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LIBRARY

OF THE

MASSACHUSETTS

AGRICULTURAL

COLLEGE

Source. 675

4*\AXLis.

I ' 9 1931

THE

CORRESPONDENCE COLLEGE
OF AGRICULTURE

FARM ENGINEERING

PART I.

FARM STRUCTURAL ENGINEERING

BY
H. BOYDEN BONEBRIGHT, B. S. A. Memb. A. S. A. E.

Department of Agricultural Engineering, Montana Agricultaral College, Bozeman, Montana

This is the first of a series of three books giving a complete course of instruction in

FARM ENGINEERING

THE CORRESPONDENCE COLLEGE OF AGRICULTURE

FORT WAYNE. INDIANA

NOTE TO STUDENTS

In order to derive the utmost possible benefit from tiiis
paper, you must thoroughly master the text. While it is not
intended that you commit the exact words of the text to
memory, still there is nothing contained in the text which is
not absolutely essential for the inteligent farmer to know.
For your own good never refer to the examination questions
until you have finished your study of the text. By follo"wing
this plan, the examination paper will show what you have
learned from the text.

This lesson book is not intended to be a " book of plans ' '
for farm buildings.

It is designed to give in a practical way, the funda-
mental, scientific knowledge which should enable the student
to plan farm buildings, which will exactly fit the purpose
for which they are built. It is also designed with a view to
putting the student into closer touch with the Experiment
Stations and the Agricultural Colleges, that he may derive
therefrom such information as he may need from time to
time.

No attempt has been made to repeat information which
may be ohtained for the asking, from the Colleges and Ex-
periment Stations.

The student should write for the list of free bulletins
given below at once, in order that he may get them in time
to avoid all delays in his studies.

LIST OF FREE BULLETINS— SEND FOR THEM.

Bulletins No. 100 and 117, Agricultural Experiment
Station, Iowa State College, Ames, Iowa.

Farmers' Bulletin No. 3, Montana Experiment Station,
Bozeman, Montana.

Bulletin No. 1, Extension Dept., Iowa State College,
Ames, Iowa.

Sewage Plants for Private Houses, Engineering Ex-
periment Station, Iowa State College, Ames, Iowa.

FARM ENGINEERING

PART 1

DEVELOPMENT OF FARM STRUCTURAL ENaiNEERING.

It is impossible to go into the history of the early development
of farm buildings because the most primitive- of men had rude forms
of caves, huts, etc., which served as a protection from the elements,
from savage beasts and from more savage men.

In fact, within the last century, the farm buildings in many
parts of the United States were usicd as shelters for man and beast
and as forts or block houses to protect our pioneers from the Indians..
Some of the buildings are still in use in the Rocky Mountain region.

Thus we see that military influence had much to do with the
early development of our farm structures. This may explain to some
extent the heavy framing of some types of the farm buildings of
today.

A careful investigation is not necessary to prove to the student
of modern times that the development of farm structures has not
kept pace with the marvelous growth and development of city
structures.

The needs of the most up-to-date of farmers are so simple when
compared with the needs, of a great manufacturing concern that the
designs of the farm buildings are comparatively simple.

This fact leads in too many cases to the substitution of guess-
work in place of design. The inevitable results are; unnecessary ex-
pense, a lack of useful qualities, unsanitary, inconvenient and un-
sightly buildings which are likely to last but a short time.

1 #^'^^*'^'//^<*.-'*-

Plates 1 and 2— SMALL BARN AND POLE SHED

A neat little barn such as is shown in Plate 1, has real value on the farm
aside from its usefulness for storage purposes. Its attractiveness adds to
the value of the farm.

Such a "shack" as is shown in Plate 2, is a disgrace to anj^ farm, and its
value is nearly alwaj^s a minus quantity.

FARM ENGINEBRINa. 5

In order to properly understand Farm Structural Engineering
it is necessary to have certain parts of several different sciences and
arts clearly in mind. The following are the principal sciences and

Plate a-SEED HOUSE

A cai'efully desig-ned seed house makes an excellent building in which to
place the farm office.

arts which need to be considered. They are enumerated alphabetic-
ally, and not in order of importance.

* Agronomy *'* Masonry.

* Animal Husbandry.' a. Brick masonry.
** Architecture b. Stone masonry
** Carpentry ** Painting

** Concrete Construction * Poultry Culture

* Farm Management * Sanitary Science.

* Horticulture

"Wliile it is impossible to take up all of these subjects completely,
those of most importance, from the designer's standpoint, will be
treated at some length.

Agronomy. — The seed houses, granaries, hay sheds, corn cribs,
etc., should be designed with a clear understanding of the require-

* Factors governing types of structures.

** Factors directly connected with the actual construction of the structure.

6 FARM ENGINEERING.

ments of each building. In general all of these buildings should be
well ventilated. In most eases the contents of the building require
some ventillation and in all cases a fair supply of fresh air adds to
the comfort of the men who must work in the buildings. The seed
houses should be provided with plenty of light, and in' the colder
climates it is advisable to have some means of heating the work room.
On large ranches the seed house is a very suitable building in
M^hich to have the ranch office.

Animal Husbandry. — In order to design the barns, stables, hog
houses, silos, etc., properly, it is necessary for the student "to have a
very definite understanding of the requirements of the live stock.

First, it is commonly conceded that all live stock requirej^ ven-
tilation. This is taken up under each different plan of structure
designed for the housing of animals.

Farm Management. — If the designer of farm structures is to
work intelligently, he must know where and how his buildings are to
be located. He must also know the relative positions of the other
buildings.

From the farm management standpoint there are many factors
which govern the location of the farm plant. The principal points are :

Nearness to Farm Land. — In the case of large ranches it is often
advisable to place the buildings as near the center of the land as
sanitary conditions will permit. Wliile this system often calls for a
good road from the buildings to the main road, the extra expense is
often more than counterbalanced by the time which is saved in going
to and from the fields.

Nearness to Roads and Markets. — In the case of smaller farms,
care should be taken to locate the buildings as near to the market as
possible, and near the best possible thoroughfares. In case a distinct
advantage is to be derived by locating on a bad road, it will often be
found profitable to improve a short section of public road at the farm
owner's expense, rather than to locate the farm building in A.n un-
desirable place.*

Location of Buildings With Respect to Each Other. — The two
systems of locating farm buildings are known as : First, centralized
plan; Second, distributed plan.

* The subject of road building and Improvement is taken up in another book of
this series.

FARM ENGINEERING. 7

In the extreme cases of the central plan, the dwelling, the stables
and out buildings are all under one roof. In some parts of the United
States such farm buildings are to be found at the present time. In
the more up-to-date of centralized plans the house is separate from
the other buildings. The hogs and chickens have separate houses and
the horses, sheep, cattle, grain, hay and machinery are all sheltered
in one large barn.

The distributed plan calls for separate buildings for the different
species of farm animals, and special buildings for grain, hay and
machinery. In many cases however, the necessary grain and hay is
stored in each of the buildings which shelters animals. Thus in some
cases the granary and hayshed are eliminated from the list.

We have every sort of variation from the extreme centralized
plan to the completely distributed plan. As the designer must choose
his own plan of location, it may be well to look into some of the ad-
vantages and disadvantages of the two systems.

The centralized plan has the advantage, in that feed is always
handy to the stock to which it is to be fed. Less material and labor
is necessary in the building and less ground is taken up by it.

Its disadvantages lie largely in the danger from fire, for in case
a large farm building takes fire, it is almost impossible to save the
building or its contents.

Again, a large percentage of the authorities are now insisting
that the different species of live stock should not be housed in the
same stables. , .

In case a contagious or infectious disease gets a foothold in a
large centralized plant it is usually very hard to stamp out. A case
was brought to the attention of the author in which the cost of clean-
ing the yards and an old fashioned barn, together with the disinfect-
ing after a siege of tuberculosis cost over $1,700.00.

The Distributed Plant. — The smaller barns of the distributed
plant, are easy to disinfect. The animals of different species are
housed in separate buildings. In case one of these buildings burns it
is, in most cases, possible to save the other buildings. These are all
distinct advantages.

The cost of the distributed plant is somewhat greater on account
of the extra amount of material and labor required to construct the

8 FAEM ENGINEERING".

smaller buildings. More of the farm land is tak^n up by the build-
ings as they are usually some distance apart and land between them
is seldom cultivated.

It is possible, however, for the man who is starting with small
capital to use one of the small buildings for several purposes at first
and later add such buildings as may be necessary.

With these points clearly in mind and with the aid of a thorough
knowledge of the different agricultural subjects, the student may
choose intelligently which plan is best suited to his needs.

Horticulture. — It is often necessary to build special buildings
for the purpose of storing roots, potatoes, fruits, cider, etc. The con-
struction of these buildings will differ greatly in different climates,
but the general principles of construction should govern the design
of all buildings for horticultural purposes.

Plate 4-ROOT CELLAR

Root cellars must be designed for the particular conditions which prevail
in each locality. A tjqDical Greely* potato cellar is shown in Plate 4.

Poultry Culture. — Nearly every authority on poultry has some
special form of poultry house which he recommends above all others.
As the general climatic conditions govern, to a great extent, the de-
sign of the coops and houses it is quite impossible to make a single
design fit all conditions.

Incubator and brooder rooms also need special attention as a
uniform temperature is almost necessary in these apartments. The

*Greely, Colorado, is noted throughout the United States for its famous
potatoes.

FARM ENGINEERING. 9

detail work of poultry house design can be taken up to better advant-
age in connection with the plans of the various buildings.

SANITARY SCIENCE.

So much of the design of up-to-date farm structures must depend
upon sanitary science that several important headings must be taken
up. We know that at present there is a tendency for the contagious
diseases of man and beast to spread rapidly over large area. This is
in many cases because the conditions under which the animals exist
are abnormal. In many cases even the lower animals abhor these con-
ditions, but they are so confined as to make it impossible to escape
them. The structures of the farm should be so built as to promote a
natural, healthy existence, not only in the lower animals, but in man as
well. That these ends may be accomplished let us take up a few of
the most important sanitary considerations.

To begin with, in the choice of a building site, one must never
overlook the sanitary or unsanitary qualities of the chosen spot. If
the desired site be unsanitary, and this condition cannot be remedied,
then the site should by all means be no longer considered as a suit-
able place for the buildings. Health must take precedence in the
choice of building" sites.

From the sanitary standpoint the building site must fulfill the
following conditions :

First : The slope must be such as to insure surface drainage awau
from the buildings and well. In the very level 'regions it is some-
times necessary to grade up the building site to some extent. If what
little natural drainage there is, be augmented by a little grad-
ing it is often possible to improve the sanitary conditions of a site one
hundred per cent.

Second: In case the soil is of such a nature as to be damp or
marshy any considerable portion of the year, there must be some outlet
into which sub-surface drainage may be emptied. Tile drains should
be laid so as to thoroughly drain the yards and the soil under the
different buildings. The outlet of these drains should be located so
that none of the impure drainage water can possibly get to the well.
It should never be used as drinking water for the farm animals.

In case the buildings are located on a steep slope, a large open
ditch should pass around the yards above the building. This will

FARM ENGINEERING.

prevent flood water from running into the yards, buildings and wells.
Make the ditch large enough to carry away the water of a flood, not
of a gentle rain.

Third: Too many people are not aware of the fact that air
drainage is just as essential as water drainage. A site for the farm
buildings is often chosen in a deep ravine, or in a dense grove. The
currents of air are not allowed to pass about the buildings and yards,
because the "wind break" is too dense. There should be a free cir^
culation of pure air about all the buildings. The wind dries the
damp soil, removes the noxious odors, and helps very materially in the
sanitation of the farmstead.

The above statement must not be taken as an objection to wind

Plate 5- SURFACE WELL

A low well platform, surrounded by mud and surmounted by chickens
is a sure sign that sickness will visit those who must drink water from
the well.

breaks or to trees. Trees are essential to the beauty of the farms, and
Avlien properly arranged aid, rather than interfere with sanitation.

Fourth : Near the building site there must be some good source
of pure wholesome water. The principal source of farm drinking
water is the farm well.

The wells may be classified and described as follows :

Surface Wells. — Those wells which are shallow and receive their
water from surface drainage are called surface wells. They are usual-
ly unsanitary because the surface drainage water gathers so much

FARM ENGINEERING. 11

filth before entering the well, that the water is rendered unwholesome
and dangerous.

Shallow Wells. — The shallow well draws its water from sub-
surface drainage, and often in times of flood from the surface. The
shallow well does not receive its water supply from beneath a layer
which is impervious to water.

The shallow well has to be placed on the ' ' doubtful ' ' list from a
sanitary standpoint, because, although the water may be pure, it
stands a chance to be contaminated with dirt and disease germs.

The Deep Well. — The deep well has its source of water supply
beneath an impervious layer. The well should be eased water tight
from the curb to the impervious layer. This keeps out all surface
impurities. While the water of such a well may contain mineral im-
purities, it is almost sure to be free from disease germs.

Artesian Wells. — The artesian well is a "deep well" which fur-
nishes a continual or intermittent flow of water without the use of a
pump.

Wells may be further classified as open, bored, drilled and driven..
In general, the ground about the well should be higher than the sur-
rounding ground. This causes surface water to drain away.

The casing, whether of stone, brick or steel should be tight to a.
point several feet below the curb. This keeps out surface water,
small animals, such as mice, rats and rabbits, as well as insects and
worms.

Some authorities lay down the rule that a well should be a dist-
ance equal to twice its depth from any source of -contamination, such
as privies, cess pools, stables, etc. This rule is in general, a good one,«
but in some instances, the distance must be greater than twice its.
depth. Again, if the well is cased water tight to an impervious layer
a short distance beneath the surface, it is not always necessary to
have the distance to sources of contamination so great.

Spring's. — In general, springs are sources of pure water. But
if flood waters sweep over the spring occasionally, there is great
danger of contamination.

The farm buildings should never be located in inconvenient,

FARM ENGINEERING.

A/yizr

Plate 6- WELLS

These three cross sections show the surface well (Fig. 1); the shallow
well (Fig. 2), and a deep well (Fig. 3)

The dotted arrows show the points where the water supply maj^ enter.
Notice the sunken condition of the ground about the surface well. Surface
water, insects and small animals can enter at will.

The shallow well is constructed in a much better manner. All surface
water drains away from the top of the well. The platforin is tight and the
pump fits the platform.

The deep well is still better. It is cased water-tight down to the slate,
so that it draws all its water from below the layers of slate and stone. Such a
well may always be considered a safe source of drinking water, unless by
some means impurities are introduced into the well by artificial means.

Dug wells may be cased with concrete or with large glazed tiles cemented
at the joints. Drilled wells are cased with riveted sheet iron tubing or with
gas pipe. The latter is the better by far.

FARM ENGINEERING. 13

unsanitary places just because of a spring. The water should be piped
to a good location, even though it becomes necessary to use a hydraulic
ram.

Streams. — In mountain regions and on the sparsely settled
plains of the west, it is often possible to find streams which are safe
sources of drinking water. In the thickly settled states, however,
this is seldom the case. Under these conditions, whenever it is possible
to avoid the use of creek or river water for drinking purposes, it
should always be done.

After the site has been chosen, the proper drainage systems put
in, and a good water supply established, there are several sanitary
conveniences which are indispensable.

Sewage Disposal. — The common system of disposing of
night soil upon most farms is by the old privy vault method. In
general this system is to be condemned as filthy and very unsanitary.
It is possible to catch the night soil in some form of box or scraper
and haul it into some distant field, where it should be buried at once.
In case it is not buried the dogs and other animals are likely to be-
come covered with it and in this way they carry disease germs fi'oni
place to place. In case quick lime is added to the soil in the ssfiraper
from time to time the latter method is found to be fairly satisfactory.

Cess Pools. — It is often convenient to drain the sewage from
the sinks, bathtub and inside closet to a cess-pool. If the cess-pool be
located far enough from the well, and in such a position that all the
drainage is from the tvell toward ^tJie cess-pool, it is altogether possible
to establish a sanitary sewage system.

In case the cess-pool is in porous soil, it is seldom necessary to
provided an outlet drain. The seepage is usually sufficient to provide
ample drainage.

In case the cess-pool is located in soil which is impervious to
water, it sometimes becomes necessary to provide a drain which will
carry away the water after it has risen to a height of from four to
six feet from the top of the cess-pool.

The sewage, after having dropped from the inlet into the cess-
pool moves slowly, and in consequence allows the solid portions to
settle out. The remaining fairly clear water flows out of the drain.
In some cases, dams are placed across the cess-pool between the in-

FARM ENGINEERING.

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FARM ENGINEERING. 15

let and outlet. The dam prevents the sewage from flowing directly
across the surface of the water and out of the drain.

A ventilator should always be provided to carry off all noxious
gases from the cess-pool.

The Septic Tank and Sewage Disposal Plants. — In this book,
a thorough discussion of sewage disposal plants is impossible. In
general, it may be stated that the sewage is carried into a tank, which
should be dark and almost unventilated. The contents are allowed
to stand for some time.

The solid matter settles out, and anaerobic bacteria decompose
the solid part of the sewage.*

The liquid, teeming with billions of germs, then passes out and is
distributed upon filter beds, where the aerobic bacteria finish the
purifiying process. The liquid from the filter beds is almost pure
water.

So many theorists have written exhaustive articles upon the
subject of private sewage disposal plants, that the student is likely
to become confused, unless he clearly understands the whole truth
in regard to these plants.

The student should write to The Iowa State College Engineering
Experiment Station, at Ames, Iowa, for the bulletin on Sewage Dis-
posal Plants for Private Houses.

The author of this bulletin. Professor Marston, (American So-
ciety of Civil Engineers) is an authority on sewage disposal plants.
No Agricultural library is complete without this^ bulletin.

Blue print plans are furnished by Professor Marston to those
who wish to build plants.

The Cremating" Pit. — A great many ignorant or thoughtless
farmers drag animals which have died of contagious diseases, some
distance from the yards and leave the carcasses to decay, and be eaten
by dogs and vultures.

What is still worse, some people sell the carcasses to the represen-
tatives of soap factories. Thus the germs are spread wherever the
Avagon load of carcasses is hauled.

The carcasses should be removed at once, to a cremating pit and

* Anaerobic bacteria work when oxygen is present in very small quantities, if
at all. Aerobic bacteria work in the presence of oxygen.

FARM ENGINEERING.

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FARM ENGINEEEING.

burned. The fire destroys all germs, and tlius all possibilities of
other animals becoming diseased from the carcass are eliminated.

In case the cremating pit is not used, the carcasses should be
removed to a deep grave and buried in quick lime which will destroy
the germs.

However a cremating pit is so cheap and so easy to build, that no
up-to-date farm is completely equipped without one.

The Hospital Stall. — The hospital stall is the farm "pest house."
It should be so located that all drainage from it, runs away from the
other farm buildings. It should be at least three hundred feet from
the nearest yards in which uninfected animals are kept. On the small
farm, the stall may be built to accommodate a sick horse or cow, or
several sick hogs or sheep.

Plate 9— HOSPITAL STALL

A hospital stall or shed costs but little, but it is often the means of
saving many hundreds of dollars.

While the building should provide protection and comfort to the
patient, it should easily be disinfected throughout.

As soon as an animal is dead or cured, all litter from the stall
should be buried, and the stall disinfected inside and out with some
powerful disinfectant such as crude carbolic acid or corrosive sub-
limate. It should also be thoroughly whitewashed from time to time.

18 FARM ENG NEERING.

Sanitary Science Governs Building Materials. — To some extent
we must choose our materials for farm buildings from a sanitary
standpoint. The materials used for floors and sides of stalls should
be impervious to moisture, easily cleaned, and strong enough not to
become displaced.

In general, the material and workmanship should be such u.? to
produce a building which will not harbor vermin, which will be strong
and which will be easy to clean and disinfect.

ARCHITECTURE.

In order that a building may be properly constructed, it is neces-
sary to have the parts correctly designed from two standpoints.

First : From the standpoint of beauty. No man can lay down
rules which will govern all the proportions of a building from the
standpoint of beauty. A few suggestions are offered below.

a. Avoid low, "squatty" buildings. The artistically designed
bungalow is an exception to the rule.

b. Sky-scrapers appear beautiful in a city, but on the farm,
high buildings which cover little ground are unsightly. They are also
more easily blown over.

c. Large buildings with very small windows are likely to appear
out of proportion.

d. A small barn with a large cupola shows poor taste on the
part of the designer.

e. A large barn should never be fitted with very small cupolas.
Use ventilator stacks. They do not appear out of proportion.

f. The cornice of a building should project at least as many
inches, as the building is feet high, (from ground to plate.)

g. Never use gaudy paints upon farm buildings. They are un-
sightly, and usually fade quickly.

h. Remember that lean-tos and odd shaped out-buildings detract
much from the symmetry of the general building plan. (See Plates 10
and 11.)

Second : The more important consideratio.n in the design of a
farm structure is strength. The 'term strength is too often miscon-
strued to mean massiveness. The farm architect should aim to com-
bine real strength with beauty. He must know that the crude fasten-
ing together of huge timbers does not always indicate strong con-

FARM ENG INEERING.

Plate 19

Plate 11
A neat little open feed shed, such as is shown in Plate 10, is very servic-
able and looks in place on any farm. But such a shed as is shown in Plate
11, is unsightly wherever it may be located.

struction. In farm practice, it seldom indicates a thorough knowl-
edge of the requirements of the structure. The various parts of the
frames of structures are called members.

^Members are subjected to one or more of five stresses.

A. Tension is the stress which tends to pull the particles of n
member apart. Example : The wires of a telephone line are sub-
jected to tension.

B. Compression is the stress which tends to crush the particles
or molecules of a body together. Example: The stones in a wall are
subjected to compressive stresses.

20 FARM ENGINEERINa.

C. Torsion is the stress which tends to twist a member. Ex-
ample: A screw is subjected to torsion when it is being screwed into
a piece of wood.

D. Bending Stress. When a member is subjected to transverse
stresses which tend to bend or distort it, it is said to be subjected to
bending stress. Example : The wagon evener is subjected to bending
stress.

E. Shear. The stress known as shear, tends to slip the mole-
cules of a member over each other. Example: Tin is subjected to
shearing stress when cut with the tin snips or shears. The torsion and
shearing stresses do not enter into this work to any great extent.

In taking up the work of design, we shall first consider the
column. No part of the farm structure receives less real thought than
the columns. In order to design the columns correctly, we must allow a
"factor of safety". In case a member would just carry a certain load,
if we were to make the member two, three, or four times as strong, we
would be using the factor of safety of two, three, or four respectively.
The factor of safety must be determined by the judgment of the
designer.

For wood, it is common to use a factor of four or more.
For steel or wrought iron, three or more.
For cast iron in tension, ten or more.
For cast iron in compression, six or more.
For good stone in compression, ten or more.
For poor stone in compression, very large.

Columns are divided into two general classes : A, short columns ;
B, long columns.

A short column is shorter than ten times its least lateral di-
mension. Such a column will be crushed Avithout bending or breaking.
All that is necessary in the design of a short column is to determine
the total load which it must carry. ]\Iultiply this by the factor of
safety, divide by the compressive strength of the material in the
column. This will give the number of square inches of cross section of
the column.

If the column is to be square, simply extract the square root of
the area of the column, and choose a timber x)f that dimension, or in
ease it proves to be an odd size, choose the next size larger.

FARM ENG INEERING. 21

Example : Design a soft pine column three feet long to carry
ten tons with a factor of safety of five, (short column.)
10 tons = 20,000 lbs. 20,000 lbs. x 5 = 100,000 lbs.
100,000 lbs. -^ 3000*=33y3. The square root of 33V3=5.7+
Use a 6''x6'\ As 6 is more than ^^ of 36", the column is "short."

Th. case the column could be only four inches thick, then we would
divide 33% by 4. Result, 81/3. Use a 4x10. As 4 is. more than jV
of "36, this colunm is also a "short one."

In case of long columns, (columns whose length is more than tftn
times the least lateral dimension) it is common to use a special
formula. These formulas vary greatly. In designing columns for farm
buildings, it is seldom necessary to apply any special formula, as it is
nearly always possible to brace the columns so that the rule for short
columns applies. In general, use only square or round columns. Use
a large factory of safety, and be sure that no side thrust is overlooked.
In case the column receives heavy side thrusts, design first as column,
and then see that the timber is strong enough to bear the side thrust
by the use of the rules for simple beams.

BEAMS.

The design of beams is much harder than the design of columns.

Beams are divided into three general classes, as follows :

Cantilever Beams. — Those beams which are held rigidly at one
end with the load applied at the free end, or at some point between
the fastening and the free end are termed cantilever beams. (See K
and A, Plate 12.)

Simple Beams. — This type of beam is supported at each end
and the load is applied between the supports. (See B and C, Plate 12.)

The Combined Cantilever and Simple Beam in which the beam is
rigidly fastened at each end while the load is applied between the
rigidly fastened ends.

When a cantilever beam is subjected to the stress of a weight,
the upper part of the beam is in tension while the lower part is in
compression. At some point between the top and bottom of the beam
there is a point at which there is neither tension nor compression.
This point is the neutral axis.

If material in a beam is placed at a greater distance from the
neutral axis, the beam is made very much stronger.

In the case of most woods, the neutral axis is near the center
of the beam.

FARM ENGINEERING.

■^^

'i -. ;■ /.•

."4 •■ i

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■r-T-J;*-,. A

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'':^:i^^

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A.- A/ •■ *.-:^'

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Plate 12-BEAMS

FAEM ENGINEERING. . • 23

In case a 4x8 is laid upon its side, the greatest distance that

. any of the Avood is from the neutral axis is about two inches. While

if the beam is placed upon edge, the greatest distance is four inches..

The average distance in the first case is one inch, and in the latter case

it is two inches.

As the strength of a beam depends upon the distance Avhich the
material is from the neutral axis, we find: Rule 1. The strength of
a beam varies as the square of its depth.

As the leverage of a beam varies directly as the length, we ob-
tain the following rule. Rule 2. The strength of a beam varies
inversely as its length.

Rule 3. The strength of a beam varies directl}^ as it thickens.

By using the above rules in connection with table 2, the strength
of an ordinary beam can be easily determined. (Fig. B, Plate 12, is
loaded with concentrated load, W. Fig. C, Plate 12, is loaded with
distributed load, such as hay, grain, etc.)

In Fig. D, Plate 12, the rod n P m is called a truss rod. The
beam nm, is designed as a column first, later it is designed as a beam,
the length being the distance from the center of the strut S, to the
points n or m-. The rod must carry all of the load.

Never use more than two struts between a beam and a rod.

The trussed beams are not very common in farm buildings.

Rafters are designed as beams, with this exception ; the beam is
considered to be the length of the run of the rafters, not the length
of the rafter itself. A very large factor of safety must be allowed on
account of the wind which exerts terrific force upon the roofs of
buildings in some localities.

TABLE 1.
SAFE STRENGTH OF MATERIAL IN POUNDS PER SQUARE
INCH OF CROSS SECTION.
MATERIAL COMPRESSION '

• Brick (in cement) 200 lbs.

Brick (in lime) 75 to 125 lbs.

Good Granite 500 lbs.

Good Limestone -^00 lbs.

Rubble Work (in lime) 100 lbs.

Concrete (one part cement, two
parts sand, clean and sharp,
two parts gravel, clean and
rough. 150 lbs.

FARM ENGINEERING.

MATERIAL COMPRESSION TENSION

Yellow Pine 1,000 lbs. lengthwise 2,000 lbs. lengthwise

125 lbs. crosswise crosswise

Wrought Iron 10,000 lbs. 10,000 lbs.

Cast Iron 2,000 lbs. 1,000 lbs.

White pine is about % as strong as yellow pine.

Hemlock is about % as strong as yellow pine.

Oak is about as strong as yellow pine.

TABLE 2.
BEST YELLOW PINE BEAMS.

In the following table the beam is considered to be one full inch
thick, and free from knots, holes, etc.

The loads are safe for perfect beams only.

To compute the strength of a 2x4, one would have to remember
that a stock 2x4 is only li/o inches thick. Consequently, multiply
by 1V2- If there are any knots make allowance for them.

The table is made for uniformly loaded beams. See Fig. C,
Plate 12.

For beams with concentrated load, divide the figures of the table
by two, (2). ■

For cantilever beams uniformly loaded, divide by four, (4).

For cantilever beams with load at the outer end, divide by eight
(8).

Width of beam 1 inch. (Full inch.)

Depth of
beam
in inches

Length of beam in feet

150

120

600

480

380

300

1400

1080

850

700

600

490

2500

1920

1500

1250

1100

960

4000

3000

2400

2000

1700

1500

1300

4300

3400

2800

2450

2150

1900

3900

3300

2900

2500

White pine is about % as strong as yellow pine.
Hemlock is about % as strong as yellow pine.
Oak is about as strong as yellow pine.
Spruce is about % as strong as yellow pine.

FARM ENGINEERING^. 25

TABLE 3
LOADS.

The following table gives the weights of the different materials
per square foot. In case of roofs, the square foot of roof surface
(not horizontal surface) is used.

MATERIAL. ^^^^^^'^ ^^l^oT^'"'''

%-in. Sheathing 2 to 2 lbs.

Lath and Plaster 7 to 10 lbs.

Shingles 2 lbs.

1-Inch Flooring About 4 lbs.

Oats 22 to 25 lbs. per foot in depth.

Corn 40 lbs. per foot in depth.

Barley 35 lbs. per foot in depth.

Wheat. 40 to 45 lbs. per foot in depth.

Hay, (loose) 4 to 5 lbs. per foot in depth.

Hay, (bales) 15 to 25 Jbs. per foot in depth.

Table of cubic feet of space needed for different animals.

A horse 600 to 800 cubic feet.

A cow 500 to 600 cubic feet.

A hog 150 to 300 cubic feet

A sheep 150 cubic feet.

A hen 15 to 25 cubic feet.

The above is merely an estimate and does not have to be ad-
hered to strictly.

MECHANICAL DRAWING.
The student does not need to be an " artist ' ' at mechanical draw-
ing. He should, however, be able to express his thoughts by means of
drawings. The necessary instruments and equipment are:

Drawing Board. — A flat board 12'' by 14". A larger board is
often desirable for larger drawings.

"T" Square.— A flat, thin, straight edge fastened at right angles
to a short thick piece of wood (%'''x2'''). The "T" square is placed
with the cross piece against the end of the drawing board and all
horizontal lines are drawn along its upper edge.

The Triangles — The triangles are usually made of hard rubber or
celluloid. To draw perpendicular lines place the triangle upon the

26 FARM ENGINEERING.

" T " square and draw lines along the edge of the triangle. Triangles
usually have one right angle and two angles of 45 degrees. 'The latter
angles on some triangles are 60 degrees and 30 degrees. A ''45 de-
gree triangle" is sufficient for this work.

Right Line Pen. — The blades of a right line pen can be adjusted
to any width of line which the draftsman wishes to use. In most
cases a pencil drawing is all that is necessary for the farm build-
ings.

Dividers. — The ordinary dividers are so made that either pen or
pencil may be fitted into them. They are used for drawing circles.

Scale. — The Scale is often called a "rule." The "Mechanical
triangular" scale is suited for this work. The inches are divide'd
into %, 1/4, Vs, etc., whereas in the engineer's scale the inches are
divided into tenths.

The outlines of a structure should be shown in heavy solid lines.
Any part inside the building which could not be seen from the outside
may be put in in dotted lines. In some cases a portion of the outside
may be "cut away" and the framing shown in light solid lines .(See
individual hog house.)

The student should draAv each floor, the roof, and at least one
view of a side and an end. For correct system of drawing see plate
of machinery shed. Never try to draw perspective drawings such
as is shown in the lower figure of the individual hog house. They
are difficult to make and they are satisfactory only for those who
cannot understand mechanical drawing of the ordinary kind.

Dimension lines should be supplied wherever necessary. They
are light, solid lines with arrows at each end, showing the exact ter-
mination of the line. Feet and inches are placed near the middle of
the line. 8' indicates eight feet, while 8'' indicates eight inches. ?'
6^' is the mechanical way of writing three feet six inches.

EXCAVATION.

In case it becomes necessary to remove earth or stone in order
to locate the foundation of a building, the student should understand
the system of laying out the work. He should also know how to
estimate the quantity of material which must be moved.

The lines of the excavation should be at least three inches

FARM ENGINEERING. 27

outside of the side line of the Avail. The space between wall and
natural earth is. filled in with sand, gravel or earth.

The quantity of material to be removed is estimated in cubic
yards.

It is often cheaper to excavate a runway at one side or end of
a basement in order to allow the use of teams and scrapers in place
of hand labor.

The estimating- of such work is very easy.

Example. — Find the number of cubic yards of earth to be re-
moved for a basement 33'x64'. Average depth, 4 feet.

(In this' case a team and scraper should be used. The runway
would be about eight feet wide and ten feet long.)

Body of excavation: 32' plus 6"=32.5'. 64' plus '^=64.5'
64.5'X32.5'X4'=8,424 cubic feet. 8,424 cubic feet ^ 27=312 cubic
yards. (27 cubic feet=:=l cubic yard.)

Runway excavation: ( 2'= average depth of runway.)

10'x2'x8'=160 cubic feet-f-27=5.9 cubic yards. (6 cubic yards.)

Total, 312 cubic yards plus 6 cubic yards equals 318 cubic yards.

MASONRY.

While a large book might be written on the subject of masonry,
a few simple statements will give the student a clear understanding
of the points to be observed.

In both brick and stone work, the walls should have all joints
broken. In Plate 13, J? indicates "Rubble" stone work wdth the
joints properly broken; r is a wall of the same type with the joints
improperly broken at the points indicated by arrows.

C and c represent properly and improperly laid walls of "Course
work."

B and b show properly and improperly laid brick walls.

All walls should be "bonded" by means of stone or bricks which
join the outer and inner layers of the wall. In case of brick w^ork,
the layers of "bonding brick" should not be more than seven layers
apart.

Fig. N of Plate 13, shows a top view of a 16-incli brick wall
bonded with ordinary brick.

FARM ENGINEERING.

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1 1 1 1 1

1 1 1 1

i^iavTg

naz

Plate 13-WALLS

FARM ENGINEERING. 29

■ Fig. M, Plate 13, shows a special type of invisible bonding brick.
Strips of iron with hooked ends are sometimes used for bonding pur-
poses.

In case walls do not cover sufficient ground to carry the weight,
the bottom of the wall is made wider in order to increase the bear-
ing surface. The extension at the foot of the wall is called a "Foot-
ing."

Fig. X, Plate 13, shows a concrete wall with footing.

Fig. Z, Plate 13, is a tapered wall which gives the desired re-
sults in many cases. The openings for all doors and windows should
be arched, or provided with a stone cap." The cap should be of ample
size and should extend out into the walls far enough to have ample
bearing surface.

All angles of a cement or concrete wall should be rounded and
the wall reinforced at the angle to prevent cracking.

Mortar. — Lime mortar consists of calcium oxide (quick lime)
which has been slacked in sufficient water to make a thick paste.
The paste, when mixed with sand and exposed to air takes up carbon
dioxide and becomes limestone.

As limestone is soluble in water containing carbon dioxide, the
lime mortar is subject to rapid disintegration. It is, however, cheap
and very satisfactory for rough work. Most farm houses are plastered
with lime mortar, the first coat containing plastering hair, the
second coat containing no hair, and the third coat, (in case one is
applied) being made of nearly clear lime plaster.

Cement mortar is made of cement and sand. When the cement
takes up water, it recrystallizes and forms stone. The mortar re-
quires plenty of moisture for the completion of the setting process.
As the cement mortar is very hard and insoluble, it is preferred for
outside work and for "Pointing up" walls.

"Pointing up" consists of digging out all loose mortar at the
outer edge of the joints and completely, filling in the joint with mortar.
The mortar, when rounded with a special trowel is said to be
"beaded."

CARPENTRY-

Several volumes of very good material have been written on the
subject of carpentry.*

* "The Steel Square," by Fred. T. Hodgson, and "The Builder and Wood Work-
er," tay F. T. Hodgson, are published by Sargent & Co., 94 Center Street,
New York. /

30 FARM ENGINEERING.

The day of the "old fashioned" carpenter who spent much time
putting in complicated sill joints, and numberless mortices is, nearly
past. The increase in the price of lumber, and the enlightenment
of the designers have reduced the size of the timber a great deal.
This makes it imperative that all unneceessary mortices should be
done away Math. Consequently, the joints of up-to-date farm build-
ings are now almost exclusively held together by spikes. The free use
of spikes in the proper places, proves to be a great help in securing
strength and rigidity in our buildings.

The pitches of .roofs and the length of rafters are considered by
many to be hard problems for the amateur carpenter.

, The common system of computing pitches is by number of inches
which the rafter rises in passing over one foot of horizontal distance.

The distance the rafter rises in passing over one foot of surface,
is. termed the "Rise". The horizontal distance over which it passes
is termed the "Run". ■

The pitch is named according to the fraction of the total width
of the building which the regular gable roof rises above the level of
the plate.

Example. — On a building twelve feet wide^ if the gable were
three feet above the plate, the pitch would-be 14. (6" rise to 1 ft. run).
If .the gable were 4; feet above the plate, the pitch Avould be %. (8"
rise to 1 foot run.) If the gable were 6 feet above the plate, the pitch
would be %-. (12'^ rise to 1 foot run.)

The Plate shows how to lay off a rafter by means of the ordinary
steel square. (See Plate 14.)

Pig. A, Plate 14, shows a 12-ft. building with 6-ft rise or i/^
pitch.

Fig. .B, Plate 14, shows a 4-ft. rise, or I/3 pitch.

Fig. D, Plate 14, shows the old method of laying off rafters. The
square is moved along upon the rafter so that the corner comes first
at d, , second above c, third above d, etc.

The distance ah is marked off for each foot of run and the final
position of h will be directly above one of the small letters, c, d or e.

By marking down along the edge of the tongue Th, the top cut
of the rafter is given. B,y marking along the edge of the square ab
in its present position, the heel cut of the rafter is given.

FARM ENGINEERING.

i C cf e

Plate 14-FRA.MING RAFTERS

32 FARM ENGINEERING.

The Author is a firm believer in the use of the framing . square,
and consequently does not dwell upon the use of the old-fashioned
square.

By means of the tables upon the side of the Nicholas framing
square, all rafter cuts may be laid out by simply consulting ,the
table. The results are accurate, and as the framing square costs no
more than the old board rule . square, there is no reason why it should
not be used by every student.

The handling of carpenter tools cannot be taken up here, but a
few hints on selecting carpenter tools are not out of place.

Buy good tools of a Standard , make.

In buying planes, get those which have blades adjustable up and
down and sidewise. The throat should also be adjustable.

Saws should . be fine for fine work ; 12 teeth to the inch is not too
fine. For coarse work, such as framing, a cross cut saw should be as
fine as 8 teeth to the inch. A rip saw should have 4, or 5 teeth to the
inch.

For finishing work, a hammer should have a round face, while
for rough work the square face is preferred by many. Don't buy
freak tools for plain work.

PAINTING.

Out-side paint for barns, fences, etc., should be made of ground
burned clay, and raw linseed oil. The common colors are yellow, red
and brown.

For house painting, lead oxide (white lead) and zinc oxide should
be mixed, with raw linseed oil. The so-called boiled linseed oil, is raw
oil with some drying agent added.

The inside finish should be bought ready-prepared, and used ac-
cording to directions.

In general, paint should be applied in thin coats, well rubbed in.

The student must choose the colors and types of finish according
to his . own particular taste in the matter.

PLUMBING.

When putting in closets, sinks, etc., remember that every fixture
must have a trap, to prevent the back flow of noxious gases from
the sewer. The trap should be vented directly to a. ventilator stack,
which must open through the roof: The stack should be the same
size as the sewer pipe.

FARM ENGINEERING. 33

The traps should be directly connected to the fixtures. The fact
that . a trap is placed at the entrance of the cess pool, in no way does
away with the necessity of the fixture traps in the house.

All plumbers' supply houses have drawings and specifications
for the installation of their fixtures.

Caution: No lead pipe should be used in the water line from
which drinking water is obtained. The water acts upon the lead
and a sloiu poison is likely to be found in, that part of the water which
has been standing in the lead pipe.

It is nearly always advisable , to have plumbing done by a com-
petent plumber, rather than to attempt the work without experience.

ESTIMATING QUANTITIES.

The student can become proficient in estimating quantities of ma-
terial by actual practice only.

A few simple rules are here given for the guidance of the student
in making estimates.

1. Begin by estimating excavations.

2. Finish foundations and chimneys.

3. Work out first floor, sides, second floor and roof in order.

4. Complete plastering estimate.

t 5. Complete inside finishing estimate.

6. It is customary to put all materials of a kind, such as 2x4 's,
siding, laths , and shingles together in the final estimate. But it is
advisable to keep a copy of the estimate of each part separate, for
the benefit of the builder.

7. Lumber, is estimated by the thousand feet.

8. Shingles are estimated by the thousand.
1 bunch = 14 of 1,000.

(If shingles are laid 4 inches to the weather, 1,000 shingles will
cover about 1 square. — 100 square feet. At five inches 1^ squares.)

9. In estimating flooring, add about I/3 the total number of sur-
face feet to the estimate to make up for tongues in 3'' or 4'', flooring.
In case of 6^' "or 8'' flooring or ship lap, add i/4 the original estimate.

For narrow siding I/3 must be added to the original estimate.

10. Good paint should cover , from 200 to 300 square feet of
new lumber per gallon for the first coat. Second coat, 300 to 400
square feet.

FARM ENGINEERING.

11. When the , necessary number of nails has been determined,
consult the following table. Divide by number of nails per pound to
find number of pounds required.*

It takes about 2% pounds, of 3d nails, or about 3i/^ pounds of 4d
nails to lay 1,000 shingles. d indicates the penny of the nail.

length

Number per lb. [

in
inches

1100 to

1200

Sometimes used, for lathing.

11/4

700 to

750

Shingle and lath nails.

400 to

450

Shingle nails.

250 to

275

Thin siding.

21/2

125 to

140

For siding, sheathing and flooring.

lOd

75 to

Sheathing and flooring.

12d

31/4

65 to

Toe-nailing rafters, etc.

16d

31/2

45 to

Toe-nailing rafters, etc.

20d

30 to

Framing work.

30d

41/2

25 to

Framing work.

40d

15 to

Framing work.

Casing and finishing nails run about Yq to ^4 more per pound than
do the common nails listed above.

CHICKEN COOPS.

The student cannot do better than to obtain "Farmers' Bulletin
No.. 3" of the Montana Experiment Station at Bozeman, Montana. As
the Bulletin contains a reprint of "Farmers' Bulletin No. 357" of
the United States Department of Agriculture, the knowledge imparted
is very complete, both in general poultry culture, , and in the details
of poultry houses construction.

HOG HOUSES.

As differences in latitude and general weather conditions in-
fluence the type of hog house which is desirable for different localities,
the student will necessarily have to investigate local conditions before
designing a hog house or "piggery."

The individual hog house shown, in Plates 15 and 16, is very de-
sirable for brood sows. It is suitable for all the central and northern
states.

* As nails are cheaper by the keg than by the pound, it often pays to buy a keg
rather than a large fraction of a keg.

FARM ENGINEERING.

All hog houses should be well lighted, provided with plenty of
fresh air, and a clean, warm floor.

Plate 15— INDIVIDUAL HOG HOUSE

FARM ENG INEERING.

D earned
HMBainer

Plate 16 - INDIVIDUAL HOG HOUSE

It is essential that a sow should be quiet during her farrowing period.
The individual hog house fills the bill exactly.

It is built with a two by four frame. The frame is covered with drop
siding or ship lap. The house is easily moved from place to place.

A small door about a foot square should be put in the end opposite the
large door. The small door should be near the top. It provides ventilation,
and allows the herdsman to drive out ugly sows. The drawings and the
picture explain how the individual hog house is built.

COW BARNS.

Cow barns, above all, should be well ventilated and lighted. The
most practical system of lighting and ventilating consists of placing
windows rather high in the sides of the barn. The windows should
be hinged at the bottom, so as to swing inward at the top. At the

FARM ENGINEERING.

sides, there should be boards set in such a manner that when the
window is open, the in-coming air must come over the top of tlie
windows. Cold drafts are thus eliminated.

The floors may be of paving brick or concrete. In case of very
smooth, cement floors, no ice should be allowed to collect upon the
floor. Cows are likely to slip upon this film of ice and become dis-
abled.

Plate 17-A BARN OF EXCEPTIONAL DESIGN

From the standpoint of arrangement, there is practically no improve-
ment that could be made. The surrounding's are sanitary, and in summer,
the flower beds in the fore-ground are very beautiful.

For the ground plan, see Plate IS.

The dairy room should be some distance from the barn, in order
to exclude all contaminating odors from the stored milk, butter or
other products.

A silo may be located near the cow barn, and connected to the
feed way by a covered alley way. ,

THE SILO.

The student should make a careful study of the most up-to-date
silos. See Bulletins 100 and 117, Iowa State , College Experiment
Station, Ames, Iowa. These Bulletins are so clear and concise, that
Lfurther discussion Avoiild be fruitless.

FARM ENGNEERING.

O O O T'

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FAEM ENGINEERING.

Plate 19-IOWA SILO

Plate 20-MACHINE SHED

FAEM ENGINEERING.

Two Retjiny Doors S*p

^rm

^t ^

-^h

^-a

^-d

:J1

FARM ENGINEERING.

Plate 22-MACHINE SHED

In spite of many theories to the contrary, tlie author has learned by
actual field investigations, that only closed machine sheds are satisfactory.
The shed in Plates 20 and 21 is considered, verj;" satisfactory.

The long-, narrow shed in Plate 22, is also verj^ satisfactory.

HORSE BARN.

The horse barn should be separated from the cow barn if possible.
The wagon, carriage, and harness rooms should also be separated
from the horse stalls by tight partitions. The ammonia arising from
the stalls will eventually ruin paint and leather.

The system of ventilating the horse stable should be the same
as in the case of the coav barn. For size of stalls see table.

TABLE OF SIZE OF STALLS.

Horse (single), 3' S^'xlO' or 4'xlO' . (From front of manger.)

*Horse (single), 5'xlO'. (From front of manger.)

Horse (double), 7'xlO' or 8"xl0^

Horse (single, box stall) lO'xlO', or 10'xl2'.

Cow (single stall), 3' 6" to 4'x7^ (From front of manger to front
of gutter.)

Total length of stall from front of manger to back wall.

For horses, 14'. 16' is better.

For cattle, 11' to 13^

*Horse stalls between 4 and 5 feet wide are often found to be un-
satisfactory, owing to the fact that when a horse lies down he may
get his feet above him in a stall wider than four feet, and not.be able
to get them under him again in a stall narrower than five feet. This
often requires the pulling of the horse out of the stall in order to , allow
him to get up.

FARM ENGINEERING.

Plate 23-A NEAT FARM COTTAGE

Plate 24-PARM HOUSE

FARM ENGINEERING. 43

DWELLING HOUSES.

As the location of the farm, the climate, the special weather con-
ditions, the size of the family, and the taste of the people who dwell
in farm houses, are all factors which govern the design of farm
liouses, no plans are included in this volume.

The student should work out plans to exactly suit the conditions
and no one else can do this for him.

Procure from the Extension Dept., Bulletin No. 1, "Healthful
Homes," Iowa State College, Ames, Iowa.

EXAMINATION

Note to Student — These questions are to be answered inde-
pendently- Never consult the text after beginning your exami-
nation. Use thin white paper about 6"x9" for the examination.
Number the answers the same as the questions, but never repeat
the question. Mail answers promptly when completed.

QUESTIONS FOR EXAMINATION.

1. Give two reasons why farm buildings used to be built of sucli
heavy material.

2. In what ways does "guess work" cause buildings to be unsatis-
. factory?

3. Name three advantages of the centralized or single barn plan for
farm buildings.

4. Tell why the "distributed" plan of building is more satisfactory
than the centralized system.

5. What factor takes precedence over all others in choosing a buil-
ding site ?

6. What is meant by "air drainage"?

7. Name. the three principal classes of wells.

8. How far from a well should all sources of contamination be kept?

9. How should a well be lined or cased?

10. What is a cess pool ?

11. What dangers are likely to attend the installation of a cess pool?

12. Why is a trap placed between the cess pool and the house sewer
pipe ?

13. What is a "septic tank"?

14. Of what use is a hospital stall? ,

15. What is a cremating pit ?

16. What qualities should building material possess to be sanitary?'

17. Give the three rules governing the strength of beams.

18. How are rafters designed?

19. Why must rafters have such a large. factor of safety?

FARM ENGINEERING-. 45

20. If a plain beam 12 feet long will bear a 1000-pound, load con-
centrated in the middle, what evenly distributed load would it
carry ?

21. A. roof has a rise of 6'' to a run of 1-foot. "What is its pitch?

22. What rise, must a roof have per foot of run, if it is a I/2 pitch
roof?

23. Where should the fixture traps be placed with respect to plumb-
ing fixtures in a house?

24. Is a column 4"x4'' (full size) two feet long, a "long" or a
"short" column?

25. What points . should be observed in designing a hog house ?

26. Plow much paint should "first coat" one side of a barn 40 feet
long, by 20 feet high?

27. Wliat. points must be observed in designing a cow barn?

28. Where should the dairy or milk room be placed with reference to
the cow barn?

29. What do we. mean by the "bonding bricks" in a brick wall?

30. Wliat do we mean by the term "footing" as applied to walls?

31. A. The student shall choose a location for a building site, de-
scribe its location from standpoints of roads, nearness to fields
and market and its sanitary qualities.

B. Decide what type of farming is to be done, whether grain,
hay, dairy, or general farming. State the size of farm and num-
ber of horses, cattle, sheep, hogs and chickens to be kept (approx-
imate).

C. Decide whether the centralized or distributed type of build-
ings are to be used.

D. Draw a rough sketch of farmyard roads, etc., locating to
scale the well, cesspool, or closet, and the buildings. Be SURE
to show slope of land by an arrow. Make the drawing as a map
not in perspective.

E. From here on the student may use all data available. Make
at least TWO drawings of each building; see that they are de-
signed CORRECTLY, and estimate quantities of material and
labor required for ONE of the larger buildings. (Note. The
student should take plenty of time to this question. The author
would not attempt to answer question 31 in less than five days
of eight hours each.)

46 FARM ENGINEERING.

WRITE THIS AT THE END OF YOUR EXAMINATION.

I hereby certify that the above questions were answered en-
tirely by me.

Signed

Address

THE

Correspondence College

of Agriculture

FT. WAYNE, INDIANA

FARM ENGINEERING— Part II

Field Engineering

By H. BOYDEN BONEBRIGHT. B. S. A., A. S. A. E.

Dept. of Agricultural Engineering
Montana Agricultural College

This is the Second of a Series of these Books giving a Complete Course of Instruction

in Farm Engineering.

NOTE TO STUDENTS

In order to derive the utmost possible benefit
from this paper, you must thoroughly master the
text. While it is not intended that you commit the
exact words of the text to memory, still there is
nothing contained in the text which is not absolutely
essential for the intelligent farmer to know. For
your own good, never refer to the examination ques-
tions until you have finishea your study of the text.
By following this plan, the examination paper will
show what you have learned from the text.

When the student takes up the work of Field
Engineering he should not labor under the impres-
sion that he is to learn "Civil Engineering at a
Glance." A Four Year Course in Civil Engineering
in any good college would only fit the student for
beginner's work as a civil engineer.

For this reason the author will endeavor to set
forth in a clear practical way those points which are
absolutely necessary in Farm Field Engineering.

The student can at the cost of a few minutes'
time and the expenditure of a few cents for postage
secure bulletins from various experiment stations
which will be very broadening so far as results oi
field engineering work are concerned. These bullte
tins do not however tell how to go about the work
and many ridiculous failures are attributed to the
so-called "errors" in these valuable little books which
are in fact due only to the lack of true principles of
Farm Field Engineering.

The student who studies these bulletins must
always ask himself this question: Do the conditions
under which I am working check with the condi-
tions under which the results set down in this bulle-
tin were obtained? Do not jump at conclusions!
Be Sure!

FARM ENGINEERING

LIST OF FREE BULLETINS. SEND FOR THEM.

1. "Land Drainage by Means of Pumps." — Bulletin 243, U.

S. Dept. of Agriculture.

2. "Duty of Water."— Bulletin .56, Agricultural College, N. M.

3. "Measurement of Water for Irrigation." — Bulletin 53,

Wyoming Experiment Station, Laramie, Wyoming.

4. "Drainage Conditions in Iowa." — Bulletin 78, Experiment

Station, Ames, Iowa.

5. "Drainage of Farm Lands." — Farmer's Bulletin 187, U. S.

Dept. of Agriculture.

6. "Land Drainage." — Bulletin 138, Experiment Station, Uni-

versity of Wisconsin.

7. "Drainage of Irrigated Lands in San Joaquin Valley, Cali-

fornia."— Bulletin 217, U. S. Dept. of Agriculture.

8. "Drainage of Irrigated Lands." — Farmer's Bulletin 371, U.

S. Dept. of Agriculture.

9. "Selection and Installation of Machinery for Small Pump-

ing Plants." — Circular 101, U. S. Dept. of Agriculture.

10. "Current Wheels." — (Their use in lifting water for irriga-

tion), Bulletin 146, U. S. Dept. of Agriculture.

11. "The Use of Windmills for Irrigation in the Semi-arid

West."— Farmer's Bulletin 304, U. S. Dept. of Agri-
culture.

12. "Practical Information for Beginners in Irrigation." — Far-

mer's Bulletin 263, U. S. Dept. of Agriculture.

13. "The Right Way to Irrigate."— Bulletin 86, Utah Agri-

cultural College Exp. Station, Logan, Utah.

14. "The Construction of Concrete Fence Posts." — Farmer's

Bulletin 403, U. S. Dept. of Agriculture.

15. "Cement Pipes for Small Irrigation Systems." — Agricul-

tural Exp. Station, Tucson, Arizona.

16. "Cement Mortar and Concrete," (For Farm Use) — Far-

mer's Bulletin 235, U. S. Dept. of Agriculture.

FARM ENGINEERING

17. "Cement and Concrete Fence Posts." — Bulletin 148, Col-

orado Agricultural College Exp. Station, Ft. Collins,
Colo.

18. "The Destruction of Hydraulic Cements by Alkali." — Mon-

tana Agricultural College Exp. Station, Bozeman,
Mont. (Bulletin 81.)

19. "Restoration of Lost Corners and Subdivisions of Sec-

tions."— U. S. Gen. Land Office, Dept. of the Interior,
Washington, D. C.

In order to properly understand the typical surveyor's
instruments, drawing instruments, etc., the student should
secure the following catalogues. When he studies in the text
about a level, a compass, a transit, a planimeter or other "In-
strument of Precision" he should turn to these catalogues and
carefully study the details of construction of the instrument.

The information will be of untold value to the student who
expects to put his knowledge into practice. By the careful
study of the various makes of instruments he will broaden
his understanding of the work as well as of the instruments,
for the makers give detailed information as to the adjustments
of their instruments and the method of using each instrument.

Gurley's Manual, of American engineers' and surveyors'
instruments, W. & L. E. Gurley, Troy, N. Y., or Seattle, Wash.

Catalogue of surveyors' instruments, C. L. Berger & .Sons,
Boston, Mass.

Catalogue of Keufifel & Esser, Keuffel & Esser, New York.

The Frederick Post Catalogue, Frederick Post Co., Chi-
cago, or San Francisco.

Catalogue of Drawing Materials, Eugene Dietzgen Co.,
Chicago, or New York,

Blasting of Ditches, E. I. Dupont & Co., Wilmington,
Delaware.

If the student establishes an Engineering Library he can-
not do better in the way of field engineering books than to
purchase the following:

FARM ENGINEERING 5

Engineering for Land Drainage (Elliot), John Wiley &
Sons, New York.

Mechanical Engineers' Pocket Book (Kent), John Wiley &
Sons, New York.

Physics of Agriculture (King), F. H. King, Madison, Wis-
consin.

Theory and Practice of Surveying (Johnson), John Wilev
& Sons, New York.

FARM ENGINEERING

PART II.

Many attempts at Farm Engineering have been made since
the history of agriculture. The results of the best work have
been handed down to us and by far the greater number of
failures have been lost sight of. Broadly speaking, the failures
have all been due to ignorance, but this by no means indicates
that those who made the blunders were not well educated. It
is easy for a man Avho is a good scholar in the true sense of
the word to make ridiculous errors in drainage. These errors
might readily be detected by a practical ditch-digger who could
neither read nor write. In case of failures, you will find that
the educated and the illiterate invariably jumped at conclu-
sions, with disastrous results.

While the higher mathematics are of great assistance in
doing very accurate engineering work, there is no good rea-
son why by far the greater part of the farm field engineering
cannot be accomplished by the man who has a thorough knowl-
edge of arithmetic and plane geometry. The following named
subjects are so interwoven, however, that he who hopes to
succeed as an agricultural engineer, must of necessity under-
stand the underlying principles upon which they are based:

Agronomy.
Animal Husbandry.
Concrete Construction.
Farm Management.
Masonry,

FARM ENGINEERING

Physics.
Sanitary Science.

In the following discussion the subjects are taken up alpha-
betically, and not in order of most importance.

Agronomy. — Few people realize that the agronomist must
know (not guess) the exact needs of the plants which are to be
grown. This often makes for success or failure on the part oi
the engineer, as his work may be condemned upon the basis
that his system of drainage or irrigation did not permit of the
raising of a certain crop upon a given field, when as a mattei
of fact, the crop is in no way suited to the conditions, even
though the engineering be done perfectly. The engineer should
be able to find out in regard to rainfall, temperature, length of
seasons, etc., so that he may not make ridiculous errors in his
claims for the improvements which are contemplated.

The United States Government has a weather bureau in
each state, and from these, the student may obtain for the
asking, statements of maximum, minimum, and average tem-
perature for the months, together with a statement of the
amount of precipitation for each month. Now, if the student
is armed with such a statement, and has a clear knowledge of
the requirements of plants, he .is in a position to advise with
some degree of accuracy. What is more, he is able to foresee
failures, which, if allowed to occur, might be attributed to the
work, rather than to the right cause.

The soil is another important branch of Agronomy which
governs very directly the growth of plants, the handling ol
drainage or irrigation water, and even the building of fences.
A system which may prove effective upon some kinds of soil,
may fail upon another kind. Later in the work, the student
will have ample opportunity to observe these points.

Animal Husbandry. — It is necessary to have a knowledge
of the needs of the different farm animals in order to make
the designs of fences fill all the needs and not merely a part
of them. The student who has observed valuable horses ruined
by wire cuts will realize that the loss of one horse would have

FARM ENGINEERING

paid well for the building of a properly designed fence in the
place of the barbed wire contraption which ruined the horse.
But perhaps the same fence which ruined the horse was an
excellent hog, sheep and cow fence. It merely needed com-
pletion before it could be justly called a horse fence.

Animals also influence the physical condition of the soil
and its chemical richness as well. The drainage of trarftped
stock yards is a much harder problem than the drainage of an
untramped field. It often occurs that the engineer can accom-
plish more by prescribing a correct method of tillage, than
could be accomplished by any other means. Study the habits
of animals, and what is required for them, and you will soon
learn that much of the field engineering which you encounter
has been poorly done.

Concrete Construction. — Unless the student has done much
work in concrete construction, he should be forewarned against
the "contractor" who claims to have "unlimited experience."
Anyone can start out as a concrete contractor and get away with
the money if one is so inclined. The student should KNOW
what is right and what is wrong and insist on the work being
done to his specifications. He will be told many things by the
contractor, but he should remember that it usually costs less
to do poor work than it does to do good work. This often
gives much color to the statements of the man who has taken
a concrete contract. Know your subject, specify plainly and
exactly, and insist upon the work being done right.

Farm Management. — The engineer must be able to com-
pute the cost of contemplated improvements and to estimate in
a fairly accurate way whether or not they will be profitable.
Not all highly scientific improvements are necessarily profit-
able. Striking examples of unsuccessful engineering projects
are to be seen in the irrigated countries. Not that the dis-
carded systems were unsuccessful from the engineers' stand-
point, but in so many cases the water did not do sufficient good
when delivered, to justify even one-half the original expense.
The same is sometimes true of drainage projects, but the rela-
tive percentage of failures is comparatively small.

FARM ENGINEERING

The laying out of a farm in the first place is something
that is too often overlooked. It is often better economy to
chance present fences, tear down some old buildings and gen-
erally rearrange the whole farm than to improve upon the or-
iginal plan. It often happens that the most undesirable spot
on the farm has been chosen as a building site simply because
of a spring being near it. The extra expense of drilling a deep
well in a more healthful location could often be saved in a
season in doctor bills alone, to say nothing of the other advan-
tages to be derived from a really desirable location.

Masonry. — The subject of masonry has been thoroughly
treated in Part One of Farm Engineering. An engineer may
make a very good design, and if this design be submitted to a
bungling mason, the engineer stands a fair chance to be
blamed for the failure which is almost sure to follow. Masonry,
like concrete work, is a field often invaded by those who have
been marked failures in other lines of work.

Physics. — The student should have a knowledge of ele-
mentary physics. The careful study of any high school text-
book will give the fundamental knowledge necessary. Many
laws of physics will be given in this book, but they will not
be listed as such.

Sanitary Science. — As in the case of Farm Structural En-
gineering, sanitary science is one of the most important factors
in the work. The student should become thoroughly acquainted
with the laws of his state which govern sanitary conditions. It
may be mentioned here that in many cases where people have,
for selfish reasons, refused to allow drainage ditches to pass
through their lands were declared a menace to public health,
and the drainage projects were subjected to no further hind-
rance. A thorough knowledge of these laws and rulings will
enable the enginer to put through projects which seem to be
opposed by hopeless odds. One should never give up until he
has exhausted all recourses to laws upon sanitary matters.
Likewise, be sure that the project in hand is not of such a na-
ture as to make it possible for some other party to ruin the

lo FARM ENGINEERING

usefulness of the work by having it declared a menace to the
public health.

The author has in mind the case of a small town which
installed a sewage system which emptied into a small creek.
This creek had previously been dammed to make a reservoir
for drinking water by a farmer who lived a short distance down
the stream. No sooner was the system ready for operation
than an injunction was granted prohibiting the emptying of
sewage into the creek. And it looks at present as though the
injunction would remain active permanently. Even a slight
knowledge of law should have warned an engineer not to empty
sewage in a creek immediately above the source of drinking
water of this farmer.

Cases are on record in which large hotels in the mountain
summer resorts have been forbidden to empty sewage into
creeks which were sources of water supply for towns at least
30 miles down stream. The student need have no trouble upon
this score if he will give careful attention to the matter before
beginning a project.

Land Survey. — The science of surveying is as old as his-
tory. To be sure, the first systems were crude, but in their
time they answered the purpose. In the history of our own
country we find that lines were often run by driving to or
from the rising sun, and that the length of these same lines
was often determined by computing the circumference of the
rear wagon wheel and then counting its revolutions until the
desired distance had been covered.

Later the land was laid off by means of the surveyor's
chain and the compass. This method was far more nearly ex-
act, but there still remained much room for improvement. The
use of the steel tape in measuring lines and the transit in de-
termining their directions is at present the most nearly exact
method of determining distances and directions which is open
to the agricultural engineer. In order to determine the length
of a line accurately, one must not only know how to use a sur-
veyor's tape, but one must practice using it until he is able to

FARM ENGINEERING

measure a line 1,000 feet long any number of times and make
each answer check within .05 of one foot. This is no easy
task, but practice will accomplish the task to the satisfaction of
all concerned.

Plate I. — No. 1. Architects level tilted to one side to show compass box.
No. 2. Large compass. The needle of this instrument can be seen.
No. 3. The surveyors transit vvath Vertical circle.
(The plumb bobs of these instruments have been drawn up so
as to be included in the photo.)

The Tape. — The tape is usually 100 feet long, although 50-
foot tapes and 200-foot tapes are not uncommon. At each end
of the tape one foot of the distance is marked off into ten equal
divisions or into tenths of a foot. In some cases the tenths are
subdivided into ten parts, or into hundredths of feet. The tape
usually has detachable wire handles. It is usually advisable to
replace the handles with a rawhide thong about ^4, of an inch
wide by one foot long. The thong makes a convenient handle
and never catches trash as the tape is dragged about. In order

12 FARM ENGINEERING

to measure straight, it is necessary to know two points on the
line (usually the ends) and then see to it that all measurements
are made exactly on that line. The "rear chainman" (the man
who attends to the rear of the tape) must signal to the "head
chainman" to move left or right until he has the front end of
the tape exactly in line with the stake at the further end of
the line. Then the tape is pulled clear of all obstructions and
the rear chainman holds the zero point at the front side of the
stake or "pin." The head chainman then sticks a pin so that
its front side is just even with the one hundred foot mark, or
such other mark as he chooses to measure to.

The pins are generally made of about No. 6 wire, with a
loop at the top, and a pointed bottom. They are about one
foot long. In case the measurements are made through grass
or underbrush, a piece of red flannel should be tied in the loop
of each stake, as they are then much easier to see. Eleven
stakes or pins are commonly used. "One to start with," and
then when ten are picked up by the rear chainman there have
been ten measurements made, 500 feet in case of the 50-foot
tape, 1,000 feet in case of the 100-foot tape, or 2,000 feet in
case of the 200-foot tape. In this way it is easy to keep track
of the distance.

Be sure to properly line in the chainman, or the measure-
ments will be ridiculously incorrect. The lining in may be
done wholly by motions or by word (in case of short tapes).
Never try to do field work accurately without the use of a
METAL tape.

"Poles" are usually set at the ends of the line to aid in
"lining in." The poles consist of wood (sometimes gas pipe),
about one inch in diameter and six feet long. They are painted
red and -white to assist the eye in seeing them. In some locali-
ties blue is easier to see than red. The pole is set upright when
th line has been determined, and it proves a great help to the
"chainmen."

In meas-uring curved lines it is often necessary to use very
short measurements. There are other methods of measuring

FARM ENGINEERING 13

these lines, but unless the operator is familiar with higher
mathematics it is better to use a tape. When a line runs up or
down hill a plumb-bob should be used to determine the point
at which the line should be held so that it is brought exactly
above the pin. The tape MUST be held HORIZONTAL, not
parallel to the earth's surface. Small grades, such as y^ foot
in one hundred, need not^be considered in tape work.

Errors. — By the time the student has tried the 1,000-foot
line a few times he will become interested in errors. For this
reason let us look into the matter. If your tape is too long
by )-2 inch, then each measurement will add to the error of
the last measurement. If the tape is too short, then there will
be an ever increasing error in the other direction. Such an
error is a cumulative error. It is a very bad type of error and
MUST be avoided. Suppose that you are using pins ^ inch
in diameter and the head chainman places the pin so that its
REAR side is at the 1,000- foot mark instead of placing the
pin so that its front side is at the 100-foot mark. Then ^
inch will be aded to the one hundred feet at every measure-
ment. 10 X ^ = 2J/2 inches.

Now when coming back, if the head chainman corrects his
error and the rear chainman brings the zero point to the rear
of the stake each time, this cuts off J4 inch each time and the
line will be 2^^ inches too short. Now you will fail to check
by just 5 inches. By this time the cumulative error will be
perfectly apparent.

The compensating error is not so bad. Such an error as
missing the placing of a pin by UlOOO of a foot is not so bad
because in one case it may be in one direction and in the next
case it will be in the other. By the law of chance it is as
likely to be one way as the other. But do' not think that it is
a good plan to depend on this law. It often proves the un-
doing of the one who depends on it. Try to abolish all errors,
both compensating and cumulative, and in spite of your best
efforts there will be plenty of errors and some to spare.

Remember that it is easier to make a mistake of 100 feet

14 FARM ENGINEERING

than of one foot, and that in your figures it is as easy to make
a mistake of 1,000 as of 1 or .01.

How to Turn Off a Right Angle With a Tape.— It often
becomes necessary to turn a line at right angles, in order to
pass an object while measuring a line or in order to find the
direction of a "right line" from a point in the line. To do this
one should measure back 8 feet on the line from the point at
which the line is to be turned ofif. At the point, 8 £eet back
from the turning point., set a pin exactly on the line. Now,
with the zero point held at the turning point or stake, scratch
the arc at the 6-foot point at what you believe to be right
angles to the main line. Make the arc cover several degrees,
in order to avoid any delays. Now, with the zero point held
at the point 8 feet back on the main line find the point in the
scratched arc where the 10-foot mark crosses the scratch. The
point is in a line which is at right angles to the main line at
the original turning point. The foregoing is based upon the
fact_that the square of the base plus the square of the side of
a right angle triangle is equal to the square of the hypothenuse.
8X8 = 64;6X6 = 36;
10 X 10 = 100; 64 + 36= 100.

In case of long lines, one may use 60 feet, 80 feet and 100
feet. This gives greater accuracy. In case the transit is handy
it is usually advisable to turn off the angles with it. It is
quicker. B)^ bisecting the right angle one is able to turn off
the 45 degree angle with little trouble.

INSTRUMENTS BY WHICH DIRECTIONS ARE
DETERMINED.

The Compass. — (See Plate 1, Fig. 2.) — In the preliminary
surveys of land the compass is often used to determine the
direction in which lines should be run. The fact that the same
end of a magnetized needle always points approximately north
enables the instrument makers to design an instrument which
can be used to determine the direction of lines. The magnetic

FARM ENGINEERING ij

needle is balanced upon a pivot in the middle of a glass covered
cavity. Around this cavity are the degree marks, by w^hich one
is able to read the number of degrees the line varies from the
approximate north and south line. The engineer who wishes
to do good work with a compass must exercise great care for
the following reasons :

1. The "North magnetic pole" lies east of due" north, and
consequently at different points on the earth's surface the
"declination" or "variation" from the true north and south line
is different in extent. And what is more, the North magnetic
pole does not remain in exactly the same place all the time.
All god instrument makers give directions in their catalogues
for the finding of the declination of the needle for different
points in the U. S. at dift'erent times. By the use of these
tables one is able to determine fairly accurately the direction
of a line. (See Gurley's Manual.)

2. Local attractions often interfere with the needle of the
compass, as for example, a bar of iron held near the instrument
will draw the needle away from the true line. The presence of
large bodies of iron ore are likely to draw the needle out of line
and make the readings entirely wrong.

From the foregoing it will be seen that the compass, while
an excellent instrument for rough work, is likely to prove of
little value to the agricultural engineer who must do accurate
work. For these reasons but little emphasis is laid upon the
instrument here. The makers of good compasses furnish cata-
logues telling how to adjust the individual instruments and how
to determine the North and South line, or the declination of
the needle. (See Plate 1, Fig. 3.)

The Transit. — Transits are provided with a compass needle
and graduated circle so that they may be used as a compass in
case one so wishes. But they are also provided with circles
so graduated that angles may be accurately measured with
them. (See Plate 1, Fig. 1.)

The Architect's Level.— The architect's level is often pro-
vided with a magnetic needle and graduated circle by which

i6 FARM ENGINEERING

one may determine the direction of the given line. The same
general rules which govern the errors in compass observations
hold true when applied to the magnetic needle readings of the
transit or the architect's level.

The Plumb Line. — By means of a weight called a "'plumb-
bob," attached to a "plumb-line," lines can be determined
which are vertical to the earth's surface. As the center of
gravity of the earth is presumed to be its center, then all plumb
lines will naturally hang with the lower ends pointing toward
the center of the earth. For this reason no two plumb lines
can be exactly parallel. For by geometry we learn that two
parallel lines will never meet, no matter how far they are ex-
tended. Now, as all plumb lines meet at the center of the
earth, it stands to reason that they are not parallel. The best
plumb-bobs are made of steel or brass, hollowed out on the
inside. The cavity is filled with mercury. This is done to
give the greatest possible weight for the size. (The wind does
not bother such a bob nearly so much as a lighter one.)

The plumb-bob is an instrument which the surveyor must
constantly use. It is simple, and under most conditions it is
very accurate. It is sometimes influenced by the presence of
great bodies of earth at O'^e side of it. but for all practical pur-
poses one need not hesitate to use the plumb-bob with absolute
confidence.

Bubbles and Bubble Tubes. — The direction of lines is also
determined by means of glass tubes nearly filled with ether.
The tubes are not straight on the inside, but they are slightly
bent. Thus, when the tube lies on the side the ether seeks the
lowest level and the bubble of ether gas is forced to the highest
point in the tube. As one end of the tube is raised the ethef
flows to the other end and the bubble seeks the higher end.
In cheap levels the glass tubes are not accurately made and
consequently are not sensitive to slight movements of the tube,
but in the high-grade instruments the tubes are so ground that
the slightest alteration in the position of the tube is instantly
shown by the position of the bubble. The two principal uses

FARM ENGINEERING

^%^

^ .S -^j

tJ3— ' ^

.S a; -M

^ ci '^

SJb cc

lC oj 4)

s tJ >

a 0)
2 3"

;5 fl +2

o -^

FARM ENGINEERING

of the bubble tubes are to determine (a) plumb lines; (b) hor-
izontal lines.

General Principles Governing the Adjustment of Bubble
Tubes. — It stands to reason that a glass tube so delicately
ground as a bubble tube must be accurately set in an instru-
ment in order to secure accuracy. Nearly all tubes are sur-
rounded by a brass tube which is held by adjusting screws.
The system used in setting the bubble tube consists of bring-
ing the tube into such a position that the center of the bubble
is directly under the center of the bubble tube. The,n the posi-
tion of the tube is reversed and if the instrument is in perfect
adjustment the center of the bubble again comes under the
center mark of the tube.

Examples. — To Adjust a Carpenter's Level. — First, lay the
level on a solid base and block up the lower end until the
bubble comes -to center. Now carefully change ends with the
level. If the bubble again comes to center the level is correctly
adjusted. If it does not, then adjust for one-half the differ-
ence and repeat the trial until the correct adjustment is arrived
at. To Adjust the Plumb Bubble. — Draw a line on a vertical
wall along the side of the level when the plumb bubble is in
center of the tube. Now turn the level on the other side of
the line with the same edge (the bottom of level) to the line.
If the bubble centers then the plumb tube is in correct adjust-
ment. If not, adjust for one-half the difference as before.

In the first place we make the axis of the bubble tube par-
allel to the bottom of the level. In the second place we make
the axis of the bubble tube at exactly right angles to the bot-
tom of the level. Thus we can determine a horizontal or
"level line" and a vertical or plumb line by the same instru-
ment (the carpenter's level).

In the case of the small bubble tubes on the compass and
transit bases, the object is to make it possible to adjust the
base of the instruments so that they will be level. In the case
of those tubes beneath the telescopes, the object is to make the
"line of sight" level, or parallel to the axis of the bubble tube.

FARM ENGINEERING 19

Thus, in the eye level the axis of the bubble tube may be par-
allel to the line of sight and accurate work may be done, even
th9ugh the wyes are out of adjustment. But in case the wyes
are out of adjustment the instrument must be leveled up each
time the tube is revolved upon the vertical axis.

*A11 makers of good instruments furnish directions for ad-
justing their mstruments, and these directions should be fol-
lowed carefully. All instruments which are so made that their
accuracy depends upon bubble tubes should be handled with
great care and frequent trials should be made in order to be
absolutely sure that none of the adjutsments are "off." For it
must be remembered that the engineer's reputation often de-
pends upon the accuracy of his instruments. It is much easier
and by far more satisfactory not to make errors than it is to
try to explain how the errors were made.

PHOTOGRAPHY.

While it is not absolutely necessary for an Agricultura^l
Engineer to be able to take photographs, yet in no other way
can he so plainly describe and show his work as by a photo.
The United States Government requires photos of the differ-
ent federal enterprises, as they progress. This not only gives
a clear and definite idea of the rate of progress, but it serves
as a record of the work after it is done. If the Engineer is
able to photograph his work it helps him in many ways. It
shows up the work to the best advantage. It saves a great
deal of time and labor which would be required in making
drawings to show progress. And in case of legal proceedings
the photo is absolute evidence. The photos are also useful in
showing prospective clients the work which you have ac-
complished.

For the above reasons it is well to have a camera and to
be able to take photos with it. (See Plate 3, Fig, 6.)

*See Gurley's Manual. It is a good text book of American
Surveyors' Instruments. Also Burger's Catalogue.

Plate III. — No. 1. Avtiiiteefs level. This level is of the Wye type with
Compass box and circle graduated in degrees.

No. 2 is a regular type of Dumpy level. Notice the absence of

Wye?.

No. 3.

No. 4,

No. 5.

No. 6.

A transit with vertical circle.

A Philadelphia rod with target.

Two steel flag staffs, or "range poles."

A 5 in. by 7 in. camera valued at $180.00 with which most
of the pictures in this book were taken. (A cheaper camera could
have been made to do better work where water is shown.)

FARM ENGINEERING 21

The Camera. — -From the standpoint of the Engineer, the
most expensive is not always the most desirable camera. The
most of the pictures in this book were taken with a $180.00
camera. Yet in those pictures which show movement there is
a blur which would not have been shown by a camera of the
Rapid Rectilinear type, which could have been bought for
$15.00. A simple, easily adjusted camera with a lens which can
be depended upon to take instantaneous exposures in bright
light is the most suitable for the Engineer. The author has
had in his charge cameras ranging in price from $5.00 to
$200.00, and for field work there is no doubt that the simple
camera with a simple lens and shutter is more suitable for the
Agricultural Engineer. An Engineer cannot take the time nec-
essary to do "artistic photography" as the term is understood
by the photographer. What is needed is clear pictures bringing
out plenty of contrast and detail, regardless of the artistic
blending of light and shade, so necessary to portrait work.

Every company furnishes directions for the manipulation
of the cameras. A few simple solutions, two or three granite
iron pans, a printing frame and a dark closet provided with a
simple "ruby" light will often take the place of a wheelbarrow
load of patent developers, fancy automatic devices and expen-
sive apparatus which some people think they must have in or-
der to "do photographing.

The detail of the work cannot be taken up here, however.
The student will find that photography, as the Engineer needs
it, is simple, and he will find that every day new cases arise
which enable him to save time and add to the efficiency of his
work by the use of a camera.

LAND SURVEYING.

Land surveying is done for one of two general purposes.
In the first place, the surveying was done to establish the
boundary lines of townships, sections, etc. The boundaries
were supposed to be marked permanently by so-called "monu-

FARM ENGINEERING

merits," constructed of stones, pegs, stumps, trees, holes in the
ground or holes filled with charcoal. The stone and the char-
coal monuments lasted pretty well but the holes in the ground
filled up, the pegs, stumps and trees rotted away, and the sec-
ond use of land surveying becomes apparent.

It is to locate the old corners, re-establish them or if need
be, locate new ones. In order to do this work correctly one
must do it according to United States regulations. These rules
are very clearly given in the little circular entitled "The Re-
storation of Lost or Obliterated Corners and Sub-divisions of
Sections." Write to the United States Land OfHce, Department
of the Interior, Washington, D. C, for this circular. Follow

t<- B'-

Plate 4. In running the line AB, the engineer found it necessary to turn a
right angle at B. He measured back 8 ft. to C. and struck the arc
FD, 10 ft. from C. Then he struck the' arc HE, 6 ft. from B. By
drawing the line from B through the intersection of arcs FD and HE,
he obtained the line BX, which is at exactly 90 degrees to AB.

its directions and do not try to do the work according to any
other method. Where a question of law is concerned, do not
permit theoretical considerations to interfere with the rules
which are so plainly laid down.

FARM ENGINEERING

It is often necessary to determine the area of irregular
fields. For the surveyor who has not had higher mathematics
this work requires more field work than for the surveyor who
has a thorough knowledge of higher mathematics. However,
the work can be done, by dividing the fields into right angled
triangles, and applying the formula. The area of a right angle
triangle is equal to Vz the product of the perpendicular and
base.

With a compass, a transit, or an architect's level set up at
a point on a boundary line which in your judgment will be the
point at which a perpendicular from a certain corner will meet
your boundary line. Turn off 90 degrees and by repeated
trials locate the desired point. Now with a tape measure the
base and the perpendicular lines of the triangle. Multiply one
by the other and divide by two to get the area of the triangu-
lar part of the field. Continue until the field has been divided
into right triangles and all of these have been measured. Now
add the areas of all and the sum will be the area of the irregu-
lar field.

Plate 5. Fig. 1. In figure 1 the field AFBE is first divided by line A D,
tlien each of the fields is divided into two right angle triangles. The
area is equal to the sum of the four triangular fields.

Fig. 2. In figure 2 a field of irregular shape is bounded on one
side by a crooked line (Pine Creek). After the right triangles Uce
and Zda have been laid off, the line X Y is laid off at right angles
to c e and d B. Then the short lines N N N N etc., are measured and
the small pieces of land calculated. The sum of all the subdivisions
will equal the area of the field.

24 FARM ENGINEERING

Example: (See Plate 5, Fig. 1.) In this example it hap-
pens to be easier to establish a new line A B upon which to
set up the instrument.

The line A B is first established. Then the point C is lo-
cated by trials. The area of A C F is equal to (AC ^ FC) -^ 2.

Now locate D by trials so that E D is at right angles to
AB, then the area of ADE will equal (AD X DE) ^ 2, and the
area of DEB will be equal to (DB X DE) - 2. Now all the
different parts of the field have been measured and all that re-
mains is to add the areas of the four triangles and the result
will be the exact area of the field.

When the lines of a field are curved, as by a creek bank,
it often becomes necessary to use ingenuity in determining the
area. It is usual to lay off as much of the land as possible in
fields having straight lines and then determine the area of the
remainder, as in example given below. (See Plate 5, Fig. 2.)
The area of C F B is equal to (FC X CB) -^ 2.
Determine area of U X Y Z, as in case of field having straight
lines for boundaries. You will have to lay out X Y. Now at
frequent intervals measure the distances n, n, nn, nn, etc., and
compute the small areas as accurately as possible. Add them
all to the area of XYZU and the area of the field is obtained.

Caution. — Always use the same units of measure on the
field and when the results are obtained in the same units one
may then change these units to any other units as desired.
Do not measure one triangle in feet and inches, another in feet
and tenths and still another in rods, feet and inches. Stick to
one unit of measure.

To Determine the Area of An Irregular Field by Means
of the Polar Planimeter. — If the student has an accurate draw-
ing putfit, including a good and accurate protractor, the work
of calculating the area of 'an irregular field is not so difficult.

Measure the sides of the field accurately and the angles
exactly. Now draw a map of the field to some scale, taking
great care to make each angle and line exactly at the right

FARM ENGINEERING

26 FARM ENGINEERING

angle and of exactly the right length. By means of the Polar
Planimeter the exact area of the field as mapped may be de-
termined in square inches. Now suppose thfit we let each rod
of the field (a small field) 'be represented by one inch. After
measuring the map we find that it has exactly 92.65 square
inches of area included inside the boundary lines. Then by
dividing the total number of square inches of area by 160 (the
number of square rods in an acre) we get .5790 of an acre.

This is all right for a small field, but suppose the. field to
be larger. Then we may let one-tenth inch equal a rod and
then each square inch will equal 100 square rods. So after the
number of square inches in the map has been determined we
multiply by 100 and divide by 160 to get the number of acres.
Any scale may be used, but when a very small map is made
for a very large field the error is likely to amount to too great
an area.

The planimeter should be used with great care and the
area of the map should be measured not less than three times.
If the answer varies more than one one-hundredth of an inch
the work should be repeated until the answer checks within
one one-hundredth of a square inch.

The different styles of planimeters vary so much that no
exact rules can be given here, which will govern the use of
the individual instrument, but a few general rules are not amiss.

1. Never try to run a planimeter when excited or ner-
vous, as the shaking of the hand will spoil the accuracy of
the work.

2. Always draw the map on a good, strong paper and do
not let it become wet after the map is made. The swelling and
the distortion of the paper will spoil the accuracy of the result.

3. Never draw the map with a blunt pencil. Always use
a sharp pencil of hard lead. The error of the width of a thick
line is often great.

4. Be careful to get all lines the right length.

5. Be sure to lay all angles off exactly right. In general,
be accurate.

FARM ENGINEERING

To Run a Division Line Through an Irregular Field Cutting
Off a Certain Number of Acres. — The Line to Be Parallel
to Another Straight Line.

^'77-

->^

Plate 7. Example. -Eiin a line through tlie. field in Cut 7 so as to leavp
seven a^-res next Bear Creek. Tlie line to run parallel to the line
A B. First we find that the side A B is 40 rods long. The angles
are right angles (90 degrees). Th^ field contains exactly 12 acres.
We now subtract 7 from 12 leaving .5. Then as field N must contain
seven acres we know that field V will contain five acre-:. Dividing the
total number of square rod?^ in five acres by forty (the length of
A B) we get twenty rods as the width of the field P. 160X5=800
square rods in five acres. 800-4-40=20. We now measure off twenty
rods along each side and establish line v/hich divide- the field at
exactly the desired -point, and at the same time it is parallel to the
line A B.

It often happens that a field has but one irregular side. If
the corners are exactly 90 degrees and the three sides straight,
then all that is necessary is to subtract the required number of
acres from the total number of acres. Measure off the neces-
sary distance along the side lines and establish the line.

But suppose the line must join the irregular side of the
field. The question becomes harder. Now by higher mathe-
matics one could calculate the location of the line. But with
the planimeter the Agricultural Engineer can locate it in a

28 FARM ENGINEERING

short time. First, calculate the area into the units of the map,
(square inches). Now draw in a light line parallel to the de-
sired line at the place where you estimate the line should be
drawn. Try with the planimeter. Keep trying new lines until
the desired area is cut off. Be sure that the line is parallel to
the desired line. Now measure off the distance which this line
is from the line to which it is parallel, change to rods and pro-
ced to measure off the distances in the field.

Plate 8. Example. Run a line parallel to C D to cut off four acres from
the field next Squaw River. The field has no angle of 90 degrees.
The field is first found to contain 9 acres. This is found by making
the map, but it is not absolutely necessary information. It does how-
ever guard the engineer from trying to cut off more than the field
contains. The map is drawn to scale and a trial line L M is drawn
(lightly). Field J is measured with the Polar Planimeter. It is too
large. Second trial line P T proves nearly correct. Line X Y proves
to be right. The distance C Y is measured on the map and the units
changed to rods. A right line from some point on D C near the
river end of the line is now measured and its length changed to rods.
Now go to the field and lay off the distance C Y and R S and establish
line X Y in the field. Field J contains the correct area and X Y is
parallel to C D.

By the use of an accurate map and the planimeter the
Engineer can perform all of the divisions of irregular fields
which may come up. But in all this work he must be accurate.

Caution. — It is not safe to take a farmer's word for the

FARM ENGINEERING 29

size of an irregular field. The engineer is likely to find that a
field has a much greater or less area than the farmer tells him
the field contains. One is likely to find himself trying to cut
ten acres off a seven acre field if one does not first determine
the area of the field.

MAPS AND DRAWINGS.

Instruments. — While it is very desirable to have a large
and expensive mechanical drawing set, it is by no means neces-
sary to good work.

A board, 12" x 14", with one end planed until it is straight
and smooth is all that is necessary for ordinary work.

(For planimeter work, a large board 30" x 36" should be
used.)

A "T" square for horizontal lines.
A 45 degree triangle. (About 6" .)
A 30-60 degree triangle. (About 5".)
A right line pen. l

A set of combination dividers, which carry either points,
pencil or pen, for circular drawing.

A triangular scale with the inches divided into tenths,
twentieths, thirtieths, etc., is necessary for this work.

A protractor with which to lay off angles is also very
desirable.

Plain drawings should be made on heavy paper. These
drawings should be made in pencil first, then inked in with
black waterproof ink.

The title of the drawing should describe the land which it
portrays, and the scale, 1 inch equals 1 rod, or 1 inch equals
10 rods, etc., should be placed in plain sight.

An arrow pointing north should also be placed in some
conspicuous place on the drawing.

30 FARM ENGINEERING

In case of creeks, arrows should be placed either in the
creek or along' the bank to show direction of flow. In case of
tile drains or irrigation ditches, this is also necessary.

In the drawing of maps remember to use the sign (') to
represent feet and the sign (") to represent tenths of feet, not
inches. It is well to write out the dimensions in fnil if the
drawing is of great importance. Thus 9 feet or 17. S feet. Tliis
excludes all possibility, of error. I'\lany do not I'ise th.2 sign
(") at all. Thus the}^ write 17. S', which , is all very v/eil unless
the point happens to be rubbed out.

/ In general, make the drawings accurate rather tlian ar-

vJtistic, plain rather than flowery, simple rather than technical.

Fences.— After the boundaries of a held have been decided
upon it becomes necessary to fence it. Tiie ff?r.r->io- of fields
has been practiced to some erTtent since -'"e - of agri-

culture began. In the first pi ace the methods were crude.
Lines of stones were laid upon the ground and n-:~'--° f.-^-ones
were piled on top of them until a kind of barrier rmed.

Tree trunks and brush v/ere also vs^d as fences. These methods
of fencing, though crude, are used in some p^arts of the United
States todav. Ljfter boards were broug-ht in_to 1^=? as fencing
material. They are used today in many parts of the country,
especially where tight board fences are buijt. These serve as
wind-breaks, as well as fences. Pole fences have also been
used a g'reat deal in the United States for confining live stock
and for protection from the attacks of hostile Indians.

By far the greater part of the modern fencing in this coun-
try is now done with wire. The wfire ma}^ be smooth or
barbed. It may be strung upon poles in single strands or it
may be woA^'en into the form of wire netting. The latter is
much the better for use in the fencing in of horses and well-
bred, valuable cattle. It is also to be preferred as a hog or
sheep fence, because it renders it next to impossible for the
animals to escape.

It is to be preferred to singde strand fence because it is
more effective as a barrier and at the same time it turns the

FARM ENGINEERING 31

stock without injuring- the animals in the slightest. Many a
farmer could well afford to take down' his barbed wire fence
and replace it with the best grade of wire net fence! The loss
caused by the old barbed wire fences has in manv cases run
into the hundreds of dollars in a single night. (Nig:ht thunder
storms often frighten horses into the wire fence which cannot
be seen in the darkness.)

For the fencing of hogs and cattle a wire net fence of
about 36" to 40" surmounted by two or three well stretched
barbed wires makes an excellent barrier, both from the effi-
ciency and the humane standpoints. For horses it is well to
use a. netting fence not less than 48" inches high with one or
two No. 8 smooth wires tightly .stretched above the netting.

The question of wire has already been settled very satis-
factorily. We can buy fence that v/ill hold out mosquitos,
stronger fence that will resist chickens or small pigs, still
stronger fence that is capable of turning hogs/ cattle and
horses, and some companies now^ build fence that will turn
Buffalo, elk and the iierce lions of the x\frican frontier.

But the post question has not been so successfully an-
swered. Wood posts are becoming scarce, and the price is
constantly going up while the qualit}^ and the size of the posts
are, just as rapidly going down. So far no iron posts have
been built which are sufficiently cheap and strong to justify
their extensive use on the farm. The logical solution now
seems to be the substitution of strongly reinforced cement
posts for the wooden ones.

Many companies have built molds for the manufacture
of cement posts. These molds have almost invariably molded
a post which does not contain sufficient cement and sand to
withstand the pressure, no matter what shape or form was
given to the post. Furthermore no matter how much rein-
forcement was used the cement could not stand the pressure.
And it should be clearly understood that the reinforcement in
posts should be of iron and placed in the corners of the posts..
In case the posts must resist animals upon both sides of the
fence the posts should be round or square, not of the triangular

32 FARM ENGINEERING

type. Wood reinforcements for posts are not satisfactory.
The wood swells and bursts the post. Then it shrinks and is
loose in the cement. Some salesmen claim that water cannot
pass through the cement and moisten the wood, but experi-
ence does not support the theory.

Some companies are now building very good cement posts
but the cost is not so low as to meet the competition of good
wood posts. The engineers and salesmen of many companies
set up the claim that their posts are strong enough to with-
stand the wind load and that that is all that is required. Posts
built upon this theory are as a rule not sufficiently strong to
provide a suitable rubbing post for a small cow. Should a
hunter climb over such a fence he almost invariably cracks
the post upon which his weight comes. This kind of theoreti-
cal design has put the cement posts into disrepute in many
localities. The claim that "Our cement post is as strong as
any wood of the same size," is usually not backed by actual
tests.

"The Bulletin on Concrete and Cement Fence posts," (Col-
orado Bulletin 148), by H. M. Bainer and the Author of this
work gives the results of actual tests with both Cement and
Concrete fence posts. The best cement and a good grade of
sand were used. The posts were well made and properly
cured. Yet in no case did they approach in strength a new
wood post of their size. As this bulletin is free and gives
the results of tests on several hundred cement and concrete
posts, the student should by all means avail himself of the in-
formation. The theory of the reinforcing material and the
placing of it in the post is thoroughly taken up in the bulletin.

There is no doubt that a very good concrete or cement
post can be built which will last longer and look much better
than the wood posts which are now being sold.

Setting the Posts. — There is no rule which can be given
as to the depth which a post should be set. In some soils a
post need not be set more than 18 inches deep while in others
the depth must be from 3 feet to 4 feet. The post should be

FARM ENGINEERING

set sufficiently deep that it may resist a side thrust sufficient
to break it at the ground line.

"How strong should a line post be?" is a frequent question.

This is a question which must be answered according to
the local conditions. A post which projects four feet from the
ground should stand a side thrust at the top, of at least 300
pounds. This is less than a 3^"x3^" new spruce post will
stand.

Before the engineer contracts for a quantity of cement
posts he should test several samples according to the follow-
ing directions: (See Plate 9.)

>R^_-^t

Plate 9. The drawing Plate 9 shows how a cement post may be tested.
The hitch of the rope a is just 4 ft. above the ground, b is an easy
running pulley, d is a barrel which is supported above the scales,
s. c. is a wooden post firmly set in earth. The weight of barrel plus
the water which must be added to break the post is the breaking
strength of the post. After the post breaks the water may be taken
from the spigot ^nd used in the testing of the next post. Th ; water
should be added slowly until post breaks. In case the scale platform
cannot be held off the knife edges which it rests on while weighing,
the barrel should be caught by a cross plank and let slowly down to
the scales. Many other pieces of apparatus may be built to do this
testing.

Corner posts and gate posts must be much stronger than
line posts. It would be necessary to know the type of fence
before the size of post could be determined. This subject is

FARM ENGINEERING

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FARM ENGINEERING 35

also thoroughly taken up in the cement post bulletin above
mentioned.

Treatment o£ wood posts to lengthen the period of use-
fulness. There are many ways in which a wood post may
be treated in order to preserve it. Coal tar when smeared
upon the post, from the ground line down will prevent rot.
A good oil paint will also do good work as a preservative.

If an iron tank is available it is a good plan to dip the
bottom of the post (up to 4" above ground line) in boiling lin-
seed oil. But the cost of linseed oil is such as to make this
expensive. Perhaps the most effective way of preserving wood
posts is by means of the creosote treatment. The wood is
treated under pressure with creosote and this renders the wood
unfit for habitation of the m3'-riads of tiny insects, fungi and
bacteria which cause wood to decay. This treatment requires
expensive apparatus and is consequently not in general use
so far as fence posts are concerned. It is used extensively for
the treatment of railroad ties and salt water piling.

For the bracing of corner posts and gate posts, see draw-
ing 10.

BRIDGES AND CULVERTS.

In many fields we find creeks and ditches. In order to
cross these creeks or ditches, some farmers resort to piling
in brush and then covering the brush with manure or dirt.
By so doing they often cause more damage to be done than
the price of a new and permanent culvert would have amounted
to in the first place. The brush culvert is likely to work all
right for a while, and then at the most inopportune moment
it may break down or clog up, and the surrounding field is
inundated. This not only destroys the crops but it is likely
to cause ditches to be washed in the land. Another point
which is often overlooked is the fact that the size of the loads
which are hauled over these improvised affairs is often limited
by them. The teamster often unconsciously lightens the load

36 FARM ENGINEERING ^

rather than run the risk of "sticking" his team in the ditch.
Again the fact that teams of young horses are so often unable
to pull through these ditches causes a great many otherwise
good horses to be balky, and consequently next to useless.
The subject of Bridges and Culverts will be taken up under
Farm Engineering Part III.

It should be mentioned, however, that all bridges and cul-
verts should be made strong enough to carry more than the
load to which the hauling of grain will subject them. If there
is any possibility that a threshing machine and engine will
have to pass over the bridge it should be designed to carry
not less than twenty-five (25) tons. The up-to-date traction
engines are being made larger and heavier and at present many
have passed the twenty-ton mark.

The culverts should be placed where they will give the
most service with the least travel, and at the same time offer
no hindrance to the free flow of the water in the ditch or
creek.

The size of the water-way beneath the culvert should be
large enough to allow the water to pass under the culvert,
even in time of heavy rains. The foundation should be strong
enough to prevent the washing out of the culvert or bridge
by swiftly moving flood water, or the jamming out of the
culvert or bridge by rapidly moving ice.

In order to properly design such a bridge for a large
stream the engineer must often do a great deal of field work
and calculation. But for the smaller creeks, drainage ditches
and irrigation ditches the work can be accomplished by the
exercise of a little common sense.

In case the bridge must span a mountain torrent, how-
ever, there is need for care no matter how small the normal
stream may be. The student should carefully study bridge
and culvert design in Part III of Farm Engineering.

FARxM ENGINEERING 37

DRAINAGE AND IRRIGATION.

When the field has been laid out and fenced, the field
engineering work is by no means complete.

In nearly all of the fertile sections of the United States,
and in fact in nearly all of the fertile sections of the globe,
the yield of desirable crops is governed, not by the abundance
or scarcity of plant food in the soil itself, but by temperature
and moisture conditions in the air and in the soil.

It is almost impossible to influence to any extent the tem-
perature or the moisture content of the_ atmosphere, but we
can govern to a large extent the moisture content of the sur-
face layers of the soil to a depth of from four to six feet.
The principal means of controlling the moisture content of
the soil are :

A. Drainage.

B. Irrigation.

C. Combined drainage and irriga,j:ion.

D. Scientific cultivation.

Drainage. — While we hear a great deal of talk, and read
a great many well written articles on the subject of irrigation,
we must admit that the greater part of the work of reclama-
tion and improvement comes under the head of Drainage. No\
only do we need drainage in the naturally wet lands, but in
many irrigated sections, drainage must be resorted to in order
to keep the soil in a fit condition for crop production.

Topography. — In order to determine the lowest or the
highest portion of a field, the grade of ditches or the proper
location for ditches, either drainage or irrigation, we must be
able to make a map of a field, which will show just what
points are the highest, the lowest, and what points are on a
uniform grade from the highest to the lowest.

The map will describe not only the boundaries of the field,
but it will show at a glance the "lay of the land."

1. Stadia Surveying. — This is done by means of a transit
and a stadia rod. The three cross wires of the transit enable

38 FARM ENGINEERING

the surveyor to tell how far the stadia rod is from the instru-
ment. At the same time he can read the elevation on the
rod by means of the center cross wire. He then reads the
vertical circle, and by higher mathematics the exact relative
elevation is obtained. . This method, when used by experi-
enced survej'ors enables them to make rapid progress in the
work, but the work when completed, is not absolutely accur-
ate. In the preliminary work of railroad location, or in the
running -of large canals for long distances, it is a very good
method of mapping the contour of the land. Then, after the
map is made, the railroad or the ditch may be located on the
map and later on, it may be laid out in the field. As stadia
work is not necessary for ordinary field engineering, no fur-
ther attention will, be given it here,

2. Level and Rod Surveying. — The surveyor's level and
rod may be used intelligently, easily, and very accurately by
anyone who understands plain, ordinary Arithmetic,

Before going into the field, the engineer should see that
his level is in adjustment. Do not guess at this. Do not as-
sume that the maker has adjusted the instrument before send-
ing it out. Beyond a doubt the instrument was in adjustment
when it left the factory, but a railroad journey often puts a
level out of adjustment. If the level sets in its case or on
the tripod during a rough wagon journey, it is likely to be
put out of adjustment. Be sure of the adjustments before you
begin to "Run Levels" over your field. The- few minutes of
time required to check adjustments are always well spent.

The Philadelphia Rod is one of the most satisfactory
levelling rods for the Agricultural Engineer. (See Plate 3,
Fig. 4.) Do not make the mistake of thinking : that only an
Architect's rod will work with an Architect's level. This is
not the case. The Philadelphia Rod reads to feet, tenths of
feet, and hundredths of feet without the use of the target,
while by using the target we may, (by means of the Vernier)
read to thousandths of a foot.

Now that we have a properly adjusted level, and a suit-
able rod, we will proceed to run levels over a certain field.

FARM ENGINEERIKi;

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FARM ENGINEERING

We will assume that the field is uneven, but that it has a
very apparent slope towards one corner. It is apparent that
the outlet of the drainage system must be at the lowest point.
The engineer first drives a stake (a solid one) into the ground
until its top is level with the surface of the ground, at the
assumed point of outlet.

The level is set up some distance (50 to 200 ft.) away,

Sco/e /D/fo</S Perlfich

Plate 12. The map, Plate 12, shows how the -surveyor began at the point
o and ran levels over the field to get a fair idea of the relative eleva-
tion of the different points. The statoins are numbered in order as
he proceeded. He was not very careful about Stations 10, 11 and
12 as the knoll or Iiill was very apparent. He made a rough sketch
of the land as he went, and by the aid of the elevations of the Station
6, he was able to make a sufficiently accurate topography map. He then
plotted in a ditch with but one bend, laid it off in 100 ft. stations and
ran a line of levels up the ditch, establishing grade and cut as he
went. The ditch is 800 ft. long and the difference in elevation between
o and 17 is approximately 3 ft. (12.95 — 10z=2.95). 3h-8=.375 ft. per
hundred ft. He decides upon 2 ft. as the depth of the ditch.
10'— 2 '=8' the grade of the ditch at o. At Station 100' the grade
will be 8' plus .375 or 8,375'. At each succeeding station he adds
.375 ft. to the height of the preceding station. Thus the bottom
of the ditch is on even grade. He also determines the cut by sub-
tracting the grade from the elevation at each station.

FARM ENGINEERING ^ 41

and the rod is placed upon the newly driven stake. The stake
will be known as the "Bench Mark." We usually assume that
its elevation is ten feet. After the level is firmly set and
levelled, the engineer looks through the level, and after hav-
ing directed the rodman to hold the rod perfectly vertical,* he
carefully reads the number of feet, tenths and hundredths
which the cross wire indicates on the distant rod.
of sight from the level to the rod is level.

The reading is added to the original (assumed) 10', and
the total recorded as the "height of instrument" (H. I.). The
reading of the rod is recorded as the "Back Sight" (B. S.). Do
the recording at once with a hard, smooth, pointed pencil.
(See specimen notes, Plate 13.)

Now it is apparent that the center of the level lens is
just as many feet, tenths and hundredths above the top of
the "Bench Mark" as the reading indicates, because the line

Now the rodman changes location and places the rod upon
the ground. The level is turned so as to bear upon the rod
and another reading is taken.

The "Bench Mark" is designated as Station 0 (zero), and
the new station is called Station 1. Whatever the reading of
Station 1 happens to be, it is recorded under foresight (F. S.),
and this subtracted from the H. I., will give t^e relative eleva-
tion of Station 1. The elevation is computed and recorded
in the column under elevation (Elev.) and on the line given
to Station 1.

The student will not notice that if the F. S. reading is
greater than the B. S. reading, station 1 is lower than 0, and
that if the reading is less than the B. S. reading, station 1 is
higher than station 0. This point often fools the beginner.

Again the beginner often imagines that the height of in-
strument is obtained by measuring from the center of the

* The vertical wire enables the engineer to see whether or
not the rod is being correctly held. The rod should "line up"
with the vertical wire.

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Plate 13. The notes shown in Plate 13 are the notes which the engineer
took in mapping the ten acre field of Mr. T. Jones shown in Plate
12. Notice that Station O is given an assumed elevation of 10'. This
is done so that if a lower point is found it will not have a "Minus
•IcTation." The three dots inside a circle indicate Avhere the level
was set up. Notice that it is not over a station. By going over the
map one can trace the movements of the engineer as he proceeded
, up the field. The student will notice that a Foresight is not neces-
sarily on the opposite side of the instrument from the station upon
which the Baclssight was taken. The stations may be within a foot
of each other, but the one with the Jcnoivn elevation is used for the
back sight while the one with the unknoion elevation calls for the
Foresight. The above process is known under the term of Differential
Leveling. The length of the Backsight and the Foresight to the
turning point should be nearly the same distance. This must be
remembered or errors are lilrely to creep in. It is not necessary if
thie instrument is in perfect adjustment.

FARM ENGINEERING 43

tube to the ground. This is not the case. The height of the
instrument is the distance which it is higher than the eleva-
tion of the station upon which the last backsight was taken.

The engineer is now able to "prospect" for a lower point
of outlet for the drain. If it is found, he marks the place and
turns his attention to the rest of the field. When he has taken
a reading with the rod about as far up the field from the in-
strument, as the 0 station was down the field from the instru-
ment, he signals the rodman to "hold the point."* He then
proceeds to pick tip the level and go to a point some distance
beyond the rodman, sets up his level, and sights back at the
rod. The reading is recorded under column B. S., and on the
line given to the last station. Now, by adding the B. S. read-
ing to the elevation of the last station, (which the rodman
is' "holding-"), the new height of instrument is obtained.

More foresights are taken and the elevation of the new
stations obtained. In this way the engineer proceeds to get
the elevation of the chosen points. (Not the elevation above
sea level, but the elevation above the bench mark.) Now he
can figure out how much grade (drop or rise) per hundred
feet he has, and where he will locate the drain.

i)uppose that in a proposed drain of 4620 feet he finds that
the total fall is 17' and 3" (seventeen and three-tenths feet).
He divides the drain into 100 foot stations and thus finds
that he has 46 1^5 stations.

If the grade is uniform, he divides the total fall into 46
parts (ignoring the 1/5 station) and finds that he may give
each 100' of the drain 17.3"^ 46 or .376 of a foot fall to the
, hundred.

He now decides on the depth of his drain at the outlet,
and if the depth is the same at the head of the drain, he is
now ready to compute the elevation of the bottom of the
ditch at each 100 ft. station.

* The rodman must make sure that he does not sink the
rod into the ground or raise it after the last F, S, is taken
until the new B. S. is read. The station is known as the
"Turning Point," T. P.

FARM EiNGINEERING

Starting- at 0 he subtracts the depth of the drain from the
elevation of 0 (IC was assumed) and adds to this reading the
.376 foot for each station above. By continuing to add, he ob-
tains the elevation of the bottom of the ditch at each station
of the ditch.

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Jiow lie laid out the ditch after the Topography map had been roughly
made. He laid out his grade and then recorded the "cut" as he went
along. The figures should be made with a hard lead pencil, so that
they will appear neat and remain plain. (For Engineers' pocket field
books see Frederick Post Catalogue.) Select what you xcant before
ordering. See also Eugene Dietzgen catalogue.

He then proceeds to lay off his station points with a
tape. A stake is driven into the earth and the number of
the station is plainly written on the stake with a crayon or
soft pencil. These stakes locate the ditch. Now at a distance
of 2, 3, or 4 feet, (depending upon the size of the ditch) to

FARM ENGINEERING

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FARM ENGINEERING

one side of each stake is placed another, the guide stake. This
is done so that the location of the first is not lost in case it
is knocked over. The engineer now goes over the ground
wiLh the level and rod and by subtracting the computed ele-
vation of the bottom of the ditch frorn the elevation of the
top of the ditch stakes, (he obtains these elevations as he
goes, by reading the rod when placed upon the stakes), he
obtains the depth of the ditch below the top of .the stake. He
then writes "the cut" on each stake. "The cut" is the depth
which the ditch must be "cut" or dug below the top of the
stake.

"* When the levels are all taken, the cuts determined, and
the width of the ditch decided upon, stakes are driven beside
th ditch. Then a notch is sawed in the side of each stake a
certain distance above the bottom of the ditch. A heavy
string, or what is better, a fine wire (No. 15 or 16) is drawn
tight along the ditch. It is tied into each notch and if the
, ditch is on even grade, the wire will be straight when tied in.
The ditch digger needs only to gauge the bottom of his ditch
from the wire and this is easily done by means of a "gauge
stick."

11" ' „!

Plate 1(5. Plate 16 sIioavs a side view of two "gauge sticlis." Fig. A
is of a stick used tor narrow ditclies and as tlie side arm is short the
digger is able to hold the stick nearly plumb and thus get the ditch
on even grade.

Fig. B is of a stick for wider ditches. There is a carpenter's level
fastened to the top of the cross arm and the stick is so held that the
bubble comes to center. The student can readily see how the use
of the string stretched an exact distance above the bottom of the
ditch, and one of these gauge sticks, will enable a digger to get an
even grade.

FARM ENGINEERING

"J'he stakes which hold the wire need not 1)e set at inter-
vale of less than 25 feet. In case of string, they should be
set ever}^ 10 feet.

When the ditch is dug, the engineer should run levels on
it A\'ith the rod set on the bottom of the ditch at frequent
intervals (ever}^ 10, IS or 20 ft.). In this Avay he can make

Plate 17. When the engineer began work on the ten acre flelrl in Plate 17
he found that the field was nearly level. He began at the S. W.
forner and ran lines of levels North and South at intervals of 100'.
He made his stations 100 feet apart. The narrow "left over" was at
the North side and the East side. When he had finished he drew
a map and giving station at S. W. corner an elevation of 10' he pro-
ceeded to write the elevation of ■ each station at the intersection of
the hundred foot lines. Then he was able, to draw in the contour
lines. He found the point X to be lowest, but he Jiad less than a
foot of fall in that direction. If he could get an outlet near X then
he could by dcepeniiu/ the lower portion of the ditch, drain the field.
Xow suppose that a deep ravine runs along one of the other sides of
the field. The engineer can drain this field to the East, North, or
South, by using a shallow drain near X and deepening it enough to
cut the banks near Y or Z. This is not an exaggerated case. Many
fields give the engineer more trouble than this one. If a "cross
section" paper has been used for the map the lines might have been
more accurately drawn, but they would not have developed any
outlet, or higher grade. (For cross section paper see Frederick Post
catalogue. )

FARM ENGINEERING

sure that the stakes and line were not molested, and that the
ditch is properly dug.

Method for Nearly Level Fields. — In case of fields which
are nearly level, the work must be done with more attention
to detail. It is best to run parallel lines of levels about 100
feet apart. The stations should not be more than 100 feet
apart. Thus the field is divided into a series of 100 feet
squares. (Checkerboard style.) When the exact elevation
of each station is obtained, draw map and put in the contour
lines on each 1/10 ft. (Ten lines to 1 ft. elevation.) The lines
now show the lay of the land. The drain can be plotted on
the map, and laid off in the field.

When the drains have been located, the engineer should
indicate on his map the number of degrees each bend throws
the ditch from the straight line. He should also show the
distance from each bend to the next bend.

The drain, near its foot, will form an angle of a certain
number of degrees with a line fence, a road, or a section line.
This angle must also be recorded. Thus, a person who later
wishes to know how the drain runs, has only to consult the
map. In case of hidden tile drains, the map is of great im-
portance.

The angle between the ditch and some permanent line
should always be used, rather than the compass bearing. Com-
passes vary, and the North Magnetic Pole also varies, but a
section line is finally established.

Change of Grade. — Sometimes the land lies so that it is
impossible to run the ditch on "even grade," that is, with the
same fall to each 100 ft. In such a case we "change grade,"
but whenever it is possible the grade should grow greater (or
steeper) as we proceed down the ditch. If the top of the
ditch is steep, and the change causes the water to flow into
a more nearly level ditch, the water will not be carried away
fast enough, and there will be flooding at the point of change.
If the lower ditch is made larger, it will take care of the
water, but the water will flow slower in the large ditch of
less grade.

FARM ENGINEERING

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FARM ENGhNEERIKG

Rio-lit here the student must know that the faster water
flows, the greater the size of soil particles it will carry. Sand
nnll settle out of slowlv moving water, while larger stones
ire carried along by a torrent.

So, when the swiftly moving water of the upper ditch of-
high grade comes into the larger ditch of lower grade, the-
water slows down, and deposits sand and silt in the ditch
bottom.. This soon fills up the ditch or tile and the ditch
proves a failure. But, if the grade of the ditch be increased
rather than decreased, the water gains speed, and there is no
tendency to fill up the ditch with deposits of sand or silt. If
it is absolutely necessary to change the . grade of the lower
part of the ditch to a lower grade, the point of change of
grade should be carefully watched.

f ^

Plate '19. Plate 19 is a cross section of a "silt basin." Viewing the basin
from the top it would appear round. It \YOuld be simply a shallow
round well loosely walled up with brick or stone or perhaps with a
concrete wall about 4 inches thick. The tile comes in at one side.
The water is r-lowed up and as it slowly flows across the well or
basin the silt and sand settles to the bottom. The water passes out
the other side into the tile of lower grade. If the basin had a
grated top and were a little lower in the ground it would be a
"Catch Basin" or "Sumj)." The water mignt then enter from the top.
The Arrow shows the direction of flow.

In case of tile drains, a "silt basin," see Plate 19, should
be placed at the point of change of grade. This may be
cleaned out from time to time.

So-called "practical ditchers" will tell the engineer that
this is not necessary, but after the credulous engineer spends
a few days locating a tile drain that has not been mapped.

FARM ENGINEERING ^i

and is now useless, digs up the tile, and pokes the solid sedi-
ment from the clog',§"ed tile with a stick, and finds in many
places that the tile has been completely clogged by deposited
sediment, he will realize that the laws of Nature AA^ork exactly
the same whether the engineer sees the process or not. Such
an experience will do more to instill a true appreciation of
the effect of change of grade in ditches, into the mind of a
student than a volume of sermons upon the suliiect.

If the student wishes to take up the work of tile' drain-
ing, he should, if convenient, procure '"Engineering for Land
Drainage," by -Elliot, from John Wiley & Sons, New York.
This large volume contains all detailed information which the
engin.eer will need. It is reliable.

Oirdets of Drains. — .It is usually advisable to wall up the
outle;;s of drains to prevent the washing away of the adjoin-
ing land. In case of tile drains a cross wall should be built
so that the tile projects through the wall. There should be a
chance for the water to flow freely away from the mouth of
the tile.

Drainage by Pumping Plants. — In Holland, the drainage
water is lifted over the protecting dykes by large windmills,
(the Dutch windmills we so often see in pictures).

in this countrv, the steam engine, the gasoline engine, and
the electric motor are now being used in connection with cen-
trifugal yumps to raise drainage water from low lands and
throw it into a drain which is higher than the land itself. See
Eidletin 2^.3.. U. S'. Deut. of Agriculture.

DIGGING THE DITCHES.

The co-dition of the earth, the kind of soil, and the rela-
tive cost of labor, V'ill determine largeh^ the methods lo be
employed in digging the ditches.

Immense plows, drawn by capstans are often used for
open ditches. .A quicker way is to place sticks of dynamite,

FARM ENGINEERING

Plate 20. Plate 20 is an instantaneous photo of a dynamite explosion
which dug 200 feet of ditch in about ten seconds. The sticks of 75
per cent dynamite weight ^ lb. each and were placed two feet apart
in holes three feet deep. The ditch is about tour feet deep. It is
about two feet wide at the bottom and four feet wide at tlie top.
The man who shot the charge and the photographer were under a loau
of straw, 200 feet away. Rocks the size or a man's head flew as
much as 400 feet from the ditch. The ditch was left smooth, straight
and in fine condition without any further labor.

(at least 75% strength) in holes about two feet apart along

the line of the ditch. By means of an electric current all the

sticks are set off at once. The earth is blown from the ditch

and falls upon the banks and in the nearby fields. A half

mile of ditch is sometimes made at a single explosion. For

information (free) write to E. I. Dupont Co., Wilmington,

Delaware.

A great many ditching machines are now built by various

companies. These machines dig the ditch by means of steam

FARM ENGINEERING 53

or gasoline power. They are successful under favorable con-
ditions.

IRRIGATION.

We have discussed the method by which we are able to
reduce the moisture content of the soil, now let us consider
how Vv^e may increase the moisture content. A few years ago
we might have been led to believe that the so-called "Rain
Makers" could, by the explosion of bombs at high elevations,
cause rain to fall at will. Now we have definitely settled upon
Irrigation as the system which must be used if we are to add
water to the soil by artificial means.

Irrigation has been practiced for many hundreds of years
in some of the older countries. It is now being practiced in
the United States, both on semi-arid lands and the lands of
the humid sections. In fact, the sprinkling of a lawn, or the
watering of garden truck is, in a way, irrigation. But, as the
Agricultural Engineer considers irrigation, the term refers to
the addition of great quantities of water to tracts of consider-
able size.

Sources of Irrigation Water. — Rivers are the principal
sources of irrigation water. The water is diverted by dams
into ditches and thus conveyed to the fields, or to storage
reservoirs. The rights to use water from these rivers are
secured by legal process, and when once secured, are valuable
property. The amount of water which may be secured for a
certain tract of land is usually limited b}^ law. The student
must look up these matters for himself, as the State lavvi
vary so much that no exact data can be given in this work.

After all the water available during the irrigation season
has been appropriated, companies are formed for the purpose
of building storage reservoirs. By placing a dam across some
narrow outlet to a large natural basin, a lake is formed. The
river water is then diverted into a ditch which leads to the
reservoir. The water is stored during the winter season and

FARM ENGINEERING

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FARM ENGINEERING 55

at the time of floods.

The water remains in the reservoir until needed for irri-
gation. The size of these reservoirs varies from a few acres
to several square miles. Sometimes natural lakes are- tapped
by ditches and they then become reservoirs. The outlet of a
reservoir is governed by a headgate, such as is shown in Plate
21. These headgates are often large enough to open a hole
four feet square. In some cases, several gates are placed
side by side.

If the student will imagine water under a head of 20 or
30 ft., spouting from two, three, or four of these great head-
gates, he will get an idea of the immense amount of water
which some of these ^vater storage companies use on the fields
beiow the reservoir.

RiA'er water is o?tcn pumped to land which lies at a
height which makes it impossible to bring the water to the
land b}' ditclies. These plants are much like the drainage
plants except that the water is pumped into large flumes and
carried to the fields. Sometimes the cost of a flume would be .
so great that the "Inverted Siphon" is used. This consists
of a v\'ater-tight pipe with the ends bent up until the intake
end is high enough to cause water pumped in at this end to
run out the outlet end. Again we sometimes see the pump
directly connected to a pipe which runs up the hill side to the
higlier ground.

Wells. — In some parts of the country, the land is under-
laid with a "stratum of water bearing gravel or sand. If this
stratum is within 40 to 50 feet of the surface, and if it carries
water in suflicient quantity, a pumping plant may be used for
irrigation. The wells are usually large in diameter (12 to 20
feet). The casing must allow the water to pour in without
difnculty. By the proper installation of the right kind of ma-
chinery, these wells are made to be excellent sources of irri-
gation water.

Do not confuse a well of this kind with a small farm well
whicli has a capacity of }4 cubic foot per minute. Some of

FARM ENGINEERING

o a

r 3 0)

K +^ 'd

.2133

ci a

i-H td

'T' o "^

uo __^ o

c3 CO ^ "

cc to S

[> CO ^j p,

o ■*"=

^^ ^ ^ .;::;

fciD o

^^ a — ■

Q, CO

p =^ §
a d^

a ^-9

d dj o
o, ^ o

o 1^

o a 0)
4j —I

3 .S

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d CO

d d

a - o
o a) ,„

cd jz '^ f— I

d) ^ OJ

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P -d 0) c)
.2; H ^ !=i >-,

-6 S

■- d o) a;

CC O OJ K

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a> be
t^ d

P.^

E.al^

<
111

<? a

s ^
'' I ^

^ d "9

FARM ENGINEERING

%£%haujt

Plate 24. In order to understand Plate 24 the student must imagine tlaat
tlie shed of tlie pumping plant has been cut by a plane which passes
t'M-ough the ridge, the ends and the soil beneath the plant. The plane-
does not cut the engine, the pump frame,' or the flume. The engine
sets on a concrete foundation and is fastened by anchor bolts. The
Gasoline tank is^ outside the building and is covered by a box. The
suction and overflow pipes run from engine to tank. (No cooling
device is shoAvn.) The well is large, and is cased with rough planks
which allow water to flow through readily. The pump is of the
Vertical centrifugal type and is fastened in a frame which slides in-
side the frame which we see. If the operator wishes to fix the pump
he attaches the tackle (suspended from the roof) to the loop on th«
frame and after having loosened the pipe elbow he arises the inside
sliding frame, with pump attached, until the pump comes to the
platform half way down in the well. He then makes repairs, drops
the pump, connects el1>ow, puts on the holt and goes ahead. As this
type of pump is alwavs in the water it is alicays primed. If the belt
is cropsed the wrong way little or no water is pumped. The student
must remember to run the centrifugal pump in the rif/Jit direction.
Notice that the pipe is enlarged just above the pump. It is thus made
easier for the pump, the engine and all connections. The enlarging
of the pipe reduces friction and thus saves gasoline. The end of
the flume is seen at the left of the pumphouse. If a ditch or creek
emptied water into the well it would then be termed a "Sump."

FARM ENGINEERING 59

these wells furnish as much as three or four cubic feet per
second.

Amount of Water Needed. — It is generally considered that
water to a depth of from one to two and one-half feet must
be added in order to properly irrigate the average soils. The
amount varies with the amount of rainfall during the growing
season, the temperature of the locality, the amount of wind,
the type of soil, and the kind of crop to be grown. So we
see that no hard and fast rule can be laid down, which will
determine the amount of water needed.

Units of Measure for Irrigation Water. — There are many
units of measure for irrigation water. Many of these units
are not standardized, and are, therefore, unreliable units.

The "miner's inch" refers to the amount of water which
will pour through an opening one inch square in the side of
a box, when under a head of six inches. But whether the
head is to be measured from the top of the opening or the
bottom is not generally stated. Therefore, the actual head is
an unknown quantity and the quantity of water which rep-
resents a miner's inch is unknown.

The "inch." This is a term that completly fools many
people. It may mean one inch of water covering an area of
one acre. It may mean the amount of water which will
flow over a weir one feet wide, with a depth of one inch at the
crest. It may mean a "miner's inch." It may mean almost
-anything, and yet people talk about the "inch" of water as
though they really knew what the term really means. No
more space will be given to inaccurate units.

Accurate Units. — The cubic foot per second. This unit is
.accurate because a cubic foot is a cubic foot and a second is
a second. Both are standard units. So when a man says, "1
own three cubic feet per second for a 90-day season, beginning
June 1st," we could figure just how many cubic feet of water
he has a right to use each year.

60 X 3=180 cubic feet per minute.
180 X 60=10,800 cubic feet per hour.

FARM ENGINEERING

Plate 25. The engineer in Plate 25 is measuring the flow of water in
the canal by means of a current meter. There is a' turbine wheel
at the end of the tube which he is holding. This wheel whirls at
a speed in proportion to the rate of flow of the water. As the
wheel revolves it is made to give a clicking sound which is heard
through the tube. The number of clicks per minute is taken and
then by consulting a chart which accompanies the meter the observer
is able to determine the rate of flow of the various parts of the current.
The engineer in the plate is using an' "Acoustic Current Meter."

10,800 X 24=259.200 cubic feet per day.

259,200 X 90=^23,280,000 cubic feet per season.

The Acre Foot. — We often use the term "acre foot," and

by it we mean that quantity of water which will cover one

FARM ENGINEERING 6t

— — J

acre of land to a depth of one foot. As the area of an acre
is 43,560 square feet, the acre foot is equal to 43,560 cubic
feet, or a stream of one second foot would have to flow 43,560
seconds, or 726 minutes, or 12 hours and 6 minutes to deliver
one acre foot.

How Irrigation Water is Measured. — There are two prm-
cipal methods of measuring irrigation water. 1. By means of
the current meter, and (2), by means of "weirs."

In case of large streams, the engineer holds a current
meter for a certain period of time in each square foot of an
imaginary cross section of the stream. He does the timing by
means of a stop watch. Now, when he has the number of
revolutions per second or per minute, he consults a table
which accompanies the meter,, and thus computes the number
of feet of flow per second of that given foot of cross section.
When he has measured all the square feet, he adds the total
number of second feet and thus gets the number of second
feet in the stream.

One must measure each square foot because there are
different rates of flow in different parts of the stream. Gen-
erally speaking, the water flows more rapidly in the center,
than at the sides, and it flows more rapidly near the surface
than near the bottom. The rough banks retard the flow.

Special "flumes" are sometimes built and each inch or
tenth foot of depth is computed with a meter. These flumes
are called "rating flumes." The ditch rider can tell at a glance
at the gauge rod, how many cubic feet per second are passing
through the rating flume.

The "Weir." — By bringing water to a standstill, and then
allowing it to pour over a clean cut notch in the side of the
pool, we are able to compute accurately, just how many cubic
feet per second go over the notch. Several forms of weirs
are used, but the cippoletti weir is the most practical. The
notch is cut in the weir board, so that the bottom of the
notch ("the crest") is at least twice as high from the bottom
of the box as the depth of water which will flow over the
crest. The ends of the crest should be twice as far from the
sides of the box as the depth of water over the crest.

FARM ENGINEERhNG

The sides of the notch slope outward at the rate of 1
inch on each side to 4 inches in height, (1 to 4). The edges
of the notch are sharp and the bevel of the edge is on the
down stream side of the board. The board may be set in a
weir box, (see Plate 27), or in the straight run of a turnout
box. (see Plate 28). The board may also be set in a con-
crete cross wall which dams up the current of a stream and
forms a little lake. The board should be at right angles to
the stream, and the stream should jump over the notch and
drop clear of everything into the stream below. It should
"jump over air." The water as it comes to the pond or box
should be brought to a standstill and allowed to pass over the

Plate 26. Plate 20 is a photo of three current meters. Fig. A is »n
Acoustic Meter such as the engineer is using in Plate 25. Fig. B
is a current meter which is fitted with an electric sounder which
gives a buzz at each recording stroke. (See Gurley's manual for
description and for the reduction tables for use with these meters.)
Fig. C is a very small, yet accurate, current meter. It is for us«
in small streams and ditches. It is not supplied with "staff." It
has electric recording device. (See Keuffel & Esser Catalogue for
detailed information.) This is a collection of strictly high grad«
current meters.)

FARM ENGINEERING 63

weir as from a large, quiet lake. This abolishes "speed of ap-
proach'' and makes the weir a very accurate water meter.

The height of the water on the crest is measured not di-
rectly over the crest, but back in the box at least 6 feet from
the weir. A stake is driven until its top is exactly level with
the crest. The rod is placed on the stake, and the depth of
the water above the top of the stake is the depth over the
crest. This is done to do away with the "sink" of the water
as it comes to the crest. Don't forget to measure back from
the weir at least six feet, (see Plate 29).

The following table, tells how much water flows over
weirs from 1 foot wide, to 10 feet wide for each 1/100 foot in
depth. The unit is cubic foot per second.

Plate 27. A weir box made of planks and timbers. The weir is of the
type known as the Cippoletti weir. Notice that the sides of the
notch slant out at the rate of one inch on each side to four inches in
height of the notch. The arrow shows which way the current passes
through the box.

FARM ENGINEERING

The following table is taken from Bulletin 72 of Montana
Experiment Station : (This bulletin is now out of print.)

i 1

1.4

j-1

t-t

o «

^ s

o
o

^_^

. +3 O

ft ,

*f-i

•M

•w

■^

J>-

Cu. tfi

tiu.ft.

Cu. It. Cu. ft.

Cu.ft.lCu. ft.

Cu. ft.

Cu.ft.lCu. ft.

Cu. ft.

reet

p'raec

p'r gee

p'r sec p'r secip'r sec p'r sec

p'r sec p'r sec p'r sec

p'r sec

e.oi

0.0034

O.0O51

0.0067

0.0101

0.0135

0.0168

0.02021 0.0236 0.0269

0.0303

0.0337

.0095

.0143

.0190

.0286

.0381

.0476

.0571

.0667 .0762

.0857

.03.52

.9S

.0175

.0262

.0350

.0.525

.0700

.0875

.10-30

.1225 .1400

.1574

.1749

.04

.0269

.0404

.0539

.0808

.1077

.1347

.1616

.1885

.2155

.2424

.2693

.05

.0676

.0565

.0753

.1129

.1506

.1882

.2258

.2635

.3011

.3388

.3764

.06

.0495

.0742

.0990

.1484

.1979

.2474

.2969

.3464

.3958

.4453

.4948

.07

.0624

.0935

.1247

.1871

.2494

.3118

.3741

.4365

.4988

.5612

.6235

.08

.0762

.1143

.1524

.2285

.8047

.3809

.4571

.5333' .6095

.6856

.7618

.08

.0909

.1364

.1818

.2727

.3636

.4545

.5454

.63631 .7272

.8181

.9090

.10

.1065

.1597

.2129

.3194

.4259

.5323

.6388

.7452; .8517

.9582

1.0646

.11

.1228

.1842

.2457

.3685

.4913

.6141

.7370

.8598! .9826

1.10-34

1.2283

.12

.1399

.2099

.2799

.4198

.5598

.6997

.8397

.9796! 1,1196

1.2595

1.3995

.18

.1578

.2367

.3156

.4734

.6312

.7890

.9468

1.1046, 1.2624

1.4202

1.5780

.14

.1764

.2645

.3527

.5291

.7034

-.8818

1.0581

1.2455 1.4106

1..5872

1.7336

.15

.1956

.2934

.3912

.5868

.7823

.9779

1.1735

1.3691' 1.5647

1.7603

1.9559

.16

.2155

.3232

.4309

.6464

.8619

1.0773

1.2928

1.5083; 1.7237

1.9392

2.1547

.17

.2360

.3540

.4720

.7079

.9439

1.1799

1.4159

1.65191 1.8878

2.1238

2.3598

.18

.2571

.3857

.5142

.7713

1.0284

1.2855

1.5426

1.79971 2.0568

2.3139

2.. 5710

.19

.2788

.4182

.5576

.8365

1.1153

1.3942

1.6729

1.9518

2.2306

2.5094

2.7882

.20

.3011

.4517

.6022

.9034

1.2045

1.5056

1.8068

2.1079

2.4090

2.7101

3.0112

.21

.3240

.4860

.6480

.9720

1.2960

1.6199

1.9439

2.2679

2.5919

2.91-"9

3.2.S99

.22

.3474

.5211

.6948

1.0422

1.3896

1.7370

2.0844

2.4318

2.7792

3.1266

3.4740

.23

.8714

.5570

.7427

1.1141

1.4854

1.8568

2.2281

2.5995

2.9709

3.3422

3.7136

.24

.3958

.5938

.7917

1.1875

1.5834

1.9792

2.3750

2.7709

3.1667

3.5625

3.9584

.25

.4208

.6312

.8417

1.2625

1.6833

2.1042

2.5250

2.9458

3.3666

3.7875

4.2083

.26

.4463

.6995

.8927

1.3390

1.7853

2.2317

2.6780

3.1243

3.5707

4.0170

4.4633

.27

.4723

.7085

.9447

1.4170

1.8893

2.3617

2.8'130

3.3063

3.7787

4.2510

4.7233

.28

.4988

.7482

.9976

1.4964

1.9952

2.4941

2.9929

3.4917

3.9905

4.4893

4.9881

.29

.5258

.7887

1.0515

1.5773

2.1031

2.6289

3.1546

3.6804

4.2062

4.7319

5.2577

.30

.5532

.8298

1.1064

1.6596

2.2128

2.7660

3.3192

3.8724

4.4256

4.9788

5.5320

.31

.5811

.8716

1.1622

1.7433

2.3244

2.9054

3.4865

4.0676

4.6487

5.2298

5.8109

.K2

.6094

.9141

1.2189

1.8283

2.4377

3.0472

3.6.566

4.2660

4.87.54

5.4849

6.0943

.6382

.9573

1.2764

1.9147

2.5529

3.1911

3.8293

4.4675

5.1058

5.7440

6.3822

.34

.6674

1.0012

1.3S49

2.0023

2.6698

3.3372

4.0047

4.6721

5.3396

6.0070

6.6745

.35

.6971

1.0457

1.3942

2.0913

2.7884

3.4556

4.1827

4.8798

5.5769

6.2740

6.9711

.36

.7272

1.0908

1.4544

2.1816

2.9088

3.6360

4.3632

5.0904

5.8175

6.5448

7.2720

.87

.7577

1.1366

1.5154

2.2731

3.0308

3.7885

4.4563

5.3040

6.0617

6.8194

7.5771

.88

.7886

1.1830

1.5773

2.3659

3.1545

3.9432

4.7318

5.5204

6.3091

7.0977

7.8863

.39

.8200

1.2300

1.6399

2.4599

3.2799

4.0998

4.9198

5.7398

6.5597

7.3797

8.1997

.40

.8517

1.2776

1.7034

2.5551

3.4068

4.2585

5.1102

5.9619

6.8137

7.6654

8.5171

.41

.8838

1.8258

1.7677

2.6515

3.5354

4.4191

5.3031

6.1869

7.0708

7.9546

8.8384

.42

.9164

1.3746

1.8328

2.7491

3.6655

4.5819

5.4983

6.4146

7.3310

8.2474

9.1638

.43

.9493

1.4239

1.8968

2.8479

3.7972

4.7465

5.6958

6.6451

7.5944

8.5437

9.4930

.44

.9826

1.4739

1.9652

2.9478

3.9304

4.9130

5.8956

6.8782

7.8608

8.8434

9.8261

.45

1.0163

1.5244

2.0326

3.0489

4.0652

5.0815

6.0978

7.1141

8.1303

9.1466

10.1629

.46

1.0504

1.5755

2.1007

3.1511

4.2014

5.2518

6.3021

7.3525

8.4029

9.4532

10.5036

.47

1.0848

1.6272

2.1696

3.2544

4.3392

5.4240

6.5088

7.5936; 8.6783

9.7631

10.8479

.48

1.1196

1.6794

2.2392

3.3588

4.4784

5.5980

6.7178

7.8372' 8.9567

10.0764

11.196«

.49

1.1548

1.7321

2.3095

3.4643

4.6191

5.7738

6.9286

8.0834

9.2381

10.3929

11.547T

.GO

I.190e

1.7854

2.3806

3.5709

4.7612

5.9515

7.1418

8.3321

9.5224

10.7127

11.9030

1.8393

2.4524

3.6785

4.9047

6.1309

7.3571

8.5833

9.8095

11.0336

12.2618

.B3

1.8936

2.5248

3.7873

5.0497

6.3121

7.5745

8.8370

10.0994

11.3618

12.6242

1.9485

2.5980

3.8970

5.1961

6.4951

7.7941

9.0931

10.3921

11.6911

12.9901

.54

2.0039

2.6719

4.0079

5.3438

6.6798

8.0157

9.8517

10.6876

12.0236

13 3595

2.0598

2.7465

4.1197

5.4929

6.8662

8.2394

9.6126

10.9859

12.3591

13.7328

X.1163

2.8217

4.2326

5.6434

7.0543

8.4651

9.8760ill.2868

12.6977

14.1085

.67

♦.1732

2.8976

4.8464

5.7953

7.2441

8.6929

10.1417 11.5905

13.0393

14.4881

.58

2.2807

2.S742

4.4613

5.9484

7.4355

8.9226

10.4097 11.8969

13.8840

14.87U

J.2888

8.0515

4.5772

8.1029

7.6287

9.1544

10.6801112.2059

13.7613

15.2578

.to

2.8470

8.1294

4.6940

6.2587

7.8234

9.3881

10.952712.5174

14.0821

15.6468

FARM ENGINEERING

a 1

o "

"53

o
o

0
0

%
§

0
0

c
0

-0

Jr^Ct

Cu.ft.
p'riM

Cu.lt.lCu.ft.lCu.lt.lCu.lt.
p'r gecip'r sec p'r lec p'r gee

Cu. ft.
p'r »ec

Cu.lt.jCu. ft.
p'r secp'r see

Cu. ft.
p'r gee

Cu. It.
p'r sec

Cu. tt.

p'r ge«

.61
62
.63
.64
.65
M
.67
.68
.00
.70
.71
.72
.73
.74
, .75
.76
.77
.78
.79
.80
.81
.82
.89
.84
.85
.86
.87
.88
.88
.90
.91
.92
.93
.94
.95
.96
.97
.98
.99
1.00
1.01
1 02

2.4059
2.4654
2.5252
2'. 5856
2.64S4
2.7077
2.7695
2.8317
2.8944
2.9576
8.0212
3.0852
3.1497
3.2147
S.2801

3.2079
S.2871
3.3670
3.4475
3.5286
3.6103
3.6927
3.77.57
3.8593
3.9435
4.0283
4.1137
4.1997
4.2863
4.3734
4.4612
4.5495
4.6384
4.7279
4.8180
4.9086
4.9998
5.0915
5.1838
5.2767
5.3700
5.4640
5.5585
5.6535
5.7490
5.8451
5.9417
6.0389
6.1365
6.2347
6.3334
6.4326
6.5323
6.6326
«.7330

4.8119

4,9307
5,0505
5,1712
5,2929
5,4155
5,5380
5,6635
5.7889
5.9152
6.0424
6.1705
6.2995
6.4294
6.5601
6.6918
6.8243
6.9577
7.0919
7.2270
7.3629
7.4997
7.6373
7.7757
7.9150
8.0551
8.1960
8.3377
8.4802
8.6235
8.7677
8.9126
9.0583
9.2048
9.3520
9.5001
9.6489
9.7985
9.9489
10.1000

6.4159

6.5743

6.7340

6.8949

7.0572

7.2206

7.3854

7.5513

7.7185

7.8869

8.0565

8.2273

8.3993

8.5725

8.7469

8.9224

9.0991

9.2769

9.4559

9.6360

9.8172

9.9996

10.1830

10.3676

10.5.533

10.7401

10.9280

11.1169

11.3069

11.4980

11.6902

11.8834

12.0777

12.2730

12.4694

12.6668

12.86(12

13.0647

13.2652

13.4667

8.0198

8.2178

8.4175

8.6187

8.8215

9,0258

9.2317

9.4392

9.6481

9,8586

10.0706

10.2842

10.4992

10.7156

10.9336

11.1530

11.3728

11.5961

11.8198

12.0450

12.2715

12.4995

12.7288

12.9595

13.1916

13.4251

13.6599

13.8961

14.1337

14.3726

14.6128

14.8543

15.0971

15.3414

15.5867

15.8335

16.0815

16.3309

16.5815

16.8333

9.6238
9.8614
10.1009
10.3424
10.5857
10.8310
11.0781
11.3270
11.5778
11.8304
12,0848
12.3410
12..599n
12.8588
13.1203
13.3836
13.6486
13.9153
14.1838
14.4539
14.7258
14.9993
15.2746
15..5514
15.8300
16.1101
16.3919
16.6754
16.9604
17.2470
17.5353
17.8251
18.1166
18.4096
18.7041
19.0002
19.2979
19.5970
19.8978
20.2000
20.5038
20.8090
21.1158
21.4240
21.7338
22.0450
22.3577
22,6719
22.9875
23.3045
23.6230
23.9430
24.2644
24.5872
24.9114
25.2370
25.5641
25.8925
26.2224
26.5536

11.2278
11.5050
11.7844
12.0ti61
12.3500
12.6361
12.9244
13.2148
13,5074
13.8021
14,0989
14.3978
14.6988
15.0019
15..3070
15.6142
15.9233
16.2345
16.5477
16.8629
17.1801
17.4992
17.8202
18.1433
18.4683
18.7952
19.1239
19.4546
19.7872
20.1216
20.4579
20.7960
21.1360
21.4778
21,8214
22.1669
22.5142
22.8632
23,2141
23.5667
23.9211
24.2772
24.6351
24.9947
25.3561
25.7192
26.0840
26.4505

12 8317
13,1486
13,4679
13,7899
14,1143
14 4413
14,7707
15,1027
15.4370
15.7738
16.1130
16.4547
16.7989
17.1450
17.4937
17.8447
18.1981
18.5538
18.9117
19.2719
19.6344
19.9991
20.3661
20.7352
21.1066
21.4802
21.8559
22.2338
22.6139
22.9661
23.3804
23.7669
24.1554
24.5461
24.9388
25.3336
25.7305
26.1294
26.5303
26.9333
27.3384
27.7454

14.4357

14.7921
15.1514
15.5136
15.8786
16.2465
16.6171
16.9905
17.3667
17.7456
18,1272
18.5115

18 898"

19 2S81
19.6804
20.0753
20.4729
20.8730
21.2757
21 6809
22.0887
22.4990
22.9118
23.3271
23.7449
24.1652
24.5879
25.0131
25.4406
25,8706
26.3030
26.7377
27.1748
27,6143
28,0561
28.5003
28.9468
29.3956
29.8467
30.3000
30.7556
31.2135

16.0396

16.4357

16.8349

17.237S

17.6429

18.0516

18.4634

18.8783

19.2963

19.7173

20.1413

20.5683

20.9983

21.4313

21.8671

22.3059

22.7476

23.1922

23,6396

24.0899

24.54.30

24.9989

25.4576

25.9191

26.383.'?

26.8502 ■

27.3199

27.7923

28.2574

28.7451

29.2255

29.7086

30.1943

30.6826

31.1735

31.6670

32.1631

32.6617

33.1629

33.6667

34.1729

34.6817

1.03
1.04
1 05

28.1544 31.6737,35.1930
28.5654 32.1361135.7067
28.9784|32.fi0O7 36.23.'JO

i.oe

1.07
1 06

29.3933 33.0675 36.7417
29.8103 '33, 5365 37.2628
30.229l'34.0O78'37.7864

109
1 10

26.8187
27 1886

30.6499 34.4812, 38.3124
31.0727 34,9568 38,8409

1.11

27.5602
27.9335
28.3084
28.6850
29.0633
29.4432
29.8248
30.2079
30.5928
30.9792
31.3672
31.7569
32.1481

31.4974|35.4346:30.3717

1.12
1.13

31.9240 35.914539.9050
32 3525i36.3965 40.4406

1 14

32.7829 36.8808 40.9786

1 15

33.2152 j37. 3671 41.5190

I.IC

1.17

, 1.18

1.19

33.6494137.8556
34.0854^38.3461
34.5234138.8388
34.963139,3335

42.0617
42.6068
43.1542
43.7039

1.20
1.21
122

35.4048

35.8483
36.2936
36.7407

39.8304
40.3393
40.8303
41.3333

44.2560
44.8103
45.3670

1 23

45.92.'io

66 FARM ENGINEERING

In case the engineer wishes to measure the depth in
inches rather than in hundredths, he may consult the follow-
ing table. He can find the number of miner's inches which
will pass over the weirs. Each miner's inch in this particular
table is equal to 1/40 of a cubic foot per second. So, by divid-
ing the number of miner's inches by 40, we get the number
of cubic feet per second.

The following table is taken from Bulletin 72 of Montana
Experiment Station : (The supply of this bulletin has been
exhausted.)

Plate 128. A concrete luru-uut hux. The ditch brhigs the water in at the
right. It may flow straight through, or by putting tightly fitting
boards in the slots of the main channel the water can be turned to
right and left. Then by putting boards in the left wing the w^ater
can be turned to the right. If boards be placed in the left slots
then the water runs into the right (closed) wing. In this case
the water is delivered into a tile which enters the bottom of the
right wing. If the side slots be closed to the top and a low board
with a weir slot in its upper edge be inserted in the main channel
of the box, then the turn-ot box is convuerted into a weir box. Tht
gauge peg should be located at least six feet upstream from the weir,
Its top should be level with the crest of the weir.

FARM ENGINEERING

* 1

[

]

;

^■s

f-,

(-.

■H ^

"53

"oJ

o;'

O "

j= 9

■^

-tJ

-tj

+3 O

ft ,

» fc

1>-

■K

c»

Min-

Min- : Min-

Min-

Inches

ers'

ers' ers'

ers'

inches

inches ' inches

inches

Inches

inches

5-16

7-16

9-16

11-16

iy8

iy4

17-16

, %

13-16

19-16

2 5-16

2y4

sys

3y2

lys

iy2

iy4

3y4

4y2

5y4

63/4

lys

iy4

2y4

3V3

4y8

678

9y8

loys

iiy*

ly^

.21

IVs

iy4

ly^

lys

2y8

100

2y4

109

107

119

102

115

128

110

124

138

103

118

133

148

2y8

111

126

142

158

102

119

136

152

169

3y8

108

125

143

161

179

3y4

114

133

152

171

190

100

121

141

161

181

201

■3y2

106

127

149

169

191

212

SVs

112

134

157

179

201

224

118

141

165

188

212

235

3y8

124

148

173

198

222

247

" 26

104

130

155

181

207

233

259

4y8

109

136

163

190

217

244

271

^■y*

114

142

170

199

227

255

284

44 59]

119

148

178

207

237

267

296

4y2

124

155

185

216

247

278

309

129

161

193

226

258

290

322

101

134

167

201

235

268

302

335

4y8

105

139

174

209

244

279

314

349

109

145

181

217

254

290

326

362

113

150

188

225

263

301

338

376

4y4

117

156

195

234

273

312

350

390

121

161

202

242

282

323

362

404

5% •

125

167

209

251

292

334

376

418

sys

130

173

216

259

303

3^16

389

432

134

179

223

268

313

357

402

447

FARM ENGINEERING

OS 1

_jj

i-t

_»H

■J3

"oj

*5j

- "S"

js 9

_jj

„

-M

5 o

a L.

Min-

Mln^

Min-

Inches

eri*

ers'

inches

Inches

inches

Inches

inches

Inches

sys

138

185

231

277

323

369

415

461

143

190

238

286

333

381

429

476

61/8

147

196

246

295

344

393

442

491

6y4

101

152

202

253

304

354

405

455

506

104

156

209

261

313

365

417

469

521

107

161

215

269

322

375

429

483

537

110

166

221

276

331

387

442

497

552

6^4

11^

170

227

284

341

398

454

511

568

117

175

234

292

350

409

467

525

484

120

180

240

300

360

420

480

540

600

71/8

123

185

246

308

370

431

493

554

616

126

190

253

316

379

443

506

569

632

130

195

260

324

389

454

519

584

649

100

133

200

266

333

399

466

532

599

665

102

136

205

273

341

409

477

5!6

614

682

7y4

105

140

210

280

349

419

489

559

629

699

107

143

215

286

358

430

501

573

644

716

110

147

220

293

367

440

513

586

660

733

113

150

225

300

375

450

525

600

675

750

81/4

115

15^

230

307

384

461

537

61'

691

768

118

157

236

314

393

471

550

628

707

785

81/2

120

161

241

■ 321

401

482

562

642

722

803

85/«

123

164

246

328

410

492

574

656

739

821

126

168

252

335

419

503

587

671

755

838

128

171

257

343

428

514

599

685

771

856

131

175

262

350

437

525

612

700

788

875

91/8

134

179

268

357

446

536

625

714

804

893

91/4

137

182

273

364

456

547

638

729

820

911

139

186

279

372

465

558

651

744

837

930

142

190

285

379

474

569

664

759

851

949

1^5

193

290

387

484

580

677

774

861

967

93/4

148

197

296

394

493

592

690

789

888

986

^4-

151

201

302

402

503

603

704

804

905

1005

154

205

307

410

612

615

717

820

922

1024

in%

157

20P

313

417

522

626

731

835

939

1044

J01/4

159

213

319

425

532

638

744

850

957

1063

10%

162

217

325

433

541

650

758

866

974

1083

:inv3

. .

165

220

331

441

551

661

771

882

992

1102

^:0%

22^

337

449

561

673

785

898

1010

1122

]^%

228

342

457

571

685

799

913

1027

1142

'07/,

232

3^9

465

581

697

813

930

1046

1162

236

355

473

591

709

827

946

106^

1182

11%

. . . _

240

361

481

601

721

841

962

1082

1202

\-ty4,

24^

367

489

611

733

856;

978

1100,

1222

.n%

. . . _

249

373

497

621

746

870

994

11191

1243

My^

. . ._

253

379

505

632

758

884

1011

1137

1263

257

385

514

6^2

770

899

1027

1156

1284

t1»4 1

- .. .

261

391 1

522!

652

783

913!

1044

1174

1305

FARM ENGINEERING

o «

Inches

ri-/8

1?%

1.214

12%

n%
■12%
13
131/3
131/4
133/^
131/2
^3%

13%

1^%

141/4

14%

141/3

14%

143/4

11%

15%

151/4

15%

153/4

15%

16%

I614

lfi%

163/,

16%

17%

171/4

17%

173/4

17%

Min- ! Min- Min-
ers' erg' era'
inches inches Inches

265
269

Min-
ers'
Inches

398
404
410
417
423
430
436
442
449
456
462
469
475

Min-
ers'
Inches

430

539

547

556

564

573

582

590

599

607

616

625

634

6^3

652

661

670

679

688

697

706

715

725

734

743

753

Min- j Min-
ers' ers'
inches inches

663
673

68-

694

705

716

726

737

748

759

770

781

792

803

815

826

837

8v9

860

871

883

894

906

918

929

941

953

965

977

989

1001

1013

1025

1037

1049

1061

1073

1086

1098;

1110

1123

1135

795
808
821
833
846
859
872
885
898
911
924
938
951
964
978
991
1005
1019
1032
1046
1059
1073
1087
1101
1115
1129
1143
1158
1172
1186
1201
1215
1229
1244
1259
1273
1288
1303
1318
1333
1348
1363
1378
1393
1408
1423
1438
l'^54
1469
1484

Min-
ers'
inches

928
943
958
972
987
1002
1017
1032
1048
1063
10781
109-'
1109
1125
1140
1156
1172
1189
120'
1220
1236
1252
1268
1285
13011
13171
133-';
1351
1368
1385
1402
1419
1437
1455
1472
1^89
1506
15^3
1539
15561
15721
1589
1607!
1625!
1642|
1660'
1678j
1696i
17141
I732I

Min-
ers'
inches

1060
1077
1094

nil

1128
1145
1162
1180
1197
1215
1232
1250
1268
1286
1303
1321
13-^0
1359

Min-
ers'
inches

1193
1212
1231
1260
1269
1289
1308
1328
1348
1368
1389
1.09
1429
1449
1469
1489
1509
1530
13761 1550
13941 1570
1412 i 15901
143li 1610!
14491 163] I
1--68' 1652!

1487: 1673:

1506 1694:
1524! 1715!
15431 1736:
1562! 1757
1580 1778

Min-
ers'
Inches

1600
lO'^O
1639
1659
1678
1698
1717
1737

1801
1822
1844
1866

1910
1932
195^

1757 1976
1777; 1999
1797i 2021
1817i 2044
1837: 2066
1857,! 2089
1877! 2112
1897! 213'
1918 2157
1938! 2181
1959| 2204
19791 2226

1326

1347

1368

1389

1410

1432

1454

1475

1497

1518

1541

1563

1585

1607

1629

1652

1675

1699

1721

1743

1766

1789

1812

1835

1859

1882

1906

1929

1953

1977

2001

2025

2049

2073

2098

2122

2147

2171

2196

2221

2246

2271

2296

2321

234R

2372

2397

2-^23

2448

2474

70 FARM ENGINEERING

Ditches. — In order to carry irrigation water or drainage
water, we need ditches. The laying out of irrigation ditches
is done in the same way as drainage ditches, except that we
sometimes use dykes to carry the water over the low places.
So we get "Fill" in the place of "Cut" if the grade happens
to have a greater elevation than the elevation of the land.

Plate 20. Measuring the depth of the ^Yatel■ over a weir. The rod stands
upon a solid post, the top of which is exactly the same height as the
crest ot the weir. This measurement must be made in the nearlj
still water at least six leet back from the weir. (The water pitches
down as it approaches the weir. There are .just four-tenths of a foot
of water going over their weir.)

Sometimes we carry water past Ioav places by the inverted
siphon. Some "Practical Drainage" men believe they can use
a true siphon made of tile drain to draw water over a hill.
Their drainage projects usually fail because the tile are not
air tight. Tile drains should be run "on grade."

FARM ENGINEERING

y, q '£

13 o

S'53

O -M

o uT

&-g

3 o^

? .:3 O

rH tfi G

p! !Z^' S *

+- "^ '^ _^

«t-^ 2 r, O-l

O "' .O, f-|

■*^ S; -G

•^ .ti -a

cd "O o

^^ ^ c3 3

„ 3 X !M

.2 = 5
o S h

s '^:::!

t §o
— op

•S "'S

^ 1i *^
o ja c

° J-. 0)

") ^ (»

U w 0)

O Bj 5
HIS &

S S M

o O aJ
■Ji i, i<

^9
■•5S

72 FARM ENGINEERING

Open Ditches. — The sides of the open ditches usually
slope out about 1 or 1^^ feet on each side to each foot of
depth. The banks are thus kept from falling in and clogging
the ditch. In general, wide ditches are preferable because
they do not wash so deep, or change courses so often.

Drain Tile.- — Drain tile are of three general classes : square
end tile, bevel end tile, and bell end tile. They may be classi-
fied according to material into the following classes: 1. Com-
mon red tile; 2. Vitrified or glazed tile; and 3. Cement tile.

The common red tile often disintegrates and causes trouble.

The glazed tile are expensive but last well.

Dach' ^'^

Plate 31. In Plate 31 is shown a cross-section of a railroad track
with an "inverted siphon" running across under the cut and the
track. The ditch comes in at the left, (as shown by arrow), and
the water runs in at the open end of the pipe which projects through
the cement cross-wall. It runs under the track and the force of
the water behind drives it up and out of the other end of the pipe,
which is a little lower than the in-take end. The siphons are now
being built as large as eight feet in diameter and several miles in
length. A great ditch is thus carried clear across the "Bitter Root
Valley" in Montana.

The cement tile are all right if rightly made, and laid
where no alkalj water runs through them. (See Bulletin 81 of
the Montana Experiment Station.) The cement tile should
be of a rich mixture and made very wet. Otherwise the flow-
ing water will soon wear holes through the loose, crumbly
cement sides.

After irrigation water has been measured and brought to
the field by the ditches, it is turned out into small ditches

FARM ENGINEERING

by means of turnout boxes. These are made of cement, con-
crete or wood. See Plates 28 and 30. In case of deep ditches,
many prefer the steel head gate. See Plate 21.

The methods of handling the water on the land vary so
much that it is impossible to go into detail for each system.
In some localities, the water is brought into tiles, and fed to
the soil from below, "sub-surface irrigation." In some locali-

K-''— M-

J-/— j

-|-~

Plate 32. This gives an idea of desirable cross-sections for drainage or
irrigation ditclies. Figure A lias a slope of 1 to 1. That is, each
side slopes out one foot to each foot of depth. Figure B is of a
ditch with a 1 to li4, that is, each side slopes out one foot and six
inches or one foot and five tenths to each foot of depth. A is
satisfactory for ditches through hard soil, heavy clay, etc., while B
should be used for sandy soil or any easily washed soil.

ties, little furrows are made, two, three or four feet apart, and
a little water allowed to run down each furrow. This is
called ''corrugated irrigation." Again, in some parts of the
country, dykes are built at the lower sides. of the fields, and
the water is allowed to flood the fields, "flooding." And so

FARM ENGINEERING

we find all of these systems changed, and combined until we
have no end of special methods of irrigation.

The Preparation of Land for Irrigation, — It is necessary

Plate 33. This shows a side view of the three different types of tile.
Fig. A is the ordinary "square-end" tile. Fig. B is a "bevel-.ioint"
tile. Fig. C is a "bell-end" tile. In each figure the side of the tile
has been cut away to show a section of a joint. The bel!-end
tiles are usually made two, three, or four feet long, while the others
are usually one foot long in small sizes and two feet long in large
sizes.

Plate 34. This is a photo of the latest and most approved tvpe of irri-
gation leveler. It is sixteen feet long by eight in width. If it is
to be used on light soil the members are 2"x(i" ; if it is to be uped
on medium soil, 2"xS'' ; if on heavy soil, 2"x]0" or even 2"xl2".
The braces are of old wagon tire and the chain by which it is pulled
is a log chain. From two to six horses are required to drag it.
It rubs off the high spots and carries the soil to the low spots and
there drops it automatically. As no company builds these useful
machines, the farmer builds them himself.

FARM ENGINEERING 75

to get the surface of the field free from little high spots and
low spots, before irrigation can be properly done. This is
accomplished by plowing the ground, and then going over it
with an irrigation leveller.

Control of Moisture, and Temperature of the Soil by Means
of Scientific Tillage. — If wet ground is rolled with a heavy
roller, the moisture near the top is readily evaporated from
the surface. The evaporation cools the soil, just as the evap-
oration of sweat cools the human body. Thus we remove
moisture and cool the soil by rolling.

If we establish a surface mulch by surface tillage, we are
able to prevent evaporation, and thus keep the soil moisture
from evaporating. This also brings the fine particles in such
a position that they can absorb heat from the sun's rays, and
as they are not cooled by rapid evaporation, the soil is warmed.

Thus we control the temperature and moisture by drain-
age, irrigation and scientific tillage.

TILE LINES.

The general use of drain tile both for the purpose of
carrying drainage water and irrigation water as well as sew-
age makes it necessary to study the matter carefully before
venturing to install a tile system of carrying water or sewage.

Capacity of Tile Drains. — No attempt is made here to go
into the infinite detail of the carrying capacity of drain tile.
It is well for the student to know that the capacity of a tile;

drain or conduit varies according to the smoothness of the
the flow also depends upon the depth of water in the soil above
the tile.

The following table gives somewhere near the flow which
we might expect from a six-inch tile system if everything was.
in good working order and the work of laying the tile had^
been properly done:

FARM ENGINEERING

Plate 35. This shows three systems of laying out tile drains or open drains.
Fig. A is the branch system. The main line goes up the main hollow
or low ravine. The branches may extend up small low places or
they may be extended into the level land on each side of the main
ditch. This system works very well on very fiat land as well. Notice
the cross-wall at the mouth of the drain. An "upstream wing" pro-
tects the bank from washing out. Fig. B is a* side branch method
which resembles a gridiron. In case one wishes to drain a side hill
the main line may extend along the base of the hill and the branches
may extend up the side of t le hill. Notice that the tile bends down-
stream in each case before the branches are allowed to enter the main
tile. Also notice that a larger tile is used below the branches than
above. If the grade of Fig. B were reversed, then this system would
be suitable for the discharge of sewage water from a water tight
cess-pool. In case there is danger of the outlets (which would then
be at the ends of the branches) clogging by freezing, the water should
be drawn from the cess-pool by an intermittent siphon. See Farm
Engineering, Part I and Iowa Engineering Experiment Station bulletin
on Sewage Plants for Private Houses. Fig. C shows a combination
of systems shown in A and B. This is good in case a large ravine
has many smaller side ravines which are separated by ridges through
which it is impracticable to dig the ditches.

FARM ENGINEERING TL

Inches of Number of second

drop per feet discharged

hundred ft. • from tile.

30 3/4

24 5/8

18 1/2

12 3/8

6 5/16

3 1/4

As the number of cubic feet of discharge will vary ap-
proximately as the square of the diameter of the tile one might
figure the capacity of the different sizes of tile from the above
table. To get the discharge of a three-inch tile. 6X6=36.
3x3=9. 36^9=4. Then a three-inch tile will carry approxi-
mately Yx ^s much as a six-inch tile.

To find the capacity of a twelve-inch tile. 6X6=36.
12X12=144. 144 is four times as great as 36 so we might ex-
pect four times as much discharge from the larger pipe. This
is based on the fact that the area of a circle increases as the
square of the diameter.

As there is more resistance per unit of area of cross sec-
tion in the small tile the increase in discharge will be greater
in proportion to the cross section in large tile than it will be
in small tile.

Systems of Laying Tile. — There are a great many systems
of laying out tile drains. The student must apply some one
of these systems and make such combinations as he sees fit.

TILE DRAINAGE.

In different parts of the country the people hold widely
different opinions in regard to the proper methods of draining
land. In general it may be said that they do not really under-
stand the advantages to be derived from drainage.

Many believe that when they have removed the surface

78 FARM ENGINEERING ^_

water they have properly drained the field. In a large ma-
jority of cases the idea is absolutely wrong. Again we often
meet those who really believe that all the water should re-
main on the land in order to produce a crop. Such people
have little or no idea of the detrimental effects which result
from a "high water table." By a high water table we mean
the height of the free water in the soil.

The student should understand that there are three types
of water in the soil :

1st — Free water, that type of water which may flow from
place to place. Such water flows into a well or cellar which
penetrates below the water table.

2nd — Capillary water. This type of water is in the form
of a thin film which covers the surface of each particle of
moist soil.

3rd — Hygroscopic moisture. This form cannot be seen
but when soil which is apparently very dry is heated, it loses
weight. This is due to the loss of water which we cannot see.

In all three cases the water is of the same composition,
but its effects on plant growth are very different. Both hy-
groscopic and capillary moisture promote plant growth, while
the free moisture causes the plants to actually drown. Of
course many aquatic plants can live with their roots in free
water, but we must remember that such plants as corn, oats,
wheat, barley, rye, clover, timothy, alfalfa, etc., are not aquatic.
The roots reach into the soil for plant food and moisture, but
when they reach a very high water table they often perish.

In the light of the above facts, it is easy to understand
why subsurface or "under drainage" often causes land, which
has previously been unproductive, to produce abundant crops.

The author has never met with a case where a thorough
system of under drainage really caused the land to "dry out"
as some people imagine it would.

As a matter of fact, neither capillary or hygroscopic mois-
ture can be drawn from the land by an underground drain.

FARM ENGINEERING 79

It is only the free water that is really affected.
Systems of underdraining :

Mole Ditches.

Some years ago a machine was devised which forced a
bullet shaped piece of iron through the soil, at a depth of
from one to three feet. The ditch worked much as a modern
tile drain works, but it soon caved in on nearly level land,
while in hilly land the water tore out deep gullies where the
ditch had been.

Brush or Stone Drains.

Many people dug ditches, filled them partly full of brush
or loose stones and filled the top of the ditch with earth.
These ditches often cave in and fill up or wash out until
gullies are formed. However, many people still believe that
such drains must be used. Such a belief rapidly dies out when
a thorough knowledge of the advantages of tile drainage is
acquired.

By means of tile drainage the engineer may regulate the
height of the water table to suit conditions. By so doing he
allows the soil to become aerated, and thus the roots of plants
may penetrate to a great depth.

The absence of the free water near the surface allows the
soil to warm up earlier in the spring, and to maintain a better
tilth throug-hout the season.

In laying out and digging ditches for tile drains the gen-
eral directions should be followed carefully. The bottom of
the ditch should be smoothed by means of a tiling hoe or
spoon. The tiles are then laid end to end in the ditch and
a little fine soil is carefully tramped on top of them.

The ditch may now be filled with a slip scraper or by

8o FARM ENGINEERING

hand. The earth should be tamped thoroughly over the tiles,
in layers not more than six inches in thickness; this will prevent
washouts.

It must be remembered that the water enters the tile
drain betweea the ends o£ the tiles. Some think that the
water soaks through the tile. The latter idea is incorrect.

One need not hesitate to use either cement tile or vitri-
fid clay tile for drainage purposes, and even though the ends
are placed close together, the water finds no difficulty in rush-
ing in and filling the line. In fact great care must be taken
to have the ends of the tile forced close together. This pre-
vents dirt entering the tile. Many prefer to use bell end tile
in place of square end tile for drainage purposes. This makes
the work more expensive, and at the same time of no more
real value.

In those localities where alkali is prevalent the vitrified
tile should always be used, as the alkali "eats up" or destroys
the ordinary tile. The cement tile is rapidly destroyed by
alkali unless it is especially treated to prevent the action of
alkali.

Size of Tiles.

In theory we might be able to use two and three inch
tile for our short drains, but in actual practice we have ceased
to use drains smaller than four inches in diameter. It is hard
to say just what size tile should be used, but the following
data will prove advantageous to those who wish to use tile
drainage :

A four-inch tile will drain from ten to fifteen acres.
A five-inch tile will drain from twelve to twenty acres.
A six-inch tile will drain from twenty to forty acres.
A seven-inch tile will drain from forty to sixty acres.
An eight-inch tile will drain from sixty to eighty acres.

FARM ENGINEERING

The above data must be used with judgment or the stu-
dent may find that he is putting in smaller tile than he should
put in. He seldom finds that he has put in larger tile than
he should put in.

It should be remembered that the carrying capacity of a
tile is approximately proportional to the square of the diam-
eter. Sonsequently one should not expect two four-inch tiles
to fill one eight-inch tile, etc., etc.

Joints.

In bringing the laterals into the mains we should always
be careful to see that the water does not approach the main
at right angles. It should gradually approach the direction
in which the water is flowing in the main tile, and the axis
of the branch should be level with the axis of the main tile.
In other words, the bottom of the tiles should not be level.

The Tiling Hoe.

The tiling hoe is made especially to smooth the bottom
of the ditch, leaving a round for the tile to lay in. All ditches
should be smoothed with a tiling hoe.

Ditch Digging Machines.

Many good companies are now building machines which
dig ditches for tile drains, at exactly the right level, and in
some cases these machines smooth up the bottom, leaving it
round for the tile. The Buckeye ditcher is an example of
this type of machine.

In running levels for tile drains, we must follow the same
rules as we use in digging ditches for drainage or irrigation.
The same method of measuring oflf and staking out is used
as in drainage and irrigation ditching.

82 FARM ENGINEERING

EXAMINATION

Note to Students — These questions are to be answered inde-
pendently. Never consult the text after beginning your exam-
ination. Use thin white paper about 6 in. x 9 in. for the exam-
ination. Number the answers the same as the questions, but
never repeat the question. Mail answers promptly when com-

1. Explain how a lack of knowledge of Agronomy may pre-
vent an Agricultural Engineer from doing successful
work.

2. Explain how an Agricultural Engineer must be governed
by the principles of Farm Management,

3. Describe accurately the construction of a surveyor's level
of the "Y" type.

4. Discuss errors in tape measurements, treating of Cumula-
tive and Compensating -Errors,

5. Explain how to turn off a right angle by means of the
tape and pins.

6. If the surveyor runs a line at 90 degrees to the direction
of the compass needle, will the line be an east and west
line? Why?

7. Explain how to bring the level bubble tube parallel with
the bearings of the "Y" rings.

FARM ENGINEERING 83

8. Tell how the area of a field with straight sides of irregular
length, and angles other than 90 degrees, may be de-
termined.

9. Tell how the area of an irregular field may be determined
with a planimeter.

10. Explain how to cut off a certain number of acres from an
irregular field, and still have two sides of the new field
parallel to each other.

11. Why is the price of wood fence posts increasing from year
to year?

12. Tell how to make a cement fence post.

13. Tell how to test the strength of a cement fence post.

14. Why are god culverts and bridges necessary on the farm?

15. Why is it desirable to govern the temperature and mois-
ture conditions of the soil?

16. In what three principal ways can the agricultural engi-
neer govern the temperature and moisture conditions of
the soil?

17. What is a topography map? How does it help in drain-
age and irrigation projects?

18. Explain the principles of differential leveling.

19. The student will now prepare a map of field shown in
Plate 17. and with a cut of three feet at X, draw in dotted
lines a proposed drainage system. He will show, (1) di-
rection of drains; (2) length of drains ;(3) angles turned
off. This map should enable any engineer to locate tile
drains, laid according to the map.

20. The student will now fill in the following page of notes,
giving the grade and cut at each 100-foot station. The
ditch is to be 2 feet deep at each end, and run on even
grade.

FARM ENGINEERING

Sta.

S. B.

H. I

F.S.

Elev.

Grade

Cut

4.50

/';

....

10.00

8.00

2.00

100

5.21

....

c .

200

4.02

• • . .

. .

300

3.65

. ,

400

3.46

. < . .

, ,

500

3.21

....

. .

600

2.84

21. The student will make a profile map showing bottom of
ditch and top of ground.

22. Tell the two main sources of irrigation water.

23. Describe an inverted siphon and tell how it works.

24. Define the second foot and the acre foot as units of meas-
ure of irrigation water.

25. Describe the cippoletti weir and tell how it should be
made and set.

26. Consult Plate 29 and weir tables. The rod reading is ex-
actly .4 foot. The crest of the weir is 1 foot long. How
many cubic feet, or what part of a cubic foot per second is
passing over the weir? •

Write this at the end of your Examination

I hereby certify that the above questions were answered en-
tirely by me.

Signed -
Address

THE,

CORRESPONDENCE COLLEGE
OF AGRICULTURE

FARM ENGINEILRING— Part III

HIGHWAY ENGINEERING

and

FARM CONCRETE CONSTRUCTION

H. BOYDEN BONEBRIGHT B. S. A. MEMB. A. S. A. E.

Agricultural Engineer

Montana State College and Experiment Station
BOZEMAN, MONTANA

This is the third of a series of three books giving a complete course of instruction in

FARM ENGINEERING

NOTE TO STUDENTS

In order to derive the utmost possible benefit from this
book you must thoroughl}^ master the text. It is not in-
tended that you should commit the exact words to memory,
but there is nothing contained in the text which is not
absolutely essential for the intelligent farmer to know.

For your own good never refer to examination questions
until you have finished the study of the text. By follow-
ing this plan the examination will show what you have
learned from the text.

This lesson book is not intended to be a book of plans
for the building of roads or for the construction of concrete
structures. It is designed to give in the most practical
possible way, the fundamental scientific knowledge which
the student must have if he is to successfully build roads,
or concrete work. With the information given in this book
the student should be able to design for himself such roads
or concrete work as will best fit the conditions under which
they are to serve.

Should the student wish to buy some bo'oks on the sub-
ject of Roads and Pavements he will find "Roads and Pave-
ments" by Ira Osborn Baker to be an excellent addition
to any engineering dibrary. "Highway construction," by
T. Byrne, is also an excellent reference book. These books
are published by John Eiley & Sons, New York. Cost five
dollars each.

The student can secure for the asking "Concrete Con-
struction about the Home and Farm" from the Atlas Port-
land Cement Co., 30 Broad St. N. Y. "Concrete Silos"
and "Concrete in the Country" from The Universal'Portland
Cement Co., Chicago, 111.

Farm Engineering Part III

Highway engineering in its crudest forms has been practiced
since the earliest history of man.

When man learned the fact that it was easier to walk around
a hill in a gradually ascending line than to climb directly up one
side, he began putting into practice some of the principles which
are now so scientifically worked out by our high salaried railroad
and highway engineers.

And it is not at all improbable that man first learned the prin-
ciples of rounding the hills from the game which he pursued, for
the trails of many wild animals show that even the beasts of the
forests understand something of laying out roads on a reasonable
grade.

Later when the ass and the ox were used by man as beasts
of burden the trails had to be widened and the steepest grades had
to be removed from the trails.

Then the crude forms of carts and sleds appeared and the trails
were widened into roads. While thousands of years have elapsed
since these crude roads began to scar the face of the earth, yet, it
remained for this generation to witness the entrance of the most
destructive vehicle, which roads have ever been made to carry.
Heavily loaded wagons and traction engines may crush the road's
surface, but in so doing they only serve to make the surface harder.
But the automobile with its round soft tires does little packing,
and in fact when driven at a moderate speed it scarcely injures the
road at all. But when the speed is increased to twenty miles an
hour the dust, the sand, and even the small pebbles, fly from be-
neath the wheels with sufficient force to carry them several feet
from the center of the road.

When the auto's speed increases to fifty or sixty miles per
hour the material is literally blown from beneath the tires and it
falls many feet from where it originally lay.

Consequently many systems of road-building which served
the purpose perfectly for thousands of years, have become imprac-
tical within the last decade, for as fast as the road surface is loos-

FARM ENGINEERING

Plate 1. In plate 1 at the top is shown an automobile wheel traveling at
slow speed. Notice that no dirt is being thrown from beneath the tire.
The lower part of the plate shows a wheel (traveling to left) at high speed.
Notice the particles of earth and the pebbles falling from beneath the tire
in the direction of camera. (Of course this picture shows a blurred wheel
owing to the speed at which the wheel passed).

FARM ENGINEERING 5

ened by the calks of horses and the wheels of slow moving vehicles,
it is knocked to the road-side or blown into an adjoining field by
the swiftly moving automobiles.

And we must figure that the automobile has come to stay.
While it is to be hoped that the extreme speed of some of our
reckless drivers will be a passing fad, we must reckon with the
swiftly moving machines as among the worst destroyers of old-
fashioned good roads.

In order to properly understand the subject of highway engin-
eering, we must have very definite knowledge of several sciences.

Surveying.

In order to properly lay out a road one must understand the
use of the level and transit, or at least the use of the highway or
architect's level. With these instruments the highway engineer
lays out the line of the road, and determines the grades. He is
also able to stake out the cuts and fills, and to locate the side ditches
and the crown in the middle of the road.

Drainage.

One of the most essential points in road construction is proper
drainage of the land through which the road runs, and especially
that land directly under the travelled portion of it.

Soils.

For the following reasons it is essential that the engineer be
able to judge the type of soil over which he lays out a road.

1st. He must know how to draiji the road, and the type of soil
has much to do with the problem of drainage.

2nd. He must be able to tell what treatment will best fit the
surface for heavy or light traffic, as the case may be.

3rd. He must be able to foretell what eiTect the climate will
have upon the soil over which he lays out a road.

4th. . He must be able to determine the effect of swiftly run-
ning water, not only on the road's surface, but its effect upon the
side ditches, and the culverts and bridges along the way.

Animal Husbandry.

The student should have a fair idea of the pulling ability of
horses, and of the effect of different road surfaces upon the feet of
horses.

6 FARM ENGINEERING

Sanitary Science.

In some cases roads either add to or detract from the sanitation
of a district. The engineer should be able to so construct the roads
that they will aid in keeping a district sanitary, or at least, not in
any way hinder the work of sanitation.

Concrete Construction.

The student should have a fair idea of the principles of con-
crete construction and masonry, in order that he may design and
build small culverts and bridges in an economical and satisfactory
manner.

Materials of Construction.

The student should have a fair knowledge of the materials of
construction used in bridges and culverts.

Sufficient material is found in Part 1 to enable the student to
figure strengths sufficiently accurately for all ordinary work. The
student must always figure on giving road structures a large factor
of safety, as traction engines and herds of farm animals often sub-
ject a structure to from 10 to 20 times the normal load.

LAYING OUT ROADS

In the laying out of a good road the engineer must first con-
sider what purpose the road is to serve. If it is to be a pleasure
road, then he need not seriously consider the problems which relate
to shortening distances between points, but aim rather at cutting
down grades by means of contours, rather than cuts and fills.

In the case of tonnage roads he should aim to have the shortest
possible road from point to point, and at the same time cut all
grades as low as possible.

In many states it has become a habit to put all highways upon
section lines. This is often very bad practice, as it often lengthens
the distance between points, while not infrequently, it places the
road in such a position that deep gulches must be crossed, and high
ridges must be surmounted. Such construction is very faulty from
the standpoint of tonnage roads.

The main thoroughfares into our larger towns and cities often
carry as much tonnage as some of the less important railroads, and
there is no good reason why the most direct route should not be

FARM ENGINEERING 7

taken by them, even though some land had to be acquired by con-
demnation proceedings.

Again, by properly laying out a road we can avoid steep grader,
and thus increase the efficiency of the road a great deal, for as
"a chain is no stronger than its weakest link," so the efficiency of a
tonnage road must be measured by its steepest grades or by its
poorest bridges.

It is unnecessary to take up here the subject of running levels
over the projected highways as the work of running levels is dealt
with thoroughly in Part II, of Farm Engineering.

Grade of Roads.

In laying out a road one of the most essential points is the
grade. A perfectly level road, while desirable from the standpoint
of draft of vehicles, is not desirable from the drainage standpoint.
It is likel}^ to become a mire during wet seasons of the year, and
when it once becomes a mire it is very slow about drying out.

On the other hand, a very steep grade is undesirable, not only
on account of the increased draft of ascending vehicles, but also
on account of the difficulty of maintaining a good road surface dur-
ing wet weather. The washing effect of hard rains, upon the steep
grades is very hard to overcome.

How Grades Are Computed.

Many authorities speak of the grade of a road in terms of feet
rise per hundred feet of travel. For instance, a rise of one foot in
traveling one hundred feet is spoken of as "a grade of one to the
hundred."

Another way of designating the amount of grade is in per cent.
That is, if the rise is one foot in a hundred feet the rise is said to
be one per cent. Five feet rise per hundred feet of travel is a five
per cent, grade, etc., etc.

In both the above cases the actual distance traveled is taken as
the basis of length of travel, while in theory the distance should
be taken on a level, yet the error is so slight that most authorities
do not take it into account. Hence, we simply measure the distance
on the road surface and divide it into the feet of rise in order to
get the grade.

Effect of Grade on Draft of Vehicles.

When a loaded wagon is pulled up an incline the power re-

8 FARM ENGINEERING

quired to move it becomes greater, due to the fact that the load,
the wagon, and the source of power, be it team, or engine, must be
elevated bodily as the load proceeds.

Some people believe that the actual pull required to move a
load up a grade varies exactly as the per cent of the grade. This
is not the case, because there are other factors which enter into the
total pull of a loaded vehicle.

Axle Friction.

A certain amount of power is required to cause the wheels to
revolve upon the axles, or in case of sleds, power is required to
cause the runners to slip upon the snow or ice.

The amount of axle friction is generally from five to ten per
cent of the total pull of a vehicle when running upon a level road.
Rolling Friction.

What really causes by far the greater part of the draft of ve-
hicles, is the fact that the wheels actually crush into the surface
of the earth and thus as they proceed they keep smashing down
the earth in front of the wheels. In general rolling friction ac-
counts for about 90 per cent to 95 per cent of the total draft of
vehicles on level roads.

T Tt J^

Plate 2. Figure 1 represents lightly loaded wagon wheel running upon a
hard road. Figure 2 represents heavily loaded wagon wheel running upon
a soft level road. Figure 3 represents a heavily loaded wheel running up
a steep grade upon a soft road. Notice the marked increase in "rolling
resistance" shown of 2 over 1 and added to the rolling resistance of 2 we find
grade resistance in 3.

Of course, on hard roads the axle friction remains nearly the
same, while the rolling friction decreases. Thus the per cent of the
axle friction is greater on hard roads and smaller on soft roads,

FARM ENGINEERING 9

while the total draft of the vehicles is smaller on hard roads and
greater on soft roads.

This explains the fact that a good team often has great diffi-
culty in moving a two-ton load over a soft earth road, while an
equally good team can easily haul a four or five ton load over a
hard paved street.

Now when the student realizes that the axle friction and the
rolling friction do not diminish when a vehicle is drawn up a grade,
he will readily understand why so much power is required in haul-
ing heavy loads over steep grades.

The following table gives approximately the draft of loaded
wagons over different types of roads.

Pull in pounds per ton of weight moved:

Good macadam road 75 to 110

Sandy road with hard bottom .150 to 200

Good hard earth road 75 to 150

Soft earth road 150 to 300

Plowed ground hard bottom 500 to 800

This may increase to nearly the weight of the load in case the
road becomes soft enough.

The student should understand clearly that nearly every type
of road offers a different rolling resistance. Hence, no exact data
can be given which can be used in all cases. And what is more,
the rolling resistance will vary in the same soil under different
climatic conditions.

Not only do we look to the grade resistance, the rolling resist-
ance, and the axle resistance to interfere with the progress of a
team, but the horses must lift their own weight at a disadvantage.
As the muscular effort of a horse while pulling is nearly all in the
hind legs and loin, the front of the horse is only of sufficient weight
to keep the front feet from leaving the ground. When the horse
attempts to pull up a steep grade, the front feet leave the ground
before his best effort can be made.

The same is true of traction engines. In many types of engines
there is great danger of the front end rising from the ground while
ascending steep grades.

Were it possible to select grades of any desired pitch the aver-
age engineer would probably select a grade of from one-tenth foot

10 FARM ENGINEERING

to one-half foot per hundred. This affords g-ood drainage and does
not increase the grade resistance to a point where it will become
troublesome. We find a great many long and troublesome hills
which have grades as steep as eight feet per hundred feet. Gener-
ally they are not considered serious impediments to traffic. A ten
per cent grade is generally considered practical if not too long. A
fifteen to twenty per cent grade should never be tolerated in a ton-
nage road unless the length of pull can be restricted to less than
100 yards. In such cases it is usually possible to reduce the grade
by cut and fill or by making the road to follow a contour around
the hill.

Grades of fifteen to twenty per cent are not only hard to ascend
but they are very dangerous of descent as well.

However, in mountainous parts of the country we find roads
in which grades as steep as twenty per cent are not infrequent.
In such localities vehicles are usually of stronger construction
than those used upon the more nearly level roads.

We have the "mountain wagon" in place of the surrey, and the
"mountain gear" in place of the lighter "valley gear" in our lumber
wagons.

Special automobiles with low gears suitable for mountain roads
are now furnished by many companies.

Traction engines, as a rule, have no trouble in ascending grades
too steep for travel by horses which are pulling heavy loads.

Regarding the descent of steep grades in mountainous sections
of the country, each vehicle, even to the lightest buggy, is equipped
with a powerful brake. The sleds are equipped with "rough-locks"
and of course the traction engines and automobiles have the reverse
gear as a last resort in case the brakes do not serve the purpose.
The above facts are not intended as excuses for extremely
steep grades in mountain roads. The engineering is faulty, but in
many cases the roads do not carry sufficient tonnage to warrant cut-
ting the grades at great expense.

Width of Highways.

In general the width of highways is determined by the laws
of the state rather than by the judgment of the engineer. Many
states require the highway to be 66 feet or 4 rods wide between
fences.

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In a great majority of cases the roads need not be this wide.
The actual graded surface is nearly always decided by the highway
engineer. While many roads of little importance are built from
20 to 24 feet wide it is a general practice to use about 30 to 34 feet

Plate 3. "Four-wheeled drive" tractor ascending 64 per cent, grade. In
general, tractors have little difficulty in climbing a steep hill which affords
a good foothold or grip.

for the graded portion. That is, from the center of one ditch to the
center of the other. The matter of width must be left to the judg-
ment of the engineer.

Crown of the Road Surface.

In order that moisture may be made to run off the traveled
portion of a road the center is usually raised higher than the sides.
The height of the crown above the bottom of the side ditches varies
from 4 to 18 inches. From 5 inches in a narrow road to 10 inches
in a wide road is considered good practice for earth roads.

The crown should be rounding, not sharp, and the side ditches
should have slanting sides. Nature tends to destroy the sharp
angles of earth surfaces and the sharp banks of a road ditch are
no exception to the rule.

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Besides the natural agencies which tend to cave in the banks,
we also have a very great action from animals and vehicles. By
smashing the sharp banks into the ditch they fill up that portion
wherein the drainage water should move freely. Thus, the sharp
banks prove very faulty in road construction. The rounded ditches
with sloping banks are little harder to make and serve the purpose
much better. In every case in which the slope of the land is not
excessive the dirt which is used to make the crown of the road

Plate 4. In the case of Fig. 1, Plate 4, the side ditches have sharp angles
at a and a. Such ditches soon crumble in and become useless. In Fig 2,
Plate 4, we see sloping ditches at b and b. These sloping ditches remain
in good condition for a long time. They do not hinder the dragging or the
grading of the road.

should be equal in quantity to that removed from the ditches.
Thus, no dirt need be moved lengthwise upon the road. In other
words the cut in the ditches equals the fill of the crown.

Drainage of Roads.

One of the serious factors which must be considered by the
highway engineer is the drainage of roads.

It is not a hard matter to keep roads reasonably dry during
favorable seasons of the year by having properly constructed side
ditches. Many people attempt to drain roads by putting tile drains
under the middle of the road's crown. The ditch which is dug for
the tile drain usually proves troublesome for several years. And
as it becomes hard, packed and puddled, the efficiency of the tile is
diminished. As a matter of fact the real efficiency of such a tile
is never very high.

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If the tile be placed under one or both of the side ditches the
results are much better. This is true for two reasons.

1st. The crown of the road tends to cause the surface water
to run to the side ditches where it soaks directly down to the tile
drain.

Plate 5. In Fig. 1, Plate 5, is shown a useless attempt to drain a road by
means of a tile running in the center of the road. As the soil is puddled and
as the center of the road is high, the water must run to the side ditch and
soak through the ground to the tile. In Fig. 2, Plate 5, we see a tile
placed under side ditch where the water can easily reach it. The auxiliary
open ditch "x" and the tile "z" are sometimes used to cut off washing and
seepage on side hills. The open drain "x" is very valuable for catching
the wash of severe rains while the tile "z" serves to drain the soil in case
the side hill has wet seepy spots or springs in it.

2nd. Because the earth in the ditches is not packed so hard
as the earth on the crown of the road.

In case of side hills it is well to do all the tile draining on the
Upper side of the road. This prevents water from rushing upon the
crown of the road during the heavy rains and it also prevents see-
page water from keeping the surface of the road wet between rains.

A large ditch near the fence on the upper side of the road often

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proves of great value, as it catches flood waters which come down
from the adjoining hillside.

In case of wet, seepy, or springy hillsides a tile drain laid along
the upper fence often intercepts the flow of ground water and thus
keeps the road dry..

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Plate 6. A little scientific road drainage would have prevented this con-
dition of the road shown in the plate.

In rare cases it becomes necessary to secure permission to put
drains into adjoining fields in order to keep roads dry, but this is
seldom the- case.

Culverts.

"Where does all this drainage water, of which we have been
speaking, go to?" we ask.

In each locality there is a general drainage system that must
be made use of. A creek, a branch of a river or, perhaps a river.
The drainage water must be conducted to some such outlet.

In case the road crosses a low spot or an undrained marsh,
it is usually advisable to build an embankment upon which the road
may be located.

FARM ENGINEERING 15

It often pays to investigate the nature of the soil beneath these
sink holes. If "hard pan" or an impervious layer of clay is found
a few feet below the surface and below this "hard pan" a layer of
gravel, or loose earth is located, it is often possible to "shoot the
hard pan" with dynamite and thus allow the drainage water to seep
down into the subsurface soil and flow away.

In draining a piece of road in this way the engineer often
drains much valuable land by the road side. In many cases it is
better practice to build a road around a swamp rather than to dyke
it. The land is seldom very valuable in the neighborhood of a
swamp, and the road bed is cheaper and often far more satisfactory
when located on the banks about the swamp. It is always advisable
to place culverts under the roads which traverse low swaxnpy
ground. While there may be no apparent movement of water in
the swamp yet rains and seepage are likely to cause water moxe-
ments from one side to the other. Thus, the culvert often sa\xs
washouts and much trouble.

Culverts.

The side ditches or the tile drains bring the water down the
grades of a road to the lower places. It often becomes necessary
to conduct the water from one side of the road to the other. This
is done by means of culverts. A culvert is simply a small bridge
It must be sufficiently strong to carry the heaviest loads, and suffi-
ciently large to carry the water from one side of the road to the
other without allowing any of the water to flow across the road bed.

Culverts are made of various materials.

1st. Stone culverts are of two general types.

A. The box culvert which consists of two parallel walls built
across the road. On top of these and reaching from one wall to
the other large flat stones are laid. The whole is covered with dirt
and the culvert is complete. These culverts are "laid up dry" (that
is, without mortar), with lime mortar, or cement mortar. The latter
is by far the best of the three types.

B. The arch culvert consists of two walls which are put par-
allel to each other at the base and the tops are so laid as to form
nearly a semi-circle at the top. There are many t3^pes of arches
but they all embody the one principle. Each stone is so laid that
it resists compression stress, and not bending stress.

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As in the case of the box culvert the arches are laid "dry", with
lime mortar, or with cement mortar. When it comes to carrying
heavy traction engines the arch usually proves superior to the box
type of stone culvert, as these heavy motors often exert a pressure
of many tons upon one "lug" or "grouter". If this stress be exerted
upon the middle of one of the flat stones of a box culvert, there is
likely to be a smashed culvert. While stone is very strong in com-

Plate 7. In Plate 7, Fig. 1, is shown section of stone box culvert. Notice
that the top stone acts as a common beam; Fig. 2 is a section of an arch
culvert or stone repression; Fig. 3 a box concrete culvert; Fig. 4 an arch
concrete culvert; Fig. 5 a monolithic round culvert made without the use
of regular outside forms. In the cases of 1, 2, 3 and 4 the side walls have
footings and the bed of the stream is covered with stones to prevent
washing.

pression it is not very strong or very reliable when subjected to
bending stresses. For this reason the arch culvert is generally
more satisfactory than the box culvert.

Concrete Culverts.

One of the most satisfactory materials for the building of cul-
verts is concrete. It is easily made in the right shape, it is not ex-
tremely expensive and it is probably the most durable material now
available for culverts.

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Types of Concrete Culverts.

The box type of culvert has met with favor in some sections.
The side walls usually have an extension or "footing" at the bottom.
The top must be heavily reinforced in order to prevent it from
breaking- down. The heavy slab of concrete which forms the top
has bars extending from side to side of the culvert, cast into the
concrete. The bars are usually about one inch to one and one-half
inches from the lower surface of the slab. Thus, the iron bars' pull
and the concrete material at the top of the slab must take on equal
stress in compression.

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Plate 8. In Plate 8, Fig. 6, we see a section of a plank box culvert. The
plank needs but to be split to render the culvert worthless. Fig. 7 shows
how cross timbers may be mortised into the side planks in order to give
the top plank support from beneath. Fig. 8 shows how the top and bottom
planks may be cut into three pieces and laid across the culvert. This, is
the best of the three types but at that, it is a rather short-lived culvert.
Fig. 9 is a tile culvert with bell and tile. Fig. 10 is a corrugated sheet steel
culvert. Fig. 11 is a cast iron or sheet steel arch. Notice that all of these
culverts are placed well down beneath the surface of the road.

A far more popular culvert is the concrete arch. The material
is so placed that each part is in compression. In theory, the smaller
arches do not require reinforcement, but in actual practice it is a
good plan to reinforce the work throughout with steel reinforcing
bars or with heavy woven wire fence. Such fence as "The Electric
Weld" and the "Page" fence give 'excellent results when used as
reinforcing material for small arches.

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Probably the cheapest, the most easily made and one of the
most satisfactory concrete culverts is the round monolithic culvert.
This is a culvert of one piece of concrete. In most cases the ground
is prepared, and a heavy layer of concrete is thrown into the trench,
the form, v^hich is nothing more than a round, collapsible sheet-iron
tube, is then laid upon the fresh concrete. The concrete is placed
about the sides of the mold and over the top. In a few days the
concrete sets, and by some patent device the mold is made to be-
come smaller in diameter. It is then withdrawn and earth is placed
over the culvert. Such culverts should be reinforced with rods or
woven wire.

All cement culverts should be coated with neat cement (pure
cement) mixed in water. Some call this material "cement paint",
"cement whitewash" or "cement wash". It is applied with a brush
and it renders the surface of the work water-proof.

Small Wooden Culverts.

For a great many years wooden culverts were more popular
than any other type. This is no doubt due to the fact that they
were cheap and quickly constructed.

In case of the box culvert a common system is to spike four

' i^A.

Plate 9. The large culvert or bridge shown in this plate had poor wooden
wing walls which allowed the water to leak through and wash out the dirt
back of the side walls. The "cave-in" came at the first heavy rain after
the installation. Proper wing-walls and a proper tamping and puddling of
the soil back of the side walls, would have made a good job out of a bad one.

FARM ENGINEERING

planks together in such a way that one plank lies upon the earth,
two others set upon edge, rest Lipon the first plank and form the
sides of the culvert. Another is then laid upon the two side planks
in such a manner as to form a top. Now all that is necessary to
break down such a culvert is to split the top plank. The weight of
traction engines will do this regularly unless there be plenty of
dirt over the culvert.

In some cases heavy hard wood cross pieces are laid under the
upper plank and mortised into the side planks. This improves the
culvert about 100 per cent.

A still better system is- to cut the top and bottom planks into
short pieces and lay them crosswise on the ground for the bottom
and on top of the side planks for the top.

All the above mentioned wood culverts are all right when new
if they be properly made and set. But when they become slightly
rotted, they are poor excuses for culverts.

Large Wooden Culverts.

In the building of the larger types of wood culverts it is com-
mon to drive posts or piles into the creek bottom. Planks are then

••«jA«i^

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Plate 10. An arch culvert and wings made in one piece (monolithic) of
concrete. When the workmen are ready to remove the inside forms, they
will move the lower cross beam after which they can remove the sides and
top of the arched form.

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spiked to these piles on the outsides and some wooden stringers are
placed upon the tops of the piles. Planks are then laid upon the
stringers and after the earth work is filled in against the sides of
the bridge it is complete. It is much better to substitute two or
three of the round concrete culverts placed side by side for these
larger wooden culverts.

It is quite possible to so build the two or three monolithic cul-
verts that they are all made of one large piece of reinforced con-
crete. Such a culvert does not wash out easily and it will last a
life time.

Steel and Iron Culverts.

It has become common of late years to substitute a piece of
"corrugated steel pipe" for the concrete or stone culvert. The price

Plate 11. A very large corrugated steel culvert installed under a high fill.
Notice the very heavy retaining wheel.

of these steel culverts is reasonable and they are easy to locate.
They last a long time when properly made and galvanized. A good
method of setting such a culvert is to build the wings of concrete
and to cover the entire iron culvert with concrete. Such a com-
bination makes a good culvert after the iron has rusted out.

Many tjq^es of steel and cast iron arch culverts are now on the

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market. When properly set they give excellent satisfaction, but it
too often happens that the}^ are not given a good foundation. Thus,
eventually they warp and in some cases give away. It is a good
plan to cover such an arch with a heavy wall of concrete. Thus
you will get a concrete backing to the sheet metal.

Plate 12. A cast-iron sectional culvert in process of erection. Notice that
a metal wing-wall and a metal bottom are provided.

Tile Culverts.

Culverts are often built of tiles. These tiles are sufficiently
large and strong to carry the weight of all types of vehicles and
motors. The proper setting is absolutely necessary if tile culverts
are to be successful. This is taken up more fully under "setting of
culverts."

Perhaps the poorest kind of tile for culverts is the red, unglazed
clay tile. As this t3^pe readily absorbs water it is very likely to
disintegrate when subjected to freezing and thawing. Concrete
tile, when made porous, is also inclined to disintegrate in the same
manner as unglazed clay tile. Well glazed "bell end" clay tile are
very satisfactory for culverts, as are water-proof cement tile.

Cast iron tile are now being used extensively by railroads and
they make a most excellent culvert.

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SETTING CULVERTS

It is one thing to select a good type of culvert, and it is very
decidedly another thing to set it as it should be set.

The author has ample opportunity to study poor methods of
setting culverts and in most cases the opportunities are less wel-
come than instructive. A few of the most common faults are :

1. Wrong location.

2. Culvert too small.

3.« Culvert not set deep enough.

4. Culvert not protected by wings.

5. Culvert not properly tamped and puddled when set.

'**j>**.ii^«*S#^^^

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Plate 13, The culvert shown in Plate 13 was not protected by wing-walls.
It was not tamped or puddled on the sides. A few days after the photo
was taken, it was washed out and down stream.

Wrong Location.

It would seem rather foolish to lay down a law requiring road
commissioners to place the culverts where the water could flow
through them, yet we often find culverts so far up on the side of a
hill that the water must seep through or run over the road way,
or else run up hill to get to the culvert. This trouble is usually due
to some so-called practical man "using his eye" to locate the lowest
point in the hollow or ravine. The use of a level would eradicate
the difficulty. It is needless to say that drainage culverts should

FARM ENGINEERING 23

be placed so that drainage water will flow to and through them.
Irrigation ditch culverts must be placed at such points as will pre-
serve the proper grades of the ditches. Thus, in some parts of the
country we find nearly all the irrigation ditch culverts on the high-
est parts of the roads.

Culvert Too Small.

It is a foolish custom among some road supervisors to choose
a size of culvert and use it regardless of the amount of water it
must carry. It is next to impossible to tell an engineer how large
a culvert should be, because of the fact that the culvert must carry
floods. Whenever possible it is well to measure the sectional area
of a stream at its highest flood and then design the culvert to carry
from one and one-half to two times the amount.

By using this method it is often found necessary to use cul-
verts which seem very large, but when such a culvert is once
installed properly it eradicates future trouble once for all.

To determine the cross section of a flood stream it is not neces-
sary to get into the water during the flood. Simply mark the points
to which the water reaches upon the banks, then after the flood
subsides, determine by level how deep the water was. Then the
width of the stream at the flood time may be determined with a
tape and the approximate number of square feet of its cross section
may be determined.

It is often possible to get from some neighbor a rather accurate
statement of how far the stream overflows its banks at flood time.
From this a fair estimate can be obtained of the cross section of
the stream.

The cross section should be determined at or near the location
of the new culvert, otherwise it is of little use. After the area is
determined the size of the culvert may be determined. For rect-
angular box culverts the approximate height may be assumed and
the cross section area divided by the height will give the width.
Now if an allowance of one and one-half is used, simply add one-
half the width of the culvert to its computed width and the result
will be the actual width of the culvert. In case an allowance of
twice the cross section is used, simply multiply the cross section
of the stream at flood by two and divide by the height of the cul-
vert. In C3,se of round culverts, the cross 3ection area should first

34 FARM, ENGINEERING

be divided by three and one-seventh. By extracting the square foot
of the ansv^er, v^e get the radius, or one-half the diameter of the
culvert.

In case the round culvert would be too large, the cross section
may be divided into tvv^o, or three parts and the culverts may be
laid side by side.

In case of arch culverts all that is necessary is to consider that
portion of the cross section w^hicli has parallel vv^alls as a rectangle
and the arched portion as a semi-circle. The sum of the areas of
the semi-circle and the rectangle w^ill be the total area of the cul-
vert.

Plate 14. In Plate 14, we see a cross section of a culvert Avhich was not
placed deep enough to be satisfactory. Notice that the top of the opening
is far above the low spots in the road as indicated by the dotted line. The
top plank is exposed to traffic. The top of the culvert should have been
lower than the dotted line.

Not all arches are semi-circles but the result will be near
enough for satisfactory results in case of culverts.

Culverts not set deep enough.

Many people fail to place culverts low enough in the ground
to allow the water to run through the culvert without passing over
the road bed. This is poor practice. In case of a deep fill it is gen-
erally good practice to put the culvert at the bottom of the em-
bankment so that no water is allowed to collect on the upper side
of the embankment.

Culvert Not Protected by Wings.

It is good practice to protect the culvert by "retaining walls"
or wings at both fhe upper and lower ends. These wings should be
nearly water tight, in order to prevent the water running in and cut-
ting away the earth at the sides of the culvert. It is well to have
the wings extend at an angle up the stream at the upper end and
down stream on the lower end of the culvert. Reinforced concrete
walls, eight or ten inches thick make very satisfactory retaining

FARM ENGINEERING

walls for small culverts. They should have a solid foundation and
be well backed by thoroughly tamped earth. Culverts which are

Plate 15. Corrugated steel culvert with concrete wing walls. The water
gets no chance to strike the embankment as the walls guide it into the
culvert. A very good installation.

not provided with wings or retaining walls are very likely to be
washed out by floods. In case of large or deep culverts the retain-
ing wall should always be surmounted by a guard wall or railing,

Plate 16. A corrugated steel culvert being poorly installed. Notice the
lack of wing walls. The large clods are being dumped loosely about the
pujivert. The first heavy rain wjll prpbably wash out the isulvert.

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to prevent teams from attempting to cross the ditch rather than
the culvert.

Culvert Not Tamped and Puddled.

It is a bad practice to dump loose dry earth in beside a culvert
by means of a scraper or shovel unless the earth be thoroughly
tamped. It is better not only to tamp the earth but to wet it as
well. This "puddles" the soil and when it dries it becomes hard
and solid, not hard and loose.

Plate 17. A corrugated steel culvert being properly installed. The concrete
wing walls are in place and the earth is being tamped and puddled as it is
filled in.

The dry, loose earth crumbles away easily when subjected to
the action of running water, while the hard tamped puddled earth
resists the action of the water. The lack of thorough tamping and
puddling of the soil about the culverts often explains why they
wash out at every heavy flood.

PAku engineIering

Plate 18. An arch culvert made by the use of a patent steel form. The log
which is shown at the right should not be allowed to remain as it will serve
to allow water to cut its way along the side of the culvert. Unless this
grade is built higher, the culvert will be subjected to great strains from
passiirg engines.

SURFACES OF ROADS

Now that we have taken up the subject of road drainage let
us consider the matter of tlie road's surface. A road- surface must
have several qualities in order to be considered good.

1st. It must be hard enough to prevent the wheels of passing
vehicles and motors from cutting into it.

2nd. It must be of such a nature as to furnish a "foot-hold"
or "grip" for animals and motors.

3rd. It must be as nearly dustless as possible.

4th. It must be tough enough that it will not crumble under
heavy traffic.

5th. It must shed water and dry off quickly after rains.

6th. It must be of such a nature that freezing and thawing
will not ruin it.

7th. It must not be too expensive.

The student will realize at once that such a road surface is
rather hard to Und, and as matter of fact; the soil of each locality

FARM ENGINEERING

is to a greater or less extent responsible for the type of road surface
found there. This is true because the cost of putting on some other
type or road surface is, in a great many cases, too expensive.

Earth Roads.

In the building of an earth road after it has been laid out and
the part to be graded has been staked out, it is common to use what
is known as a "reversible grader." That is, a grader with a blade
which can be set to throw the earth to either side. If the soil is
hard and tough several furrows may be plowed on the lines
where the ditches will be. Then with the grader the earth is moved
toward the center of the road until the proper crown is obtained.
The graders should be driven along the road and not across it. The
blade, when set on an angle of about forty-five degrees, pushes the
earth sidewise and thus, by repeated operations lands it at or near
the center of the road.

Plate 20. A gasoline road roller rolling a road as it is being graded by
reversible gTader. This is an- excellent sclieme for making a hard well-
packed road.

The road should then be rolled with a heavy roller. Few of the
horse drawn rollers are heavy enough to accomplish the desired

F'ARM ENGIN^EklMd

result. A ten to fourteen ton steam roller is very satisfactory. If
the soil is, moist at the time of rolling, so much the better.

In case of high grades with deep side ditches, an elevator
grader is often used. This type of machine is equipped with a plow
which throws the earth upon a moving apron. The apron carries
the earth up to the desired height and deposits it upon the bank.
It is later levelled to its proper position by the reversible grader.
Such a bank should be rolled, and packed thoroughly before it is
put into service as a road. Otherwise "pot holes" or "chuck holes"
are likely to form within a few days.

Plate 21. An elevator grader or "excavator". This machine is equipped
v\^ith push-cart to which four horses are hitched. Such a machine attached
to a good traction engine makes a very good rig for rapid excavation.

The elevator grader if often used for the purpose of loading
dump wagons when the earth must be moved some distance as in
the making of cuts and fills.

Cuts and Fills.

In case it becomes necessary to cut down a portion of a hill in
order to give a road the proper grade, it is usually found advisable
to move the earth to the adjoining low spot in the road and thus
make what is known as a fill. In this way less earth needs to be
moved.

ParU engineering^ §i

In case but little earth needs to be moved "slip scrapers" are
Used. These little scrapers are so common that they need no des-
cription.

Plate 22. Fig. 1 shows longitudinal section of road through a hill. The.
dark-shaded portions are fill and the light-shaded portion is cut. By hauling
dirt from a cut to the low places and thus making the fills the amount of
labor was greatly lessened; Fig. 2 is a cross section of the cut showing
banks with 1 to 1 slope; Fig. 3 is section of fill with banks made 2 to 1
(8 to 4) slope. Note: The longitudinal section is not made to the same
scale as the two cross sections.

For hauls of a hundred feet or more it is common to use wheel
scrapers or "wheelers". These scrapers are provided with wheels
and are so designed that after the scraper has been filled with
earth it is raised clear of the ground by means of a lever. It is then
hauled to the desired location and dumped much the same as the
slip scraper. . i ; * I

For long hauls, and for rapid work an elevator grader drawn by
a traction engine and several dump wagons drawn by horses make
an ideal outfit.

Only the best of traction engineers and expert elevator grader
men should be employed on such an outfit, as a few hours lost in
"tinkering" means a great loss of time and money.

The side banks of a cut should not be left perpendicular as such
banks crumble in, and fill up the side ditches. The slope should be
at least "one to one". That is, they should recede one foot to each
foot in height.

Fills should slope about one and one-half to one or two to one.
This is, they should recede one and one-half or two feet to each foot
of rise. The earth work is usually figured in cubic yards of earth
moved. Prices vary with the kind of earth, the length of haul, and
local prices of labor, etc.

3^ FARM ENGINEERINC^

In case of hard earth, or rock, dynamite proves to be a very
cheap and efficient excavator.

Maintenance of Earth Roads.

The best method of caring for or maintaining the earth road is
by the use of the King drag or some other implement of like nature.

The drag consists of two planks, each about six or seven feet
long, these planks set upon edge and are dragged along the road,
thus acting as a pair of scrapers, one following the other. The rear

Plate 23. Front view of a home-made King drag. The lower planks are
3"x8"x6'; top planks are 2"xl0"x4'.

plank is about three feet behind the front one. The hitch is so ar-
ranged that the end of the drag nearer the center of the road is
behind the outer end. Thus, the loose earth is moved toward the
middle of the road. The right time to use a King drag is just as the
mud is beginning to dry enough to harden. When the mud is thin
and soft the drag does little good, and when the earth is dry and
hard it does little or no good.

The King drag, when properly used : Fills the ruts, maintains
the crown, keeps the side ditches open, and so puddles and packs
the soil as to give a hard, firm, even road surface.

In many rural communities each farmer drags that portion of
the road which adjoins his farm. Such public spirit is commend-
able, and profitable as well. For we must remember that "A com-
munity is judged by the quality of its roads." Good roads indicate
that the community is up-to-date, prosperous and intelligent; bad
roads indicate that the opposite conditions prevail.

Stone Roads.

For centuries it has been the custom to build roads with stone
gurf^cesr Many roads were built with the surfaces of larp fi9,t

FARM ENGINEERING

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34 FARM ENGINEERING

stones. Such roads are unsatisfactory for the following reasons :

They do not allow the horses' feet to secure a good grip.

When wet or muddy the stones are very slippery.

Such a road is very expensive.

When smaller stones are properly set they make an excellent
paving for city streets, but this system of road making is rarely
found in country districts in the United States.

Macadam Roads.

The term macadam applies to broken stone roads which are
prepared by putting a thick layer (10 or 12 inches) of broken stone
on the earth surface of the road. This may be rolled in by steam
or gasoline rollers or left to be rolled down by traffic. Such roads
are readily destroyed by a combination of team and automobile
traffic. The maintenance of such a road under both team and auto
traffic is a hard proposition and a most expensive one.

Telford Roads.

In case of Telford roads a layer of large rough stones is laid
in the bottom of the traveled portion of the road. On these a four-
inch layer of crushed stones is placed and rolled in by roller or by
traffic. This layer is in turn covered by a layer of fine broken stones
which is rolled into the coarser bottom material.

The macadam and Telford roads, when made of a good tough
wear-resisting stone are very good for roads which have team
traffic only. They wear well and the slow-moving vehicles roll
the material, thus making it hard and firm. But when the auto
with its soft tire speeds over the road at 35 to 50 miles an hour,
the maintenance of one of these roads becomes a puzzling matter
for the best of highway engineers.

NEW TYPES OF ROADS.

Had this book been written ten years ago many pages would
have been taken up in minute directions for the building of stone
roads, but since the advent of the automobile the subject of hard
road surfaces is a matter for experiment.

Some authorities took to petroleum which has an asphalt base,
as the solution of the problem. This asphalt is worked into an
earth road and then rolled. It gives a hard, smooth surface which
is impervious to water. It do^s not allow larg^e ruts to form, and

FARM ENGINEERING 35

there is little or no loose dirt for the auto wheels to kick into the
adjoining fields. Other authorities believe that the coming road
will be made of concrete.

Some new materials are now being used which form a soft

Plate 25. A type of commercial pavement which the company claims will
•yyithstand teani and ^utoniobile traffic,

36 FARM ENGINEERING

road surface that is water-proof and nearly dustless. They are, as
a rule, very expensive.

Some companies now use asphalt, tar, and other materials for
the holding- of crushed stone in place. These are known as bitu-
minous concretes, or' bitrolithic pavements. They are very ex-
pensive and should be cautiously experimented with. Of one thing-
we are certain and that is that we have the Question of a good,
cheap, and satisfactory combination tonnage and auto road to solve.'
We now have good roads which are very expensive, and cheap
roads which are not good.

With the best efforts of our high grade highway engineers
concentrated upon the subject, we should look for pretty positive
results within the next decade. In the meantime let us make tlie
best possible earth roads by careful attention to grading, draining
and dragging them.

Bridges are now as much a commercial article as are engines,
or road graders, so that in deciding upon a type of bridge the engin-
eer needs but to ascertain the length and width of the bridge which
is needed, and submit the specifications of length, width and maxi-
mum load to the bridge building firms for bids. These compani?-
have standard designs which fit nearly ever}^ recjuirement, and as
they make and erect the bridges on a large scale they are, as a rule,
able to underbid any small contractor.

The subject of bridge selection and bridge design should be
left to an engineer who devotes his whole attention to the subject
of bridges.

The day of wooden bridges is past. It is now a matter of steel
or concrete, with here and there a stone arch.

All modern highway bridges should be able to carry a moving
load of twenty-five tons with safety.

ROAD MACHINERY.

A few special points will be taken up under this head although
many of the more important points have been brought out in prev-
ious paragraphs.

Slip Scrapers.

One of the simplest of road machines is the slip scraper. It
has been defined as a "horse scoop." The scraper should be pro-

FARM ENGINEERmG 37

vided with strong, smooth, wood handles, a rigid steel bail with
swivel, and a pair of steel runners on the bottom of the scraper.
The slip is suitable for moving earth short distances. It should
not be used where a reversible grader can be made to operate.

Wheel Scrapers.

Wheel scrapers should be strongly and simply built. The
tongue of the scraper should be provided with a loop or hook to
which the "snap team" or "helper" may be attached during the
loading. It often happens that two horses can, with little effort,
haul a load of earth, which requires the best efforts of four horses
to load.

The wheels of wheel scrapers are often made too light. One
should always see to it that the scrapers are provided with strong
wheels.

Wheel scrapers are often used in hauling earth from one hun-
dred feet to several hundred yards.

Buck Scrapers.

Buck scrapers are much like slip scrapers except that they
have greater width, and they are provided with shoes, so that as
they turn over in dumping, they scatter the earth over considerable
area instead of dumping it in a pile.

Reversible Graders.

A good reversible grader has many adjustments which should
be easily made by the operator. A seat is usually provided at the
front of the grader for two drivers.

The rear wheels should be mounted on extension axles so that
the wheels may be set out to one side or drawn in near the grader.
By this means the wheels are adjusted so that they always run on
hard ground. The blade should be adjustable so that it may be
made to throw earth to either side.

The two ends of the blade should be supplied with separate
adjustments so that they may be raised or lowered at will.

Many other adjustments are found on up-to-date graders,
but the above are the principal ones. The grader should be strong-
ly built of steel.

The Elevator Grader (Excavator).

The elevator grader requires a very great tractive effort in

Farm engineering

order to keep moving. For this reason we find that many of the
best makes have push carts attached to the rear of the machine.
From six to ten horses are attached in front and four or six are
attached behind. The rear driver simply guides his horses by
means of a w^heel which controls the direction of the travel of the
cart wheels. The plow of the elevator should be very strong and
well braced. The conveyor is usually made of a wide piece of
rubber belting. The carrier or conveyor should be adjustable at all
points. All bearings should be as nearly dust-proof as possible.
The bearings should be equipped with hard oiling devices.

The Grader Hitch.

When traction engines are used to draw reversible or elevator
graders an adjustable hitch should be used, by means of such a
hitch the grader may be steered separately, without it following
directly behind the engine.

•^r^1\'

>"^ss:^

Plate 26. A good type of dump wagon showing how the bottom doors drop
down to discharge the load. Beside the wagon is a patent steel King drag.
It is equipped with lever by which the blades may be set at any desired
angle. The picture also shows how not to store road machinery.

Dump Wagons.

Good dump wagons are now being built by many companies.
The front wheels should be so hung that they can turn at an angle
of at least ninety degrees to the body. This makes short turns pos-

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44 FARM ENGINEERING

sible. The rear wheels and axle should be very strong as they must
carry most of the load. The dumping boards or doors should be
so hung that they may be let down slowly, for it often happens that
it is desirable to allow the load to sift out over considerable area,
rather than to have it all dumped in a pile.

Road Rollers.

In general, road rollers are of two types, steam and gasoline.
Steam rollers give good service, but vv^ater and coal must be hauled
to them, and in many states a licensed engineer must be hired.
The wheels should have flat tires so made that spikes or "grouters"
may be attached in case of heavy pulls, or in case it is necessary to
"roughen up" an old piece of road. This is often done when a road
surface is being refinished. The rollers should be provided with a
differential or compensating gear so as to make the drive wheels
each pull an equal amount, both on straight roads and on curves.

Gasoline or kerosene engines are now mounted on forms and
are made to act as road rollers. When they are built sufficiently
strong and heavy they make excellent rollers. They may also be
used to operate stone crushers when standing in the belt.

Portable Stone Crushers.

Some companies now build stone crushing plants which may
be moved from place to place, in the same way as threshing ma-
chines are moved. These machines are operated by traction en-
gines or road rollers. They give excellent results when they are
operated by competent men.

All road machinery should be stored in a closed shed. It should
have all bright parts greased when not in use.

FARM ENGINEERING 45

FARM ENGINEERING— PART III, A.

Farm Cement Work or Concrete Construction.

Each year sees the structures of the farms being made les:-- of
wood and other materials which do not possess the quahty of great
durability.

Concrete is rapidly taking the place of wood in our farm struc-
tures, and it is fitting that we. give the subject of concrete con-
strviction careful attention.

Cement.

We have two general classes of cement: Natural and Port-
land. In the natural cement the "cement rock" is used as it comes
from the earth. It is simply converted into cement by a baking and
grinding method. Now if the cement rock happens to be good the
resultant cement will be good, and if the rock is bad the cement will
also be bad. For this reason natural cement is generally considered
to be unreliable. It is, as a rule, slightly cheaper than Portland
cement. Portland cement is made of chemically analyzed rocks
mechanically mixed in chemically correct proportions. This ren-
ders the strength and setting qualities of good grades of Portland
cement very uniform.

(Some people foolishly believe that Portland cement is made
in Portland, Maine or Oregon. The name refers to the process, not
to the city where it is made.)

Setting of Cement.

When cement sets the powdered rock takes up its water of
crystallization and again becomes a stone. It adheres to the sand
or stone which it touches and then we get concrete. There are some
intricate chemical processes in the setting of cement, but if we re-
member that cement work must be kept moist while setting and
that the setting process continues for several weeks, w5 will have
the main part of the practical side of the process in hand.

Cement and Concrete.

When we speak of cement work we refer to a cement and sand
mixture which is free from gravel or broken stone. Thus, when we
say a post is made of a one, three mixture, we mean that one part

FARM ENGINEERING

FARM ENGINEERING 4t

by measure of cement has been added to three equal parts of sand.
In speaking of concrete we refer to the mixture as 1, 2, 2 or 1, 2^,
2^, or 1, 3, 3, etc. Thus, we mean that one part of cement has
been added to two parts of sand and two parts of stone (all propor-
tions by measure, not by weight.)

Thus the first number indicates cement, the second sand, and
the third gravel or broken stone.

Sand.

Sand for good cement or concrete work should be free from
dirt, sticks, leaves, etc. It should have sharp angular grains, not
smooth rounded particles.

Gravel.

Gravel should be clean and angular. Smooth glassy pebbles
usually make poor concrete.

Broken Stone.

Crushed stone is generally much better for concrete than
gravel, as the particles are rough and freshly broken the cement
gets a better grip on them than on smooth gravel.

Proportion to Use.

Neat Cement is used for the purpose of giving water-proof
coatings to cement or concrete work. Neat cement is pure cement
as it comes from the sack. It is mixed with water and applied as
a paint or wash to the surfaces of walls, etc., for the purpose of
filling the pores of the cement or concrete. It does the work very
well when properly applied.

A 1-3 mixture is a very rich mixture. It is used for the purpose
of making cement fence posts, and for top-coating cement floors,
sidewalks, etc.

A 1-4 mixture is used for the building of posts, troughs, side-
walks, floors, engine bases, sills, etc.

A 1-5 mixture is not very desirable as it could be greatly
strengthened by substituting some gravel or broken stone for part
of the sand.

A 1, 2, 2, mixture makes a very strong concrete, suitable for
almost any kind of work which requires a dense, hard concrete.

A 1, 21^, 2y2, mixture is also strong and hard. It is used for
the building of silos, walls, floors and side walks, but care should be

FARM ENGINEERING

taken to give the walks and floors a top dressing of 1-3 cement
mixrare. This top dressing should be from one-half to one inch
thick. It should be applied immediately after the body of the floor
is laid.

1, 3, 3 mixtures and 1, 3^, 3^ mixtures are often used for the
building of walls, blocks and side-walks, but it is a practice of
doubtful economy to use a mixture weaker than 1, 3, 3 for farm
purposes.

Mixing Cement or Concrete,

Proportioning. It is common to measure out the cement, sand
and gravel in boxes or pails, so as to get the right proportions.
Thus we use one box cement, three boxes sand and three boxes
gravel for a 1, 3, 3 mixture.

Now we do not get seven boxes of concrete, because the sand
settles in among the gravel, and the fine cement sifts in among the
sand and gravel. Thus when the setting is complete we get a
solid rock.

One aiithority has computed the amounts of cement, sand and
stone necessary to make a yard of rammed concrete as follows :

Mixtures

Aoiounts

-1.9

-a

atone
1 inch and under

2.(

4.0

2.5

5.0

3.0

5.0

Stone
2i inch and under

2.0

4.0

2.5

5 0

3.0

5.0)

□9

p»l

Clean
Materials

0.44

0.89

0.46

0.91

0.5]

0.86

Clean
Materials

0.45

0.91)

0.46

0 92

0.52

0.87

FARM ENGINEERING

Mixing.

Hand mixing- is very common in farm practice. The gravel
and sand are spread upon a large board platform and then the ce-

Plate 33. At the top is shown a home-made concrete mixer at work. The
engine is geared by jack-shaft and rope-belt to the square box. The right
amount of sand, cement and gravel is put in the box, the lid is put on, and
the box is then revolved. When the dry mixing is complete, the water is
added through the axle which is a pipe with perforated bottom. When
the wet mixing is complete, the clutch is released, the lid of the box is
loosened and raised to the position shown in the bottom picture. The con-
crete is then dumped by revolving box one-half turn. Two men can thor-
oughly mix a yard per hour with this simple machine, It costs about $6.00,

50 , FARM ENGINEERING

ment is spread over the pile of sand and gravel. The whole is "dry-
mixed" twice by shoveling from one part of the platform to the
other. Water is then added and the whole mass is wet mixed two
or three times by thoroughly shoveling it.
Machine Mixing.

Batch mixers are very popular because the right proportions
of cement, sand and gravel are thrown into a steel box, and this
is revolved until the material is thoroughly dry mixed. Then
water is added while the machine is in motion and the wet mixing
is done without trouble. The whole is then dumped to the floor
or to a waiting wheel-barrow.

Continuous Mixers.

Continuous mixers are so built that the right amounts of ce-
ment, sand and gravel are continually dropped into the mixing
drum or trough. The material is dry mixed at one end of the drum
or trough and as it is moved to the other end water is added.

Unless these mixers are used by careful workmen there is
likely to be an uneven proportioning of the mixture due to clogging
of one of the feeding devices.

Should the cement feed remain clogged for any great length of
time the resultant concrete would be a mixture of sand, gravel and
water. Thus a whole job of concrete work may be spoiled by one
minute's carelessness on the part of the operator.

Reinforced Concrete.

When concrete work is subjected to bending stresses, as in the
case of fence posts or beams the side of the member which is sub-
jected to tension should be reinforced with steel or iron wires or
roughened rods.

This is done because cement or concrete is very strong in com-
pression, but it is rather weak in tension.

For flat slabs such as the sides of tanks, arch culverts, etc.,
a piece of heavy woven wire fence makes excellent reinforcing
material.

For such pieces of work as fence posts, roller wheels, engine
bases, etc., barbed fence wire is very good.

In case a lot of old barbed wire is available, it is possible to
twist two or more strands together to make a rough, wire cable.
This, when twisted, is straight and strong.

FARM ENGINEERING 51

The twisting process is easily accomplished by twisting the
ends of wires about the spokes of a wagon wheel and the other
end to a post. Raise the wagon wheel from the ground and
turn it until the wires are tightly twisted into a cable. If the
wires are kept tight while the twisting is being done the resultant
cable will be straight, and therefore easily placed in any type of
cement or concrete work. Cables are often made as much as 200
to 300 feet long and then cut up into pieces of desired length. This
provides an excellent wa}'- of getting some desirable service out of
old barbed wire.
Dry Mixtures.

When we add but sufficient water to moisten the cement or
concrete we speak of it as a dry mixture. Such a mixture may be
tamped into a mold and the mold may be immediately removed.
While this is a desirable feature, yet it is more than offset by the
fact that such cement or concrete is nearly always very porous.

As these porous concretes permit water to soak through very
readily they are not very desirable for tanks, floors, etc. When
alkali is present in the water they are very readily destroyed, as
the alkali water gets all through the concrete and causes it to dis-
integrate.
Wet Mixture.

When sufficient water is added to concrete to cause it to flow
from the shovel like soft batter it is said to be a wet mixture. This
type of mixture forms a hard and dense concrete which will, when
properly made, be nearly water-proof.

As the wet mixture will not stand up when placed in the molds,
it becomes necessary to leave the molds in place for some time.
The molds may be removed as soon as the work is hard enough
to stand, but it is better to leave them on for a week at least.

As the wet mixture is being poured into the molds it is well to
move the large pebbles back from the sides of the molds by means
of a flat shovel or a crowder. The crowder is nothing more than
a large hoe with the goose neck straightened out.

As the shovel or crowder pushes back the large stones or
gravel, water carrying sand and cement rushes in between the wall
and the shovel. Thus a coating of cement and sand is given to
the concrete work. This improves its appearance and at the same
time renders it more nearly water-proof.

52 FARM ENGINEERING

Silos.

Silos are built of monolithic cement work, of monolithic con-
crete and of cement blocks. In all cases they must be strongly re-
inforced. See Atlas Portland Cement Bulletin.

Houses.

The foundations for houses are often made of solid concrete
while the portions of the walls above the foundation are made of
cement blocks, laid up like stones or bricks. Unless the blocks are
made of a rich mixture they absorb water readily. This often
causes the walls of cement houses to be damp and unhealthy.

Sidewalks.

In building- a side-walk we use about four inches of 1, 3, 3
mixture and put on a top dressing of about ^-2 inch of 1, 2 or 1, 3
mixture.

The side walk should be made in sections not more than five
feet long. The edge of one section should be greased with oil or
axle grease before the other section is laid. In this way the joint
forms a line of cleavage, or what is known as an "expansion joint."
This joint becomes small in summer as the walk expands, and wide
in winter when the walk contracts.

Concrete Floors.

The floors are made the same as walks but the blocks may be
as large as 10 feet square. ^ ,.j \

Plate 34. A very desirable hog trough can be made of cement. This trough
cost 90 cents and labor. The trough weighs about 450 pounds. It is need-
less to say that the hogs do not root it over.

FARM ENGINEERING

Fence Posts.

Strong durable fence posts can be made by the use of a wet
1-3 mixture in molds which make line posts not less than five inches
square and corner posts not less than eight inches square at the
ground line.

The line posts should be reinforced by two strands of barbed
wire in each corner while the corner posts should have not less than
six strands in each corner.

Pig Troughs.

Pig troughs should be made with the insides sloping outward
in order to make it easy for the pig to drink, and in order to pre-
vent the ice which may form in the trough from breaking the sides
of the trough. Pig troughs should be well reinforced.

Plate 35. A concrete watering trough made of 2, 2^, 2^. The mixture
was poured in the moulds and all coarse material worked back from the
surface by means of a grader. Sixteen pounds of reinforcing wire was used
in the tank. It stood filled with water for three seasons during winter
and summer. At times the mercury fell to 29 below zero, but the trough
showed no signs of giving way.. The inside walls of the tank slope out-
ward as they approach the top, thus preventing the ice from bursting them.

Large Troughs.

Large troughs, for cattle and horses may be made with walls
six or more inches thick at the top. The walls should become
thicker toward the bottom of the trough so that the inside of the
trough slopes outward toward the top. This prevents ice from

FARM ENGINEERING

breaking- the sides of the tank. The ends, sides and bottoms of all
tanks should be strongly reinforced. All sharp angles should be
rounded or filleted, as cement work usually cracks from some sharp
internal angfle.

mmMmim^ssmmm^SM^mmm

Plate 36. Cross section of a watering trough showing, "a", sloping internal
side walls; "b", filleted or rounded corners or angles; "c", the placing of
reinforcing wires. The large dots represent the ends of the side and bottom
wires. The position of the wires which reach from the top at one side
around the bottom and up to the top at the other side, is also shown.

Plate 37. Very desirable land rollers are now being made by casting cement
wheels in patent rims. The rims remain on the wheels and form a steel
tire for them. These rollers are heavy, but due to the fact that the weight
is in the wheels, they are not very hard to pull.

FARM ENGINEERING

Plate 38. Cement contractor's yard where cement tiles are being con-
structed by pouring the cement in tile moulds. These tiles are hard and
almost impervious to moisture.

The field of farm cement construction is spreading daily, and
the ingenious farmer may make nearly any of the farm buildings of
concrete if he but applies his ingenuity to the task.

Examination

Note to Student — These questions are to be answered inde-
pendently. Never consult the text after beginning your examina-
tion. Use thin white paper about 6x9 in. for the examination.
Number the answers the same as the questions, but never repeat
the question. Mail answers promptly when completed.

1 — Explain how the automobile affects the old types of road sur-
faces.

2 — What is axle friction of vehicles?

3 — Tell how the hardness of a road surface afifects the rolling
friction,

4 — Why is the pull required to move a vehicle not exactly propor-
tional to the grade?
5 — How may we drain roads which run along side hills?

56 FARM ENGINEERING

6 — Why is the "arch type" of stone or concrete culvert superior to

the "box type"?
7 — Of what use are wing walls when used with culverts?
8 — Tell how to set a corrugated steel culvert properly.
9 — What qualities must a road surface have if it is to be considered
as good?

10 — Tell how to grade a road with a reversible grader.

11 — Tell how and in what cases elevator graders are used.

12 — Tell under what conditions wheel scrapers are used.

13 — What is the object of rolling a new road surface?

14 — How heavy should a good road roller be?

15 — Why should the banks of cuts and fills be sloping?

16 — Tell how to maintain the surface of an earth road.

17 — What is a King drag? How is it used?

18 — What adjustments should we look for in a good reversible
grader?

19 — Tell some of the good points to be looked for in an up-to-date
road roller.

20 — What is Portland Cement?

21 — AVhat is meant by 1, 3 mixture?

22 — What is meant by a 1, 3, 3 mixture?

23 — What kind of sand and gravel should we select for concrete
work?

24 — Tell how to properly mix a batch of concrete.

25 — Tell how to build troughs in such shape as to prevent the freez-
ing of water in the trough from bursting it.

Write This at the End of Your Examination.

I hereby certify that the above questions were answered entirely
by me.

Signed

Address

B=ll— II 6)@ It— H=

gen IB

^ Correspondence College
of Agriculture

FARM ENGINEERING—PART ONE

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