, but of more complex con-
struction, is shown in fig. 270, where the upper circle
moves around Avith the wheel and vane on the fixed lower
circle, to Avhich it is strongly secured so as to admit of
turning freely. In other respects it is similar to the pre-
ceding.

11*

250

MACHINERY IN CONNECTION WITH AIR.

ri;;:. 270.

Wind-mills, like the preceding, which have fixed sails,
should not he more than three or four feet in diameter^
and even then will require care in storms. If larger,
they will become broken by severe winds. The remedy is
either to move the sails by hand at every considerable
change in the force of the current, which would require
hearly constant attention ; or to use the self-regulating ma-
chines, of which there have been several invented, some
of which have proved useful and durable.

SdlUday's wind-mill has been much used for several
years, and is made of various sizes, the larger possessing
the power of several horses. It is self-regulated, in the
following manner : When the mill begins to run too fast,
it pumps water rapidly into a chamber or cylinder, and
this increase of water moves an arm which turns the fans

brown's wind-mill.

251

edgewise to the wind. When the wind slackens, a re-
verse movement takes place.

Brown'' s wind-mill, made by the Empire Wind-mill Com-
pany, of Syracuse, is a more recent invention, and has
proved very successful. The annexed figure (fig. 271), rep-

Fis. 271.

liroiL-iCs {or Emjnre) Wind-mill.

resents one of the smaller sizes, adapted to farm purposes
and pumping water for cattle. It is regulated in part by
the centrifugal force of weights, and partly by the direct
pressure of the wind. This regulating contrivance ren-
ders the mill safe, even in a gale of wind. The larger

252 MACHINERY IN CONNECTION WITH AIR.

sizes, which are fifty feet or more in diameter, possess
much power, and are used for grinding grain, and other
purposes.

The work which a wind-mill is capable of doing de-
pends very much on the site. If placed where the wind
has a long, uniform, and steady SAveep, it will accomplish
much more, and to better satisfaction, than if among hills
or other obstructions, where the blasts are uncertain and
changing.

Wind-mills of large size are peculiarly adapted to pump-
ing water into reservoirs, or from mines or quarries, w^here
a few days of calm weather wuU not result in inconven-
ience ; but they are not suited to manufactories where a
constant power is required to furnish employment to men,
but can be used for work which may be intermitted or
changed.

Brown's wind-mill is sold at 175 dollars for the small
size, with increase of prices up to $1,200 for large ones.

CAUSES OF WIND.

The motion of air, in producing wind, is explained by
the action of heat, although there are many irregular cur-
rents whose cause is not well understood. The simplest
illustration of the effect of heat in causing currents is fur-
nished by the land and sea-breezes in warm latitudes.
The rays of the sun during the day heat the surface of
the land, and the air in contact with it, also becoming
heated, and thus rendered lighter, flows upward ; the air
from the sea rushes in to fill the vacancy, and causes the
sea-breeze. During the night, the radiation of heat from
the land into the clear sky above cools the surface to a
lower temperature than that of the sea ; consequently,
the air in contact with the sea becomes heated the most,
and rising, causes the wind from the land to flow in and
supply the place. Trade-winds are caused in a similar

CHIMNEY CUKEENTS. 253

way, but on a much larger scale, by the greater heat of
the earth at the equator, which produces currents from
colder latitudes. These currents assume a westerly tend-
ency, in consequence of the velocity o£ the earth being
the greatest at the equator, and which, outstripping the
momentum which the winds have acquired in other lati-
tudes, tends to throw them behind, or in a westerly di-
rection.

CHIMNEY CUKREXTS.

Chimney Currents are produced by the heat of the fire
rarefying the air, which I'ises, and carries the smoke with
it. The taller the chimney is, the longer will be the
column of rarefied air tending upward ; and, as a conse-
quence, the stronger will be the draught. In kindling a
fire in a cold chimney, there is very little current till this
column becomes heated. The upward motion of heated
currents is governed by laws similar to the downward mo-
tion of water in tubes, where the velocity is increased
with the height of the head. But as air is more than
eight hundred times lighter than water, slight causes will
afiect its currents, which would have no sensible influence
on the motion of Hquids. For instance, a strong wind
striking the top of a chimney may send the smoke down-
ward into the room ; and a current can not be induced
through a horizontal pipe without connecting with it an
upright pipe of considerable height.

CONSTETJCTION OF CHIMNEYS.

In constructing chimneys to produce a strong draught,
the throat immediately above the fire, which should have
a breadth equal to that of the fireplace, should be con-
tracted to a width of about four inches, so that the column

254

MACHINERY IN CONXECTION WITH AIR.

of rising air above may draw the air up through the

Fig. 2T2. throat with increased velocity, as
shown in fior. 272. This arranore-

Fig. 273.

raent also allows the fire to be built
so as to throw the heat more fully
out into the room. By leaving the
shoulder at b square or flat, it will
tend to arrest any reversed or
downward current in a better man-
ner than if built sloping, as shown
by the dotted line at a, which
would act like a funnel, and throw
the smoke into the room. The
throat should be about as high as
the extreme tip of the flame; if
much higher, the chimney will not
draw so well, and if lower, too
much of the heat will be lost.
.^. 273 shows a fireplace without a contracted throat,
the current of which is comparatively feeble. Many
chimneys draw badly by being made too large for the fire
to heat sufficiently the column of air they contain.

A badly-buUt
Chimney.

CIIIMXEY-CAPS.

When wind sweeps over the roof of a high part of the
building, or over a hill, it often strikes the Fig. 274.
tops of chimneys below, and drives the smoke
downward. This may be often prevented
by placing a cap over the chimney, like that
represented by fig. 274, which is supported at
its comers, the smoke passing out at the four
sides just under the eaves of this cap. But
it sometimes happens that there is a confusion of currents
and eddies at the top of the chimney, over which this cap

CHIMNEY-CAPS.

255

Fig. 275.

has no influence. In tliis case, the cap represented by fig.
275 furnishes a complete remedy, and is, in-
deed, perfect in its operation under any cir-
cumstances whatever, for the chimney sur-
mounted by it will always draw when there
is wind from any quarter, with or without a
fire. It has efi*ected a perfect cure in some
chimneys which before were exceedingly

troublesome, and were regarded as incurable.

Fig. 276 is

intended to show the mode of its
operation ; the wind, as shown by
the arrows, being deflected for a
considerable distance on the lee
side, so as to form a vacancy at «,
which the wind from the other end
and from the chimney both rush in to supply. Being
fixed on without turning in the chimney, it is both simpler
and less noisy than any caps furnished with a vane.
JEmer soil's Chimney-cap is different in construction.
Fig. 277. but quite simi-

lar in principle

to the i:>reced- '^^/^/

ing. It is shown

by fig. 277. A

sheet-iron pipe

is set in the top

of the chimney,

furnished with
the conical rim, and a plate
or fender on the top, which ex-
cludes the rain. Between the
plate and rim is a space quite
similar in form or section to
that represented by fig. 276.
In exposed situations, chim-
neys are found to draw more uniformly by contracting

250

MACHINERY IX CONNECTION TVTTH AIE.

the top about a third less than the rest of the flue. The
Fig. 279. current at the moment of escape is swifter
than below, and less acted upon by any down-
ward blast of the wind, at the same time
that the surface is smaller on which the wind
can strike the current, as shown in fig. 278.
A chimney of this character may be very
easily made by contracting the tiers of brick,
thus giving to it an ornamental appearance,
as seen in lisr. 279.*

^j

^^

p^

—J i

K=V

-".■J'<

if'f^T

T.~'-i

ft

/^&te4

p]^--!r-,Bg|j?i

■'•*4^-'eN-"!'I

V- _

5^^"jJ

* Where different fires communicate with the same chimney, separate
flues shoiild be built for each fire, anrt Icept separate in the same chim-
ney-staclc, carried up independently of each other. But even with this
precaution, smolvy rooms will not be avoided, unless the termination of
the chimney is of the right form, of which the folloAving illustration is
given in Allen's Rural Architecture :

"Fifteen years ago we purchased and removed into a most substantial
and well-built stone house, the chimneys of which were constructed
with open fireplaces, and the flues carried up separately to the top,
where they all met upon the some level surfiice, as chimneys in past times
usually were built thus (fig. 280). Every fireplace in the house (and some
of them had stoves in) smoked intolerably ; so much so, that when the
wind was in some quarters, the fires had to be put out in every room
but the kitchen, which, as good luck would have it, smoked less — al-
though it did smoke there — than the others. After balancing the mat-
ter in our own mind some time whether we would pulldown and re-
build the chimneys altogether, or attempt an alteration — as we had

Fig. 281.

given but little thought to the sub- Fig. 2S0.

jcct of chimney draught, and to try

an experiment was the cheapest —

we set to work a bricklayer, who,

under our direction, simply built

over each discharge of the several

flues a separate top of fifteen inches

high, in this wise : Fig. 281. The '^

remedy was perfect. We have had no smoke in the house since, blow

the wind as it may, on any and on all occasions. The chimneys cavi^t

smoke ; nnd the whole expense for four chimneys, with their twelve

flues, was not twenty dollars ! The remedy was in giving each outlet a

distinct current of air all around, and on every side of it."

VENTILATION OF ROOMS.

257

VENTILATION.

Impure air may be breathed for a short time without
any serious detriment, but to live in it and respire it for
years can not fail to produce permanent injury to the
health. During the heat of summer, open doors and win-
dows will usually furnish plenty of fresh air, so long as
this season lasts, which in the Northern States is not one
half the year. During the rest of the time, rooms are
heated with close stoves, and unless special care is taken
to secure fresh air, pale or sickly inmates Avill be the most
likely results.

Even with a common open fireplace, which causes more
circulation of the air in a room than stoves, the ventila-
tion is very imperfect. The following figure (fig. 282)

represents the fresh air
as passing in from an
open window opposite
the fire, producing a
direct current from the
window to the chim-
ney, and leaving all the
upper portion of the
room filled with bad
air, unafifected by tliQ.
change. The cold air
can not rise, nor the
hot air descend. This

Ficr. 2S2.

A hadbj-vcrUilaied Room.

difficulty may be easily removed by placing a register
(which may be closed or opened at pleasure) at a, in the
upper corner, so that the confined air may escape into the
chimney. Without this provision, it is nearly impossible
to preserve the air in proper condition for breathing, for
the upper part, being warmest and lightest, remains un-
changed at the top. In rooms heated by stoves, registers
for the escape of the foul air are still more important, where

258

MACHINERY IN CONNECTION AVITII AIR.

the thermometer frequently indicates twenty degrees dif-
ference in the heat above and at the floor, the lower
stratum of air resting like a cold lake about the feet,
while the head is heated unduly.

When the draught of the chimney-lire is not strong,
the smoke may, however, escape through the ventilating
register into the room. To avoid this difficulty, it is best
to provide separate air-flues in the walls when the house
is built, for effecting perfect ventilation. In rooms strong-
ly heated by fires, the fresh air should be admitted near
the ceiling, producing descending
currents, and effecting a complete
circulation in the air of the room.
But in sleeping apartments, and in
closets, not heated artificially, and
where the descending currents will
not take place, the fresh air should
Mode cf Ventilating- Garrets. \)q admitted througli a rcgistcr or
small rolling blind near the floor, and discharged near the
ceiling into an air-flue.

The excessive warmth of garrets in midsummer may

Fig. 285.

Fiu:. 284.

Mode of Ventilating half-story Bed-
rooms.

GnffitlCs Ventilator.

be avoided by placing a ventilator at the highest part,

259

and admitting air at windows or openings near the eaves
(fig. 283), thus sweeping all the hot air out by tlie cur-
rent produced; or the oppressive heat of half-story bed-
rooms may be similarly avoided, by creating a current of
air between the roof and the jDlastering (fig. 284). Two
modes may be adopted, as represented on each side of the
figure.

Fig. 285 represents Griffith's patent ventilator, for chim-
neys, and for giving a current of air through apartments.
It is made of iron, working as a screw fan^ the slightest
wind causing it to revolve and establish a current through
the pipe which it surmounts.

PART IV.

H EAT.
CHAPTER I.

CONDUCTING POWER OF BODIES.

Wlien any substance or body lias become heated, it
loses its heat in two different ways, by conduction and by
radiation. When conducted, heat passes off slowly or
gradually through bodies, as when a pin is held by the
hand in a candle, the heat advances from one end to the
other till it burns the fingers ; or, when an iron poker is
thrust into the fire, the heat gradually passes through it
till the whole becomes hot. Iron and brass are, there-
fore, said to be good conductors of heat. The end of a
pipe-stem may, however, be heated to redness, and a
wooden rod may be set on fire without even warming the
other extremity, because the heat is very slowly conducted
through them. Wood and burned clay are, therefore,
poor conductors.

The comparative conducting power of different sub-
stances may be shown by placing short rods of each with
one of their ends in a vessel of hot sand, the others to be
tipped with wax. The different periods of time required
to melt the wax indicate the relative conducting powers.
It will speedily melt on the copper rod ; soon after, on
the rod of iron ; glass will require longer time ; stone or
earthenware, still longer; while on a rod of wood, it
will scarcely melt at all. These rods should be laid hori-
zontally, that the hot air rising from the sand may not
260

UTILITY OF THE COXDUCTIXG POWER OF BODIES. 261

affect the wax. The conducting powers may be judged
of, likewise, Avith considerable accuracy in cold weather,
by merely placing the hand upon the different substances.
The best conductors will feel coldest, because they with-
draw the heat most rapidly from the hand. Iron will feel
colder than stone ; stone colder than brick ; wood, still
less so ; and feathers and down, least of all, although the
real temperature of all may be precisely the same.

UTILITY OF THIS PEIXCIPLE.

A knowledge of this property is often very useful. For
instance, it is found that hard and compact kinds of wood,
as beach, maple, and ebony, conduct heat nearly twice as
rapidly as light and porous sorts, like pine and bass-wood.
Hence, doors and partitions made of light wood make a
warmer house than those that are more heavy and com-
pact. Pine or bass-wood would, in this respect, be better
than oak or ash.

Porous substances of all kinds are the poorest conduct-
ors ; sawdust, for example, being much less so than the
wood that produced it. For this reason, sawdust has
been used as a coating around the boilers of locomotives,
to keep in the heat, and for the walls of ice-houses, to ex-
clude it. Sand, filled in between the double walls of a
dwelling, renders it much warmer in winter, and cooler
in summer, than if sandstone were made to fill the same
space. Ashes, being more porous, are found to be still
better. Tan, which is similar to sawdust, is well adapted
to filling in the walls of stables and poultry-houses, where
more than usual warmth in winter is required. Confined
air is a very poor conductor of heat ; hence the advantage
of double walls and double windows, provided there are
no crevices for the escape of the confined air. This prin-
ciple has been lately applied in the manufacture of hollow
hriclc for building the walls of dwellins^s.

262

HEAT.

The light and porous nature of snow renders it eminent-
ly serviceable as a clothing to the earth in the depth of
winter, preventing the escape of the heat from below, and
protecting the roots of plants from injury or destruction.
Hence the very severity of the cold of the Northern re-
gions, by producing an abundance of those beautiful
feathery crystals which form snow, becomes the means of
protecting from its own effects the tender herbage buried
beneath this ample shelter.

CONDUCTIJfG POWER OF LIQUIDS.

Fij. 23G,

Liquids are found to conduct heat very slowly, and
they were for a long time considered perfect non-conduct-
ors. Some interesting experiments have been performed
in illustration of this property. A large glass jar may be
filled with water (fig. 286), in which may be fixed an
air thermometer, which is always quickly sensitive to
small quantities of heat. A shallow cup of ether, floating
just above the bulb, may be set on
fire, and will continue to burn for
some time before any effect can be
seen upon the thermometer. The
upper surface of a vessel of water
lias been made to boil a long time
with a piece of unmelted ice at the
bottom. Liquids are found, how-
ever, to possess a conducting power
in a very slight degree.

When a vessel of water is heated
in the ordinary way over a fire,
the heat is carried tlirough it merely by the motion
of its particles. The lower portion becomes warm,'
and expands; it immediately rises to the surface, and
colder portions sink down and take its place, to ascend in
their turn. In this way, a constant circulation is kept up

EXPANSION BY HEAT.

363

among the particles. These rising and descending cur-
rents are shoAvn by the arrows in fig. 287. This result
maybe easily shown by filling a flask with water into
which a quantity of sawdust from some green hard wood
has been thrown, which is about as heavy as water. It
Avill traverse the vessel in a manner precisely as shown
in the figure.

These results indicate the importance of applying heat
directly to the bottom of all vessels i:i which water is in-
tended to be heated. A considerable loss of heat often
occurs when the flame is made to strike against the sides
only of badly arranged boilers.

EXPANSION BY HEAT.

An important efi*ect of heat is the expansion of bodies.
Among many ways to show it, an iron rod may be so fit-
ted that it will just enter a hole made for the purpose in
a piece of sheet-iron. If the rod be now heated in the
fire, it expands and becomes larger, and can not be thrust

^ Fl<r. 2SS.

M ^ ^

into the hole. The expansion may be more visibly shown
and accurately measured by means of an instrument called
the Pyrometer (fig. 288). The rod a J, secured to its

264

HEAT.

place by a screw at a, presses against the lever e, and this
against the lever or index d, both of which multiply the
motion, and render the expansion very obvious to the eye
Avhen the rod is heated by the lamps. If the rod should
expand one-fiftieth of an incli, and each lever multiplies
twenty times, then tlie index (or second lever) will move
along the scale eight inches ; for 20 times 20 are 400, and
400-50ths of an inch are 8 inches.

Many cases showing the expansion of heated bodies oc-
cur in ordinary practice. One is afforded by the manner
in which the parts of carriage wheels ara bound together.
The tire is made a little smaller than the wooden part of
the wheel; it is then heated till, by expanding, it be-
comes large enough to be put on, when it is suddenly
cooled with water, and, by its jDowerful contraction, binds
every part of the wheel together with great force. Hogs-
heads are firmly hooped with iron bands in the same way,
with more force than could ever be given by driving
with blows of the mallet.

This i^rinciple was very ingeniously applied in drawing
together two expanding brick walls of a large building in
Paris, which threatened to burst and fall. Holes were
drilled in the opposite walls, through which strong iron
bars across the building projected, and circular plates of
iron were screwed on these projecting ends. The bars
were then heated, which increased their length ; the plates
were next screwed closely against the walls. On cooling,
they contracted, and drew the walls nearer together. The
process was repeated on alternating bars, until the walls
were restored to their perpendicular positions.

All tools, where the wooden handles enter iron sockets,
will hold more firmly if the metal is heated before insert-
ing the wood.

The metallic parts of pumps sometimes become very
difficult to unscrew, and a case has occurred where two
strong men could not start the screws, until a bystander

EFFECTS OP SUDDEN EXPANSION.

265

suggested that the outer piece be heated, keeping the in-
ner cool, "when a force of less than ten pounds quickly
separated them. In other cases, where the large iron nuts
have been thoughtlessly screwed, while warmed with the
hands, on the cold metallic axles of wood-sawing ma-
chines in winter, they have contracted so that the force
of two or three men has been insufficient to turn them.

The sudden expansion of bodies by heat sometimes
causes accidents. Thick glass vessels, when unequally
heated, expand unequally, and break. Heated plates of
cast-iron or cast kettles are liable to be fractured by
suddenly pouring cold water upon them. The same ef-
fect has been usefully applied in splitting the scattered
rocks which encumber a farm, and which are too large to
remove while entire. Fires are built upon them ; the up-
per surface expands while the lower remains cold, and
large portions are successively separated in scales, and
sometimes the whole rock is severed. The only care
needed is to observe attentively and remove with an iron
bar any parts which may have become loosened by the
heat, and which would prevent the heat from passing to
other portions. One man will thus attend to a large
number of fires, and will split in pieces ten times as many
rocks in a day as by drilling and blasting.

THE STEAM-ENGINE.

The Steam-engine owes its power to
the enormous exj^ansion of water at the
moment it is converted into steam, which
is about 1,600 times its bulk when in
a liquid state. The principle on which
the steam-engine acts may be understood
by a simple instrument, represented
in fig. 289. A glass tube with a small
bulb is furnished with a solid, air-
light piston, capable of working up and
12

266 HEAT.

down. The water in the bulb, «, is heated with a
spirit-lamp or sand-bath ; the rising steam forces up the
piston. 'Now, immerse the bulb in cold water or snow,
•and the steam is condensed again into water, the tube is
left vacant, and the pressure of the atmosphere forces
down the piston. By thus alternately applying heat and
cold, it is driven up and down like the piston of a steam-
engine. The only difference is, the steam-engine is fur-
nished with apparatus so that this application of heat and
cold is performed by the machine itself The bulb repre-
sents the boiler, and the tube the cylinder ; but in the
steam-engine, the boiler is separate, and connected by a
pipe with the cylinder ; and instead of applying the cold
water directly to the cylinder, it is thrown into another
vessel, called the condenser, connected with the cylinder.

When Newcomen, who made the first rude regularly
working engine, began to use it for pumping water, he
employed a boy to turn a stop-cock connected with the
condenser, every time the piston made a stroke. The
boy, however, soon grew tired of this incessant labor, and
endeavored to find some contrivance for relief. • This he
effected by attaching a rod from the piston or working-
beam to the cock, which was turned by the machine itself
at every stroke. This was the origin of the first self-
acting engine.

The different parts ol a common steam-engine may be
understood from the following figures, one representing
the boiler, and the other the working machinery.

- The boiler, J^ (fig. 290), contains water in the lower
part, and steam in the upper ; i^ JB is the fire ; ^; o is the
feed-pipe ; v, a valve, closed by the lever b c a, whenever
the boiler is full enough, by means of the rising of the
float, S, and opened whenever the float sinks from low
water. M, barometer gauge, to show the pressure of the
steam ; w, weight on the lever, e b, for holding down the
8((fety-valoe : this lever being graduated like a steelyard,

THE STEA^f ENGINE.

the force of the steam may be accurately weighed. Uia
a valve opening downward, to prevent the boiler being
crushed by atmospheric pressure, by allowing the air to
pass in whenever the steam happens to decline. Two

Fis. 293.

Boiler of Stcam-ensme.

tubes, with stop-cocks, c and d, one just below the water-
level, and the other just above it, serve to show, by open-
ing the cocks, whether the water is too high or too low.

The working part of the engine is represented in the
figure on the following page (fig. 291). The steam enters
by the pipe, s, from the boiler on the other side of the
brick wall, as shown in fig. 290. The steam passes through
what is called a four-xaay-coch^ «, first into the lower, then
into the upper end of the cylinder, (7, as the piston, P,
moves up and down ; this is regulated by the levers, y y.
The piston-rod, E^ is attached to the working-beam, 3
F^ turning on the centre, A. The rod, F i?, turns the fly-
wheel, H H^ and drives the mill, steam-boat, or machinery
to be set in motion.

268

HEAT.

The condenser, J, shown directly under tlie cylinder, re-
mains to be described. It is immersed in a cistern of cold
water, and is connected by pipes with the upper and lower
end of the cylinder. Through these pipes the steam

Fi- 291.

Low-pressure Steam-engine.

passes out of the cylinder, first from one end and then
from the other, and is condensed into water by a jet of
cold water thrown into it by the hijection-cock. When
condensed, it is pumped out by the pump, O, into the well
or reservoir, TFJ and then again into the feed-pipe of the
boiler. Warm water is thus constantly supplied to the
boiler, and effects a great saving of fuel.

The supply of steam and the motion of the engine are
regulated by the governor, G. When the motion is too
fast, the two suspended balls, which revolve on a vertical
or upright axis, and which hang loosely like pendulums,
are thrown out from the axis, producing the movement of
a rod which shuts the steam-valve. When the motion

QUALITIES OF THE STEAM-ENGINE. 209

is too slow, the balls approach the axis, and open the
Talve.

In high-pressure engines, the steam is not condensed,
but escapes into the open air at every stroke of the piston,
which produces the loud, successive ^:>wjfoi of all engines
of this kind.

The steam-engine, in its most perfect form, is a striking
example of human ingenuity, and its qualities are thus
described by Dr. Arnott : "It regulates with perfect ac-
curacy and uniformity the number of its strokes in a given
time, and records them as a clock does the beats of its
pendulum. It regulates the quantity of steam ; the brisk-
ness of the fire ; the supply of water to the boiler ; the
supply of coals to the fire. It opens and shuts its valves
with absolute precision as to time and manner ; it oils its
joints; it takes out any air accidentally entering parts
which should be vacuous; and when any thing goes
wrong which it can not of itself rectify, it warns its at-
tendants by ringing a bell ; yet, with all these qualities,
and even when exerting a force of six hundred horses, it
is obedient to the hand of a child. Its aliment is coal,
wood, and other combustibles. It consumes none while
idle. It never tires, and wants no sleep. It is not sub-
ject to any malady when originally well made, and only
refuses to work when worn out with age. It is equally
active in all climates, and Avill do work of any kind ; it is
a Avater-pumper, a miner, a sailor, a cotton-spinner, a
weaver, a blacksmith, a miller, a printer, and is indeed of
all occupations ; and a small engine in the character of a
steam pony may be seen dragging after it, on an iron rail-
way, a hundred tons of merchandise, or a thousand per-
sons with the speed of the Avind."

Steam-engines have been much used on large farms in
England for thrashing, grinding the feed of animals, cut-
ting fodder, and for other purposes. A successful English
farmer has used a six-horse steam-engine to drive a pair

270

HEAT.

of mill-stones, for thrashing and cleaning grain, elevating
and bagging it, pumping water for cattle, cutting straw,

turning a grindstone,
and driving liquid ma-
nure through pipes
for irrigating his fields,
employing the waste
steam in cooking
food for cattle and
swine. In this country,
where horse labor is
cheaper, steam-engines
have not come into so
general use;, but on
large farms, where a
ten - horse - power or
more is required, they have been employed to much
advantage, consuming no food, and requiring no care

Fi-. 203.

WaxTs Farm Engine.

when

Wood's Engine on Wieds, with "Pipe Fdded Down.
idle. Excellent steam-en seines for this

purpose

are manufactured by A. iN". Wood & Co., of Eaton,

271

Madison Co., N. Y., a representation of which is given
in the accompanying figure (fig. 292.) When intended to
move from place to place, these engines are furnished ready
mounted on wheels (fig. 293). The twelve-horse-power
engines cost about $1,000, and have thrashed over a hund-
red bushels per hour, nsing half a cord of wood, or 300
or 400 lbs. of coal for ten hours. A Western farmer
thrashed 14,250 bushels of wheat in five consecutive weeks,
working five and a half days each, Avith one of tijese en-
gines. The smoke-pipe is guarded, so that straw placed
within a few inches cannot be set on fire.

More difficulty obviously exists in adapting the steam-
engine to plowing than for stationary purposes. In order
to possess sufficient power, when used as a locomotive,
the engine must be made so heavy as to sink in common
soft soil even with large and broad wheels ; and this
tendency is increased by the jar of the machinery Avhich
these wheels support. For this reason, all locomotive
plows have failed. Better success has attended the use
of stationary engines, employed for drawing gangs of
plows, by means of wire rope, across the fields. In Eng-
land, where much of the soil is tenacious, and w^here fuel
and manual labor are cheap, and horse labor expensive,
this mode of plowing has been found profitable when em-
ployed on an extensive scale, and is now much used.

EXCEPTIOX TO EXPAXSIOX BY HEAT.

A Striking exception to the general law of expansion by
;ieat occurs in the freezing of water.* During its change
to a solid state, it increases in bulk about one-twelfth, and
this expansion is accompanied with great force. The
bottoms of barrels are burst out, and cast-iron kettles are
split asunder, when water is suffered wholly to freeze in

* There are a very few other substauces which expand on passing
from a liciuid to a solid state.

272 HEAT.

them. Lead pipes filled with ice expand ; but if it is
often repeated, they are cracked into fissures. A strong
brass globe, the cavity of which Avas only one inch in di-
ameter, was used by the Florentine academicians for the
purpose of trying the expansive force of freezing water,
by which it was burst, although the force required was
calculated to be equal to fourteen tons. Experiments
were tried at Quebec, in one of which an iron plug, nearly
three pounds in weiglit, was thrown from a bomb-shell to
the distance of 415 feet ; and in another, the shell was
burst by the freezing of the water which it contained.

This expansion has a most important influence in the
pulverization of soils. The water which exists through
all their minute portions, by conversion to frost, crowds
the particles asunder, and when thawing takes place, the
whole mass is more completely mellowed than could pos-
sibly be effected by the most perfect instrument. This
mellowing is, however, of only short duration, if the ground
has not been well drained to prevent its becoming again
packed hard by soaking with water.

But this is not the most important result from the ex-
pansion of water. Much of the existing order of nature
and of civilized life depends upon, this property ; without
it the great mass of our lakes and rivers would become
converted into solid ice ; for, as soon as the surface became
covered, it would sink to the bottom, beyond the reach of
the summer's sun, and successive portions being thus add-
ed, the great body of all large rivers and lakes would
become permanently frozen. But instead of this disas-
trous consequence, the ice, by resting upon the surface,
Torms an effectual screen from the cold winds to the wa-
ter below.

LATENT HEAT.

If a vessel of snow, which has been cooled down to
several degrees below freezing by exposure to the severs

LATENT HEAT. 273

cold of Trinter, be placed over a steady fire with a ther-
mometer in the snow, the mercury will rise by the increas-
ing heat of the snow until it reaches the freezing point.
At this moment it will stop rising, and the snow will be-
gin to melt ; and although the heat is all the time passing
rapidly into the snow, the thermometer will remain per-
fectly stationary until it is all converted to water. The
heat that goes to melt the snow does not make it any hot-
ter ; in other words, it becomes latent (the Latin M'ord for
hidden)^ so as neither to affect the sensation of the hand
nor to raise the thermometer. ISTow it has been found that
the time required to melt the snow is sufficient to heat the
same quantity of water, placed over the same fire, up to
172 degrees, or 140 degrees above freezing ; that is, 140
degrees have become latent, or hidden, in melting the
snow.

This same amount of heat may be given out again by
placing the vessel of water out of doors to freeze. A
thermometer will show that the water is growing colder
by the escape of the heat, until freezing commences. Af-
ter this it still continues to pass off, but the water becomes
no colder until all is frozen, as it was only the latent heat
of the water that was escaping.

A simple and familiar experiment exhibits the same
principle. Place a frozen apple, which thaws a little be-
low freezing, in a vessel of ice-cold water. The latent
heat of the water immediately passes into the apple and
thaws it, and in an Iiour or two it will be found like a
fresh apple and entirely free from frost ; but the latent
heat having escaped from the water next the apple, a thick
crust of ice is found to encase it.

The amount of latent heat may be shown in still an-
other way. Mix a pound of snow at 32 degrees, or at
freezing, with a pound of water at 172 degrees. All will
be melted, but the two pounds of water thus formed will
12*

274 HEAT.

be as cold as the snow, showing that for melting it the
140 degrees in the hot water were all made latent.

APVANTAGES OF LATENT HEAT.

If no heat became latent by the conversion of ice and
snow to water, no time would, of course, be required for
the process, and thawmg would be instantaneous. On
the approach of warm weather, or at the very moment
that the temperature of the air rose above freezing, snow
and ice would all dissolve to water, and terrific floods and
inundations would be the immediate consequence.

LATENT HEAT OF STEAM.

A still larger amount of latent heat is required for the
conversion of water into steam; for, again place the ves-
sel of water with its thermometer on the fire, it will rise,
as the heat of the water increases, to 212 degrees, and
then commence boiling. During all this time it will now
remain stationary at 212, until the water is all boiled away.
This is found to require nearly five times the period need-
ed to heat from freezing to boiling ; that is, nearly one
thousand degrees of heat are made latent by the conver-
sion of water into steam.

When the steam is condensed again to water, this heat
is given out. Hence the use made of steam conveyed in
pipes for heating buildings, and for boiling large vats or
tubs of water, by setting free this large amount of latent
heat which the fire has imparted to it.

GREEN AND DRY WOOD FOR FUEI^

A great loss is often sustained in burning green wood
for fuel, from an ignorance of the vast amount of latent
heat consumed to drive off the water the wood contains.
When perfectly green, it loses about one-third of its weight

GREEX AND DRY AVOOD FOE FUEL. 275

by thorough seasoning, which is equal to about 25 cubic
feet in every compact cord, or 156 imperial gallons. Kow
all this water must be evaporated before the wood is burn-
ed. The heat thus made latent and lost, being five times
as great as to heat the water to boiling, is equal to enough
for boiling 780 imperial gallons in burning up every cord
of green wood. The farmer, therefore, who burns 25
green cords in a winter, loses heat enough to boil more
than fifteen thousand gallons of water, which would be
saved if his wood had been previously well seasoned un-
der shelter.

The loss in using green fuel is, however, sometimes
overrated. It has been found by experiment that one
pound of the best seasoned wood is sufficient to heat 27
lbs. of water from the freezing to the boiling point.*
This will be equal to heating and evaporating four pounds
of water by every pound of wood. The 25 cubic feet of
water, therefore, in every cord of green wood, weighing
about 1,500 pounds, would require nearly 400 pounds of
wood for its evaporation, or about one-seventh or one-
eighth of a cord. Hence we may infer that seven cords
of dry wood are about equal to eight cords of green.
This imperfect estimate will apply only to the best hard
wood, and will vary exceedingly with the different sorts
of fuel ; the more porous the wood becomes, the greater
will be the necessity for thorough seasoning.

* The following results show the heatmg power of several combust-
ibles :
1 lb. of wood (seasoned, but still holding 20 per cent of water)

raised from 32° to 212° 27 lbs. Avater.

lib. ofalcohol 68 "

1 lb. of charcoal 78 " "

1 lb. of oil or wax 90 " "

1 lb. of hydrogen 216 " "

It should be remembered that by ordinary modes of heating water, a
very large proportion of the heat is wasted by passing up the chimney
and into surrounding bodies, and the air.

276 HEAT.

Superficial observation often leads to very erroneous
conclusions. Seasoned wood will sometimes burn with
great rapidity, and, producing an intense heat for a short
time, will favor an overestimate of its superiority. Green
wood, on the other hand, kindles with difficulty, and
burns slowly and for a long time; hence, where the
draught of the chimney can not be controlled, it may be the
most economical, because a less proportion of heat may
be swept upward than by the more violent draught pro-
duced from dry materials. Where the draught can be
perfectly regulated, however, seasoned wood should be
always used, for convenience and comfort, and for economy.

Where wood is to be drawn to a distance, the preceding
estimate shows that the conveyance of more than half a
ton of water is avoided in every cord by seasoning.

CHAPTER II.

RADIATION OF HEAT.

The passage of heat through conducting bodies has
been already explained. There is another way in which it
is transmitted, termed radiation, in which it is thrown off
instantaneously in straight lines from hot bodies, in the
same way that light is thrown off from a candle. A
familiar instance is furnished by the common or open fire-
place, before which the face may be roasted with the
radiated heat, while the back is chilled with cold. A
screen held in the hand will intercept this radiated heat,
showing that it flies in right lines like tlie rays of light. .

Radiated heat is reflected by a polished metallic surface,

KADIATIOX OF HEAT.

277

in the same way that light is reflected by a looking-glass.
A plate of bright tin held near the fire will not for a long
time become hot, the heat being reflected from it without
entering and heating it. But if it be blackened with
smoke, it will no longer reflect, but absorb the heat, and
consequently will speedily become hot. This experiment
may be easily tried by placing a new tin cup containing
water over a charcoal fire, which yields no smoke. The
heat will be reflected into the fire by the tin, and the w^a-
ter will scarcely become warm. But if a few pine shav-
ings be thrown on this fire, to smoke the surface of the tin,
it will then absorb the heat rapidly, and soon begin to
boil. This explains the reason that bread bakes more
slowly in a new tin dish, and that a polished andiron be-
fore a fire is long in becoming hot.

A concave burning-mirror, which throws the rays of
heat to a focus or point, may be made of sheet-tin, by

Fig. 294.

beating it out concave so as to fit a regularly curved
gauge. If a foot in diameter, and carefully made, it will
condense the rays of heat so jiowerfuUy at the focus, when
held several feet from the fire, as to set fire to a pine stick
or to flash gunpowder (fig. 294).

The reflection of radiated heat may be beautifully ex-
hibited by using two such concave tin mirrors. Place
them on a long table several feet apart, and ascertain the
focus of each by means of the light of a candle. Then
place in the focus of one a red-hot iron ball, or a small
chafinoc-dish of burning^ charcoal. In the focus of the

278

HEAT.

other place the wick of a candle with a small shaving of
phosphorus in it. The heat will be reflected, as shown by

Fig. 295.

the dotted lines (fig. 295), and, setting fire to the phos-
phorus, will light the candle.

If a thermometer be placed in the focus of one mirror
while the hot iron ball is in the other focus, it will rise
rapidly ; but if a lump of ice be substituted for the ball,
the thermometer will immediately sink, and will continue
to do so until several degrees lower than the surrounding
air ; because the thermometer radiates more heat to the
mirrors, and then to the ice, than the ice returns.

DEW AND FROST.

All bodies are constantly radiating some heat, and if an
equal amount is not returned by others, they grow colder,
like the thermometer before the lump of ice. Hence the
reason that on clear, frosty nights, objects at the surface
of the earth become colder than the air that surrounds
them. The heat is radiated into the clear space above
without being returned ; plants, stones, and the soil thus
become cooled down below freezing, and, coming in con-
tact with the moisture of the air, it condenses on them
and forms dew^ or freezes into white frost. Clouds return
or prevent the passage of the heat that is radiated, which
is the reason there are no night-frosts in cloudy weather.
A very thin covering, by intercepting the radiated heat,
will often prevent serious injury to tender plants. Even

FROST IN VALLEYS. 279

a sheet of thin muslin, stretched on pegs over garden
vegetables, has afforded sufficient protection, when those
around were destroyed.

FEOST IN VALLEYS.

On hills, where the wind blows freely, it tends to re-
store to plants the heat lost by radiation, which is the
reason that hills are not so liable to sharp frosts as still
valleys. When the air is cooled it becomes heavier, and,
rolling down the sides of valleys, forms a lake of cold air
at the bottom ; this adds to the liability of frosts in low
places. The coldness is frequently still fuither increased
by the dark and porous nature of the soil in low places
radiating heat faster to the clear sky than the more com-
pact upland soil.

A knowledge of these properties teaches us the import-
ance of selecting elevated places for fruit-trees, and all
crops liable to be cut off by frost ; and it also explains
the reason that the muck or peat of drained swamps is
more subject to frosts than other land on the same level.
Therefore, corn and other tender crops upon such porous
soils must be of the earliest ripening kinds, so as to escape
the frosts of spring by late planting, and those of autumn
by early maturity.

REMARKABLE EFFECTS OF HEAT ON WATER.

The effects of heat and cold on water are of a very in-
teresting character. Without its expansion in freezing,
the soil would not be pulverized by the frost of winter,
but would be found hard, compact, and difficult to culti-
vate in spring ; without its expansion into steam, the
cities which are now springing up, and the continents that
are becoming peopled, through the influence of rail-ways,
steam-ships, and steam manufactures, would mostly re-

280 HEAT.

main unbroken forests ; "without the crystallization of wa-
ter, the beautiful protection of plants by a mantle of snow,
in northern regions, would give place to frozen sterility ;
without the conversion of heat to a latent state in melt-
ing, the deepest snows would disappear in a moment from
the earth, and cause disastrous floods ; Avithout its con-
version to a latent state in steam, the largest vessel of
boiling water would instantly flash into vapor. All these
facts show that an extraordinary wisdom and forethought
planned these laws at the creation ; and even what appears
at first glance as an almost accidental exception in the
contraction of bodies by cold, and which causes ice to
float upon water, preventing the entire masses of rivers
and lakes from becoming permanently frozen, furnishes
one out of an innumerable array of proofs of creative de-
sign in fitting the earth for the comfort and sustenance of
its inhabitants.

APPENDIX.

SIMPLE APPARATUS FOR ILLUSTRATING MECHANICAL
PRINCIPLES.

For tbe assistance of lecturers, teachers, and home students, the fol-
lowing list is given of cheap and simple apparatus and materials for
performing most of the experiments described in tlie first part of this
work. These experiments, although simple, exhibit principles of much
practical importance.

1. Inertia apparatus, 15. 12. The concave post or stand is sufficient,
the snapping being done by the finger, although a spring-snap performs
the experiment more perfectl}'.

2. Weight with two hooks and fine thread, p. 13,

3. The inertia of falling bodies may be simply shown, and the pile-
engine illustrated, by placing a large wooden peg or rod upright in a
box of sand, and then dropping a weight upon its head at different
heights, which will drive the rod into the sand more or less, according
to the distance passed through by tlie falling weight.

4. A straw-cutter, so made that the fly-wheel can be easily taken off,
will show in a very striking manner the efficacy of this regulator of
force.

5. Two lead musket balls Avill exhibit the experiment in cohesion,
p. 27. Balls or lead weights with hooks may be separated by sus-
pending weights, to show the amount of force required to draw tlieni
asunder. Metallic buttons or plates an inch in diameter, with hooks,
will show the great strength needed to separate them when coated with
grease, p. 27.

6. Capillary tubes of dilTerent sizes, two straight small panes of glass,
and a vessel of water, highly colored with cochineal or other d3'e, to ex-
hibit capillary attraction.

7. Glass tube, piece of bladder, and alcohol, for experiment described
on p. 33.

8. The cylinder for rolling up the inclined plane, represented by
fig. 18, p. 34, may be very easily made by using a round pasteboard
box a few inches in diameter, and securing a piece of lead inside by
loops made with a needle and thread. The object shown by fig. 19
may be cut in one piece out of a pine shingle, the centre rod being
lengthwise with the grain ; the two extremities are shaved small, and
Avouud with thick sheet-lead, and the whole then colored or painted a

281

282 APPENDIX.

dark hue, to render the lead inconspicuous. The experiment with the
penlvnives, p. 35, is very simple, care being taken to insert them low
enou^^h in the stick.

9. Irregular pieces of board, variously perforated with holes, and fur-
nished with loops to hang on a pin, may be used to determine the centre
of gravity, according to the principle explained by fig. 21, p. 35.

10. Portions of plank and blocks of wood, with the centre of gravity
determined as in the last experiment, may have a plumb-line (which
may be a thread and small perforated coin) attached to this centre, and
then be placed on differently inclined surfaces, to show their upsetting
just as this line of direction falls without the base. Toy-wagons, bought
at the toyshops, may be variously loaded and used in experiments of
this sort.

11. Experiments with the lever of the first kind may be easily per-
formed by the use of a flat wooden bar, two or three feet in length,
marked into inches, and placed on a small three-cornered block as a
fulcrum. Weights, such as are used for scales, may be variously
placed upon the lever. Levers of the second and third kind, which are
lifted instead of borne doAvn, may have a cord attached to the point
where the power is to be applied, running up over a pulley or wheel,
with a weight suspended to the other end.

12. An axle, furnished with wooden wheels with grooved edges, of
different sizes, may be used to exhibit the principle of the wheel and
axle, in connection with scale-weights that are furnished with hooks.
The power of combined cog-wheels may be shown by a combination
like that represented on p. 57, using weights for both cords.

13. Interesting experiments with the inclined plane, at different de-
grees of slope, by a contrivance similar to that represented by fig. 96,
p. 83, with the addition of a small wheel at the upper side for a cord to
pass over. This cord is fastened at one end to a light toy-wagon, run-
ning up and down the plane, and at the other to a weight suspended
perpendicularly just beyond the upper edge of the plane. The wagon
is variously loaded witli weights, to counterpoise the suspended weight
at different degrees of inclination.

14. A lecturer may quickly demonstrate before a class the small in-
crease in the length of a road, in consequence of a considerable curve
to one side of a straight line (as shown by fig. 69), by using a cord for
measuring, the diagram being marked on a board or the wall.

15. A round stick-of wood, and a long, Avedge-sliaped slip of paper,
easily show the principle of fig. 75, j). 70.

16. A cog-wheel with endless screw and Avinch (fig. 77, p. 71), exhibits
distinctly the great power of the screw in this combination.

17. Pine sticks, two feet long, and ono-fourth to one-half inch through,
of different shapes and sizes, supported at each end, and with weights
hung at the middle till they break, may be made to illustrate the princi-
ples described on pp. 80, 81.

18. Some of the urinciplcs of draught may be shown, and especially

APPARATUS FOR EXPERIMENTS. 283

tbosc in relation to the different angles of inclination for hard and soft
roads, by usiuj; a common spring-balance as a dynamometer, attached
to a hand-wagon, and also to a sliding block of wood.

19. Bent glass tubes, with arms of different sizes, to indicate the up-
ward pressure of liquids, may be procured cheaply at glass-works. The
experiment described by fig. 231, p. 204, may be rendered easy and inter-
esting by purchasing a large and perfectly-working syringe, and attach-
ing to its nose, by means of sealing wax, a slender glass tube two or
three feet long. Fill the syringe with water, leaving the tube empty ;
then, with the tube upright, drive the water up Ihrough it with the pis-
ton of the syringe, and the increased Aveight felt on the piston as the
column of water rises will be very evident.

20. A hydrostatic bellows a foot in diameter, made by any good
mechanic, will answer the purpose well, and exhibit an important prin-
ciple.

21. Specific gravities may be shown before a class by a common
balance and a fine cotton or silk thread.

23. A tin pail, with a hole half an inch or an inch in diameter at the
bottom, will show the contracted stream which pours from it, p. 212.
A short tin tube, with a slight flange at the upper end (quickly made
by any tin-worker), fitted into this hole, will increasti the discharge, as
shown by figs. 236, 237, and the difference in time for emptying the ves-
sel may be measured by a stop-watch.

23. Archimedes' screw is readily made by winding a lead pipe round a
wooden cylinder.

24. A glass syphon, filled with cochineal water, shows distinctly the
theory of waves, by bloAving with the mouth into one end.

25. Any vessel, filled with sand which has been heated over a fire,
with rods of different substances, nearly of an equal size and length,
and thrust with one end into the hot sand, in an inclined or nearly hori-
zontal position, will exhibit the various conducting powers of these
rods by melting pieces of wax or tallow placed on the ends most remote
from the sand.

26. The expansion by heat may be demonstrated by fitting an iron
rod to a hole in sheet-iron ; on heating the bar it can not be made to
enter. Oi-, if a hot iron ring be slipped on a tapering cold iron rod, it
will contract on cooling so that the force of a man can not withdraw the
rod.

27. The rising and descending currents in a vessel of heating water
are easily rendered visible by throwing into a glass vessel, or flask, over
a lamp, particles of sawdust from any hard, green wood, Avhose specific
gravity is about the same as that of water.

28. Instrument figured on p. 265, for showing the principle of the
steam-engine.

29. Experiments in latent heat may be easily exhibited with the as-
bistance of a common thermometer.

30. Tin mirrors for showing radiation, p. 278.

284

APPENDIX.

DISCHARGE OF WATER THROUGH PIPES.

Table showing the amount of water discharged per miuute through
an orifice one inch iu diameter ; also throui^h a tube one inch in diame-
ter and two inches long, according to experiment. To ascertain the
amount in gallons, divide the cubic inches by 231.

Height of head Amount discharged Amount discharged

of water. through Orifice. through Tube.

1 Paris foot* 2,722 cub. in. 3,539 cub. in.

2 " 3,846 " 5,002

3 " 4,710 " 6, 6

4 " 5,436 " 7,070

5 " 6,075 " 7,900 "

6 " 6,654 " 8,654

7 " 7,183 " 9,340

8 " 7,672 " 9,975

9 " 8,135 " 10,579

10 " 8,574 " 11,151

11 " 8,990 " 11,693 "

12 " 9,384 " 12,0 5 "

13 " 9,764 " 12,699 "

14 " 10,130 " 13,177

15 " 10,472 " 13,620 "

VELOCITY OF WATER IN PIPES.

The

following table shows

the height of a head of water required to

overcome the friction

in horizontal pipes

100 feet Ion

ig, and to produce a

certain velocit}', according to Smeaton :

Bwe of

Pipes. 6 Inches.

1/00^.

\%feet

, 2

Jeei.

Zfeet.

Afeet

hfeet.

in.

in.

In.

in.

ft.

in.

ft. in.

ft.

in.

ft. in.

X

4.5

16.7

35.1

4

9.7

10 1.0

17

10.0

28 0.2

%

3.0

11.1

23.3

3

2.5

6 8.6

11

10.6

18 8.1

1

2.3

8.4

17.5

2

4.9

5 0.5

8

11.0

14 0.0

1J<

1.8

6.7

14.0

1

11.1

4 0.4

7

1.6

11 2.5

IK

1.5

5.6

11.7

1

7.2

3 4.3

5

11.3

9 4.1

Wa.

1.3

4.8

10.0

1

4.5

2 10.6

5

1.1

8 0.1

2

1.1

4.2

8.7

1

2.4

2 6.2

4

5.5

7 0.0

2^

1.0

3.7

7.8

1

0.8

2 9.9

3

11.6

6 2.7

^%

0.9

3.3

7.0

0

11.5

2 0.2

3

6.8

5 7.2

3

0.7

2.8

5.0

0

9.6

1 8.2

2

11.7

4 8.0

3K

0.6

2.4

5.0

0

8.2

1 5.3

2

6.6

4 0.0

4

0.6

2.1

4.4

0

7.2

1 3.1

2

2.7

•3 6.0

* A Paris foot is about 12 4-5 U.
16 U. S. feet.

S. inches, and 15 Paris feet are about

RULE FOR THE DISCHARGE OF WATER. 285

Look for the velocity of the water per secoud ia the pipe, in the up-
per line ; Mud in the column beneath it, and opposite the given diameter
of tlie pipe, is the height of the column or head required to obtain the
required velocity.

To tind the quantity of water discharged each minute, multiply the
velocity by 12, which will give the inches per second ; then multiply
this product by 60, which will give the inches per minute; then, to
change these cylindrical inches into cubic inches, multiply by 4 and
divide by 5.* Divide the cubic inches by 231, and the result will be
gallons.

By comparing this table with the next preceding, we shall perceive
that the water flows from three to four times as fast through the tube
two inches long, as through a tube onelmndred feet long, the diameter
of the tube and the head of water being the same.

RULE FOR THE DISCHARGE OF WATER.

The following general formula or rule, applicable to different cases,
has been furnished by a practical engineer. It may be useful in ascer-
taining the quantity required to fill the driving pipe of a water-ram, and
for various other purposes occasionally occurring in practice.

Let A represent the fountain or reservoir from which water is to be
conveyed to the trough B through the pipe L. Let JI be the height of
the surface of the water in the reservoir, above the place of discliarge,
L the length of the tube in feet, and let D be the diameter of the tube
in the smallest part. It is required to llnd the quantity, Q, which will
be discharged in a second of time. The length and height being given
in feet, and the diameter of the tube in inches, the formula, when the
quantity is required in gallons, is as follows :

Q = 0.608 |/(^ l)

• This gives the cubic inches very nearly; but, to be more accurate, multiply
the decimal .7S54. which represents the difference between the area of a square
and of a circle.

286

APPENDIX.

In order to make the above formula more intelligible:
Let L = 80 rods or 1320 feet.
" H = 50 feet.
" D= 2 inches.
" Q = gallons.

Then Q =0.608 V (32 x-,f|o) = 0.67; or, the same maybe thus ex-
pressed in words :

Divide the height (50) by the length (1320); multiply the quotient by
the fifth power of the diameter (fifth power of 2'= 32); extract the
square root of the product, which, being multiplied by 0.60S, will give
(0.67) the number of gallons the tube will discharge in one second;
which, in this case, is 40 gallons in one minute.

VELOCITY OF WATER IN TILE DRAINS.

An acre of land in a Avet time contains about one thousand spare
hogsheads of water. An underdrain will carry off from a strip of laud
about two rods wide, and one eighty rods long will drain an acre. The
following table will show the size of the tile required to drain an acre in
two days' time, (the longest admissible), at different rates of descent, or
the size for any larger area :

Diameter of Bore. Rate of Descent.

2 inches. 1 foot in 100

2 inches. 1 foot in 50

2 inches. 1 foot in 20

2 inches. 1 foot in 10

3 inches. 1 foot in 100
3 inches. 1 foot in 50
3 inches. 1 foot in 20

3 inches. 1 foot in 10

4 inches. 1 foot in 100
4 inches. 1 foot in 50
4 inches. 1 foot in 20
4 inches. 1 foot in 10

A deduction of one-third to one-half must be made for the roughness
of the tile or imperfection in laying. The drains must be of some
length, to give tlie water velocity, and these numbers do not, therefore,
apply to very short drains.

Yelocity of

Hogsheads

Current per

discharged

second.

in 24 hours

22 inches.

400

32 inches.

560

51 inches.

900

73 inches.

1290

27 inches.

1170

38 inches.

1640

67 inches.

3100

84 inches.

3600

32 inches.

2500

45 inches.

3500

72 inches.

5600

too inches.

7800

GLOSSARY

OF TERMS USED IN MECHANICS AND FARM MACHINERY.

Axis, a real or imaginary line, passing thiougli a body, on wliicli it is
supposed to revolve.

Axle or axle-tree, the bar of metal or timber, on tlie ends of Avhicli
the wheels of a carriage or wagon or other wheels revolve.

Babbett metal, an alio}', usually of tin and copper, for casing the
supports of journals, cither for repair, or for easier running.

Back fckrow, to throw the earth from two plow-furrows together. .

Ball-cock, a self-regulating stop-cock, closed or opened by the rising
or falling of a floating hollow ball.

Ball-valve, a valve consisting of a loose ball, fitting closely, pre-
vented from moving beyond a certain limit.

Band-wheel, a wheel in machinery on which a band or belt runs.

Beam, the main lever of a steam-engine, turning on the centre, with
the piston rod at one end, and the working-rod at the other. Also, the
main timber or bar of a plow.

Bearing, the part of a shaft or spindle which is in contact with the
supports.

Bed, the foundation on which a fixed machine rests, as " the bed of an
engine."

Bell-crank, a crank resembling that by which the direction of a bell-
wire is changed.

Bevel-gear, the gearing of cog-wheels placed obliquely together, or
with the two axes forming an angle.

Bolster, the cross-bar of a wagon, resting on the axle, holding the
box, and through which the king-bolt passes.

Brake, a lever or other contrivance used for retarding the motion of
a wheel by friction against it.

Breast-wheel, a water wheel where the current is delivered upon it
about one-half or two-thirds its height, which distinguishes it from un-
dershot and overshot wlieels.

Bridle, the forward iron on the beam of a plow, to which the team
is attached.

BjiusH-WEEEL, a wheel in light machinery, turned by friction merely,
instead of cogs ; bristles or brushes being often fixed to them to increase
the friction of their pressing surfaces.

Bush, the hollow box fitted into the centre of a wheel to take the
bearing of an axle or journal.
28T

288 GL03SAKT.

Cam, the projecting part of an eccentric or -wavy wlic?-l, to produce
alternate or reciprocating motion.

Cant-hook, a wooden lever with an iron hook near one end, used for
moving heavy articles, particularly saw-logs, etc. The end of the lever
is usually placed on the fulcrum, and the hook is fixed into the weight,
making it a lever of the second kind.

Capillaky attkaction, the attraction which causes liquids to I'isc in
very small tubes, or which retains Avater among sand and the particles
of soil.

Centhe of gravity, that point in a body or mass of matter, around
which all parts exactly balance each other.

Centkifugal. force, tending to fly from the centre, as the stone from
a sling.

Centripetal force, drawing towards the centre, like the cord of a
sling.

Chamfer, a slope, channel, or groove, cut in wood or metal.

Chase, a wide groove.

Chilled, applied to cast-iron rendered harder by casting the melted
metal against cold metal in the mould, for rendering certain parts harder
which are most liable to become worn.

Chine, the ends of the staves of a barrel, outside the heads.

Clamp, a cross-bar used to give additional strength, or to prevent
warping. Also, a piece of metal or wood, generally resembling in shape
the letter U, furnished with a screw, to fasten objects to a table or other
fixed bodies, or to each other.

Cleat, a piece of wood nailed across, to give strength or security.

Clevis, a draught iron, usually somewhat in the form of a bow or let-
ter U, placed on the forward end of a plow-beam for draught, or for
similar purposes.

Click, a pawl, a latch, or the ratchet of a wheel.

Cog, the tooth or projection of a cog-wheel.

Collar, a metal ring around the cud of a cylinder of wood to prevent
splitting, or a ring around a piston or a journal, for securing tightness
or steadiness.

Colter or Coulter, the upright cutting iron of a plow.

Compass, an instrument for describing circles, measuring distances, etc.

Counter-sink, a cavity made to receive the head of a screw.

Coupling-box, a contrivance for connecting shafts,' or throwing
wheels in and out of gear.

Crab, a small portable crane.

Cradle, a scythe with fingers, for cutting grain by hand.

Crane, a machine for raising weights and then swinging them side-
Avise ; generally made by attaching a pulley to a swinging bar or frame.

Crank, an axle Avith a crooked portion for changing a rotary to an
alternate motion, or the reverse. A tJiree-throw crank has three bends,
for driving three pumps, each stroke separated from the others by the

GLOSSAET. 289

third of a revolution, tlius making a regular aud uniform application of
the force.

Cross-cut Saw, a large saw worked by a man at each end, for cutting
logs.

Cutter-bar, the cutthig apparatus of a mowing or reaping machine.

Cycloid, a curve made by any point in a circle rolling on a straight
line, and marking the curve on a plane surf\ace at the side of the circle.
A rail driven in the rim of a wagon- wheel, driven through a snow bank,
will mark a cycloid on the snow. An epiajcloid is made by a similar
revolution of a circle, rolling on the circumference of another circle,
externally or interually.

Dead centre, a centre which does not revolve.

Dead furrow, the furrow where the plow throws the earth in oppo-
site directions, or where the furrows meet in plowing a strip of land.

Derrick, a pole or upright timber for supporting a crane, used in lift-
ing heavy materials in building and for other purposes.

Dog, an iron catch or clutch, driven into the end of a saw-log, to hold
it in a fixed position while sawing.

Double-tree, the central whiffle-tree of a two-horse set.

Dowel, a short iron or wooden pin to join tAVO pieces of timber, pro-
tecting from one timber into a hole in the corresponding one. A
familiar example occurs in the manner in which a cooper secures two or
more boards in forming the head of a cask.

Draught, Ai^gle of, the angle made by a line of draught with a line
drawn on ^he surface over which the body is drawn.

Dredge, or Dredging Machine, a machine for scooping np mud or
earth from under water, for clearing the channels of canals, rivers, aud
harbors.

Drill, a furrow for the reception of seed, or a row of growing plants ;
also a machine for sowing seed in continuous rows.

Driving-avheel, the wheel of a mowing or reaping machine, which
runs on the ground, and propels the gearing.

Drum, a revolving cylinder, around which belts or endless straps are
passed, to communicate motion.

Dynamics, the science of motion and forces.

Dynamometer, an instrument for measuring forces, applied to plows,
mowing machines, thrashing machines, etc., to show the amount of
ibrce lequired to work them.

Eccentric, out of centre; applied to wheels, discs, or circles, with
the axle out of centre, to create reciprocating motion. Eccentric rod is
the rod that transmits the motion of the eccentric wheel.

Elevator, an endless revolving leather strap, set with sheet-iron
boxes or cups, for raising grain. The term is also applied to buildings
into which grain is thus elevated and stored.

Emery wheel, a wheel set with emery at the circumference, for
grinding or polishing metals.

Endless chain, a chain with the ends connected together, rui^ning on
1^

290 GLOSSARY.

two drums or cylinders ; as in the endless chain or tread-powers to
thrashing machines.

Endless screw, a screw working in a toothed wheel or cog-wheel,
and imparting a motion to the wheel equal to the advance of one tooth
to each revolution of the screw.

Epicycloid, see Cycloid.

EncYCLOiDAL WHEEL, a whccl with cogs on its interior rim, fitting
into another cog-wheel precisely one-half its diameter, for converting
circular into alternate motion ; any point in the circumference of the
smaller wheel, while in motion, describing a straight line.

EvENER, the central or larger wliiffle-tree of a set of whiffle-trees for
two horses, called also a double-tree.

Fan, the vane of a wind-mill, to keep the sails facing the wind.

Feather, the thin cutting part of a plowshare, on the right-hand side.

Felloe, or Felly, the circumfei*euce or rim of a wheel, or a segment
of it, into which the spokes are inserted.

Ferrule, a ring or band on the end of a wooden rod or bar, to pre-
vent splitting.

Female screw, a hole cut with the threads of a screw, into which a
screw fits.

FiNGER-BAR, that poi'tiou of the cutting-bar of a mowing or reaping
machine, in which the knife-bar works.

Flange, a projection from the end of a pipe or from any piece of
mechanism, so as to screw to another part ; a term also applied to tlie
projection of a car-Avhcel to keep it from running off the rail.

Flash-wheel, a water-wheel used for elevating water, resembling a
breast-wheel with a reversed motion.

Float-board, one of the boards forming the exterior of a water-
wheel, against which the stream of water dashes.

Flume, the water passage of a mill, usually a box of plank.

Fly-wheel, a wheel with a heavy rim, for retaining inertia and equal-
izing the motion of machinery.

Foot-valve, a valve in a steam-engine, opening from the condenser
towards the air-pump.

Force-pump, or Forcing-pump, a pump with a solid piston, which
drives instead of sucking water.

Friction-wheel, made by two wheels overlapping each other, and
bearing between them the axle or journal of another wheel, thus dimin-
ishing the friction of the latter.

Fulcrum, a support; applied to the support used for the lever, in
raising weights.

Furrow slice, the strip of earth thrown out by the plow at a passing.

Furrows, flat and lapping; when the slice is laid flat or level, and
when the edge of one overlaps the preceding, respectively.

Gang-plow, a compound plow made of a series of plows running side
by side.

Gavel, a sheaf of grain reaped but not bound.

GLOSS AEY. 291

Gearing, a series of cog-wheels -svorking together.

Governor, a self-regulator of a steam-engine, so constructed that
centrifugal force throws up weights A^hen the cni;ine runs too flist, and
partly closes the admission pipe of steam ; and, dropping again whsn it
runs too slow, opens the steam pipe.

Gravitation, the attraction between bodies iii mass, as distinguished
from cohesion between the parftc?es; the force which causes bodies to fall
by the attraction of the earth.

Guard, one of the fingers in the cutting apparatus of a mowing or
reaping machine, for protecting the knives from injury from external ob-
jects. Open Guard has an opening above the knives, to prevent clog-

Hat-tedder, a machine for spreading and turning hay.

Header, a reaping machine which cuts the heads of the grain and
leaves most of the straAV standing.

Head-land, the strip or border of nnplowed land left at the ends of
the furrows.

Hound, the forward portion of a wagon, to which the tongue is at-
tached.

Hydraulic Ram, see Ham.

Hydraulics, the science of water in motion, or the laws of motion
and force as applied to running water, and to machinery driven by it.

Hydrodynamics, the laws of motion and force, as applied to liquids,
both in motion and at rest, and embracing Hydraulics and Hydrostatics.

Inclined plane, a plane or surface deviating more or less from a
level.

Inertia, the property or force of matter by which it retains its state
of motion or rest,— requiring force to start a body at rest or to stop one
in motion.

Jack, an engine or machine for raising heavy weights.

Jack-screw, a strong iron screw for raising timbers, buildings, etc.

Journal, the portion of a shaft or axle which revolves on a support.

Kerf, the opening or slit made by the passage of a saw.

Key, a wedge of wood or metal driven into a mortise or opening, to
secure two parts together.

Knee-joint, or Toggle-joint, a contrivance for exerting power or
pressure, by straightening a double bar with a joint like that of the knee.

Land, a term applied to the oblong portion of a field around which
the team passes in plowing, the field being usually divided into several
layids for this purpose. The term is also applied to the side of a plow
opposite the mould board, and a plow is said to run to land when it takes
too wide a furrow-slice.

Land-side, the side of that portion of a plow which runs in the
soil, opposite the mould-board, and next the unplowed portion of ground.

Lantern wheel, a pinion made of two small wheels connected by
parallel rods which form the teeth.

292 GLOSSARY.

Lever, a bar or rod for raising weights, resting on a point called a
fulcrum.

Lever-power, see Sweep-power.

Male screw, a screw with a spiral thread, fitting into a hole with cor-
responding threads called a. female screw.

Mechanical powers, the simple machines or elements of machinerj',
consisting essentially of the Lever and Inclined Plane ; the lever com-
prising the Wheel and Axle and the Pulley, and the inclined plane com-
prising the Wedge and the Screw.

Masu, or Mesh, to interlock, as the teeth of cog-wheels.

Mechanics, the science that treats of forces and powers, and their
action on bodies, and particularly as applied to the construction of ma-
chines.

Mitre, to cut to an angle of 45 degrees, so that two pieces joined
shall make a right angle.

Momentum, impetus ; the force of a moving bod}'.

Monkey, an apparatus for disengaging and securing again the ram of
a pile-engine.

Mortise, a hole cut to receive the end or tenon of another piece.

Nut, a piece of iron furnished with a screw-hole, used on the end of a
screw for securing tlie parts of machinery.

Overshot wheel, a water-wheel, the circumference of which is fur-
nished with cavities or buckets, into which the stream of water is deliv-
ered at the top, turning the wheel by its weiglit.

Pall, or Pawl, the catch of a ratchet-wheel ; a click.

Pent-stock, an upright flume.

Perambulator, a measurer of distances, consisting of a wheel, and
index to show by wheelwork the number of its turns.

Percussion, Centre of, that point of a moving body at which its im-
petus is supposed to be concentrated.

Pile-driver, or Pile-engine, an engine for driving piles into the
ground, eflccted by repeatedly dropping a heavy weight on the heads of
the piles ; used mostly in swamp or water when the bottom is mud.

Pinion, a small-tootlied wheel, working in the teeth of a larger one.

Pitch, the distance between the centres of two contiguous cog-wlieels.

Pitch line, the circle, parallel with the circumference, which passes
through the centres of the teeth of a wheel.

Pitman, a rod connected with a wheel or crank, to change rotary to
reciprocating motion, or the reverse.

Planet-wheels, two elliptical wheels connected by teeth running
into each other, and revolving on their foci.

Plow-beam, the main timber of a plow, by which it is drawn.

Plow-share, tlie front part beneath the soil, which performs the cut-
ting— sometimes cq\\(^(\ plow-shoe^ or plow-point.

Plunger, the piston of a forcing pump.

Pneumatics, tlie science treating of the mechanical properties of air.

Pole, the tongue of a reaping or other machine.

GLOSSARY. 293

Po\rER, the moving- force of a machine, as opposed to the weight,
load, or resistance of the substance wrought upon ; also called prime
mover.

Projectile, a body thrown throu<;h the air.

Pulley, one of the mechanical powers, consisting of a grooved wheel
called the sheave^ over which a rope passes ; the box in which the wheel
is set is called the block. The term is also applied to a fixed wheel over
which a band or rope passes.

Pump, a hydraulic machine for raising water; or one for withdrawing
air. The handle is called the brake.

Quantity of motion, the velocity of a moving body multiplied by its
mass.

Rabbet, to pare down the edge of a board or timber.

Rack, a straight bar cut with teeth or cogs, working into a correspond-
ing cog-wheel or pinion which drives or follows it.

Rag-wheel, a M-heel with teeth or notches, on which an endless or re-
volving chain usually runs. Also applied to a ratchet wheel.

Rake-head, the cross-bar of a rake, which holds the teeth.

Ram, Hydraulic ram, or Water-ram, a hydraulic machine or engine
for raising water to a height several times greater than that of the head
of water, by employing the momentum of the descending current in
successive beats or strokes.

Ratchet-avheel, a wheel cut with teeth like those of a saw, against
which a click or ratchet presses, admitting free motion to the wheel in
one direction, but insuring it against reverse motion.

Reach, the bar which connects the forward and rear axles of a wagon
or carriage.

Ream, to bevel out a hole.

Reciprocating motion, alternate motion, or a movement backwards
and forwards in the same path.

Reel, the revolving frame of a reaping machine, to throw the stand-
ing grain towards the knives.

Resolution of forces, dividing a force into two or more forces act-
ing in different directions ; rendering a compound force into its several
simple forces.

Resultant, a force produced by the combination of two or more
forces.

Safety valve, a valve opening outwards from a steam boiler, and
kept down by a Aveight, permitting the escape of steam when the press-
ure reaches a certain point, regulated by the degree of weight. The
term also applies to a valve opening inwards, and similarly regulated, to
prevent the pressure of the atmosphere from crushing in the boiler when
the steam cools and leaves a vacuum.

Scoop- wheel, a water-wheel with scoops or buckets around it, against
which the current dashes.

Screw-bolt, a bolt secured by a screw, or with a screw cut upon it.

Screw-propeller, an instrument for driving a vessel, by means of

294 GLOSSARY.

blades twisted like a screw, revolving beneath the water, the axis being
parallel with the keel.

Section, one of the knives or blades on the cutter-bar of a mowing
machine.

Self-raker, a contrivance attached to a reaping machine, to throw
off the cut grain in gavels, to obviate raking off by hand.

Shears, or Sheers, two poles lushed together like the letter X, for
placing under heavy poles, etc., in raising them ; also to single vertical
poles supporting pulleys, for a similar purpose.

Sheave, the wheel of a pulley set in a block.

Shoot, or Shute, a passage-way down which grain, hay, or straw, is
slid or thrown.

Side-draught, the side pressure of a machine on tlie team which
draws it, as distinguished from centre draught.

Single-tree, a single whifHe-tree, the cross-bar to which the traces of
a horse are attached, as distinguished from a doubletree^ or two-horse
whiffle-tree.

Siphon, or Syphon, a bent tube for drawing off liquids; the column
of liquid in the outer or longer leg overbalancing the inner column,
and producing a current.

Skein, the iron casing of a wagon-axle on which the wheel runs.

Skim-coulter, a coulter of a plow so constructed as to pare the sur-
face before the mould-board.

Skim-plow, the small forward mould-board of a double Michigan or
Sod-and-subsoil plow.

Slide-rest, the rest or support of the chisel in a turning lathe, made
to slide along the frame for cutting successively the different jDarts of the
work.

Slot, a slit or oblong aperture in any part of a machine, to admit an-
other part.

Snath, the handle or bar to which the blade of a scythe is attached.

Sod, the slice of earth cut by the passing of a plow.

Sole, the bottom plate under a horse-shoe tile, in draining.

Spindle, a small axle in machinery, as distinguished from a shaft or
large axle.

Spirit-level, a glass tube containing alcohol with an air-bubble, her-
metically sealed at both ends, the position of the bubble at the middle
showing the tube to be level.

Spur-wheel, or pinion, a cog-wheel Avith teeth parallel to the axle.

Standard, an upright supporting timber; the front upright bar in a
plow to which the mould-board is fastened.

Steam chest, a box attached to the cylinder of a steam-engine, in
which the sliding valves work.

Stirrup, an iron band encasing a wooden bar, for attaching to some
other part.

Stud, a short, sto it support.

rf

GLOSSARY. 295

Subsoil-plow, a plow running: below the furrow of a common plow,
for breaking up or loosening the subsoil or lower soil of a field.

Swage, to give shape to a substance by stamping with a die.

SwEEP-POWEK, a horse-power for driving thrashing and other ma-
chines, where the horses arc attached to a pole and walli in a circle.

Swingle-tree, also called swing-tree, single-tree, whipple-tree,
and whiffle-tree ; the cross-bar to which traces are attached.

Swing-plow, a plow with no wheel under the beam.

Swivel, a ring and axis in a chain, to admit of its turning.

Swivel bridge, a bridge Avhieh turns round sideways on its centre.

Swivel plow, a side-hill plow, or a plow with a reversible mould-board.

Tackle, a pulley, or machine with ropes and blocks for raising heavy
weights.

Tail-race, the channel which carries off the water below a water
wlieel.

Tedder, a machine for turning and spreading hay.

Thill, one of the shafts of a wagon between which the horse is put
— often corrupted to Fill.

Throttle-valve, a valve which turns at its centre on an axis — gener-
ally used to regulate the supply of steam to the cylinder of a steam-en-
gine.

Thumb-screw, a screw with its head flattened in the direction of its
length, so as to be turned with the thumb and finger.

Tide-wheel, a wheel adapted to currents flowing both ways — the float-
boards pointing from the centre.

Tine, the tooth or prong of a fork.

Tire, the iron band which binds together the fellies of a wheel.

Toggle-joint, or knee-joint, a mechanical power exerted by straight-
ening a double bar with a hinge at the middle or connection.

Torsion, the act of twisting by the application of lateral force. The
force of torsion is the elasticity of a twisted body.

Track-cleaner, an attachment to a mowing machine, to throw the
cut grass away from that which is uncut.

Traction, Angle of, the angle between the line of draught and any
given plane, as that of the earth's surface.

Trammel, an instrument used by carpenters for drawing an ellipse.

Tread-power, a machine on which the horse or other animal working
it walks. It may be either a horizontal or slightly inclined wheel; or
an endless-chain power, the term being more frequently applied to tlie
latter.

Trench-plow, a plow cutting deep furrows and bringing the subsoil
up to the surface; as distinguished from a subsoil plow, which only
loosens the subsoil and leaves it below the surface.

Trundle-head, a wheel turning a mill-stone.

Tub-wheel, a horizontal water-wheel, driven by the percussion of the
stream against its floats, and not submerged in water.

/

296 GLOSSARY.

Tumbler, a latch in a lock, wliicli, by means of a spring, detains the
holt in its place until lifted by the key.

Tumbling rod, the rod which connects the motion of a horse-power
with tliat of a thrashing or other machine.

Turbine wheel, a horizontal water-wheel, so constructed tliat the
current strikes all the floats or buckets around the circumference at the
same time, thus imparting to it great power for its size. It is sub-
merged, the water escaping towards the centre and below, or above and
below together.

Undershot wheel, a water-wheel moved by the current striking
against the lower portion of its circumference.

Universal joint, a connecting joint between two rods, consisting of
a sort of double hinge, admitting motion in any direction.

Valve, a lid for closing an aperture or i^assage, so as to open only in
one direction.

Velocity, speed or swiftness ; which may be uniform, or equal
throughout ; accelerated, or increasing ; or retarded, or rendered slower.

Virtual velocities, Principle of, that by which certain powers are
equal to each other, where tlie force and space moved over, whatever
these may be, are the same when multiplied together.

Washer, a circular piece of metal, pasteboard, or leather, placed be-
low a screw-head, or nut, or within a linch-pin, for protection.

Water-ram, see Ram.

Whiffle-tree, or Whipple-tree, the cross-bar to which the traces
of a horse are attached ; see Single-tree.

WiiiP-SAW, a large saw, Avorked by a man at one end, with a wooden
spring at the other ; a cross-cut saw.

Winch, a bent handle or right-angled lever, for turning a wheel or
grindstone, or producing rotary motion for otlier purposes.

Windlass, a machine for raising heavy weights, by the Avindiug of a
rope or chain on a horizontal axle, and turned by a winch or by levers.

WiNROW, or Windrow, the ridge of hay raked up on a meadow.

Wrest, a partition which determines the form of the bucket in an
overshot wheel.

INDEX

Air, Pressure of 230

" Mode of weighing 239

" Pump ..240

'' Hand fostened by 241

'' Motion of. 245

" Eesistance of. 247

Alden's Cultivator 146

Allen's Farm Mill 195

Altitudes measured by the Barome-
ter 243

American Hay-tedding Machine 165

Apparatus for Experiments 281

Aqueducts of the Romans 199

Archimedean Root Washer 193

Screw 217

Archimedes, would move the earth

with a lever 55

Artesian Springs and wells 201

Atmosphere, Height and Weight

of 239,241

Bags, How to cany 41

Balance, a lever 47

Balls, Why they roll easily 38

Barometer 241

Bars of w1)od, Strength of. 79

Bcardsley's Hay Elevator 177

Bellows, Hydrostatic 204

Bevel Wheels or Bevel Gear 60

Billings' Corn Planter 155

Binders for Reaping Machines 163

Boat, Compound motion of. 20

Broadcast Sower, Seymour's 154

Brown's Wind-mill 251

Brush Harrow 142

Buckeye Mower 159

Ballard's Hay-tedding Machine 165

Bulk of a ton of different substances.210
Burrall's Corn-shellcr 191

297 13*

c

Capillary attraction 31

" " its great import-
ance .. 32

Cayuga Chief Mower 160

*' " Dropper 162

Cements, Effects of. 28

Centre of Gravity 34

" " curious examples

of 35

" how determined 35

Centrifugal Force 21

Chain Pump 221

Cheese Press 72

" '• Dick's 74

" " Kendall's 73

Chimney Currents .253

" Caps 254

Chimneys, Construction of 254

" To prevent smoking 256

Churn with fly-wheel 17

" worked by dog-power 191

Cistern Pumps 219

Cisterns, To calculate contents of. .237

" Proper sizes for 238

Clod Crusher 149

" " CroskiU's and Ameri-
can 150, 151

Cog, Hunting 60

Cogs, Form of 58

" and Cog-wheels 58

Cohesion, Attraction of 27

" between lead balls 27

" weak in liquids 31

Complex Machines, objectionable.. 116

Compound motion 19

" " How to calculate. 20

Comstock's Rotary Spader. . . .148, 117

Conducting power of bodies 260

" " liquids 261

Corn Planter, Billings' 155

" Sheller, Burrall's .191

298

INDEX.

Corn Sheller, Horse-power 192

Richards' 192

Corn Planters 155

Cost of Implements and Machines. 117

Cotton Gin, Emery's 196

Coulter for Plows 127

Crested Furrow-slice 126

Crosskill's Clod-crusher 150

Crow-bar, a simple power 43

Crown Wheels 60

Cubic foot of different substances,

Weight of 210

Cultivator, or Horse-hoe 145

" Claw-toothed 146

Alden's Thill 146

" Duck-foot 146

" Two-horse 148

" Harrington's 157

Cutter for the Plow 127

'■' Bar in Mowers and Reapers. 158

Dederick's Hay-press 185

" Capstan 185

Deep-tiller Plow, Holbrook's 126

Deep Wells, Pump for. 220

Dew and Frost ^ 278

Discharge of water through pipes.. 284

" Rule for 285

Ditches, Velocity of water in.. 214, 286
" Leveling instruments for. .115

Dog-power Churn 191

Draught, Combined 96

Draught of wheels, explained 37

" Line of 95

" Principles of 93

" How to measure 94

" of Plows 95

Drilling wheat 153

Drills, Hand 157

Drive-pump 220

Dropper, attachment to reapers 162

Dynamometer, applied to roads 85

" Construction and use

of 98

" Self-recording 101

" Waterman's 102

" for rotary motion... 106

Elevators for Hay 173

Emerson's Chimney Cap 255

Emery's Horse-powers ..188

Cotton Gin 196

Empire Wind-mill 251

Endless-chain power 188, 189

Engine, Garden 230

Experiments, apparatus for 281

F

Falling Bodies, Velocity of 23

" " Resistance of air on 25

" " in vacuo 25

Farm, Seventy-thousand-acre 8

" implements. Construction

and use of. 115

" implements. Cost of 117

" mills 195

Finger-bar in mowers and reapers.. 158

Flail, Old sort 187

" Estimate of comparative work

with 187

Flash-wheel 231

Flea, power of leaping ,115

Fly-wheel 16

" used on horse-pump 16

Forcing-pump 223

Fork Handles, Proper form of 76

Forsman's Farm Mill 195

Friction 81

" Nature of 82

" How to Measure 83

" not influenced by velocity. 88

of axles 89

'' of wheels 90

" Lubricating substances for. 91

" Advantages of 92

Frost and Dew 278

" in valleys 279

Fuel, Green wood for 275

Furrow-slice, Crested 126

Furrows, Lapping and flat 127

Galileo's experiment on falling bod-
ies 26

Garden Engine 230

Garrett's Horse-hoe 147

Geddes' Harrow 143

Gladding's Hay-fork 175

Glossary of terms 287

G ra V i t a t i on . . . .^ 2^

Gravily, Centre of, 34

INDEX,

299

Gravity, Specific, how measured. . .208
" "of difierent sub-
stances 209

Green wood for fuel , 274

H

Hand-drills 157

" ralce?, sulky 160

Harrington's Seed sower 157

" Cultivator 157

Harrow, Norwegian ^ 144

"■ Morgan 144

" Scotch . or square 143

Harvester, Marsh s. 163

Hayforli?, Horse 173

" carriers 180

" loaders 186

" ralie, Revolving 168

'• " Warner's 169

" rakes 166

" " Simple 167

" stacking machine 184

" tedder, BuUard's 165

" " American 166

" presses 184

" sweep 171

Headers 163

Heat, Properties of. 260

" Expansion by 263,271

" Latent 273

" Radiation of 276

Hicks' Hay-carrier 180

High pressure steam-engines 269

Hoe-handle, Proper form of 77

Holbrook's Plow 125

" Swivel or side-hill Plow.133
Horse, day's work at difierent de-
grees of speed 110

" hoe, Garrett's 147

" power. Estimating 109

" Hay-forks, Operation of. . . .174

fork. Cladding's 175

Palmer's 176

Myers' 177

Beardsley's 177

Raymond's 178

Harpoon 179

Walker's 179

Sprout's 179

Hydraulic Ram 226

" " Regulating 227

Hydrostatic Paradox 203

Hydrostatic Bellows 204

" Press 203

Hydrostatics 198

Implements required for the farm. . 7

9,117

" Construction and use

of 115

Improvements in Farm Machinery. 8

Inclined Plane 63

Inertia 11

" apparatus 12

" Effects of, on wagons. . . . .13, 17

J

Joint, Universal 60

K

Kirby Mower and Reaper 159

" Reaper, Hand-i*ake for 160

" " Self-raking 161

Knee-joint, or Toggle-joint 71

Knives in mowers and reapers,

Form of 158

Kooloo Plow 118

li

Labor, Application of 108

" of men and horses 110

Ladders, Self-supporting 40

Lapping and flat furrows 127, 128

Latent heat 273

" " Advantages of. 275

Law of virtual velocities 43

Leveling Instruments 215

Levers 45

" of the second kind 45

" " first kind 46

" " third kind 46

" Calculating power of. 49,50

" Examples of. 46

" Combination of 50

Line of direction 36

Liquids, Velocity of, in falling 211

" Discharge through pipes. .212

Loads on sideling roads ,.,...■ 37

Lubricating substances 90

300

INDEX.

M

Machinery in connection withwater.l9S

Macliines, Advantages of 42

Models of. 113

" Complex, objectionable.. 116
" Construction and use of. .115
" Required for the Farm . 7,

9,117

Marsh's Harvester 163

Materials, Measuring strength of. . . 29

Mechanical powers 42

" principles, Advantages

of 10

Mechanical principles. Application

of 75

Models of machines .113

Moline Plow 120

Momentum 14

" Calculating quantity of,. 18

" of railway trains 18

Moorish Plow 118

Morgan's Harrow 144

Motion, Compound 19

Monldboard of the Plow, Form of.. 124
Mountains, Height of, measured by

barometer 243

Mowing Machine, Wood's. 158

" " Kirby's 159

" " Buckeye 159

" " Cayuga Chief.... 160

Mowing Machines, Construction of.l58

" " How to select... 164

Myers' Horse-fork 177

N

Norwegian Harrow 144

O

Ogle, inventor of the Finger-bar.... 159
Ox-yokes 78

P

Packer's Stone Lifter 62

Palmer's Horse-fork 176

" Hay-stacking Machine — 183

Paradox, Hydrostatic 203

Pile Engine or Driver 15

Pinions, Operation of 60

Pipes, To determine strength of 200

" Discharge of water through,
213,284

Pitts' Straw-carrier and Thrasher. . .190
Plank roads, Amount of resistance

on 84, 86

Planting Machines 152

Plaster Sower, Seymour's 155

Platform Scales 52, 53

Plow, Kooloo 118

" Moorish 118

" German 119

" Modern improved 119

" Moline Steel 120

" Woodruff & Allen's 120

" Double Michigan 131

" Mole 139

" Ditching 138

" Side-hill or Swivel 132

" Subsoil 133, 135

" Trench 134

" Paring 137

" Gang 137

" Defects in 122

" Character of a good one 121

" Cutting edge of. 121

" Resistance of different parts.. 122

" Form of the mouldboard 124

" Appendages to 140

" Wheel coulter and Weed-hook

on 140

Plowing, Operation of. 128

" Fast and slow 130

" Requisites for success in. .129

Potato Planter, Truc's 156

" Digger 144

Power of a horse, Estimating 110

Press, Hydraulic 205

Presses for hay 184

Pressure of liquids, Determining... 202

" Upward, Measuring 199

" " in liquids 198

Pulley 61

Pulverizers 142

Pump, Cistern 219

" Non-freezing 219

" Drive 220

" for deep wells 220

" Chain 221

" Rotary 222

" Suction and Forcing 223

Pumping water by wind 248

Pumps, Construction of 218

Pyramids, Firmness of 33

Pyrometer, how made 26?

IXDEX.

301

R

Rake, Simple form of, 167

" Revolving 108

" " Warner's 109

" Spring-tooth 170

" " " Holliugs\vorth's.l71

Ram, Hydraulic 226

Raymond's Hay Elevator 178

Reaping Machines during the wan. 8
" Self-rakers for.. 161

" " Headers laS

" " How to select... 164

Revolving Hay Rake 168

Roads, importance of good ones.... 63

" How to form the bed of 67

" Measuring the friction on... 84
" Amount of resistance on — 86

" Good and bad 69

" Ascent in 63,60

" Cost of going up and down

hill 65

Rocks, Machines for removing 62

Rorkers, How to make 41

Roiicra 152

Rolling Mill, Principle of 74

Root Washer 193

" Slicersv 194

Rotary Spader, Comstock's 148, 117

" Pump 222

S

Sack-barrow, a lever 48

Sap, Ascent of. 33

Scotch or Square Harrow 143

Screw 70

" Archimedean 217

" Estimating power of. 71

Seed Sower 153

" " Harrington's 157

Self-raking Reapers 161

Seymour's Broadcast Sower 154

Shares' Harrow 145

Side-hill or Swivel Plow 132

Single-tree, Wier's 98

Sowing Machines 152

Specific gravities, how determined. 208

Table of. 209

Springs of water ,201

Stacks, Building by machinery 182

Steam engine, Construction of. 265, 267
" " for farm purposes,... 270

Steel Plows 120

Steelyard 47

Stone-lifter 62

Straw-cutters .16, 75

" carrier, Pitts' 190

Strength of materials 29

" " wood, iron, and ropes. 30

" " rods and bars 79,80

" " pipes. To determine... 200

Stubble Plow, Holbrook's 126

Stump-puller 54

Subsoil plowing 133

" Plows 135

Swivel Plow 132

Syphon 244

" used for draining 243

T

Teeth of wheels 58

Thill-cultivator, Alden's 146

Thrashing by machinery 187

" machine, Comparative

cheapness of. 188

Thrashing machine, Endless-chain

power for 188

Thrashing machine, Pitts' 190

Toggle-joint power 71

Tread horse-powers 188

" " " To determine

Avork of 188

Turbine Water-wheel 223

" " " Reynolds' 224

" " " Van de Wa-
ter's 224

U

Universal joint 60

Upward pressure of liquids 198

V

Vacuum, Machine rnnning in 11

Velocity affects friction but slightly, 88

' ' of fall ing water 211

" of water in ditches .... 214, 286

" " through pipes 284

Ventilation 257

" through walls and gar-
rots 258

Ventilator, Griffith's 258

" Emerson's 255

Virtual velocities, Law or rule of... 43

INDEX.

W

Wagon yprings, Advantages of 17

" wheels, Proper width for 87

Warner's Eevolving Kake 169

Washing Machine 72

Water, Remarliable effects of heat

on , 279.

Water, Velocity of 211, 213

" Discharge of, through pipes. 212

" in ditches 214

" wheels, Turbine 223

" ram 226

" engines 230

Waves, Nature of. 232

" Velocity of 234

" Breadth and height of 233

" To prevent inroads of. . 235, 236

Weather glass 243

Wedge 69

Weed hook on plows 140

Weighing machine, or platform

scales 52, £©

Wheat drill 152

" " Bickford & Huffman's,

Construction of 153

Wheel and axle 55

" " " Modifications of 57

Wheelbarrow, Operation of 47

Wheel-cutter to plows 140

Wheels, large ones mn best. 39

" for wagons Proper width

for 87

Whiflle-treep for three horses 50, 97

Wind, Causes of 252

" Velocity of 246

" mill 247

" " Pumping Avater by 24S

" " Brown's 251

Wooden legs, why hard to wallc on. 40

Wood's Plow 119

Work of men and horses, Estima-
ting ..110

NEW AMERICAN FARM BOOK.

OKIGESrAXLY BY

AUTHOR OF "DIS2:ASE3 OF DOMESTIC AXIMALS," AND FOKMERLT 3DIT0B OF

THE "AMEKICAK AGRICULTURIST."

REVISED AND ENLARGED BT

AUTHOR OF " A3IEBICAK CATTLE," EDITOR OF THE
HERD BOOK," ETC.

C O ^ X E: IS" T S :

AMERICAN SnOBT-HORN

Introduction. — Tillage Husbandry
— Grazing — Feeding — Breeding —
Planting, etc.

Chapter I. — Soils — Classification —
Description — Management — Pro-
perties.

Chapter II. — Inorganic Manures —
Mineral — Stone — Earth — Plios-
phatic.

Chapter III. — Organic Manures —
Their Composition — Animal— Ve-
getable.

Chapter IV. — Irrigation and Drain-
ing.

Chapter V. — Mechanical Divisions
of Soils — Spading — Plowing— Im-
plements.

Chapter VI. — The Grasses — Clovers
— Meadows — Pastures — Compara-
tive V^alues of Grasses — Implements
for their Cultivation.

Chapter Vll. — Grain, and its Culti-
vation — Varieties — Growth — Har-
vesting.

Chapter VIII.— Leguminous Plants
— The Pea— Bean — English Field
Baan- Tare or Vetch— Cultivation
—Harvesting.

Chapter IX. — Roots and Esculents —
Varieties — Growth — Cultivation —
Securing the Crops — Uses — Nutri-
tive E:iuivalent3 ol Different Kinds
of Forage.

Chapter X.— Fruits— Apples— Cider
— Vinegar— Pears — Quinces— Plums
Peaches — Apricot? — Nectarines —
Smaller Fruits-Planting— Cultiva-
tion—Gathering— Preserving.

Ch-apfer XI.— Miscellaneous Objects
of Cultivation, aside from the Or-
dinary Farm Crops— Broom-corn —
Flas—Cotton—Hemp— Sugar Cane
Sorghum— Maple Sugar— Tobacco —
Indigo— Madder— Wood— Sumach-
Teasel — Mustard — Hops — Castor
Bean.

Chapter XH. — Aids and Objects of
Agriculture — Rotation of Crops,
and their Effects— Weeds— Restora-

tion of Worn-out Soils— Fertilizing
Barren Lands — Utility of Birds —
Fences — Hedges — Farm Roads —
Shade Trees— Wood Lands— Time
of Cutting Timber— Tool-!— Agri-
cultural Education of the Farmer.

Chapter XHI. — Farm Buildings —
House — Barn — Sheds — Cisterns —
Various other Outbuildings— Steam-
ing Apparatus.

Chapter XIV.— Domestic Animals
— Breeding — Anatomy— Respiration
— Consumption of Food.

Chapter XV.— Neat or Homed Cattle
Devons — Herefords — Ayreshires —
Galloways — Short -horns — Alder-
neys or Jerseys — Dutch or Ilolstein
— Management from Birth to Milk-
ing, Labor, or Slaughter.

Chapter XVI.— The Dairy— Milk—
Butter— Cheese — Different Kinds-
Manner of Working.

Chapter XVII. — Sheep — Merino —
Saxon — South Down — The Long-
wooled Breeds— Cotswold— Lincoln
— Breeding — Management — Shep-
herd Dogs.

Chapter XVIII. — The Horse— De-
scription of Different Breeds— Their
Various Uses — Breeding — Manage-
ment.

Chapter XIX. —The Ass— Mule —
Comparative Labor of Working
Animals.

Chapter XX. — Swine — Different
Breeds — Breeding— Rearing — Fat-
tening— Caring Pork and Hams.

Chapter XXI. — Poultry— Hens, or
Barn-door Fowls — Turkey — Pea-
cock—Guinea Hen — Goose — Duck
— Honey Bees.

Chapter XXII. —Diseases of Ani-
mals—What Authority Shall We
Adopt ? — Sheep — Swine — Treat-
ment and Breeding of Horses.

Chapter XXIII.— Conclusion— Gene-
ral Remarks — The Farmer who
Lives by his Occupation- The Ama-
teur Farmer— Sundry Useful Tables.

SENT POST-PAID, PKICE $2.50.

ORANGE JUDD & CO.,

245 Broaditvay, Ne\r-York.

HOW CROPS GROW.

Oil tie Clieiical Compsition, Structure, M Life of ae Plant,

FOR ALL STUDENTS OF AGRICULTURE.

WITH NUMEROUS ILLUSTEATIONS AND TABLES OF ANALYSES.

BY

SAMUEL, W. JOHNSON, M.A.,

PROFESSOR OP ANALYTICAIi AND AGRICULTURAIi CHEMISTRY IN YALE COLLEGB ;

CHEMIST TO THE CONNECTICUT STATE AGRICULTURAL SOCIETY ;

MEMBER OF THE NATIONAL ACADEMY OP SCIENCES.

Tliis is a volume of nearly 400 pages, in which Agricultural
Plants, or " Crops," are considered from three distinct, yet closely
related, stand-points, as indicated by the descriptive title.

THE CHEMICAL COMPOSITION OF THE PL INT.

Ut— The Volatile Part.

2d. — The Ash — Its Ingredients ; their Distribution, Variation, and
Quantities. The Composition of the Ash of various Farm
Crops, with full Tables ; and the Functions of the Ash.

3d. — Composition of the Plant in various Stages of Growth, and the
Relations subsisting among the Ingredients.

THE STRUCTURE OF THE PLANT AND THE OFFICES
OF ITS ORGANS.

The Primary Elements of Organic Structure.

The Vegetative Organs — ^Root, Stem, and Leaf, and their Func-
tions ; and

The Reproductive Organs, nam,ely, Flowers and Fruit, and the
Vitality of Seeds with their Influence on the Plants they produce.

THE LIFE OF THE PLiNT.

Germination, and the conditions most favorable and unfavor-
able to it.

The Food of tJie Plant when independent of the Seed.

Sap and its Motions, etc., etc.

The Appendix, which consists of twelve Tables exhibiting
the Composition of a great number of Plants viewed from many
different stand-points, will be found of inestimable value to practi
cal aarri<*iilturists, students, and theorists.

eENT POST-PAID. PRICE, $2.

ORANGE JUDD & CO.,

245 Broad way, New-York.

THE TIM BUNKER PAPERS;

Or, YANKEE FARMING.

TIMOTHY BUNKER, Esq.

OF HOOKERTOWN, CT.

With Illustrations hy Hoppin,

CONTENTS.

10.

11.

12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
2G.
27.
28.
29.
30.
81.
32.
33.
34.
35.
36.
37.

A Stroke of Economy.

Ornamental Trees.

Timothy Bunker, Esq.

View ol the Bird Law.

Guano in the Hill.

On Moss Bunkers.

On Subsoilin^.

Going to the Fair.

In Tall Clover.

On Horse Racing.

At the Farmers' Club.

On an Old Saw.

Book Farming in Hookcrtowu.

Pasturing Cattle in Roads.

The Weaker Brethren.

Curing a Horse Pond.

Domesticities at Tim Bunker's.

Takes a Journey.

On Farm Roads.

A New Manure.

Losing the Premium.

A New Enterprise.

Making Tiles.

The Clergy and Farming.

Women Horse Racing.

Beginning Life.

An Apology for Tim Bunker.

On County Fairs.

At Home A^iin,

On Raising Boys.

On Raising Girls.

A New Case of the Black Art.

A Letter from Neighbors.

The Shadtown Parsonage.

Views of Dress.

A Rustic Wedding.

Saving a Sixpence.

On Giving Land a Start.

On Giving Boys a Start.

A Tile in the Head.

Jake Frink Sold.

The New-York Central Park.

On Irrigation.

77.

81.

84.

Feeding with Oil Meal.

The Farmers' Club.

On Bad Water.

Cattle Disease.

On Seed.

On Breastworks in War.

Lightning Rods.

Buying a Farm.

Topdressing and Feeding After

math.
Painting Buildings.
The Value of Muck.
On Family Horses.
The Horn-ail,
A Commentary on Roots.
Stealing Fruit and Flowers.
The Cost of Pride.
Swamps Tuming Indian.
Tim Bunker in his Garden.
On Running Astern.
On Extravagance.
The Farmer's Old Age.
On Sheep Traps.
Old Style Housekeeping.
On Keeping a Wife Comfortable.
Starting a Sugar Mill.
Reasons against Tobacco.
Trip to Washington.
The Sanitary Commission.
Raid among the Pickle Patches.
Raid among the Pickle Patches.
On Striking He.
Visit to Titus Oaks, Esq.
The Pickle Fever in Hookertown.
On Curing Pickles and Eating

them.
The Cotton Fever and Emigration.
The Cotton Fever and Emigration.
The Food Question.
On Jim Crow.
The Eight-Hour Law.
Base Ball Clubs.
The Rise of Real Estate.

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THE

TRANSLATED FROM THE FRENCH OF

CHARLES DU HUTS,

Author of the "Dictionary of the Pure Eace," "Trotters," "The Horse
Breeder's Guide," etc.

inH^ELY IIL.IL,TJSTRj?LTEr).

TABLE OF CONTENTS.

Production, Rearing, and Improvement of the Percheron Horse.

PART FIRST.

Greatness and Decline of the Percherons.

Glance at Perclie.

Sketch of the Percheron Race.

Origin of the Percheron.

Modifications of the Percheron Race.

His First Modification Due to Contact with the Brittany Race. '

Conditions under which they are Bred.

Causes of the Degeneracy of the Percheron Horse.

Starting Point of this Degeneration.

PART SECOND.

Of the Means of Regenerating the Percheron Horse.

Regeneration of the Percheron Breed.

Regeneration of the Breed through Itself or by Selection.

Consanguinity.

Ought the Gray Coat of the Percheron to be Inflexibly Maintained ?

Preserve Pure, and without Intermixture, the Three Types of the

Percheron Race — the Light Horse, the Draft Horse, the Inter-

mediate Horse.
Improvement of the Breed by Means of Foreign Crossings.
The Arab Cross.
The English Cross.

Improvement by Means of the Stud-Book.
Recapitulation.

PART THIRD.

Information to Strangers wishing to buy Percheron Horses.

Food and Breeding.

Trade. Glance at the Most Celebrated Breeding Districts.

Speed and Bottom of the Percheron Horse.

Tests of Speed of the Percheron Horse.

Tests of Endurance of the Percheron Horse,

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DARWIN'S NEW WORK.

TME VAK,I^TIO]V

ANIMALS AND PLANTS

UNDER DOMESTICATION.

BY

CHARLES TyJ^lET^^llSr, IVL.J^., IF.R.S., ETC.

AUTHORIZED EDITION.

"W-ITH -A. I* n DB IP -A. O 3E3

BY

PROFESSOR ASA GRAY.

This work treats of the variations in our domestic animals and cultivated
plants, discussing the circumstances that influence these variations, inherit-
ance of peculiarities, results of in-and-in breeding, crossing, etc.

It is one of the most remarkable books of the present day, presenting an
array of facts that show the most extraordinary amount of observation and
-esearch. All the domestic animals, from horses and cattle to canary-birds and
noney-bees, are discussed, as well as our leading culinary and other plants,
making it a work of the greatest interest.

Its importance to agriculturists, breeders, scientific men, and the general
reader will be seen by its scope as indicated in the following partial enumera-
tion of its contents : Pigs, Cattle, Sheep, Goats ; Dogs and Cats, Horses
AND Asses ; Domestic Rabbits ; Domestic Pigeons ; Fowls, Ducks, Geese,
Peacock, Turkey, Guinea Fowl, Canary-bird, Gold-fish ; Hive-bees ;
Silk-moths. Cultivated Plants ; Cereal and Culinary Plants ; Fruits,
Ornamental Trees, Flowers, Bud Variation. Inheritance, Reversion
OR Atavism, Crossing. On the Good Effects op Crossing, and on thh
Evil Effects of Close Interbreeding. Selection. Causes of VariabiIi-
iTY, Laws of Varlation, etc., etc.

Published in Two Volumes of nearly 1100 pages.

EINELY IL.IL.TJSTRA.TEr>.
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VALUABLE AND BEAUTIFUL WORK.

HARRIS'

Insects Injurious to Yegetation.

BT THE LATE

THADDEUS WILLIAM HARRIS, M.D.

A New Edition, enlarged and improved, with additions from the author'i
manuscripts and original notes.
Illustrated by engravings drawn from nature under the supervision of

FJROFJKSSOI?. ^G^^SSIZ.

Edited by CHAELES L. FLINT,
Secretary of the Massachusetts State Board of Agriculture.

O OnSTTElSTTS.

CHAPTER I.

NTRODUCTION.— Insects Defined— Brain and Nerves— Air-Pipes and Breath-
ing-Holes— Heart and Blood— Metamorphoses or Transformations-
Classification ; Orders and Groups.

CHAPTER II.

COLEOPTERA.— Beetles— Scarabaeians— Ground-Beetles-Tree-Beetles-Cock-
chafers—Flower, Stag, Spring, Timber, Capricorn, Leaf-mining, and Tor-
toise Beetles— Chryaomelians—Cantharides.

CHAPTER III.

ORTHOPTERA.— Earwigs — Cockroaches-- Soothsayers — Walking-sticks or
Spectres— Mole, Field, Climbing, and Wingless Crickets— Grasshoppers —
Katydid— Locusts.

CHAPTER IV.

HEMIPTERA.— Bugs— Squash-Bug—Clinch-Bug— Plant Bugs— Harvest Flies—
Tree-Hoppers- Vine-Hoppers — Plant-Lice — American Blight— Bark-Lice.

CHAPTER V.

LEPI DOPTERA.— Caterpillars — Butterflies — Skippers — Hawk-Moths-^ge-
rians or Boring Caterpillars — Moths— Cut- Worms— Span-Worms—Leaf-
Rollers— Fruit, Bee, Corn, Clothes, and Feather-Winged Moths.

CHAPTER VI.

HYMENOPTERA— Stingers and Piercers—Saw-Flies and Slugs— Elm, Fir,
and Vine Saw-Fly — Rose-Bush and Pear-Tree Slugs — Horn-Tailed
Wood-Wasps— Gall-Flies— Barley Insect and Joint Worm.

CHAPTER VII.

DlPTERA.— Gnats and Flies— Maggots and their Transformations— Gaii
Gnats— Hessian, Wheat, and Radish Flies— Two-Winged Gall-Flies, an(»
Fruit-Flies.
APPENDIX.— The Army Worm.

Published in two beautiful editions ; one plain, with steel engravings, 8vo.
•xtra cloth, $4 ; the other in extra cloth, beveled boards, red edges, engrav-
ings colored with great accuracy, $6.
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THE

SMALL FRUIT CULTURIST.

BY

ANDREW S. FULLER.
beautifully Illustrated.

We have heretofore had no work especially devoted to small
fruits, and certainly no treatises anywhere that give the information
contained in this. It is to the advantage of special works that the
author can say all that he has to say on any subject, and not be
restricted as to space, as he must be in those works that cover the
culture of all fruits — great and small.

This book covers the whole ground of Propagating Small FruitB,
their Culture, Varieties, Packing for Market, etc. While very full on
the other fruits, the Currants and Raspberries have been more care-
fully elaborated than ever before, and in this important part of hia
book, the author has had the invaluable counsel of Charles Downing.
The chapter on gathering and packing the fruit is a valuable one,
and in it are figured all the baskets and boxes now in common use.
The book is very finely and thoroughly illustrated, and makes an
admirable companion to the Grape Culturist, by the same author.

Chap. 1. Barberry. Chap. VII. Gooseberry.

Chap. II. Strawberry. Chap. VIII. Cornelian Cherry.

Chap. III. Raspberry. Chap. IX. Cranberry.

Chap. IV. Blackberry. Chap. X. Huckleberry.

Chap. V. Dwarf Cherry. Chap. XL Sheperdia.

Chap. VI. Currant. Chap. XII. Preparation pok

GATHERING FrUIT.

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ORANGE JTJDD & CO., 245 Broadway, New-York

GARDENING FOR PROFIT

In the Market and Family Grarden-
By Peter Henderson.

This is the first work on Market Gardening ever published m thu
oountry. Its author is well known as a market gardener of eighteen
years' successful experience. In this work he has recorded thia
experience, and given, without reservation, the methods necessary
to the profitable culture of the commercial or

It is a work for which there has long been a demand, and one
which will commend itself, not only to those who grow vegetables
for sale, but to the cultivator of the

FAMILY GARDEN,

to whom it presents methods quite different from the old ones gen-
erally practiced. It is an original and purely American work, and
not made up, as books on gardening too often are, by quotations
from foreign authors.

Every thing is made perfectly plain, and the subject treated in all
its details, from the selection of the soil to preparing the products
for market.

CONTENTS.

Men fitted for the Business of Gardening,

The Amount of Capital Required, and

"Working Dtf'orce per Acre.

Profits of Market Gardening.

Ijocation, Situation, and Laying Out.

Soils, Drainage, end Preparation.

Manures, Implements.

TTses and Management of Cold Frames.

Formation and Management of Hot-bade.

Forcing Pits or Green-houses.

Seeds and Seed Haising.

How, W^hen, and Where to Sow Beedo.

Transplanting, Insects.

Packing of Vegetables for Shipping.

Preservation of Vegetables in "Winter.

Vegetables, their Varieties and Cultivation.

In the last chapter, the most valuable kinds are described, and
the culture proper to each is given in detail.

Sent post-paid, price $1.50.
ORANGE JUDD & CO., 245 Broadway, New-York.

DRAINING FOR PROFIT

DRAINING FOR HEALTH.

BY

GEO. E. WARING, Jr.,

ENQINEEll OF THE DRAINAGE OF THE CENTRAL PAllK, NEW-TORK.

"BVBRT ItlPOETED CASK OF FAII.T;itE IN DEAINAGE WHICH WK HATE INVBBTX
SATED, HAS RESOLVED ITSELF INTO IGKOBANOE, BLUNDEBINQ, Bil> li'^JTAOEMEHT.

OB BAD vxxauTioj{."—Oisbortie.

CONTENTS:

chapter I.-L.AND TO BB DRAIXEID AND THS RBASONS

"WHY.
Chapter n.-HOAV DRAINS ACT, AND HOAV THEY AFFECT

THE SOIL..
Cbapter III.-HOIV TO GO TO 'WORK TO liAY OUT A

SYSTEM OF DRAINS.
Chapter IV.-HOW TO SLAKE THE DRAINS.
Chapter V.-HOW TO TAKE CARE OF DRAINS AND

DRAINED liANDS.
Chapter VI.-"WHAT DRAINING COSTS.
Chapter VII.-WIIiL IT PAY?

Chapter VIII.-HOW TO MAKE DRAINING TILES.
Chapter IX.-THE RECLAIMING OF SALT MARSHES.
Chapter X.-MALARIAL DISEASES.
Chapter XI.-HOUSE AND TOWN DRAINAGE.

Sent post-paid. Price $1.50.

NEW-YORK;

ORANGE JUDD & CO., 245 Broadway.

PRACTICAL FLORICULTURE;

A Glide to the Successful Propagation and Cultivation

OP

FLORISTS' PLAIffTS.

By peter HENDERSON, Bergen City, N. J.,
AUTHOR or "gardening for profit."

Mr. Henderson is known as tlie largest Commercial Florist
in tlie country. In tlie present work he gives a full account of liis
modes of propagation and cultivation. It is adapted to the wants
of the amateur, as well as the professional grower.

The scope of the work may be judged from the following

TABLE OF CONTENTS.

Aspect and Soil.

Laying out La-wn and Flow-
er Gardens.

Designs for Flower Gardens.

Planting of Flower Beds.

Soils for Potting.

Temperature and Moisture.

The Potting of Plants.

Cold Frames — Winter Pro-
tection.

Construction of Hot-Beds.

Greenhouse Structures.

Modes of Heating.

Propagation by Seeds.

Propagation by Cuttings.

Propagation of Lilies.

Culture of the Rose.

Culture of the Verbena.

Culture of the Tuberose.

Orchid Culture.
Holland Bulbs.
Cape Bulbs.

Winter-Flowering Plants.
Construction of Bouquets.
Hanging Baskets.
Window Gardening.
Rock-Work.
Insects.

Nature's Law of Colors.
Packing Plants.
Plants by Mail.
Profits of Floriculture.
Soft- Wooded Plants.
Annuals.

Hardy Herbaceous Plants.
Greenhouse Plants.
Diary of Operations for each
Day of the Year.

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245 Broadway, Neiv-YorJc,

TTXTTTrr.-»k«-

7 DAY USE

RETURN TO DESK FROM WHICH BORROWED

c

This publication is due on the LAST DATE
stamped below.

LD 21-lOOm-ll

RB 17-60m-8,'61
(01641810)4188

General Libraiy

University of California

Berkeley

YB 27305

GENERAL LIBRARY -U.C. BERKELEY

BDDDaTflS21

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