LIBRARY OF THE MASSACHUSETTS AGRICULTURAL COLLEGE Source. 675 B6 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 COPYRIGHT. 1911 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 10 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, 12 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- 14 FARM ENGINEERING. ■ V - :l-'v- L'^ ,C C g aT ! i il il|*i ! i l ' !l : 'i |ilil ! „:;l'!:i! No:n'',';;;;;i;:ijv^' ■ "MM M lll'l'll '"' I ill' -. ;,'"i;;;;;|;;m;ii l""""*"'IHI"llll-''''"l'' '".2 " S o c c S =" is S g 3 S 1 " O O c m a o c 3 o -a ° ^MjiRr--^ 111- -B a; g'S :52s 3-° o — m 13 h c «H O C N O K i o oi o ft o a) OS'S 5 bo a).E =4-1 " o a) ^< K '^ ° cS Site-- +5 0) (u a) o b c rt o a> « -■t3 aj^ •r iicS =« . -- „ P C -C a> u >jT3 Oij S"^ i. « "! . c) i> ^ -P QJ o oj' 1 J- !: " ^ - r: R o =H "^^ -r « 3 .5 » C S &( > 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. 16 FARM ENGINEERING. ^ ^ ^:r,,,^-i^, -^ -«c 1-1 73 QJ ft dj q p, 0) o ^ 1 bJ3 H 5ft (D > -C o Eh o tu . . o ho M ' -c f=^ .S , "^ be OJ "C "^ <1J oj -^ o -S "a o ;:r^ ^ "" 2* a '" !m P g Z 5 02 Sz O LL +j 0) 5 ^-1 O ^ £ « C ■^ o --: a> 5 03^=^0 i "^ -^ -C <1^ C °^ te « >. .< '"' (j3 f>il -!-> ?2 .2 ^ CD -- cc xl CO C roc <^ ■<-' fl O s:) ■• '':^:i^^ • - A •■■■*■ - >■>• '.;■;'. A.- A/ •■ *.-:^' p »-"■ •■■•■».•. 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. 24 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 6 8 10 12 14 16 18 2 150 120 4 600 480 380 300 6 1400 1080 850 700 600 490 8 2500 1920 1500 1250 1100 960 10 4000 3000 2400 2000 1700 1500 1300 12 4300 3400 2800 2450 2150 1900 14 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. 28 FARM ENGINEERING. | i ', I , 1 , I , J I . .'■'■■ ■■ « i ?= F^ T— r -A\'!'.i,',|.',;;, ' ,', ' .'.|.',i.M ^>^ i; ! ; ■ \ \ \ \ : \ ; ! ^ /k 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 >v i^iavTg naz 2^ sz 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. 31 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. 34 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. d length Number per lb. [ in inches 2d 1 1100 to 1200 Sometimes used, for lathing. 3d 11/4 700 to 750 Shingle and lath nails. 4d W2 400 to 450 Shingle nails. 6d 2 250 to 275 Thin siding. 8d 21/2 125 to 140 For siding, sheathing and flooring. lOd 3 75 to 90 Sheathing and flooring. 12d 31/4 65 to 70 Toe-nailing rafters, etc. 16d 31/2 45 to 50 Toe-nailing rafters, etc. 20d 4 30 to 35 Framing work. 30d 41/2 25 to 30 Framing work. 40d 5 15 to 20 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. 35 All hog houses should be well lighted, provided with plenty of fresh air, and a clean, warm floor. Plate 15— INDIVIDUAL HOG HOUSE 36 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. 37 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. ^1 38 FARM ENGNEERING. O O O T' y\ X \ " X ". /3'x /O' ^ ~ ,:^ : < l^ : i - I c i-^ ; ^ I ^ > : h > <~^ : -K : -^ : Ik c -^ : Jo ,' i ^ 1 1 ^ 1 * I k'; ! ^! ■ ; k1 ■ I *^' ; ^' :k; ■ ^ ; ■ s K '. ^ : VJ ^liiiliiniiliiii N5 V s r I ft • , o < \ ■ ■ la ( ■ < I ■ 1 < ^ 1 • ^ ■ < 5s > L i^ -I I ■ \ ' ... -1 -^ <=> O Q J Q < <^^ 27 y A/ / FAEM ENGINEERING. 39 Plate 19-IOWA SILO Plate 20-MACHINE SHED 40 FAEM ENGINEERING. Two Retjiny Doors S*p ^rm s EL I ^t ^ -^h ^-a ^-d S :J1 FARM ENGINEERING. 41 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. 42 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. COPYRIGHT, 1912 Iht CORRESPONDENCE COLLEGE OF AGRICULTURE 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 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 II 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 17 ^%^ ^ .S -^j tJ3— ' ^ .S a; -M ^ ci '^ SJb cc lC oj 4) s tJ > O) Ui 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. J 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- 22 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 23 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 25 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 27 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. Xo ^'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. c 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 ENGINEERIN G 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 33 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 34 FARM ENGINEERING 1) ■JP i) i' Ml. ' 1 .i *T 1 — 1 s-i ci o ^ ;3 9 ti c h tJj x "^ ,^j <^ ?" S "£ LO ^ '^ "g "" vj ■— c -=:+;■£ 5ti J-- . if, b{. s o s c -^ . rt ^ . o o - fl ^ o <^, '^": -t . ,- ? ?; ^ 5 rt s ^ s ^ ^ E"^; c C2J — r c a; 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; 39 ? ^ d -;:: rt d o aj OJ +J 13 ^ TJ M g-d d d •r; tiJ d 7^ rd O bi --^ TS •<-< aj d o 0) ^ £1 -J-' ~^- lijf J' ypf im HSH J/J 7 L 11&7 //Jf 7 Ln /Z%S f i^p' iXP7 i J/* /KS't /c i//^ i'j^t. // .i.-v^ i/^fil. /^ ///^ if.^^ J) S^Hi n^t Ht'^ i)-P i/i-. sy? ij^ft /r 4>/ /x/^^ /^ M^"^ /l^^ . n ij.hi> /2~:7.f \ , 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 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. 44 FARM EiNGINEERING Starting- at he subtracts the depth of the drain from the elevation of (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. PJ3. Dnchdrade of m.r^e/{P3(. Sta BS y/ F.^ ^/ei^ Cro^c Cut, M,9^^ I'^.fZo /O.OOb ^.C^^ %/^^ /od U,»10 / 06-^0 S,S7S x^/^^ t^cv' 14^,0 (S /o.9d!f 8,76'o ^.^SB 30 d B.7SS- //. /er 9,^o.T XC t^£> i^OCS i^jf^' Ji>.6li S-^"^^' //.V7j- cjs^^ /.f7S ^i>0' ^,9n- n,773 9^7!r f'ify l^ofi ^■^^^ I2<^oo h,%S^ 1.950 10 6 5,f<55L /a.7i^ /A^2.r %^1B p^o i>^^ 1300X N.oQO Xpcx ' .. Plate 14. Plate 14 is a page (33) of an engineer's- note boolv. It shows 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 45 00 <=> '^ J2 CO P 5 O '0-5 1-3 -i:; -i-j oj as ° » 0; .a S 0) 'OPh '^3 S"^ -^r^ " •" ^ ,J — ^ '-' ■ 'i "D !^ '*) ^ 9 o .^ Q -r; 'C £ 0) ij P ci , , c ^ o ' — ' rvi rt -M M t-l .^ 3 t;-! o X: .2 3 ^ C5 O -y:' 3 -^j £ ^ '3 ."-. +-* a.' ^ g 0/ ii ■v: ij j'Z Q, _, ^ c w ^«j QJ tc ■»-^ +-1 cd OJ cc ^ =(-l o ^ ;S-, •^ & O a aJ S ^ o t/3 '^ m !-. O O p o o CC ci ^ 00 ^ =i-i =M i-H o "^ CI 4-J c; "^ S ^ o ci a o x o -t-J X3 t/3 OJ !^ .:^ QO 1— I "•^ o 0) p '^ _cc bj. -^3 S tw ^ rj p .2 9 tX5 O ? p cX 3 CO +^ (D b S ;2 o O a; ?5< s 3 o Oi E^ X k- ^ ^ IH) 1— -« O 4) M • T-i +j . £C ^ r^ ^ 0) o M 6B a 03 .9 ^ cc '^ O E ' ' ^ o ^~,