> -r •.^^ '^, oo 4 "T* ,0 o O^ '^^ -^ '/ ii>^ %^^- >:^'^ '^^' ,<>^''' " « X " ,o - '^ o 0^ ..'?v' v^'^' # -^ ' » . s •> \ \ O ^ ' « * cP-.^ \.,^ ''-<.f ^./ ^ v^ ^ -^ 0^ ,0 ^- .^^ -^^K ^ • o * .. ^ „ ^ .'t'^ ,•; ,X^^ % ^.,^'^<.0- ..,/°^A ^^' FARM MACHINERY AND FARM MOTORS By J. BROWNLEE DAVIDSON, B.S., M.E. Junior Member American Society of Mechanical Engineers Professor of Agricultural Engineering Iowa State College LEON WILSON CHASE, B.S., M.E. Associate Member American Society of Mechanical Engineers Associate Professor of Farm Mechanics University of Nebraska ILLUSTRATED NEW YORK ORANGE JUDD COMPANY LONDON Kegan Paul, Trench, Trubner & Co., Limited 1908 n LIBRARY of C0N63ESS. Two Oopies Hect!vsG FEB 4 1908 potiyiiKiK ciiirv 0US8 A Uc i*u. COPY a.' Copyright, 1908 By ORANGE JUDD COMPANY All Rights Reserved [entered at stationers' hall, LONDON, ENGLAND] PREFACE Instruction pertaining to Farm Machinery and Farm Motors has b^en quite recently added to the agricultural course in the majority of the agricultural colleges in the United States. Although the need and importance of such a study was self-evident, it was a new field, one in which the knowledge pertaining to the subject had not been prepared and systematized for instructional pur- poses. The latest book on the subject of Farm Machinery was written by J. J. Thomas in 1869, before the general introduction of labor-saving machinery for farm work. Many books have been written on the various motors used for agricultural purposes, but it is not believed that an attempt has been made to place in one volume a dis- cussion of them all. The authors have felt the need of a text for instructional purposes, and it is this need that has prompted them to prepare this book. It is a revision of the lecture notes used before their classes for several years. These notes were prepared from a careful study of all the available literature on the subject, and from observation made in the field of the machines at work and in the factories where they are made. A list of the literature consulted is given at the close of the book. Free use has been made of all this as well as all the trade literature available, and for this an efifort has been made to give due credit. Many of the illustrations have been prepared from original drawings by the authors ; however, the larger number are those of machines upon the current market. A discussion of all the farm machines did not seem possible, and attention may be called to the omission of VI PREFACE ^ seed grading and cleaning machinery, cotton machinery, potato machinery, garden machinery, and other classes. The amount of information at hand concerning these classes of machinery did not justify their inclusion. Farm Motors has been made more complete, but some of the motors used to a limited extent in agricultural practice, as hot-air engines and water-wheels, have been omitted. Although electrical machinery is not much used in agri- culture, its use is increasing and the interest in the sub- ject has been so general that a chapter on the same has been included. As the efificiency and life of farm machinery depends largely upon the way and manner it is repaired, a short chapter on the Farm Workshop has been added. To make instruction in Farm Machinery and Farm Motors efficient it should in all cases be supplemented with laboratory and field instruction, and it is not the purpose of this book to displace such instruction. An attempt has been made to make the material practi- cal, useful and helpful, and although written primarily for a text book, it is hoped that it will be useful to many engaged in practical work. The authors know that their attempt to prepare a text book has not been perfect, and not only will errors be found in the subject matter, but the material will lack pedagogic form in places. Any criticism or suggestions from instructors in these respects will be duly appre- ciated. They wish also to acknowledge the obligations they owe many friends for suggestions and aid in many ways. Thanks are due the publishers for their work in preparing the illustrations, which at first seemed to be an almost endless task. J. B. Davidson. L. W. Chase. CONTENTS PART I CHAPTER PAGE Introduction i I. Definitions and Mechanical Principles 8 II. Transmission of Power 28 III. Materials and the Strength of Materials .... 43 IV. Tillage Machinery 51 V. Tillage Machinery (Continued) 78 VI. Seeding Machinery . 102 VII. Harvesting Machinery 136 VIII. Haying ]\Iachinery 162 IX. Manure Spreaders IQI X. Threshing Machinery 203 XI. Corn Machinery 221 XII. Feed Mills 234 XIII. Wagons. Buggies, and Sleds 241 XIV. Pumping Machinery 258 XV. The Value and Care of Farm Machinery .... 277 P.^RT II CHAPTER PAGE Introduction 281 XVI. Animal Motors 284 XVII. Windmills 298 XVIII. Steam Boilers 3i7 XIX. Steam Engines 3oi XX. Gas. Oil. and Alcohol Engines 40i XXI. Traction Engines 436 XXII. Electrical Machinery 46i XXIII. The Farm Shop 499 FARM MACHINERY PART 1 INTRODUCTION I. One of the requirements for a steady, healthy growth of any people or nation is a bountiful supply of food. The earth can be made to produce in abundance only when the soil is tilled and plants suitable for food are cultivated. As long as the people of the earth roamed about obtaining their subsistence by hunting and fishing, conditions were not favorable for a rapid increase in population or an advance in civilization. Tribes or nations constantly encroached upon each other's rights and were continually at war. History shows that when any nation, isolated so as to be protected from the attacks of other nations, devoted itself to agricultural pursuits, its government at once became more stable and life and property more secure. Protected in this way, a great nation, shut off from the rest of the world by natural means, and located in a fertile country, arose along the banks of the Nile long before any other nation reached prominence. The Gauls became mighty because they devoted themselves to agriculture and obtained in this way a more reliable supply of food. Pliny, the elder, in his writings tells of the fields of Gaul and describes some of the tools used. It has been estimated that there never were more than 400,000 Indians in North America, and they were often in want of food. Compare this number with the present population. The tribes that flourished H, FARM MACHINERY and increased in numbers were those who had fields of grain and a definite source of food. 2. Change from hand to machine methods. — When people began to turn their attention to farming they began to devise tools to aid them in their work. Various kinds of hoes, crude plows, sickles, and scythes were invented, but were practically all hand tools. Work with these was necessarily very laborious and slow. The hours of labor in consequence were very long, and the social position of the tiller of the soil was low. He was in every sense of the term "the man with the hoe." He became prematurely old and bent ; his lot was anything but enviable. For more than 3.000 years the farmers of Europe, and in this country until after the Revolutionary War, used the same crude tools and primitive methods as were em- ployed by the Egyptians and the Israelites. In fact, it has been, relatively speaking, only a few years since the change from hand to machine methods took place. In the Twelfth Census Report the following statement is made : ''The year 1850 practically marks the close of the period in which the only farm implements and machinery other than the wagon, cart, and cotton gin were frhose which, for want of a better designation, may be called implements of hand production." McMaster, in his "History of the People of the United States," says : "The Massachusetts farmer who witnessed the Revolution plowed his land with the wooden bull plow, sowed his grain broadcast, and when it was ripe, cut it with a scythe and threshed it out on his barn floor with a flail." He writes further that the poor whites of Virginia in 1790 lived in log huts "with the chinks stuffed with clay ; the walls had no plaster, the windows had no glass, the furniture was such as they themselves had lN"IR0m'CT10N' 3 made. Their grain was threshed by driving horses over it in the open field. When they ground it they used a rude pestle and mortar, or placed it in a hollow of a stone and beat it with another." 3. Effects of the change. — At any rate, a great change has taken place and all in little over a half century. This great change from the simplest of tools to the modern, almost perfect implements, has produced a marked eft'ect upon the life of the farmer. He is no longer "the man W'ith the hoe." but a man well trained intellectually. 4. Physical and mental changes. — It is not dillficult to realize that a great change for the better has taken place in the physical and mental nature of the farmer. It is vastly easier for a man to sit on a modern harvester, watch the machine, and drive the team, than it is to work all day with bended back, scuffling along, running a cradle. How much easier it is to handle the modern crop, though much larger, with the modern threshing machine, where the bundles are simply thrown into the feeder, than to spend the entire winter beating the grain out with a flail. The farmer can now do his work and still have time to plan his business and to think of im- provements. 5. Length of the working day. — One of the marked effects of the change to modern machinery methods has been a shortening of the length of the working day. When the work was done by hand methods, the day during the busy season was from early morn till late at night. Often as much as 16 hours a day were spent in the fields. Now field work seldom exceeds 10 hours a day. 6. Increase in wages. — According to AIcMaster,* in 1794 ''in the States north of Pennsylvania" the wages of *Mc]\Iaster: "History of the People of the United States," Vol. II., p. 179. 4 FARM MACHINERY the common laborer Avere not to exceed $3 per month, and "in Vermont good men were employed for £18 per year." Even as late as 1849, the wages, according to sev- eral authorities, did not exceed $120 a year. Under pres- ent conditions, the farm laborer is able to demand two, three, and even five times as much. In countries where hand methods are still practiced, wages are very low. Men are required to work all day from early morning till late at night for a few cents. In some of the Asiatic countries it is said that men work from four in the morn- ing until nine at night for 14 cents. Women receive only 9 or 10 cents and children 7 or 8 cents. 7. The labor of women. — Woman, so history relates, was the first agriculturist. Upon her depended the plant- ing and tending of the various crops. She was required to help more or less with the farm work as long as the hand methods remained. Machinery has relieved her of nearly all field work. Not only this, but many of the former household duties have been taken away. Spinning and weaving, soap-making and candle-making, although formerly household duties, are now turned over to the factory. Butter and cheese making are gradually becom- ing the work of the factory rather than that of the home. Sewing machines, washing machines, cream separators, and numerous other inventions have come to aid the housewafe with her work. 8. Percentage of population on farms. — During the change from hand to machine methods there was a great decrease in the percentage of the people of the United States living upon the farms. It has been estimated that in 1800 97 per cent of the people were to be found upon the farms. By 1849 this proportion had decreased to 90 per cent, and according to the Twelfth Census Report it was only 35.7 per cent. INTRODUCTION 5 9. Increase in production. — Notwithstanding this de- crease in the per cent of the people upon the farms, there has been, since the introduction of machinery, a great in- crease in production per capita. In 1800 it is estimated that 5.50 bushels of wheat were produced per capita; in 1850, according to the Division of Statistics of the De- partment of Agriculture, production had decreased to 4.43 bushels. This was before the effect of harvesting machinery had begun to be felt. People were leaving the farms and the production of wheat per capita was falling off. The limit with hand methods had been reached. Economists were alarmed lest a time should come when the production would not supply the needs of the people. Through the aid of machinery the production increased to 9.16 bushels per capita in 1880, 7.48 bushels in 1890, and 8.66 bushels in 1900. Perhaps this also shows that the maximum production of wheat per capita with present machinery has been reached. The production of corn has also increased, but the increase is not so marked. The production of corn per capita in 1850 was 25.53 bushels ; in 1900 it was 34.94 bushels. ID. Cost of production. — Although the cost of farm labor has doubled or trebled, the cost of production has decreased. According to the Thirteenth Annual Report of the Department of Labor, the amount of labor required to produce a bushel of wheat by hand was 3 hours and 3 minutes, and now it is only 9 minutes and 58 seconds. The cost of production, as compiled by Quaintance,* was 20 cents by hand (1829-30) and 10 cents by machinery (1895-96). It is also stated in the Year Book of the De- partment of Agriculture for 1899 that it formerly required II hours of man labor to cut and cure i ton of hay. Now *Tlie Influence of Farm Machinery on Production and Labor. Publications of the American Economic Association. Vol. V., No. 4. FARM MACHINERY the same work is accomplished in i hour and 39 min utes. The cost of the required labor has decreased from 83 1/3 cents to 16 1/4 cents a ton. Not only is it true that machinery has revolutionized the work of making hay, but nearly every phase of farm work has been essen- tially changed. 11. Quality of products. — Machinery has also improved the quality of farm products. Corn and other grains are planted at very nearly the proper time, owing to the fact that machinery methods are so much quicker. By hand methods the crop did not have time to mature. It was necessary to begin the harvest before the grain was ripe, and hence it was shrunken. The grain is obtained now cleaner and purer. It would be difficult at the present time to sell, for bread purposes, grain which had been threshed by the treading of animals over it. 12. Summary. — Great changes can be accounted for by the introduction of machine methods for band methods. For all people this has been beneficial. It has caused the rise of our great nation on the Western Hemisphere. To no class, however, has this change been more beneficial than to the farm worker himself. J. R. Dodge sum- marized the benefits derived by the farm worker when he wrote : "As to the influence of machinery on farm labor, all intelligent expert observation declares it bene- ficial. It has relieved the laborer of much drudgery; made his work and his hours of service shorter; stimu- lated his mental faculties; given an equilibrium of effort to mind and body ; made the laborer a more efficient Avorker, a broader man, and a better citizen."* Conditions in America have been very favorable for the development of machinery. We have never had an *American Farm Labor in Rept. of Ind. Com. (1901), Vol, XL, p. III. :■« INTRODUCTION 7 abundance of farm labor. The American inventor has surpassed all others in his ability to devise machines. By this machinery the farmer receives good compensa- tion for his services and is able to compete on foreign markets with cheap labor of other countries. Lastly, it seems conclusive that an agricultural college course is not complete in which the student does not study much about that which has made his occupatio'n exceptionally desirable. It should be an intensely prac- tical study, for under present conditions success or failure in farming operations depends largely upon the judicious use of farm machinery. CHAPTER I DEFINITIONS AND MECHANICAL PRINCIPLES 13. Agricultural engineering is the name given to the agricultural achievements which require for their execu- tion scientific knowledge, mechanical training, and engi- neering skill. It has been but quite recently that departments have been organized in agricultural colleges to give instruction in agricultural engineering. The name is not as yet uni- versally adopted, the term farm mechanics or rural en- gineering being preferred by some. It is hoped that in time "agricultural engineering" will be generally accepted, as it seems to be the broadest and most appropriate term to be given instruction defined as above. Implement manufacturers in Europe have been pleased to call them- selves agricultural engineers, and the term is not alto- gether a new one. Agricultural engineering embraces such subjects as: (i) farm machinery, (2) farm motors, (3) drainage, (4) irrigation, (5) road construction, (6) rural architec- ture, (7) blacksmithing, and (8) carpentry. 14. Farm machinery. — Part I. of this treatise, after the present chapter of definitions and mechanical principles and chapters on the transmission of power and the strength of materials, will be a discussion of the con- struction, adjustment, and operation of farm machinery, and will include the major portion of the implements and machines used in the -growing, harvesting, and preparing of farm crops, exclusive of those used in obtaining power. These will be considered in Part II. under the title of 10 FARM MACHINERY P'arm Motors. The following definitions and explana- tions will prove helpful : 15. A force produces or tends to produce or destroy motion. Forces vary in magnitude, and some means must be provided to compare them. Unit force corresponds to unit weight and is the force of gravitation on a definite mass. This unit is arbitrarily chosen and is called the pound. The magnitude of all forces, as the draft of an implement, is measured in pounds. Forces also have direction and hence may be represented graphically by a line. For this reason a force is sometimes called a vector quantity. Two or more forces acting on a rigid body act as one force called a resultant. Thus in Fig. i, O A and O B rep- resent in direction and magnitude two forces acting through the point O. O C is the diagonal of a paral- lelogram of which O A and O B are sides, and represents the combined ^^^" action of the forces represented by O A and O B, or is the resultant of these forces. This principle is known as the parallelogram of forces. 16. Mechanics is the science which treats of the action of forces upon bodies and the effect which they produce. It treats of the laws which govern the movement and equilibrium of bodies and shows how they may be util- ized. 17. Work. — When a force acts through a certain dis- tance or when motion is produced by the action of a force, work is done. Work can therefore be defined as the product of force into distance. Work can be defined in another way as being proportional to the distance through which the force acts, and also to the magnitude of the force. DEFINITIONS AND MECHANICAL PRINCIPLES II i8. Unit of work. — It has been stated that the unit of force is the pound. The unit of distance is the foot. The unit of work is unit force acting through unit distance and is named the foot-pound. A foot-pound is then the amount of work performed in raising a mass weighing I pound I foot. It is to be noted that the amount of work done in raising i pound through lo feet is the same as raising lo pounds through i foot. It is to be noted further that, in considering the amount of work, time is not taken into account. It is the same regardless of whether i minute or many times i minute was used in performing the operation. The horse-power hour is an- other unit of work commonly used and will be under- stood after power has been defined. 19. Power is the rate of work. To obtain the power received from any source the number of foot-pounds of work done in a given time must be determined. The unit of power commonly used is the horse power. 20. A horse power is work at the rate of 33,000 foot- pounds a minute, or 550 pounds a second. That is, if a w^eight of 33.000 pounds be raised through i foot in i minute, one horse power of work is being done. This unit was arbitrarily chosen by early steam engine manufac- turers to compare their engines with the power of a horse. If a horse is walking 2.5 miles an hour and exerting a steady pull on his traces of 150 pounds, the effective energy which he develops is : 1 50 X 5 280 X 2.5 _ J pj p 60 X 33000 21. A machine is a device for applying work. By it motion and forces arg modified so as to be used to greater advantage. A machine is not a source of work. In fact, the amount of work imparted to a machine always ex- 12 FARM MACHINERY ceeds the amount received from it. Some work is used in overcoming- the friction of the machine. The ratio be- tween the amount of work received from a machine and the amount put into it is called the efficiency of the machine. 22. Simple machines are the elements to which all ma- chinery may be reduced. A machine like a harvester, with systems of sprockets, gears, and cranks, consists only of modifications of the elements of machines. These elements are six in number and are called (i) the lever, (2) the wheel and axle, (3) the inclined plane, (4) the screw', (5^ the wedge, and (6) the pulley. These six may be conceived to be reduced to only two — the lever and the inclined plane. 23. The law of mechanics holds that the power multi- plied by the distance through which it moves is equal to the weight multiplied by the distance through which it moves. Thus, a power of i pound moving 10 feet equals 10 pounds moving i foot. This is true in theory, but in practice a certain amount must be added to overcome friction. 24. The lever, the simplest of all machines, is a bar or rigid arm turning about a pivot called the fulcrum. The object to be moved is commonly designated as the weight, and the arm on which it is placed is called the weight arm. The force used is designated as the power, and the arm on which it acts is called the power arm. Levers are divided into three classes ; for an explanation of the classes refer to any text on physics.* The law of mechanics may be applied to all levers in this manner. The power multiplied by the power arm equals the weight multiplied by the weight arm. *"General Physics." Bj' C. S. Hastings and F. E. Beach and others. DEFINITIONS AND MECHANICAL PRINCIPLES 13 If P = Power, Pa = Power arm, W = Weight, and Wa = VVeiglit arm, P X Pa — W X Wa. If three of these quantities are known, the other is easily calculated. The arm or leverage is always the perpendicular distance between the direction of the force and the fulcrum. 25. The two-horse evener or doubletree. — The two- horse evener is a lever of the second class where the clevis pin for the whififletree at one end acts as the fulcrum for ' "V J ZZ' *1' 435 Ids i..i FIG. 2 — WAGON EVENER IN OUTLINE. SHOWING THE ADVANTAGE THE LEADING HORSE HAS WHEN THE CLEVIS HOLES ARE NOT A STRAIGHT LINE the power applied by the horse at the other end. The weight is the load at the middle. If the three holes for the attachment of each horse and the load be in a straight line and the arms be of equal length, each horse pulls an equal share of the load even if the evener is not at right angles with the line of draft. But more often the end holes in the evener are placed in a line behind the hole for the center clevis pin. Then if one horse permits his end of the evener to recede, he will have the larger portion of the load to pull because his lever arm has been short- 14 FARM MACHINERY ened more than the lever arm of the other horse. The author's attention has been called to a wagon doubletree in which the center and end holes for clevis pins are made by iron clips riveted to the front and back sides of the wood. The center hole was thus placed 4^ inches out of the line of the end holes. This evener is shown in out- line in Big. 2. By calculation it was found that if one horse was 8 inches in the advance of the other, the rear horse would pull 8.4 per cent more than the first, or 4.06 per cent more of the total load. If this difiference was 16 inches, the rear horse would pull 19 per cent more than the first, or 8 per cent more of the total load. 26. Eveners. — When several horses are hitched to a machine as one team, a system of levers is used to divide the load proportionately. The law of mechanics applies in all cases, noting that the lever arm is the perpendicular distance between the direction of the force and the ful- crum or pivot. In general, it may be said that there is nothing" to be gained by a complicated evener. If there is a flexible connection and an equal division of the draft, the simple evener is as good as the complicated or so- called "patent" evener. The line of draft cannot he offset without a force acting across it. This is accomplished with a tongue truck, which seems to be the logical method. Fig. 3 illustrates some good types of eveners. 27. Giving one horse the advantage. — It often occurs in working young animals or horses of different weights that it is desired to give one the advantage in the share of work done. This is accomplished by making one evener arm longer than the other, giving the horse which is to have the advantage the longer arm. This may be done by setting out his clevis, setting in the clevis DEFINITIONS AND MECHANICAL PRINCIPLES 15 of the other horse, or placing- the center clevis out toward the other horse. The correct division of the load between horses of different sizes is not definitely known, but it is Five Horse Tandem. FIG. 3 — GOOD TVPES OF EVENERS WHICH WILL DIVIDE EQUALLY THE DRAFT thought that the division should be made in about the same proportion as each horse's weight is of their com- bined weight. 28. Inclined plane. — The tread power is an example of the utilization of the inclined plane, in which the plane is an endless apron whose motion is transferred to a shaft. The tread power is illustrated in Part II., Farm Motors. 29. The screw is a combination of the inclined plane i i6 FARM MACHINERY and the lever, where the inclined plane is wrapped around a cylinder and engages a nut. The pitch of a screw is the distance between a point on one thread to a like point on the next, or, in other words, it is i inch divided by the num- ber of threads to the inch. Thus, 8 threads to i inch is i/8 pitch, 24 threads 1/24 pitch. There is a great gain of power in the screw because the load is moved a short distance compared with the power. A single-pitch thread ad- vances along the length of the screw once the pitch at each turn ; a double pitch advances twice the pitch. The part of a bolt containing a screw thread on the inside is spoken of as a nut. The name burr is often given to the nut, but burr applies more particu- Yj^ larly to washers for rivets. The tool used in making the thread in a nut is called a tap, and the one for making outside threads a die. 30. A pulley consists primarily of a grooved wheel and axle over which runs a cord. A simple pulley changes only the di- rection of the force. By a combination of pulleys the power may be increased indefinitely. The wheel which carries the rope is called a sheave, the cover- ing and axle for the sheave the block, and the whole a pulley. A combination of blocks and ropes is called a tackle. With the common tackle block, the power is multiplied by the number of strands of rope less one. The mechanical advantage may be obtained in another FIG. 4 — SIMPLE PUL- LEY, WHICH ONLY CHANGES THE DI- RECTION OF A FORCE DEFINITIONS AND MECHANICAL l^RINCIPLES 17 way, as it is equal to the number of strands supporting the weight. This will agree with the former method when the power is acting downward. If the power is act- ing upward instead of downward, the power strand would be supporting the weight, and so should not be deducted from the total number to obtain the mechanical advantage. Fig. 5 illustrates a tackle which has six strands, but FORCE MAY BE MULTIPLIED MANY TIMES BY A TACKLE OF THIS KIND FIG. 6 — DIFFEREN- TIAL TACKLE BY WHICH HEAVY WEIGHTS MAY BE RAISED only five are supporting the weight, so the mechanical advantage in this case is five. If the weight be 1,000 pounds, as marked, a force of 200 pounds besides a force sufficient to overcome friction \yill be needed to raise the weight. This tackle has a special designed sheave which, when the free rope end is carried to one side and let out i8 FARM MACHINERY slightly, the rope is wedged in a special groove and the weight held firmly in place. The differential pulley shown in Fig. 6 is a very power- ful device for raising heavy weights and is very simple. The principle involved is that the upper sheaves are of different diameters, fastened rigidly together and en- gaging the chain in such a manner as to prevent it from slipping over them. Thus, as the sheaves are rotated, one of the strands of chains carrying the load is taken up slightly faster than the other is let out, shortening their combined length and raising the load. 31. Dynamometers* are instruments used in determin- ing the force transmitted to or from a machine or imple- FIG. 7 — PRONY brake: ONE FORM OF ABSORPTION DYNAMOMETER ment. They are, therefore, very important instruments for the study and testing of machinery. Having deter- mined with this instrument the force, it is an easy matter to calculate the power. 32. Absorption dynamometers are those which absorb the power in measuring the force transmitted. The Prony brake as illustrated in Fig. 7 is the common device used *For additional literature on the measurement of power see "Experimental Engineering," by R. C. Carpenter. DEFINITIONS AND MECHANICAL PRINCtPLES 19 in measuring the output of motors. The force trans- mitted is measured by a pair of platform scales or a spring balance. The distance through which this force acts in i minute is calculated from the number of revolutions of the rotating shaft per minute and the distance through which the force would travel in one revolution if released. The revolutions of the shaft are obtained by means of a speed indicator, a type of which is illustrated in Fig. 8. pjG 8— SPEED indicator: an instrument for determining the speed If 77^ ratio between diameter of circle and the circumfer- ence ^3.1416, a =^ length of brake arm in feet, G = net brake load (weight on scale less weight of brake on scale), )i = revolutions a minute, 2 TT (J a jj "■"■ 33000 Dynamometers which do not absorb the power are called transmission dynamometers. 33. Traction dynamometers. — Dynamometers used in connection with farm machinery to determine the draft of implements are called traction dynamometers. They are instruments on the principle of a pair of scales placed between an implement and the horses or engine. They indicate the number of poimds of draft or pull required to move the implement. The traction dynamometer is a transmission dynamometer. The power is not all used 20 FARM MACHINERY up in the measuring", but transmitted to the implement or machine where the work is being done. The operation of the traction dynamometer is the same as that of a heavy spring balance. The spring may be a coil, flat or elliptical, or an oil or water piston may be used in place of the spring and the pull determined by the pressure produced.- 34. Direct-reading dynamometers. — The more simple types of dynamometers have a convenient scale and a needle which indicates the pull in pounds. A second needle is usually provided which shows the maximum pull which has been reached during the test. A dyna- mometer of this kind is illustrated in Fig. 9. This has FIG. 9 DIRECT-READING DYNAMOMETER elliptical springs and a dial upon wdiich the draft is regis- tered. It is difficult to obtain accurate readings from a dynamometer of this sort on account of vibration caused by the change of draft due to rough ground or the un- steady motion of the horse. 35. Self-recording dynamometers. — A recording dyna- mometer records by a pen or pencil line the draft. A strip of paper is passed under the needle carrying the pen point, whose position is determined by the pull. The height of the pen line above a base line of no load is pro- portional to the pull in pounds. A diagram obtained in DEFINITIOXS AM) M ICCII AN HAL I'K I XCI IMJvS 21 lliis way is shown in I'ii;'. lo. L)ftcn the paper is ruled to scale so that direct readings may be made from the paper. Methods of rotatinj;' the reel or spool vary in different makes. Some German dynamometers rotate the m^^^^^ FIG. 10 A RECORD OF DRAFT OBTAINED BY A RECORDING DYNAMOMETER reel by a wheel W'hich runs along on the ground and is connected to the reel by a flexible shaft, as in Fig. ii. This method is very satisfactory, except that the wheel is FIG. II — A GERMAN RECORDING DYNAMOMETER WHICH HAS THE REEL DRIVEN CY CLOCK-WORK often in the way. Distances along the paper are in this case proportional to the distance passed over by the im- plement. h 22 FARM MACHINERY Another method is to rotate the reel b}^ clock-work. Then distances along" the paper are proportional to time. FIG. 12— GIDDINGS KECUKDING DYNAMOMETER, WHICH HAS THE REEL DRIVEN BY CLOCK-WORK If the velocity be uniform, the distances are appioxi- mately proportional to the distance passed over as be- DEFINITIONS AND MECHANICAL rUINCII'LES 2^ fore. \\ hen the distances alonj; the i)ai)er arc propor- tional" to the ground passed over, the amount of work may be obtained easily. The (jiddings dynamometer, as illustrated in Fig. 12. is made in this way. It also has elliptical springs. Still another method is made use of in another type of dynamometer, in which the in-and-out movement of the pull head is made to rotate the reel. This method is not FIG. 13 — THE PLANIMETER USED TO KIND THE AVERAGE DRAFT FROM DYNAMOMETER RECORDS. THERE ARE SEVERAL TYPES OF THIS INSTRUMENT SO satisfactory because distances along the paper are not proportional to anything. Tf the draft remains constant, there is no rotation of the reel at all. Various devices are provided dynamometers to add the draft for stated distances, and in this way obtain the work done. A tape line 100 feet long is sometimes used to rotate the reel of the dynamometer. To obtain the mean draft a line is drawn through the graph of the pen point, eliminating the sharp points. Then the diagram may be divided into any number of equal parts and the sum of the draft at the center of these divisions divided by the number of divisions. The quotient will be the mean draft. An instrument called the planimeter (Fig. 13) will de- 24 FARM MACHINERY I termine the area of the diagram when the point is passed aronnd it. To obtain the mean height and the average draft it is only necessary to divide the area of the diagram by its length. This can only be done when distances along the paper are proportional to the distance passed over by the implement. 36. Steam and gas engine indicators. — The indicator, although not used much in connection with farm engines, FIG. 14 — THE STEAM OR GAS ENGINE INDICATOR. AN INSTRUMENT USED TO OBTAIN A RECORD OF THE PRESSURE IN THE ENGINE CYLINDER AT VARIOUS POINTS OF THE STROKE should be mentioned at this point under a discussion of the methods of measuring work. Fig. 14 illustrates a steam engine indicator complete, and also a section of it showing the mechanism inside. In brief, the indicator consists in a drum, upon which a paper card is mounted to receive the record or diagram, and a cylinder carefully fitted with a piston upon which the pressures of the steam or gases from the engine cylinder act. The drum by a mechanism called a reducing motion is given a motion corresponding to that of the engine DEl^INITIONS AND MECHANICAL PRINCIPLES 25 FIG. 15— AN ACTUAL INDICATOR DIA- GRAM OBTAINED FROM A GAS EN- GINE, WITH THE SCALE OF THE SPRING APPENDED piston, and the pressure of the gases from the engine cylinder acting on the piston of the indicator compresses a calibrated spring above. The amount of pressure is re- corded with a pencil point by a suitable mechanism on the paper card. Thus if a diagram is obtained from an engine at work, it not only permits a study of the engine in regard to the action of valves, igniter, etc., but also enables the amount of work performed in the en- gine cylinder to be calcu- lated. Fig. 15 shows an actual diagram taken from a gas engine. As the pressure varies throughout the stroke, an instrument like the planimeter of Fig. 13 must be used to average the pres- sure for the entire working stroke of the piston, and sub- tract the pressure required in the preliminary and ex- haust strokes. This average pressure is called the mean effective pressure (M.E.P.). Knowing the distance the engine piston travels a minute doing work, the area of the surface on which the pressure acts, and the mean ef- fective pressure, it is possible to calculate the rate of work or the horse power. The horse power obtained in this way is called the indicated horse power (I.H.P.), and differs from the brake horse power (B.H.P.) by the power required to overcome friction in the engine. The ratio of the brake horse power to the indicated horse power is called the mechanical efficiency of the engine. If P = Mean effective pressure, L = Length of stroke in feet, A 3= Area of piston in square inches, N = Number of working strokes a minute, PLA.N I.H.P.:::^ 33>ooo 26 FARM MACHINERY It is to be noted that in double-acting engines the faces of the piston on which the pressure in the engine cylinder acts differ by the area of the cross section of the piston rod. IL is customary to calculate the indicated horse power for each end of the cylinder, and take the sum for the indicated horse power of the engine. 37. Heat. — Work, as measured by the foot-pound, is mechanical energy or the energy of motion. Energy is defined as the power to produce a change of any kind and manifests itself in many forms. It may be transformed from one form to another without affecting the whole amount. Heat represents one form of energy, and it is the purpose of all heat engines to transform this heat energy into mechanical energy. Like work, heat may be measured. The unit used for this purpose is the British thermal unit. I'he British thermal unit (B.T.U.) is the amount of heat required to raise the temperature of i pound of water 1° F. To make the unit more specific, the change of tem- perature is usually specified as being between 62° and 63° F. The work equivalent of the British thermal unit is sometimes called the Joule (J) and is equal to 778 foot- pounds of work. Thermal efficiency is a term used in connection with heat engines to represent the ratio between the amount of energy received from the engine in the form of work and the amount given to it in the form of heat. The thermal efficiency of a steam engine seldom exceeds 15 per cent and of a gas engine 30 per cent. 38. Electrical energy. — By means of a dynamo, mechan- ical energy may be converted into electrical energy or the energy of an electric current. An electric current may be likened to the flow of water through a pipe in that it has pressure and volume. In the water pipe the pressure DEFINITIONS AND M I-XII ANICAL I'Kl NCI ri.KS 2^ is measured in pounds to the square inch, and the vohime by the area of the cross section of the pipe. \Vith an electric current the pressure is measured in volts and the volume or amount of current in amperes. Thus a current may have a pressure or voltage of i lo volts and a vi)lume or amperage of 7 amperes. The product of volts into am- peres gives watts. An electrical current of 746 watts is equal to one horse power. Electric energy is bought and sold by the watt-hour, or the larger unit, the kilowatt- hour, which is 1,000 watt-hours. CHAPTER II TRANSMISSION OF POWER It is the function of all machines to receive energy from some source and distribute it to the various parts where it will be converted into useful work. This chapter will treat of the devices used in the transmission and dis- tribution of power and the loss of power during trans- mission. 39. Belting. — Belting is one of the oldest and most com- mon devices used for the transmission of power from one rotating shaft to another. The transmission depends upon the friction between the belt and the pulley face ; that is, the belt clings to the pulley face and causes it to rotate as the belt travels around it. The sides of a belt, when connecting two pulleys and transmitting power, are under unequal tension. The effectual tension or actual force transmitted is the difference between the tensions on each side. The effectual tension multiplied by the velocity of the belt in feet a minute will give the foot- pounds of work transmitted a minute. Thus the power varies directly with effectual tension and the velocity of the belt. 40. Horse power of a leather belt. — It is possible to make up a formula with the above quantities to be used in the calculation of the power of a belt or the size required to transmit a certain povver. The fol- lowing is a common rule for single-ply belting, which assumes an eft'ectual tension of 33 pounds an inch of width : TRANSMISSION OF TOWER 29 H. P. ^ Horse power, t':= Velocity in feet a minute, zv = Width of belt in inches. H. F-^:^ 1000 The quantity z' may be calculated from the number of revolutions a minute and the diameter of the driving pulley. The velocity of belts rarely exceeds 4,500 feet a minute. The highest efficiency of belt transmission is ob- tained from belting when there is no slipping and little stretching, and when the tension on the belt does not create an undue pressure on the bearings. 41. Leather belting, — Good leather belting will last longer than any other when protected from heat and moisture. A good belt should last for lo to 15 years of continuous service. Best results are obtained when the hair or grain side of the leather is run next to the pulley. When the belt is put on the opposite way, the grain side, which is firmer and has the greater part of the strength of the belt, is apt to become cracked and the strength of the belt much reduced. 42. Care of leather belts. — Belts should be occasionally cleaned and oiled to keep them soft and pliable. There are good dressings upon the market, and others that are certainly injurious. Neatsfoot oil is a very satisfactory dressing. Mineral oils are not very satisfactory, as a rule. Rosin is considered injurious, and it is doubtful if it is necessary to use it on a belt in good condition. With horizontal belts it is desirable to have the under side the driving side, for then the sag of the slack side causes more of the belt to come in contact with the pulleys and will prevent slippage to some extent. 43. Rubber belting. — Good rubber belting is of perfect uniformity in width and thickness and will resist a greater degree of heat and cold than leather. It is especially well 3© FARM MACHINERY adapted to wet places and where it will be exposed to the action of steam. Rubber belting, which clings well to the pulley, is less apt to slip and may be called upon to do very heavy service. Although not as durable as leather, it is quite strong, but offers a little difficulty in the making of splices. Rubber belting is made from two- ply to eight-ply in thickness. A four-ply belt is consid- ered the equal of a single-ply leather belt in the trans- mission of power. All oil and grease must be kept away from rubber belting. 44. Canvas belting is used extensively for the trans- mission of power supplied by portable and traction en- gines. It is very strong and durable, and is especially well adapted to withstand hard service. When used in the field it is usually made into endless belts. It has one characteristic which bars its extended use between pul- leys at a fixed distance, and that is its stretching and con- tracting, due to moisture changes. Canvas belting, like rubber belting, is made in various thicknesses from two- ply up. A four-ply belt is usually considered the equal of a single leather belt. 45. Length of belts. — Length of belts is usually deter- mined after the pulleys are in place by wrapping a tape line around the pulleys. When this cannot be done con- veniently, the following approximate rule taken from Kent's Mechanical Engineer's Pocketbook may be used : "Add the diameter of the two pulleys, divide by two, and multiply the quotient by 3^4 > and add the product to twice the distance between the centers of the shafts." 46. Lacing of belts. — Lacing with a rawhide thong is the common method used in connecting the ends of a belt. A laced belt should run noiselessly over the pulleys and should be as pliable as any part of the belt. The holes TRANSMISSION OF POWER 3T should be at least five-eighths inches from the edge and should be placed directly opposite. An oval punch is the best, making- the long diameter of the hole parallel with the belt. With narrow belts only a single row of holes need be punched, but with wide belts it is necessary to punch a double row of holes. By oiling or wetting the end of the lace and then burn- ing to a crisp with a match the lacing may be performed more easily. Begin lacing at the center of the belt and never cross or twist the lace or have more than two thicknesses of lace on the pulley side of the belt. In lacing canvas belts, the holes should be made with a belt awl. When the lacing is finished it may be pulled through a small extra hole and the lace cut so as to catch over the edge. By this method, ty- ing of the lace is avoided. Fig. i6 illustrates four good meth- ods of lacing a belt with a thong. I shows a method of lacing a belt with a single row of holes. 2 shows a light hinge lace for a belt to run around an idler. 3 shows a double row lace. 4 shows a heavy hinge lace. 47. Wire belt lacing makes a very good splice. The splice when properly made is smooth and well adapted for leather and canvas belting. When this lacing is used, FIG. 16 — FOUR GOOD STYLES OF BELT LACING 32 FARM MACHINERY m the holes should be made with a small punch, the thick- ness of the belt from the edge and twice the thickness apart. The lacing should not be crossed on the pulley side of the belt. 48. Pulleys. — Pulleys are made of wood, cast iron, and steel. They are also constructed solid or in one piece and divided into halves. It is best to have a large cast pulley divided, as the large solid pulley is often weakened by contraction in cooling after being cast. For most purposes the iron pulley is the most satisfactory, as it is neat and durable. Belts do not cling to iron pulleys well, and hence they are often covered with leather to increase their driv- ing power. Often the driving power is in- creased one-fourth in this way. Pulleys are crowned or have an oval face in order to keep the belt in the center. The tendency of the belt is to run to the highest point, as shown in Fig. 17. The pulley that imparts motion to the belt is called the driver and the one that receives its motion from the belt the driven. 49. Rules for calculating speed of pul- leys. — Case I. The diameters of the driver and driven and the revolutions per minute of the driver being given, to find the number of revolu- tions per minute of the driven. Rule : Multiply the diameter of the driver by its r.p.m. and divide the product by the diameter of the driven ; the quotient will be the r.p.m. of the driven. Case II. The diameter and the revolutions per minute of the driver being given, to find the diameter of the driven that shall make any given number of revolutions \ FIG. 17 — SHOW ING THE EFFECT OF CROWN ON PULLEYS TRANSMISSION OF POWER 33 FIG. l8 — MALLEABLE LINK BELTING OF ROTATING SHAFTS per minute. Rule : Multiply the diameter of the driver by its r.p.m. and divide the product by the r.p.m. of the driven ; the quotient will be its diameter. Case III. To ascertain the size of the driver. Rule: Multiply the diameter of the driven by the r.p.m. de- sired that it should make and divide the product by the revolu- tions of the driver; the quotient will be the size of the driver. No allowance is made in the above rules for slip. 50. Link belting. — A common means of distributing power to various parts of a machine is by link belting. Chain link belting is adapted to almost all purposes except high speed. Two kinds of link belting are now found in general use. One 'Style is made of malle- able iron links (Fig. 18) and the other crimped steel (Fig. 19). In regard to the desira- bility of each, data is not at hand. However, it is stated that the steel links wear longer, but "^- i'^steel link belting cause the sprockets to wear faster. If this be true, the steel belting should be used on large sprockets and the malleable confined to the smaller sprockets. 51. Rope transmission often has many advantages over belt transmission in that the first cost of installation is 34 FARM MACHINERY less, less power is lost by slippage, and the di- rection of transmission may be easily changed. Transmission ropes are made of hemp, manila, and cotton. Cotton rope is not as strong as the others, but is much more durable, especially when run over small pulleys or sheaves. The groove of the pulley or sheaves should be of such a size and shape as to cause the rope to wedge into it, thus permitting the effective tension of rope to be increased to its working strength. Fig. 20 illustrates a rope transmission system. Transmission ropes, to insure the highest efficiency in respect to the amount of power transmitted and the durability of the ropes, should have a velocity of from 3,000 to 4,ooo feet a minute. To lubricate the surface of the rope and prevent it from .fraying, a mixture of beeswax and graphite is good. 52. Wire rope or cable transmission. — For transmission of power to a distance and between buildings, wire rope has many advantages. If the distance of transmis- sion be over 500 feet, relay stations with idler pulleys should be installed to carry the rope. Pulleys or sheaves for wire rope should not have grooves into which the rope may wedge, as this is very detrimental FIG. 20 — TRANS- MISSION OF POWER BY ROPES TRANSMISSION OF POWKR 35 (o the durability of the rope. The sheaves for wire rope should have grooves filled with rubber, wood, or other material to give greater adhesion. Fig. 21 illustrates how a wire rope may be used to transmit power between buildings. For tables useful in FIG. 21 — TRAN.SMISSION OF POWER BY A WIRE ROPE determining the size of rope required for a rope trans- mission, see any engineering handbook. They require too much space to be included in this work.* 53. Rope splice. — To splice a rope the ends should be *^^^2^222^ZS2EZ2?2a FIG. 22 — METHOD OF SPLICING A ROPE cut ofT square and the strands unbraided for not less than 23/2 feet and crotched together as shown at i in Fig. 22. After the strands of one end are placed between the strands of the other, untwist one strand as at C and *" Mechanical Engineers' Pocket Book." By William Kent. 36 FARM MACHINERY wind the corresponding strand of the other rope end into its place until about 9 to 12 inches remain. After this is done, the strand should be looped under the other, form- ing the knot shown at B, with the strand following the same direction as the other strands of the rope. Another strand is now unwound in the opposite direction and the same kind of knot formed. The long ends of the un- wound strands are cut to the same length as the short ones, and the short ends woven into the rope by passing over the adjacent strand and under the next, and so on. This is continued until the end of the strand is com- pletely woven into the rope. The same operation is fol- FIG. 23 — THE TRANSMISSION OF THE POWER OF A WINDMILL TO A PUMP AT A DISTANCE BY MEANS OF TRIANGLES AND WIRES lowed with all of the strands until a smooth splice is ob- tained. The above directions apply well for splicing ropes used with haying machinery. The same method may be used with transmission rope, although with the latter the splice is often made much longer. 54, Triangles, — A very handy method of transmitting the power of a windmill to a pump at a distance is by means of triangles, as illustrated in Fig. 23. These tri- angles are attached to each other by common wire, and, if the distance is great, stations with rocker arms are provided to carry the wires. When triangles are used to connect a windmill to a pump the wires are often crossed TRANSMISSION OF TOWFR 37 in order that the up stroke of the pump will be made with the up stroke of the windmill. 55. Gearing. — Spur gears are wheels with the teeth or cogs ranged around the outer or inner surface of the rim in the direction of radii from the center, and their action is that of two cylinders rolling together. To trans- mit uniform motion, each tooth must conform to a definite profile designed for that particular gear or set of gear wheels. The two curves to which this profile may be constructed are the involute and the cycloid. Gear wheels must remain at a fixed distance from each other, or the teeth will not mesh properly. Fig. 24 illustrates some of the common terms used in connection with gear wheels. Bevel gears have teeth MOENOUM a«at PITCH CIRat moTciKCLt FIG. 24 — SPUR GEARING similar to spur gears, and their action is like that of two cones rolling together. The teeth of gear wheels are cast or machine cut. Most of the gear wheels found on agricultural machines have the teeth simply cast, as this is the cheaper method of construction. Where smoothness of running is de- sired, the teeth are machined in, and the form of each tooth is more perfect, insuring smoother action. The 38 FARM MACHINERY cream separator has machine-cut gears. Very large gear wheels have each tooth inserted in a groove in the gear wheel rim. Such a tooth is called a cog; hence the term cog is often applied to all forms of the gear tooth. Cogs may be made of metal or wood. Like pulleys, gear wheels are spoken of as the driver and the driven. To find the speed ratio of gear wheels, the following rule may be used : Rule : Revolution of driver per minute, multiplied by the number of teeth in driver, equals the revolution of the driven per minute, multiplied by the number of teeth in driven. 56. Shafting. — Where several machines are to be operated from one power unit, it is necessary to provide shafting on which pulleys are placed. Shafting should be supported by a hanger at least every 8 feet, and the pulleys placed as near as possible to the hangers. Thurs- ton gives the following formula for cold-rolled iron shaft- ing: d'R H. P.: 55 when H.P. is the horse power transmitted, d is the diameter of shaft in inches, R the revolutions per min- ute. Steel shafting will transmit somewhat more power than iron, and some difterence may be made for the way the power is taken from the shaft ; but the above rule is considered a safe average. 57. Friction. — It has been stated that a machine will not deliver as much energy as it receives because a cer- tain amount must be used to overcome friction. Friction is the resistance met with when one surface slides over another. Since machines are made of moving parts, friction must be encountered continually. In the majority of cases it is desired to keep friction to a minimum, but in 4 TRANSMISSION OF TOWER 39 Others it is required. In the case of transmission of power by belting it is absolutely necessary. 58. Coefficient of friction is the ratio between the force tending to bring two surfaces into close contact and the force required to slide the surfaces over each other. This force is always greater at the moment sliding begins. Hence it is said that friction of rest is greater than sliding friction. The following table of coefficients of friction is given to show the eft'ect of lubrication ( Enc. Brit.) : Wood on wood, dry 0.25 to 0.5 soaped 0.2 Metals on oak, dry 0.25 to 0.6 ' wet 0.24 to 0.26 " " " soaped 0.2 " " metal, dry 0.15 to 0.2 " " " wet 0.3 Smooth surfaces occasionally lubricated.... 0.07 to 0.08 thoroughly " .... 0.03 to 0.036 FIG. 25 — ROLLER BEARINGS AS APPLIED TO A MOWER 59. Rolling friction. — When a l)ody is rolled over a surface a certain amount of resistance is offered. This resistance is termed rolling friction. Rolling friction is due to a slight compression or indentation of the surfaces under the load, hence is much less with hard surfaces 40 FARM MACHINERY than with soft. Rolling friction is that met with in ball and roller bearings, and is much less than sliding friction. Roller bearings reduce friction greatly. Ball bearings may be used advantageously when end thrust is to be overcome or where they can be used in pairs. They are not suitable for carrying heavy loads. 60. Lubrication. — The object of lubrication is to reduce friction to a minimum. A small quantity of oil is placed in a box and a thin film adheres both to the surface of the journal and also to the bearing, so in reality the friction takes place between liquid surfaces. The lubri- cant also fills the unevenness of the surfaces, so that there is no interlocking of the particles that compose them. Friction with a lubricant varies greatly with the quality of lubricant and the temperature. 61. Choice of lubricant. — For heavy pressures the lubri- cant should be thick so as to resist being squeezed out under the load, while for light pressures thin oil should be used so that its viscosity will not add to the friction. Thus, for a wagon, heavy grease should be used, while for a cream separator of high speed a thin oil is necessary. Temperature must also be taken into account in choosing a lubricant. Solid substances in a finely divided state, such as mica and graphite, are used to reduce friction. The practice seems to be a very good one. This is especially true with graphite in bearings that can be oiled only occasionally, as the bearings of a windmill. 62. Bearings should be of sufBcient size that the lubri- cant will not be squeezed out from between the journal and the bearing. In the design of machinery a certain pressure limit must not be exceeded. It is better to have the journal and bearing made out of different materials, as the friction in this case is less and there is a less ten- TRANSMISSION OF TOWER 41 dcncy for the surfaces to alirade. Brass, bronze, and babbit arc used for bearings with a steel journal. It is highly essential that the bearing be kept free from all dirt and grit. Occasionally it is better to let some minor bearings go entirely without lubrication, for the oil only FIG. 26 — A SELF-OILING AND SELF-ALIGNING BEARING. OFTEN THE OIL RESERVOIR BELOW THE RINGS IS ENLARGED AND THE WICK DISPENSED WITH causes the gathering of grit and sand to grind out the bearing. 63. Heating of boxes ma}^ be due to (i) insufficient lubrication, (2) dirt or grit, (3) the cap may be screwed down too tight, (4) the box may be out of line and the shaft may bind, (5) the collar or the pulley bears too hard on the end, or (6) the belt may be too tight. Self-oiling boxes are very desirable where they can be 42 FARM MACHINERY used, as they have a supply of oil which is carried up to the top of the shaft by a chain or ring. It is necessary to replenish the supply of oil only at rather long inter- vals. 64. Electrical transmission.* — Power may be trans- mitted by converting mechanical energy into electrical energy by the dynamo, and after transmission to a dis- tance be converted into mechanical energy again by the electric motor. This form of transmission has many ad- vantages where the electric current is obtained from a large central station, and no doubt will be an important form of transmission to the farmer of the future, as electric systems are spread over the country for various purposes. *See Chapter XXIL, Part II. CHAPTER III MATERIALS AND THE STRENGTH OF MATERIALS A knowledg-e of the materials used in the construction of farm machinery and the strength of these materials will be helpful in the study of farm machinery. 65. Wood. — At one time farm machinery was con- structed almost entirely with wooden framework, but owing to the increase in the cost of timber and the re- duction in the cost of iron and steel, it has been super- seded largely by the latter. Progress in the art of work- ing iron and steel, making it more desirable for many purposes, has also been a factor in bringing about the sub- stitution of iron and steel for wood. The woods chiefly used in the construction of farm machinery are hickory, oak, ash, maple, beech, poplar, and pine. It is not possi- ble to discuss to any length the properties of these woods. The wood used in the construction of machinery must be of the very best, for there is no use to which wood may be put where the service is more exacting or severe. Wood used in farm machinery must be heartwood and cut from matured trees. It should be dry and well sea- soned, and protected by paint or some other protective coating. Moisture causes wood to swell, and for this reason it is difficult to keep joints made of iron and wood tight, for the iron will not shrink with the wood. Excessive moisture in wood greatly reduces its strength, and wood subjected to alternate dryings and wettings is sure to check and crack. W^ood is especially well adapted to parts subject to shocks and vibrations, as 44 FARM MACHINERY the pitman of a mower. Iron, and especially steel, when subjected to shocks tends to become crystallized. Tliis reduces its strength very much. 66. Cast iron is used for the larger castings and most of the gears used in farm machines. At one time cast iron was used to a larger extent than at the present time, as it is being superseded by stronger but more expensive materials. Cast iron is of a crystalline structure and can- not be forged or have its shape changed in any other way than by the cutting away of certain portions with machine tools. Cast iron has a high carbon content, but the carbon is held much as a mechanical mixture rather than in a chemical combination. 67. Gray iron is the name applied to the softer and tougher grade of cast iron, which is easily worked by tools ; and white iron to a very hard and brittle grade. White iron is used for pieces where there are no changes to be made after casting. 68. Chilled iron. — When it is desired to have a very hard surface to a casting, as the face of a plow, the in- side of a wheel box, or other surfaces subjected to great wear, the iron is chilled when cast by having the molten iron come in contact with a portion of the mold made up of heavy iron, which rapidly absorbs the heat. Chilled iron is exceedingly hard. 69. Malleable iron is cast iron which has been annealed and perhaps deprived of some of its carbon, changing it from a hard, brittle material to a soft, tough, and some- what dwctile metal. The process of decarbonation usually consists in packing castings with some decarbonizing agent, as oxide of iron, and baking in a furnace at a high temperature for some time. Malleable iron is much more expensive and more reliable than common cast iron. MATERIALS AND THE STRENGTH OF MATERIALS 45 70. Cast steel. — The term cast steel, as usually applied to the material used in the construction of t^ears, etc., is cast iron which has been deprived of some of its carbon before beini;" cast. 71. Mild and Bessemer steel. — It is from this material that agricultural machinery is largely constructed. The hardness and stiffness of liessemer steel varies and de- pends largeh' upon the carbon content. Steel with a high per cent of carbon (0.17 per cent) is spoken of as a high- carbon steel, and steel with a low per cent (0.09 per cent) low-carbon steel. Bessemer steel is difficult to weld. 72. Wrought iron. — Wrought iron is nearly ])ure iron, and is not as strong nor as stiff as mild steel, but can l)e welded with greater ease. 73. Tool steel is a high-carbon steel made by carbon- izing wrought iron, and owing to the carbon content may be hardened by heating and suddenly cooling. Tool steel is used for all places where cutting edges are needed. FIG. 27— DRAWING ILLUSTRATING THE CONSTRUCTION OF SOFT-CENTER STEEL 74. Soft-center steel, used in tillage machinery, is made up of a layer of soft steel with a layer of high-carbon steel on each side. The high-carbon steel may be made glass hard, yet the soft center will support the surface and prevent breakage. In making soft-center steel, a slab of high-carbon steel is welded to each side of a soft steel 46 FARM MACHINERY slab and the whole rolled into plates (Fig. 27). A soft- center steel may be made by carbonizing a plate of mild steel by a process much the reverse of malleable making. STRENGTH OF MATERIALS All materials used in construction resist a stress or a force tending to change their form. Stresses act in three ways: (i) tension, tending to stretch; (2) compression, tending to shorten ; and (3) shear, tending to slide one portion over another. 75. Tension. — Material subjected to a stress tending to stretch it, as a rope supporting a weight, is said to be under tension, and the stress to the square inch of the cross section required to break it is its tensile strength. 76. Compression. — Material is under compression where the stress tends to crush it. The stress to the square inch required to crush a material is its compressive strength. 77. Shear. — The shearing strength of a material is the resistance -to the square inch of cross section required to slide one portion of the material over the other. 78. Transverse strength of materials. — When a beam is supported rigidly at one end and loaded at the other, as in Fig. 28, the material of the under side of the beam is under a compressive stress, and that of the upper part is subjected to a tensile stress. The property of materials to resist such stresses is termed their transverse strength. 79. Maximum bending moment (B.M.) is a measure of the stress tending to produce rupture in a beam, and for a cantilever beam (i. e., one supported rigidly at one end. Fig. 28) is equal to the load times the length of the beam (W X L). The maximum bending moment de- pends upon the way a beam is loaded and supported ; thus with a simple beam loaded at the center and sup- MATERIALS AND THE STRENGTH OF MATERIALS 47 ported at both ends the bending moment is one-half the weight times the length. The maximum bending moment for the cantilever beam of Fig. 2.8 is at -the point where it is supported. If the beam be of a uniform cross section, it will rupture at this point before it will at any other. The bending OOMPcaessioM FIG. 28 — A CANTILEVER BEAM moment in the beam at hand grows less as the distance from the weight becomes less. As the bending moment becomes less, less material is needed to resist it, and hence a beam may be designed of such a section as to be of equal strength at all points, or it is what is called a beam of uniform strength. Much material may be saved by placing it where most needed. The location as well as the value of the maxi- mum bending moment depends upon the way the beam is loaded. 80. Modulus of rupture (M.R.). — It is seldom that a material has a tensile strength equal to its strength to 48 FARM MACHINERY resist compression, so neither of these may be used for transverse stresses. The modulus of rupture is a measure of the transverse stresses necessary to produce rupture FIG. 29 — BEAMS OF UNIFORM STRENGTH FIG. 30 and is determined experimentally. It is usually a quan- tity lying" between the compressive and tensile strengths of the material. 81. Section modulus (S.M.) is the quantity represent- ing the ability of the beam to resist transverse stresses. It has been noticed by all that a plank will support a greater load on the edge than on the fiat. For a rectan- gular cross section, Fig. 30, if h =: depth in inches and b =: breadth in inches, the section modulus is 6 ' that is, the strength of a rectangular beam is propor- tional to its breadth and to the square of its depth. MATERIALS AND THE STRENGTH OF MATERIALS 49 When a beam is loaded to its limit, bending moment = section modulus X modulus of rupture. This is a general ecjuation which applies to all beams. 82. Factor of safety. — In the design of machinery it is customary to make the parts several times as strong as would be needed to carry normal loads. The number of times a piece is made stronger than necessary simply to carry the load is called the factor of safety, and in farm machine design it varies from 3 to 12. For a more complete discussion of this subject see any work on mechanics of materials. AVERAGE STRENGTH OF MATERIAL PER SQUARE INCH Material Hickory Oak White pine. . . Yellow pine. . , Cast iron Steel Wrought iron Tensile Strength 18,000 60.000 50,000 Compressive Strength 9,000 8,500 5-400 8,000 80,000 52,000 48,000 Modulus of Rupture 15,000 13,000 7,900 10,000 45,000 55,000 48,000 Values for the strength of timber were obtained from U. S. Forestry Circular No. 15. If the load or stress be continued for a long time the ultimate strength of timber will be only about one-half the above and for this reason much lower values are often given in architects' hand- books. For a more complete table see any engineers' hand- book.* *" Architects' and Builders' Pocket-Book." By "Materials of Construction." By J. B. Johnson. F. E. Kidder. 50 FARM MACHINERY Problem : Find the safe load on an oak doubletree 4 feet long, 4 inches wide, 2 inches thick. Factor of safety = 6. Let L = length in inches, IV = load in pounds, b = thickness, d = width in inches. Bending moment = y2lVL = ^^^^48 = 24W. Section modulus — -z — = —^ = 5-333- 6 6 Modulus of rupture for oak =13,000. „ ,. , Sect. Mod. X Mod. of Rupt. Bendmg moment = ^^ — : , ^ r .. Factor of Safety 3^^^5-333X13,000 J'F =481.5 pounds. (Ans.) CHAPTER IV TILLAGE MACHINERY 83. Object of tillage. — Agricultural implements and machines used in preparing the soil for the seeding or growth of crops may be classed as tillage machinery. Tillage is the art which includes all of the operations and practices involved in fitting the soil for any crop, and the caring for it during its growth to maturity. Tillage is practiced to secure the largest returns from the soil in the way of crops. Its objects have been enu- merated in other works about as follows : (i) To produce in a field a uniform texture to such a depth as will render the most plant food available. (2) To add to the humus of the soil by covering be- neath the surface to such a depth as not to hinder further cultivation, green crops and other vegetable matter. (3) To destroy and prevent the growth of weeds, which would tend to rob the crops of food and moisture. (4) To modify the condition of the soil in such a way as to regulate the amount of moisture retained and the temperature of the soil. (5) To provide such a condition of the soil as to pre- vent excessive action of the rains by washing and the wind by drifting. At the present time practically all of the various opera- tions of tillage are carried on by aid of machinery, and 'for this reason tillage machinery is of greatest impor- tance in modern farming operations. Modern tillage machinery has enabled the various objects as set forth to 52 FARM MACHINERY be realized, thus not only increasing the yield an acre, but at the same time permitting a larger area to be tilled. THE PLOW 84. The development of the plow. — The basic tillage operation is that of plowing, and for this reason the plow will be consid- ered first. Some of the oldest races have left sculptural records on their monuments describing their plows. From the time of these early records civilization and the plow have developed in an equal proportion. The first plow was simply a form of hoe made from a crooked stick of the proper shape to penetrate and loosen the soil as it was drawn along. The power to draw the plow was furnished by man, but later, as animals were trained for draft and burden, animal power was substituted and the plow was enlarged. The records of the ancient Egyptians illustrate such a plow. At an early time the point of the plow was shod with iron, for it is recorded that about 1,100 years B.C. the Israelites, who were not skilled in the working of iron, "went down to the Philistines to sharpen every man his share and his coulter." In the "Georgics," Virgil describes a Roman plow as being made of two pieces of wood meeting at an acute angle and plated with iron. During the middle ages there was but little improvement over the crude Roman plow as described by Virgil. The first people to improve the Roman model were the Dutch, who found that a more perfect plow was needed to do satisfactory work in their soil. The early Dutch plow seems to have most of the funda- mental ideas of the modern plow in that it was made with a curved moldboard, and was provided with a beam and two handles. The Dutch plow was imported into Yorkshire, Eng- land, as early as 1730, and served as a model for the early English plows. P. P. Howard was one whose name may be mentioned among those instrumental in the development of the early English plow. Howard established a factory, which re- mains to this day. James Small, of Scotland, was another who did much toward the improvement of the plow. Small's plow was designed to turn the furrows smoothly and to operate with little draft. TILLAGE MACHINERY 53 Robert Ransome, of Ipswich, England, in 1785 constructed a plow with the share of cast iron. In 1803 Ransome succeeded in chilling his plows, making them very hard and durable. The plows of Howard and Ransome were provided with a bridle or clevis for regulating the width and depth of the furrow. These plows were exhibited and won prizes at the London and the Paris expositions of 1851 and 1855. 85. American development. — Before the Revolutionary War the plows used in America were much like the English and Scotch plows of that period. Conditions were not favorable to the development of new machinery or tools. The plow used during the later colonial period was made by the village car- penter and ironed by the village smith with strips of iron. The beam, standard, handles, and moldboard were made of wood, and only the cutting edge and strips for the moldboard were made of iron. Among those in America who first gave thought to the im- provement of the plow was Thomas Jefferson. While represent- ing the United States in France he wrote : "Oxen plow here with collars and harness. The awkward figure of the moldboard leads one to consider what should be its form." Later he specified the shape of the plow by stating: "The offices of the moldboard are to receive the sod after the share has cut it, to raise it gradually, and to reverse it. The fore end of it should be as wide as the furrow, and of a length suited to the construc- tion of the plow." Daniel Webster is another prominent American who, history relates, was interested in the development of the plow. He designed a very large and cumbersome plow for use upon his FIG. 31 — WEBSTER S PI/)W 54 FARM MACHINERY farm at Marshfield, Massachusetts. It was over 12 feet long, turned a furrow 18 inches wide and 12 inches or more deep, and required several men and yoke of oxen to operate it. Charles Newbold, of Burlington, New Jersey, secured the first letters patent on a plow in 1797. Newbold's plow differed from others in that it was made almost entirely of iron. It is stated FIG. 32 — THE NEWBOLD PLOW that the farmers of the time rejected the plow upon the theory that so much iron drawn through the soil poisoned it, and not only retarded the growth of plants, but stimulated the growth of weeds. Jethro Wood gave the American plow its proper shape. The moldboard was given such a curvature as to turn the furrow evenly and to distribute the wear well. Although Wood's plow was a model for others which followed, he was unrewarded for his work, and finally died in want. William H. Seward, former Secretary of State, said of him: "No man has benefited his country pecuniarily more than Jethro Wood, and no man has been as inadequately rewarded." 86. The steel plow. — 'As farming moved farther west the early settlers found a new problem in the tough sods of the prairie States. A special plow with a very long, sloping moldboard was found to be necessary in order to reduce friction and to turn the sod over smoothly. Owing to the firmness of the sod, it was found that curved rods might be substituted for the mold- board. Later when the sod became reduced it was found that the wooden and cast-iron plows used in the eastern portion of the country would not scour well. This difficulty led to the TILLAGE MACHINERY 55 use of steel in the making of plows. Steel, having the prop- erty of taking an excellent polish, permitted the sticky soils to pass over a moldboard made of it where the other materials failed. In about 1833 John Lane made a plow from steel cut from an old saw. Three strips of steel were used for the moldljoard and one for the share, all of which were fastened to a "shin" or frame of iron. John Lane secured in 1863 a patent on soft- center steel, which is used almost universally at the present time in the making of tillage tools. It was found that plates made of steel were brittle and warped badly during tempering. Weld- ing a plate of soft iron to a plate of steel was tried, and. although the iron supported the steel well when hardened, it warped very badly. The soft-center steel, which was formed by welding a heavy bar of iron between two bars of steel and rolling all down into plates, permitted the steel to be hardened without warping. It is very strong on account of the iron center, which will not become brittle. In 1837 John Deere, at Grand Detour, Illinois, built a steel plow from an old saw which was much similar to Lane's first plow. In 1847 Deere moved to Aloline, Illinois, and established a factory which still bears his name. William Parlin established a factory about the same time at Canton, which is also one of the largest in the country. FIG. $3 — THE MODERN STEEL WALKING PLOW WITH STEEL BE.'\M FOR STUBBLE OR OLD GROUND 56 FARM MACHINERY 87. The sulky or wheel plow. — The development of the sulky or wheel plow has taken place only recently. F. S. Davenport invented the first successful sulky plow, i. e., one permitting the operator to ride. February 9, 1864. A rolling coulter and a three- horse evener were added to this by Robert Newton, of Jersey- ville, Illinois. But E. Goldswait had patented a fore carriage in 1851 and M. Furley a sulky plow with one base December 9, 1856. Much credit for the early development of the sulky plow is due to Gilpin Moore, receiving a patent January 19, 1875. and W. L. Cassady, to whom a patent was granted May 2, 1876. Cassady first used a wheel for a landside. Too much space would be required to mention the many inventions and improve- ments which have been added to the sulky plow. FIG. 34 — AN UNDER VIEW OF THE MODERN STEEL PLOW, SHOWING ITS CONSTRUCTION 88. The modern steel walking plow. — Fig. 34 shows the modern steel walking plow suitable for the prairie soils. The parts are numbered in the illustration as follows : 1. Cutting edge or share. The point is the part of the share which penetrates the ground, and the heel or wing is the outside corner. A share welded to the landside is a bar share, while one that is independent is a slip share. 2. Moldboard : The part by which the furrow is turned. The shin is the lower forward corner. 3. Landside : The part receiving the side pressure pro- duced when the furrow is turned. A plate of steel covers TiLi..\(;i': maciiini:ky 57 the landside bar, furnishing- the wearing surface. When used for old ground, the plow is usually constructed with the bar welded to the frog, forming the foundation to which the other parts are attached. Landsides may be classed as high, medium, and low. FIG. 35 — STEEL PLOWSHARES. THE UPPER IS THE SLIP SH.\RE, AND THE LOWER THE BAR SHARE FIG. 36 — THE FORM OF THE HIGH, MEDIUM, AND LOW LANDSIDES FOR WALKING PLOWS 4. Frog: The foundation to which are attached the share, moldboard, and landside. 5. Brace. 6. Beam : Alay be of wood or steel. The beam in a wooden-beam plow is joined to the plow by a beam standard. 7. Clevis, or hitch for the adjustment of the plow. 8. Handles : The handles are joined to the beam by braces. 9. Coulter: Classified as rolling, fin, or knife coulters. 89. Material. — While in the cheaper plows the mold- board and share may be of Bessemer or a grade of cast steel, in the best plows these and also the landside are usually made of soft-center steel or chilled iron. The beam is usually of Bessemer steel, while the frog may be of forged steel, malleable iron, or cast iron. 58 FARM MACHINERY go. Reenforcements. — A patch of steel is usually welded upon the shin, the point of the share, and the heel of the landside. These parts are also made interchangeable so new parts may be substituted when worn. 91. Size. — Walking- plows are made to cut furrows II FIG. 2>] — ROLLING CASTER AND ROLLING STATIONARY COULTERS, FIN HANGING, KNEE, DOUBLE ENDER, AND KNIFE CUTTERS OR COULTERS from 8 to 18 inches. A plow cutting a 14-inch furrow is considered a two-horse, and one cutting a 16- or an 18- inch furrow a three-horse plow. 92. The modern sulky plow. — The name sulky plow is used for all wheel plows, but applies more particularly to single plows, while the name gang is given to double or TILLAGE MACHINERY 59 larger plows. Fig. 38 illustrates the typical sulky plow, and reference is made to its various parts by number: I. The nioldboard, share, frog or frame, and landside is called the plow bottom. Most sulky plows arc made with interchangeable bottoms, so it is possible to use the same carriage for various classes of work by using suit- able bottoms. 2 and 3 are the rear and the front furrow wheels, re- spectively. These wheels are set at an angle with the FIG. 38 — THE MODERN FOOT-LIFT BF.AM-HITCH SULKY PLOW WITH STEEL PLOW BOTTOM vertical in order that they may carry to better advantage the side pressure of the plow due to turning the furrow- slice. 4. The largest wheel traveling upon the unplowcd land is spoken of as the land wheel. 5. The connections between the plow beam and the frame are called the bails. 60 FARM MACHINERY 6. A rod called the weed hook is provided to collect the tops of high vegetation. 7. Practically all wheel plows are now provided with inclosed wheel boxes, which exclude all dirt and carry a large supply of grease. The inclosed wheel box has a collar which excludes the dirt at the axle end of the wheel box, and has the other end entirely inclosed with a cap. The grease is usually stored in the cap, which is made detachable from the hub. 8. Wheel plows are now generally provided with a foot lift, b}^ which the plow is lifted out and forced into the ground. 9. For plowdng in stony ground, it is necessar}^ to set the plow to float, so that in case a stone is struck the plow will be free to be thrown out of the ground without lifting the carriage, otherwise the plowman will be thrown from his seat and the plow damaged. 10. The various parts of the sulky plow are usually attached to the frame, and this is an important part in the construction of the plow. Not all sulky plows, how- ever, are made with a frame. 93. Types of sulky plows. — Sulky plows differ much in construction. The two-wheel plow is not used exten- sivel}^ at the present time because it does not carry the side pressure of the plow w^ell and does not turn a good square corner. One type of construction is that of a frame with wheels attached by means of brackets, making a carriage. To this carriage the plow proper is attached by bails. The hitch to frame plows may be to either the frame or to the plow beam. The former is known as a frame hitch and the latter as a beam hitch. There are good plows upon the market with a frame hitch, but the beam hitch plow^ seems to be preferred. A cheaper type of plow than the frame plow is the TIIJ.ACI-: ^jACHINKRV 6i frameless, with the wheel braekets bolted directly to the ])lo\v beam. Such plows will often do very satisfactory work, but are not quite so handy. Frame plows are gen- erally high-lift plows in that the plow may be lifted sev- eral inches abo\-e the plane of the carriage. A high-lift plow offers an advantage for cleaning and transporting from field to field. With the cheaper plows there is no attempt to guide or steer the plo\v other than let it follow the team. Such plows may be classed as tongueless. A tongueless plow may, howe\er, be provided with a hand lever either to shift the hitch or guide the front furrow wheel. Such a plow may be called a hand-guided plow, and the lever for guiding or adjusting is called the landing lever. There is still another type of frameless plow which is guided by the hitch. In the hitch-guided plow the front FIG. 39 — THE MODERN G.\NG TLOW 62 FARM MACHINERY furrow wheel or the front and rear furrow wheels are steered by a connection to the plow clevis. A tongue may be used with this type of plow to keep the team straight and to hold the plow back from off the horses' heels while being transported. The higher class sulky plows are guided with an ad- justable tongue, the tongue being connected to the front and rear furrow wheels. Sulky plows are usually fitted with a 14-, 16-, or 18-inch plow bottom, the 16-inch being the common size. 94. Gang plows. — Nearly every sulky plow upon the market has its mate among the gang plows, which, as stated before, do not differ greatly from it, only in that they have two or more plow bottoms instead of one. Gang plows usually have a hand lever to assist the foot lift in raising and lowering the plow. The common sizes of gang-plow bottoms are 12- and 14-inch. FIG. 40 — TYPES OF PLOW BOTTOMS. NO. I IS THE STUBBLE OR OLD GROUND BOTTOM. NO. 7 IS THE BREAKER BOTTOM FOR TOUGH NATIVE SODS. NOS. 2, 3, 4, 5, AND 6 ARE INTERMEDIATE TYPES FOR GENERAL PURPOSE PLOWS TILLAGE MACHINERY 63 95. Types of plows' bottoms. — I'he plow bottom, as stated before, is the plow proper, detached from the beam or standard. Owing" to the varying conditions under which ground is to be plowed, a few general types, each with its own form of moldboard and share, have been established. These forms are illustrated in Fig. 40, and vary from No. 7, the breaker, with its long sloping share and moldboard, for natural sods, to No. i, the stubble plow with short, abrupt moldboard for old ground. The FIG. 41 — A STEEL WALKING PLOW WITH INTERCHANGEABLE MOLDBOARDS, BY WHICH IT MAY BE MADE INTO A BREAKER OR STUBBLE PLOW intermediate forms are given the name of turf and stubble, or general purpose, plows, being used for the sod of the cultivated grasses or for stubble ground. The breaker is suitable for the native sods of the Western prairies, as it turns the furrows very smoothly and covers the vegetation completely, that it may decay quickly. The abrupt curvature of the moldboard in the stubble bottom causes the furrow slice to be broken and crumbled in making the sharp turn, and thus has a more pulver- izing action and is designed for old ground. The general purpose plow is designed for the lighter sods, such as those of the tame grasses. 64 FARM MACHINERY Some manufacturers make plows with interchang'eable moklboards, and sulky plows are usually built with inter- changeable bottoms, so the plow or carriage may be used for a variety of soils. 96. The jointer. — The jointer is used in soils inclined to be soddy. It enables the plow to do cleaner work and cover all vegetation, throwing a ribbon-like strip of. turf into the furrow. It will often render excellent service FIG. 42 — TYPES OF JOINTERS. THE TWO AT THE LEFT ARE MADE OF steel; THE ONE AT THE RIGHT IS A CHILLED IRON JOINTER WITH AN ADJUSTABLE SHANK where sod ground is to be plowed deep and left in shape for immediate pulverizing to fit it for crops. It will cut out a section of the sod, turning it into the bottom of the furrow, where it will be completely covered, and at the same time leave the upper edge of the furrow slice com- posed only of comparatively loose earth. By cutting out the corner of the furrow slice, the furrows will be com- pletely inverted, leaving the surface smooth. If the fur- row slice is perfectly rectangular, the furrows are inclined to pile or lap over each other. TILLAGE MAClItNF.RY 65 97. The chilled plow. — In many places, especially in the eastern United States, many of the plows used are of chilled cast iron. A chilled plow with a reversible point FIG. 43 — A MODERN CHILLED WALKING PLOW WITH JOINTER .'XND GAUGE WHEEL is shown in Fig. -43. Chilled plows are very hard, but will not scour in all soils. The share can only be ground to an edge when dull, or it may be replaced at a small cost. 98. The hillside plow. — In localities too sloping to throw the furrow uphill, hillside or reversible plows are FIG. 44 — A REVERSIBLE OR HILLSIDE PLOW WITH KNIFE COULTER used. A plow which may be made a right- or left-hand plow by turning it under on a hinge to the standard is shown in Fig. 44. In irrigated districts where dead fur- 66 FARM MACHINERY rows interfere with the carrying of water upon the land, reversible plows are used. These are of many forms, but the type will not be further discussed. 99, The subsoil plow. — Where it is desirable to loosen the ground to a greater depth than can be done with a surface plow, the subsoil plow is used. It is used with FIG. 45 — A SUBSOIL PLOW FOR LOOSENING THE SOIL IN THE BOTTOM OF THE FURROW MADE BY THE COMMON PLOW the regular plow, following in the furrow made by it. Opinions in regard to the value of this plow dififer, but the subject will not be discussed here. 100. The disk plow. — The disk plow is the result of an efifort on the part of inventors to reduce the draft due to the sliding friction upon the moldboard. Figs. 46 and 47 show the modern disk plow made for horse and engine power, respectively. A plow consisting of three disks cutting very narrow strips was about the first one pat- ented, M. A. and I. N. Cravath, of Bloomington, Illinois, being its inventors. Under certain conditions, it is said, this plow did very satisfactory work, but the side pressure was not sufficiently provided for. M. F. Han- cock succeeded in introducing the disk plow into localities TILLAGE MACHINERY 67 where conditions were well adapted to its use, and be- came prominent as a promoter of the disk plow. FIG. 46 — A DISK G.\NG PLOW TO UE Ol'ER.MED BY HORSE POWER The draft of the disk plow is often heavier in propor- tion to the amount of work done, and the plow itself is FIG. 47 — AN ENGINE DISK GANG PLOW TURNING 8-, I0-, OR 12-INCH FURROWS 68 FARM MACHINERY more clumsy than the moldboard plow; sp where the latter will do good work there is no advantage in using the former. In sticky soils, however, or in very hard ground, where it is impossible to use the moldboard plow, the disk will often be found to do good work, and in the latter case with much less draft. The moldboard plow is recommended by the manufacturers of both plows where it will do good work. Disk plows have been made in the walking style within the past few years, but have proved rather unsatisfactory. A few of this style are suitable for hillside and irriga- tion plows, being made reversible. loi. The steam plow. — Where steam power is used for other purposes, or where farming is carried on exten- sively, steam may be used at a saving over horse power in plowing. This has been attempted for many years, but it has only recently become very successful, and even now the steam plow is used onl}^ on large farms and on level land. If the soil is not firm, the great weight causes the traction wheels of the engine to sink into the ground until the plow cannot be pulled. The modern steam plow, direct connected, steered from the rear, and having a steam lift, is a very successful machine. Its advantages are its capacity and unlimited power for deep plowing. The cost of plowing with a steam plow varies with the cost of fuel and other condi- tions, but it should be from 75 cents to $1.50 an acre. Outfits capable of plowing and at the same time pre- paring the seed bed and seeding 40 to 50 acres in a day are now in use. A ty])e of steam plow which has been successful in Europe is operated by a system of cables. The plow is drawn back and forth across the field by means of the cable, the engine being placed at one end of the field. TILLAGE MACHINERY 69 The steam plow may, in some cases, in certain soils, be the means of producing" an increase of yield of crops, by plowing to a greater depth than could be done by horse power. 102. The set of walking plows. — The original set of a plow, or the proper adjustment of its point, share, and beam, is given by the maker. Each time when the plow is sharpened the smith is depended upon to return this set to the plow. 103. Suction. — The suction of a plow is usually meas- ured as the width of the opening between the landside and a straight edge laid upon it when the plow is bottom side up. It is usually about yi inch, but may vary slightly FIG. 48 — THE SUCTION OF WALKING PLOWS SOMEWHAT EXAGGERATED without detriment to the plow. It may also be described as the amount the point is turned down to secure pene- tration. The point of the share is also turned slightly outward, which makes the line of the landside somewhat concave. The beam of a three-horse plow is in a line with the land- side, but in a two-horse plow it is placed a little to the furrow side of the line of the landside, usually about 3 inches, in order that the hitch may be more directly behind the team. For ordinary plows tbe point of the beam stands 14 inches high, but it is higher for hard soils. Some bearing must be given at the heel of the share in walking" plows, to carry the downward pressure of the 70 FARM MACHINERY furrow. One inch width of bearing surface for 12- and 14- inch plows and 1^4 inches for 16-inch plows is the average width of this bearing, more being needed for soft, mellow soils than for firm soils. This fact necessitates a change in the plow in changing from hard to mellow soils, as a share set for a hard soil will swing to one side or work poorly in the mellow soil. A handy device called a heel plate is sometimes used to vary the width of surface at the heel. 104. The set of sulky plows. — With the sulky plow, when the share lies on a flat surface, the distance from the heel of the landside to the surface is called the suction. 1 FIG. 49 — THE BEARING SUkKACt kt.^ inch, the ^/s, inch size being suit- able for heavier work. The number of teeth to the foot of the harrow may vary from five to eight, and this num- ber as well as their size should correspond to the kind of work and conditions under which the harrow is to be used. Originally wooden harrow frames were the only kind used, but now they are generally made of steel pipe, angle and channel bars. The later styles of harrow are much more durable, and, the same amount of material being used, there is little choice between the styles of steel harrows. Lever harrows have an advantage in that 82 FARM MACHINERY the angle of the tooth may be adjusted, making the im- plement capable of performing a variety of work. Some levers are more easily operated than others. This lever adjustment facilitates transportation. Some harrows are so constructed that the sections may fold upon each other for easy transportation. Harrows in which the ends of the tooth bars are protected are suited for orchard work, as the bars will not catch and bark the trees. FIG. 54 — A STEEL LEVER HARROW WITH A RIDING ATTACHMENT OR HAR- ROW CART. THIS HARROW HAS THE TOOTH BARS MADE OF STEEL CHANNEL BARS WITH PROTECTED ENDS 120. The harrow cart. — In order that the operator may ride, this device is sometimes attached behind the harrow. The attachment is made to the eveners by angle bars, and the wheels are made to caster so that in turning it will follow the harrow. It is very laborious to walk behind the harrow on plowed ground, and the harrow cart re- moves this difficulty ; at the same time the rider has easy control of the team and is above the dust. The extra draft should be very little, but the wheels should have wide tires to prevent them from cutting into the soft ground. TILLAGE MACHINERY 83 121. The disk harrow. — This tool is perhaps the best ada])tccl for pulveri/.inj:^ and loosening the ground of any yet devised. On account of its rolling action, it can l)e used for a great variety of conditions. It does excellent service in reducing plowed ground which is inclined to be soddy, and may even be used to prepare hard and dry soils for plowing. It may also be used to advantage in destroying weeds after they have grow^n beyond the con- trol of the smoothing harrow. In fact, the disk harrow should be in use on every farm. FIG. 55 — A TWO-LEVER DISK HARROW. SCRAPERS OPERATED BY THE FEET 122. The full-bladed disk harrow. — This class of har- row may be used to good advantage as a pulverizer, and the blades are easily sharpened when dull, either by grinding or turning to an edge. The diameter of the disks may vary from 12 to 20 inches. For general purposes, the medium-sized, or 14- or 16-inch, disk is the size best adapted, although the larger sizes may have slightly less draft. The penetration of the disk blades into the ground 84 FARM MACHINERY is determined by (i) the line of draft, (2) the angle of gangs, (3) the curvature of the disk blades, (4) the weight of the harrow, and (5) the sharpness of the blades. 123. The cutaway or cut-out disk harrow. — As may be judged from the name, portions of the periphery of the blade of this harrow are notched out, allowing the re- maining portions to penetrate the ground to greater FIG. 56 — A SINGLE-LEVER CUTAWAY DISK HARROW depth. The entire surface, however, is not so thoroughly pulverized as with the full-bladed disk. It has a dis- advantage of being hard to sharpen. The cutaway har- row seems to be especially adapted to work among stones and may be used to cultivate hay land. 124. Spading harrow. — This type of harrow has blades curving at the ends, forming a sort of sprocket wheel, with the cutting edges out. Tt works much like a cut- away. To sharpen it the blades must be separated and TILLAGE MACIllNLRY 85 drawn out much as a plow is sharpened. A special form of spading harrow with sharp spikes is used in cultivating FIG. 57 — A SPADING HARROW alfalfa, and is given the name of "alfalfa harrow." The orchard disk differs from the common disk only in that it has an extension frame, so that it may be used to FIG. 58 — AN ORCHARD DISK HARROW WITH WIDE FRAME TO WORK UNDER TREES. THE GANGS MAY BE SET TO THROW IN OR OUT cultivate rows of small plants as well as to reach under trees and cultivate the soil under the branches. The disk 86 FARM MACHINERY gangs often may be set to throw in or out from the center, to suit the nature of the work. Usually the first parts of the disk harrow to wear out are the bearings. There are many styles of ball and chilled iron bearings in the market now, but those of hard wood seem to be as satisfactory as any, since they may be easily replaced. The construction of the bearings should be such as to exclude all dirt. A reliable means of oiling should be provided, and it is well to have an oil pipe to the bearings which extends above the weight pans or frame. The scrapers or cleaners to keep the disks clean are another important feature of the disk harrow. These may be made stationary or so arranged as to be operated by the feet of the driver or otherwise when needed. They are not needed when working in dry soil, and when stationary they cause undue friction. A scraper that is made to oscillate by horse power over the face of the disk blades, and clean them automatically once in six revolutions, is sometimes used. When not needed it may be thrown out of gear. Disk-harrows with bumpers to carry the end thrust of the sections are usually made with one lever in order that the gangs or sections may be adjusted and the bump- ers kept squarely together. A scheme to surmount this difficulty is to adjust the outer end of the gangs only. A two-lever disk harrow ofifers several advantages by ad- justing the gangs at different angles for side hill work and for double disking by lapping one-half each time. I'he soil when disked once is not as firm as the undisked ground, and if lapping one-half, it may be necessary to set the gangs at different angles in order to cause the harrow to follow the team well. It is advisable to have good clearance between stand- TILLAGE MACIIINLRY 87 ards and the disks and between the weis^ht boxes and the disks. Good clearance will prevent clog-^ing in wet and trashy ground. In order to secure flexibility of the gangs it is almost essential to have spring pressure to keep the inside ends of the gangs down. There is a natural tend- ency for the gangs to raise at the center. If three horses are to be used, it is advisable to have a stub tongue and an offset pole. Patent three-horse eveners to remove side draft with the pole set in the center are not to be advised. A liberal amount of material must 1)e used in the con- struction as well as good workmanship — for instance, a heavy gang bolt with a lock nut. A scpiare gang bolt is considered better than a round one. 125. Tongueless disk harrows are now made with a truck under a stub-tongue. These harrows, no doubt, make the work lighter for the team, but sacrifice a certain amount of control in handling the harrow. This feature is of more importance under certain conditions than others. A tongue truck is also used and is a very satis- factory addition to the harrow^ 126. Plow-cut disk harrows, — Harrows have been con- structed for several years with disks which have a raised or bulging center, the idea being that the dirt in being forced up over the raised center is turned over much like it would be from the moldboard of a plow. It is claimed by the manufacturer that this shape enables the harrow to cover the small trash better, that it leaves the ground leveler, and the harrow has better penetration on account of the shape of the disk blades. All these claims are de- nied by other manufacturers. THE ROLLER AND FLANKER 127. The land roller is a very efficient tool for working up a fine tilth and for making the ground smooth and »5 FARM MACHINERY firm. The first rollers were constructed out of suit- able logs and were drawn by yokes engaging pins in the ends of the rollers. It was soon found that if a log of any width was used, it would not work well on uneven ground, and it was clumsy to turn. Rollers made in two or three sections were then introduced, which were found in a great measure to overcome these difficulties. If the soil moisture is to be conserved, the roller should be followed by a smoothing harrow, FIG. 59 — A SMOOTH IRON ROLLER as the former smooths and packs the ground, permitting the escape of the capillary water into the air. The har- row will roughen the surface, thereby decreasing the wind velocity, and will also put a dust mulch over the surface. The ground will be in much better condition for a mower or other machine after the roller has passed over it. TILLAGE MACHINERY 89 Certain advantages over the plain smooth rollers are claimed for the corrugated or tubular rollers, several styles of which have been invented. They are said to FIG. UO— A TUBULAR ROLLER crush the clods better, and they do not leave a smooth surface. FiQs. 60 and 61 illustrate two rollers of this FIG. 61 — A FLEXIBLE RuLLKK AND CLOG CRUSHER OK SPECIAL DESIGN type. H. \V. Campbell invented a tool of this nature called the subsurface packer, for packing the ground be- neath the surface. This tool (illustrated in Fig. 62) con- sists of a series of wheels with wedge-shaped tread. 90 FARM MACHINERY Campbell advocates a method of surface cultivation to conserve the moisture in semi-arid regions. The inter- tillage of wheat and other small grains is included in this system. An authority states that rollers should be at least 2 feet in diameter, and should not weigh more than FIG. 62 — THE SUBSURFACE PACKER 100 pounds to the foot of width. If intelligently used, the roller is no doubt a valuable implement to the average farm. 128. The common planker, although a home-made tool, is a very valuable imple- ment for crushing clods and smoothing the sur- face. It is not inclined to push surface clods into the soil like the roller, but will catch them and pulverize them. The planker does not adapt itself well to any unevenness of the surface and does not pack the soil like the roller. FIG. 63 — THE COMMON PLANKER, A SERVICEABLE TOOL USUALLY MADE ON THE FARM TILLAGE MACHINERY 9I THE CULTIVATOR 129. Development.- — The modern cultivator, which is a very- efficient aid to the cultivation of growing plants, has developed under the addition of animal power from a kind of crude hoe used in the early days. The original single shovel was changed for the double shovel, this in turn was supplanted by the straddle-row cultivator, and even the latter was increased in size until in some cases the modern cultivator will take two rows at a time. A horse hoe and drill was invented l)y Jethro Tull early in the eighteenth century, but this was never a popular machine. Until i860 country blacksmiths generally made the double shovels used by farmers. A patent was granted to George Esterly, April 22. 1856, on a straddle-row cultivator for two horses, and his was the first of the line of implements in the manufacture of which millions are now invested. 130. Classification of cultivators. Single- and double-shovel cultivators. One-horse cultivators. Five- and nine-tooth cultivators. Straddle-row cultivators. Walking — Tongue, Tongueless. Riding. Combined. Smgle-row. Double-row. Surface cultivators. 131. Single- and double-shovel cultivators, although used xery extensively at one time, have their use con- fined almost entirely to garden and cotton culture. 132. The one-horse cultivator is used largely in gar- dening and for cultixating corn too high to be cultivated with the straddle-row cultivator. It may be provided with almost any number of teeth from 5 to 14. The teeth may vary from the harrow tooth designed for producing a very fine tilth, to the wide reversible shovels used on 92 FARM MACHINERY the five-tooth cultivators. Also a spring tooth may be used similar to those used on the spring-tooth harrow. 133. Features of cultivators, with suggestions in regard to selection. — The gangs (sometimes called rigs) are the beams, shanks, and shovels. Usually several styles of gangs may be fitted to each cultivator. The shovels may vary in number from four to eight for a pair of gangs. The larger number is to be preferred for producing the FIG. 64. — FIVE- AND ELEVEN-TOOTH ONE-HORSE CULTIVATORS. EACH HAS A LEVER FOR VARYING THE WIDTH, AND ALSO GAUGE WHEELS. ONE HAS A SMOOTHING ATTACHMENT proper tilth of the ground, but are very troublesome in being easily clogged with trash. The six-shovel gangs are very popular for corn culture. The eight-shovel gangs may have each set of four shovels arranged either obiquely or in what is called a zigzag. Best cultivator shovels are made of soft-center steel. They are made of almost any width, and may be straight or twisted. The twisted shovel has a plow shape designed to throw the dirt to one side or the other, while the straight shovel must be adjusted on its shank to do this. The beam may be made of wood, steel channel, flat bar, or pipe. The wood beam is somewhat lighter, but not so strong or TILLAGE MACHINERY 93 dural)le. The shanks may be constructed of the same material as the l)eani and are provided either with a break-pin device or knuckle joint to prevent breakage when an obstruction is struck. Flat springs may l)e used for the shanks, and when so used the term spring tooth is applied. Gopher shovels are arranged to take the place of a special surface culti- vator. Such an arrangement is not generally satisfactory. A device is sometimes added to keep the shovels facing directly to the front. Such a gang is spoken of as having a parallel beam. Seats are of two styles : the hammock and the straddle. The hammock seat is supported by the frame at each side and oflers a good opportunity to guide the gangs with the feet. The straddle seat is more rigid, hence is well adapted to the treadle- or lever-guided cultivators. The pivotal tongue is a device enabling the operator to vary the angle with which the tongue is attached to the cultivator frame. It may be used as a steering device, or to set the tongue at such an angle that the cultivator will not follow directly behind the team. It is very use- ful in side hill work wdiere the cultivator tends to crowd down the hill. It may also be used in turning in a limited space. The expanding axle permits the width of track to be varied, necessary on account of various widths of rows. It is accomplished by a divided steel axle or by the use of collars upon the axles. The divided axle permits of the use of the inclosed wheel box. It is an advantage to have the half axles reversible in that when the axle end becomes worn the opposite end may be substituted. Spacing. — Some provision should be made to widen or narrow the spacing of the gangs or rigs. On single-row cultivators this is accomplished by slipping the couplings 94 FARM MACHINERY in and out upon the front arch. The spacing in two- row machines should be accomplished by a lever which permits the change to be made while in operation. Suspension. — The gangs should be so suspended as to swing freely in a horizontal plane. If the point of sus- pension is too far back and the suspending arm or chain too short, the shovels will be lifted out of the ground as FIG. 65 — A TONGUELESS FOUR-SHOVEL CULTIVATOR WITH WOODEN GANGS. THE SHOVELS ARE NOT IN PLACE the gang is carried to either side. The farther ahead the gang is suspended and the longer the suspending arm, the more nearly the gang will swing in a plane. Con- siderable difference is experienced in the ease with which a long gang is guided compared with a short gang. This is due to the fact that as a short gang is swung to one side more work is done, as the shovels must be carried ahead ; while with a long gang the shovels are not carried ahead to such an extent. Coupling. — The double hinge joint by which the culti- vator gang is attached to the frame is called the coupling. Due provision should be found in the coupling for taking up wear. It is impossible to guide properly a gang with much lost motion in the coupling. TILLAGE MACTIINRRY 95 Raise of rigs. — Springs should be provided to aid the operator in lifting the heavy rigs. Also these springs are often used to aid in forcing the shovels into the ground. Levers. — In riding cultivators the lifting levers should FIG. 66 — A RIDING BALANCE-FRAME FOUR-SHOVEL CULTIVATOR WITH HAM- MOCK SEAT AND STEEL GANGS be so placed as to be easily handled from the seat. In two-row machines it is very essential to be able to work each gang independently in raising and lowering. Tn this way one gang may be freed from trash without molesting the others. Balance frame is a name applied to cultivators so con- structed that the position of the wheels may be so ad- justed, either by a lever- for the purpose or by the move- ment of the gangs, as to balance the weight of the driver and cultivator on the axle. 96 FARM MACHINERY Cultivator wheels should be high and provided with wide tires. Wheel boxes. — A notable improvement is found in the closing of the ends of the wheel boxes, making it possible to keep the bearings well lubricated. The spread arch is a device to cause the gangs to swing in unison, and should be made adjustable in width. Hitch. — It is a great advantage to have the height of hitch adjustable to horses of various sizes. |p-'4,^kfc^n FIG. 67 — A COMBINED WALKING AND RIDING SIX-SHOVEL CULTIVATOR WITH STRADDLE SEAT AND TREADLE GUIDE. THE HANDLES TO BE USED WHEN WALKING ARE NOT ATTACHED Treadle guide. — Upon many cultivators a device has been added to guide the gangs as a whole by foot levers. i\ TILLAGE MACHINERY 97 Such a device is called a treadle guide, and is often a very desirable feature. Pivotal wheels are a scheme for guiding cultivators. The wheels may be connected to a treadle device or to a lever worked by the hands. This plan permits of an easy control of the cultivator. FIG. 68 — A RIDING SURFACE CULTIVATOR A walking, tongueless cultivator with four-shovel gangs is illustrated in Fig. 65. The tongueless offers one advantage in requiring less room for turning. It is essen- tial that the team work very evenly to do good work. Fig. 66 illustrates a balance-frame six-shovel riding culti- vator with a hammock seat. The wheels may be drawn 98 FARM MACHINERY back by a lever when the gangs are lifted in order to be more directly under the weight and prevent the tongue from flying up. The combined cultivator, walking and riding, is illus- trated in Fig. 67. This cultivator has a straddle seat and a balancing lever to adjust for the weights of different riders. The surface, or the gopher, cultivator (Fig. 68) is used for surface cultivation. It is very effective in destroying III j«, a I' ft. ^,. FIG. 69 — A TWO-ROW CULTIVATOR, GUIDED WITH A LEVER weeds when small, conserving the soil moisture, and does not prune the corn roots when working close to the corn. The two-row cultivator is the latest production in the line of cultivators. It is a very useful tool v/here farm labor is scarce, and will do very creditable work for subsequent cultivations when the plants are of some height. Fig. 69 illustrates a cultivator of this type. The disk cultivator illustrated in Fig. 70 is a tool which will move large quantities of dirt to or from the corn. . ' r/ .» TILLAGE MACHINERY 99 It is useful on this account for covering large weeds. Fig. 71 illustrates the eagle-claw gang, or the usual ar- rangement of shovels in the eight-shovel cultivator. FIG. 70 — A DISK CULTIVATOR 134. Listed corn cultivators.— For localities where the listing of corn is practiced, a cultivator has been FIG. 71 — AN E.\GLE-CLA\V FUUK-SHOVEL GANG LOFC. lOO FARM MACHINERY 1 designed to follow the listed furrow for the first two cultivations. The machine is guided either by sled runners or roller wheels which run in the furrow. The shovel equipment varies between shovels and disks. The cultivator is made for one or two rows, and is a very suc- cessful tool. 135. Stalk cutter. — An implement in general use in corn and cotton regions and which should be men- tioned here is the stalk cutter. Its purpose is to cut cotton and corn stalks when left in the field into such lengths as not to interfere with the cultivation of the next crops. The implement, primarily consists in a cylinder with five to nine radial knives. It is rolled over the stalks, FIG. 72 — A SIMPLE LISTED CORN CUL- TIVATOR. DISKS ARE OFTEN USED IN PLACE OF THE SCRAPERS. THE IM- PLEMENT IS ALSO MADE TO CULTI- VATE TWO ROWS AT A TIME !iGlilllMpi|iiii||M|| Mlll|!|l FIG. 72, — A SINGLE-ROW STALK CUTTER TILLAGE MACHIXI^^Y lOI cutting them into short lengths. Stalk hooks are pro- vided which gather the stalks in front of the cylinder. Two types are found upon the market, the spiral and the straight knife cutters. The spiral knife cutter carries practically all of the weight of the machine on the cylin- der head while in operation, the side wheels being raised and the cylinder head brought in contact with the ground. Stiaight knife cutters have the cylinder head mounted in a frame, and when placed in operation are forced to the ground with spring pressure. The latter machine is much more j)Ieasant to operate, as it rides more smoothly. Some cutters are equipped with reversible knives with two edges sharpened. A stalk cutter attachment is made for a cultivator carriage. The implement in general may be had as a sinerle- or double-row machine. 1 CHAPTER VI SEEDING MACHINERY Seeders and Drills 136. Development. — Seeding by hand was practiced universally until the middle of the last century. Seed was either dropped in hills and covered with the hoe, or broadcasted and covered with a harrow or a similar implement. In fact, in certain •localities in the United States hand dropping is practiced to some extent at the present time. Broadcasting seed by hand is practiced in many places. A sort of drill plow was developed ih Assyria long before the Christian era. Nothing definite is known of this tool, but it was evidently one of the crude plows of the time fitted with a hopper, from which the seed was led to the heel of the plow and drilled into the furrow. Just how the seed was fed into the tube we do not know. The Chinese claim the use of a similar tool 3,000 or 4,000 years ago. Jethro Tull was perhaps the first to develop an implement which in any way resembles our modern drill. In 1731 he pub- lished a work entitled "Horse Hoeing Husbandry," in which he set forth arguments to the effect that grain should not be broad- casted, but should be drilled in rows and cultivated. This is, in a measure, like the system promulgated by Campbell, and which bears his name. Tull designed a machine which would drill three rows of turnips or wheat at a time. He used a coulter as a furrow opener and planted seed at three diflferent depths His reason for this was that if one seeding failed, the others coming up later would be sure to be successful. Tull, like many others who spent their lives in invention, died poor, but he was successful in developing a line of drills, horse-hoes, and culti- vators. American development. — The first patent granted to an Ameri- can was that Eliakim Spooner in 1799. Nothing remains to tell us of the nature of this device. Many other patents followed SEEDING MACHINERY IO3 the first, but none are worthy of mention until a patent was granted to J. Gibbons, of Adrian, Michigan, August 25, 1840. Gibbons's patent was upon the feeding cavities and a device for regulating the amount delivered. A year later he patented a cylindrical feeding roll with different-sized cavities. M. and S. Pennock. of East Marlboro, Pennsylvania, obtained a patent March 12, 1841, for an improvement in cylindrical drills. The patent pertained to throwing in and out of gear each seeding cylinder, and also to throwing the machine in and out of gear while in operation. These men manufactured their drill and sold it in considerable quantities. Following the patent issued to the Pennock brothers came a long list of patents upon "slide" and "force-feed" drills. Slide drills are distinguished from the others in that a slide is pro- vided to vary the size of the opening through which the seed has to pass, and in this way the amount of seed sown is varied. Force-feed drills carry the seed from the seed box in cavities in the seed cylinder, in which the amount is varied either by varying the size of seed pockets or by varying the speed of the seed cylinder. The first patent upon a force-feed grain drill was issued November 4, 1851, to N. Foster, G. Jessup, H. L. and C. P. Brown, and was the introduction of the term force feed. In 1854 the Brown brothers incorporated as the Empire Drill Com- pany and established a factory at Shortsville, New York. In 1866 C. P. Brown devised and patented a modification which has been known ever since as the "single distributer." One of Brown's employees, in connection with a Mr. Beckford, removed to Macedonia, New York, and in 1867 took out several patents which presented the "double distributer." The double distributer was a seed wheel with a flange on each side, one with large cavities and the other with small to suit the different sizes of grain. This system was adopted by the Superior Drill Com- pany, of Springfield, Ohio. In 1877 a patent was granted to J. P. Fulghum for a device for varying the length of the cavities of the seed cylinder, and thus varying the amount of seed drilled. This principle is now used by many manufacturers. The first drills were provided with hoes, but later a shoe was found to be more satisfactory. Perhaps the shoe was introduced by Brown, who devised the shoe for corn planters. I04 FARM MACHINERY 137. Classification of seeders. Broadcast seeders : . Hand, rotating distributer. Wheelbarrow. End-gate, rotating distributer. Wheeled broadcast : Wide track. Narrow track. Agitator feed. Force feed. Combination with cultivator. Combination with disk harrow. 138. The hand seeder with rotating distributer consists of a star-shaped wheel which is given a rapid rotation either by gearing from a crank or by a bow, the string of which is given one wrap around the spindle of the ! FIG. 74 — A CRANK HAND SEEDER. SEEDERS OF THIS KIND ARE ALSO OPERATED WITH A BOW distributing wiieel. Fig. 74 shows a seeder of this order. A bag is provided with straps which may be carried from the shoulders and the distributing mechanism placed at the bottom. The use of this seeder is confined to small areas, and the uniformity of its distribution of the seed is not the best. «l SEEDING MACHINERY 105 139. The wheelbarrow seeder is used to some extent for the sowing- of grass seed, and seems to l)e the survivor of this type of seeder, which was at one time used exten- FIG. 75 — A WHEELBARROW SEEDER sively in England. A vibrating- rod passes underneath the box and by stirring- causes the seed to flow out of the openings on the under side of the seed box. 140. The end-gate seeder is provided with a rotating or whirling distributer much like the hand machine first described. Formerly nearly all of this type of machine FIG. 76 — AN END-GATE SEEDER WITH A FORCE FEED AND FRICTION GEAR- ING. THIS MACHINE HAS TWO SEED DISTRIBUTERS io6 FARM MACHINERY had only one distributer, bvit now the better makes are provided with two and a force-feed device to convey the seed to the distributer, i'ower to operate the seeder is obtained from a sprocket bolted to one wheel of the wagon on which the seeder is mounted, and transmitted to the seeder with a chain. The distributer is geared either by bevel or friction gears. It is stated that the friction gear relieves the strain on the machine when starting, and also runs noiselessly. The bevel gear drive FIG. ^]^ — AN AGITATOR-FEED BROADCAST SEEDER WITH CULTIVATOR COVER- ING SHOVELS. THIS IS A WIDE-TRACK MACHINE is more durable and is recommended as being preferable by manufacturers who manufacture both styles of gears. The same criticism may be made of this machine as of the hand machine. The distribution of the seed is not the best, and great accuracy in seeding is not possible. As the seeder is high above the ground, the wind hinders the operation of the machine to such an extent as to prevent its use in anything but a light wind or calm. In order to secure greater accuracy, the seed in some makes is fed the distributer by a force-feed device. A small seeder of this type has been arranged to be placed upon SEEDING MACHINERY 107 a cultivator to sow a strip of ground the width of the cultivator as the ground is cultivated. This seeder has not as yet reached an extended use. 141. Agitator feed. — A broadcast seeder is still upon the market not provided with a force feed, but having what is known as an agitator feed. This feed is composed of a series of adjustable seed holes or vents in the bottom of the hopper, and over each is an agitator or stirring wheel to keep the seed holes open and pass the seed to them. The agitator feed, although cheaper and more simple than others, is not so accurate as the force feed described later. Fig. jy illustrates a broadcast seeder with an agitator feed and cultivator gangs attached. This seeder is usually used without any covering device ; however, it may be procured with the cultivator gangs or with a spring-tooth harrow attachment. FIG. 78 — A FORCE-FEED DEVICE. THE FEED IS VARIED BY EXPOSING MORE OR LESS OF THE FLUTED FEED SHELL 142. Force-feed seeders and drills derive their name from the manner in which the grain is carried from the io8 FARM MACHINERY seed box. A feed shell is provided which is attached to a revolving shaft receiving its motion from the main axle. F"ig. 78 shows the most com- mon force-feed device. In the fluted cylinder, the de- vice illustrated, the feed is regulated by exposing more or less of the cylinder to the grairi. The feed shell is also designed in other ways. The seed cells may be on the inside and without any means of regulating the size of the cell. The feed or the amount of seed is regulated by varying the speed of the shaft carrying the feed shells by gearing as shown in Fig. 80. 1 FIG. 79 — ANOTHER TYPE OF FORCE FEED FIG. 80 — A FEED-REGULATING DEVICE USED IN CONNECTION WITH A FORCE FEED SIMILAR TO THAT SHOWN IN FIG. 79 SEEDING MACHINERY 109 In order lo handle successfully seeds of dififerent size, the feed shell is made with two flans^es with seed cells FIG. 81 — A FORCE-FEED BROADCAST SEEDER WITH NARROW-TRACK TRUCK of different sizes in each. The cells best suited to the grain drilled are used, while the others are covered. 143. Width of track. — Broadcast seeders are now made FIG. 82 — A COMBINED DISK HARROW AND SEEDER. THIS MACHINE MAY ALSO BE SET TO DRILL FROM SEED SPOUTS AT THE REAR no FARM MACHINERY with either wide or narrow track. Perhaps the wide track is the stronger construction and permits of higher wheels, but the narrow track permits of greater ease in turning and there is not the tendency to whip the horses' shoulders as with the wide track. 144. Combination seeders. — Broadcast seeders with cultivator and spring-tooth harrow attachments have been referred to. A popular tool now is the seeder at- tachment for the disk harrow. This attachment resem- bles very closely the force-feed broadcast seeder mounted above each of the harrow sections, and is operated by suitable sprocket wheels and chain from the main shaft of the disk. By the use of this tool two tools may be combined in one. The disk gangs, owing to their tend- ency to slip occasionally, do not make an entirely satis- factory drive. This is especially true in trashy ground. To surmount this difficulty, combination seeders are made with a follower wheel to drive the seeder. DRILLS Drills are provided with a force feed much like those used upon seeders, but are distinguished from each other in the type of furrow opener and covering devices used. 145. Classification of drills. Furrow openers : Hoe. Shoe. Single-disk. Double-disk. Covering devices : Chains. Press wheels. Press wheel attachment. Interchangeable disk and shoe drills. 146. The hoe drill was the first to be developed, and it is not difficult to see why this should be. The ^ 4 SEEDING MACHINERY III hoes are provided with break pins or spring trips in order that they may not be broken when striking an obstruction. These trip de\iccs reseml)le very much those used upon cultivators. The hoe drill has good penetration, but clogs badly with trash. It is used extensively as a five-hoe drill for drilling in corn ground between rows of standing corn. 147. The shoe drill came into use about 1885 and has many advantages over the hoe drill. In fact, it was used almost entirely until the more recent development in the nature of the disk drill. Fig. 83 illustrates a shoe drill with high press wheels. The shoes are pressed into the ground with either flat or coil springs, which permit an independent action and prevent to a certain extent clog- ging with trash. It is claimed that flat springs do not tire as readily as coil springs, but coil springs seem to be almost universally used. FIG. 83 — A LOW-DOWN PRESS DRILL WITH SHOE FURROW OPENERS 112 FARM MACHINERY 148. Disk drills are the more recent development and consist of two classes : those with single- and double- disk furrow openers. In the single-disk type the disk is formed much like those used on disk harrows. Some form of heel or auxiliary shoe is provided to insert the grain in the bottom of the furrow made. It is desirable that the passage for the seed be so arranged that there can be but little chance for it to become clogged with dirt. The furrow opener that allows the seed to come into direct contact with the disk is not to be advised, but an inclosed boot should be provided to lead the seed into the bottom of the furrow. Some ingenuity is displayed by different makers in securing the desired results in this respect. In some drills the grain is led through the center of the disk. The single-disk may be given some FIG. 84 — A STANDARD SINGLE-DISK DRILL WITH A PRESS-WHEEL ATTACH- MENT. THE STEEL RIBBON SEED TUBES ARE ALSO SHOWN SEEDING MACHINERY 113 suction, and therefore has more penetration than any other form of disk opener, fittinc^ it especially for hard FIG. 85 — THE HOE, DOUBLE-DISK, SINGLE-DISK, AND SHOE FURROW OPENERS USED ON DRILLS. THESE ARE OFTEN MADE INTERCHANGEABLE 114 FARM MACHINERY and trashy ground. The single disk has one objection, and that is that it tends to make the ground uneven, since the soil is thrown in only one direction. The double-disk furrow opener has two disks, or really coulters, as they are flat and their action is much like that of the shoe. One disk usually precedes the other by a short distance. The double-disk has not the penetration of the single-disk, but will not ridge the ground as the single-disk does. They often have another bad feature in that they allow dry dirt to fall on the seed, and hence prevent early germination. The single-disk drill does more to improve the tilth of the ground than any other furrow opener. The fact that a slight ridge is left in the center of the furrow with the double-disk is considered by some an advantage, as the seed is better distributed; in fact, two rows are planted instead of one. 149. Interchangeable parts. — Most manufacturers now design their drills in such a way that any one of the various styles of furrow openers may be used. Fig. 85 shows furrow openers which may be used on the same drill. 150. Press wheels. — Not a few years ago drills were equipped to a large extent with press wheels, but now they are not so popular. The press wheel, when sufficient pressure can be applied, is evidently a very good thing, as the earth is compacted around the seed and the moisture is drawn up to the seed, causing early germina- tion. The pressure upon each press wheel must neces- sarily be very small, as most of the weight of the drill is required to force the furrow openers into the ground, and the balance is to be divided over a number of press wheels. It is not an uncommon thing to see an old drill running with some of the press wheels entirely off of the ground. Drills have been made in two distinct types, one SEEDING MACHINERY 115 known as the standard drill with the large wheels at the end of the seed l)ox and ccjuipped with small press wheels, and another where large press wheels were used and the large wheels at the end of the seed box dispensed with, which is spoken of as a low-down drill. 151. Press-wheel attachment. — In order to make their machine become more universal, manufacturers have pro- vided press-wheel attachments for those who wish them, and the}^ are detachable and do not interfere with the use of the drill whether with or without them. It is to be mentioned here that the drill has many conditions to meet, and a drill which will do satisfactory work in one section may not in another. Thus in a wheat territory, where the ground is not plowed every year and a drill with great penetration is needed. In other sections where the ground is carefully prepared this particular feature is not so important. Press-wheel attachments are a nuisance in turning, and it is out of the question to back the machine. 152. Covering chains. — Chains are often provided to follow after the furrow openers, and their sole purpose is to insure a covering of the grain. Formerly the grain tube or the spouts which convey the grain to the furrow opener were made of rubber, but the best used at the present time are made either of steel wire, or, still better, steel ribbon. 153. Disk drills. — Indications point toward the dis- placement of all forms of furrow openers by the single- disk opener. The single-disk will meet nearly all of the many conditions to be encountered. The double-disk is not much better in many respects than the shoe. The single-disk has good penetration, and besides is especially well adapted to cut its way through trash. Against it stand two objections: One is that there is a tendency for ii6 FARM MACHINERY it to clog when the ground is wet, and the other is its weak point, the bearing. With the shoe drill, the wear is upon the shoe itself, but with the disk there is a spindle, and being so close to the surface of the soil, it is in a bad place to keep free from dirt and to lubricate. The bear- ings in use consist almost universally of chilled iron. Wood has proved itself to be especially well adapted for -A STANDARD SINGLE-DISK DRILL WITH COVERING CHAINS a place of this kind, but does not seem to be used. At any rate, in the purchase of a drill a close inspection should be made of the bearings to see that they are so designed as to give a large wearing surface, to be as nearly as possible dust proof, and to be provided with the proper kind of oil cups or other device for oiling. 154. Distance between furrow openers. — Drills are usually made 5, 6, or 7 inches between furrow openers. Perhaps 6 inches is the width generally used. They are SEEDixr, ^rA(•|| i.N'KRY 117 placed 14 t(-» 16 inches or more a])arl in the Campbell system, and then the i^rain cultivated during the growing season. It is thought desiral)le by some to have a slight ridge between the rows in order to hold the snow and to protect the young plant seeded in the fall from being affected so much by heaving. The action of the wind is to wear the ridges down, and in this way tend to cultivate the plants. 155. Horse lift. — The gangs of drills are very heavy and somewhat difficult to handle with levers, the levers being called upon to force the furrow openers into the ground while at work. To assist in this an automatic horse lift is provided on the larger drills. 156. Footboard. — To replace the seat a footboard is often placed on the drill. The operator in this case rides standing and is in a handy position to dismount. 157. Grass-seed attachment. — The feed shell arranged to drill the larger field grains does not have the refinement to drill grass seed with accuracy. It is often desired to drill the grass set^l at the same time as the grain, and good results cannot be had by mixing and drilling to- gether. The grass-seed attachment does not differ much from other devices except in size. Grass-seed attach- ments are often poorly constructed and become so open as to prevent their use after a few years' service. 158. Fertilizer attachment. — Practically all drill manu- facturers can now furnish their machines with an attach- ment for drilling commercial fertilizer at the time of seeding. The fertilizer is usually fed by means of a plain rotating disk, which carries the fertilizer out from under the box. The seed mechanism will not work with ferti- lizer, as there is a great tendency to corrode on the part of some of the fertilizers. 159. The five-hoe or disk drill. — This tool is used for ii8 FARM MACHINERY putting fall grain in corn ground v/hile the corn is stand- ing. The disk drill has been displacing the hoe drill because it does not clog as easily with corn leaves. Fig. 87 shows a five-disk drill with a footboard so arranged that the operator may ride when it is necessary to add his weight to secure greater penetration. 160. Construction. — In purchasing a drill it might be well to investigate the construction. The implement, be- FIG. 87 — A FIVE-DISK DRILL FOR DRILLING BETWEEN CORN ROWS. THE CENTER FURROW OPENER IS A DOUBLE DISK cause it is so heavy and often wide, should be provided with a strong frame. Angle bars or either round or square pipes are used to make the main frame. The frames are often provided with truss rods in order to stiffen them as much as possible. Some of the heavier drills are now made with tongue trucks much like disk harrows referred to in a preceding chapter. They are a very satisfactory addition. 161. Draft of drills. — Drills are not as a rule light of draft for the number of horses used. The following re- J SEEDING MACHINERY II9 suits are ^qivcn from experiments made at the Iowa ex- periment station : Distance Distance Total Kind of Apart at No. of covered Draft Draft Drill Disk Drill Rows Disks in Feet in Pounds per Foot No. 4. Double 8" 10 6.7 450 67.1 No. 5. Single 8" lO 6.7 460 68.6 Neither of the above drills was provided with any form of covering" device other than chains. It is to be noted from the above tests that the single-disk drill requires more power than the double-disk in pulverizing the ground, but the difference is small. 162. Calibration. — The scales or gages placed upon driller and seeders to indicate the amount of seed drilled per acre arc not as a rule to be depended upon for great accuracy. If they are correct at first, there is a tendency for them to become inaccurate as the drill becomes old. The operator should make calculations of the ground drilled and the amount of grain used, and in this way check the scale of the drill. Drills calibrated have shown the scale to be in error as much as 25 per cent. 163. Clean seed. — The drill is displacing, to a large ex- tent, the broadcast seeder because the farmer desires to place all of the seed in the ground and at the proper depth. With the broadcast seeder, where various meth- ods of covering of the seed are resorted to, the seed can- not be covered a uniform depth. Practically all fall seed- ing is now done with drills, and the broadcasting is used for the seeding of spring grains alone. Experiments at the Ohio, Indiana, North and South Dakota stations give, without an exception, better results from drilling, the in- creased yields for the drilling being from 2 to 5 bushels. In order to have a drill do its best work, great stress should be laid upon the fact that all grain should be clean I20 FARM MACHINERY and especially free from short lengths of weed stems, which are often found in grain as it comes from the threshing machine. These stems or pieces of straw may lodge in the feedway and prevent the grain from getting into the seed wheel. CORN PLANTERS 164. Development. — Corn planters are strictly an American invention. This is not strange, for corn, or maize, is peculiarly an American crop. The development of the planter has also been recent; not much over 50 years have elapsed since the planter has been made a success. The Indians were the first to culti- vate corn, but they never had anything but the most primitive of tools. Until the development of the horse machine, corn was almost universally planted and covered by means of the hoe, and in localities where a very limited amount of corn is grown the method is followed to-day. The first machines used for seeding were universal in the respect that they were used for the smaller grains as well as corn. Perhaps the first patent granted on what may be styled a corn planter was given March 12, 1839, to D. S. Rockwell. In this planter may be seen in a somewhat primitive form some of the features of the modern planter. The furrow openers were vertical shovels, and the planter was supported in front and in the rear with wheels with the dimensions of rollers. The corn was dropped by means of a slide underneath the box. The jointed frame was patented by G. Mott Miller in 1843. George W. Brown, of Galesburg, Illinois, devoted much of his time to the development of the corn planter and secured patents on many features. To Brown's efforts is credited the shoe furrow opener, the rotary drop, and a method of operating the drop by hand. A patent on a marker was granted to E. McCormick in 1855 as a device projecting from the end of the axle. The present marker was set forth in a patent secured by Jafvis Case, of La- fayette, Indiana, in 1857. In about 1892 the Dooley brothers, of Moline, Illinois, brought out the edge-selection drop used ex- tensively on the more recent planters. 165. Development of the check rower. — It seems that all the early planters were automatic, in that an operator was not needed to work the dropping mechanism. In 1851 a patent was SEEDING MACHINERY 121 granted to E. Corey, of Jerscyvillc, Illinois, for a device to mark the point where the corn was planted, and this device led to the use of a marker in laying oflf fields and putting the hills of corn in check. Brown's patent previously referred to was the first patent to cover the hand-dropping idea. ]\I. Robbins, of Cincinnati, patented in 1857 a checking device for a one-horse drill using a jointed rod and cliain pro- vided with buttons for a line. The check rower was developed to a practical de- vice by the Haworth brothers. The Haworth was for a long time the stand- ard machine. The check wire in this implement was made to travel across the machine. Among the first of the side- drop check rowers was the Avery, which became at one time very popular. Recent changes in check rowers have been con- fined to reducing the amount of work done by the machine. 166. Hand planters have never come into any extended use, as they are not any great improvement over the hoe. This planter is made now much like it was years ago. Fig. 88 shows the common style and is used to some extent in replanting. A slide extends from one handle to the other and passes under the small seed box. ^^^^en the slide is under the box a hole of the proper size is filled with the desired number of grains. When the handles are opened so as to close the pomts the hill of corn is drawn from under the seed box and allowed to fall to the point. There are modifications of this hand planter in which a plate is used FIG. 05 — A HAND CORN PLANTER. THE CORN IS DRAWN FROM UNDER THE SEED BOX BY A SLIDE UPON CLOSING AND OPENING THE HANDLES 122 FARM MACHINERY and made to revolve by pawls which act by opening and closing the planter. 167. The modern planter. — Although most planters are called upon to do about the same work, they differ much in construction. The essentials of a good, successful FIG. 89 — A MODERN CORN PLANTER WITH LONG CURVED FURROW OPENERS, VERTICAL CHECK HEAD, AND OPEN WHEELS planter have been set forth as follows: (i) It must be accurate in dropping at all times ; (2) plant at a uniform depth; (3) cover the seed properly; (4) convenient and durable; and (5) simple in construction. 168. Drops. — The early planters had slides or plates in which holes or seed cells were provided which were large enough to hold a sufficient number of kernels to make an entire hill of corn. Planters are constructed in this SEEDING MACHINERY 123 manner and offer some advantages in droppinq^ uneven seed. This style of drop is known as the full-hill drop. The cumulative drop was the result of an effort to raise the accuracy of dropping. In the cumulative drop the grains are counted out separately (a seed cell being pro- vided in the seed plate for each kernel) until a hill is formed, the theory of the accuracy being that there is less chance for one less or more kernels when the cell is nearly FIG. 90 — THE ROUND-HOLE SEED PLATE FIG. 91 — THE EDGE-SELECTION PLATE the size of each kernel, while in the larger cell three small kernels could easily make room for the fourth. 169. Plates. — The round-hole plate is a flat plate with round holes for seed cells ; hence the name. The round- hole plate may belong to a full-hill or a cumulative drop planter. The edge-selection or edge drop plate has deep narrow cells arranged on its outer edge, in which the corn kernel is received on its edge (Fig. 91). The arguments ad- vanced in favor of this plan are that the corn kernel is more uniform in thickness than any other dimension, and owing to the depth of the cells is not so apt to be dislodged by the so-called cut-off. The majority of planter manufac- turers within the past few years have brought out an 124 FARM MACHINERY edge-selection drop-plate planter and claimed great accu- racy for it. Varieties of corn differ very much in the width of kernel, and for this reason provision has been made by at least one manufacturer to vary the depth of the edge-selection cell by substituting grooved bottoms to the seed box over which the plate travels. A device is provided with the flat plate for the same purpose. ' The outside edge of the cell is made open, into which a spring fits, excluding all but one kernel. 170. Plate movement. — Plates are made to revolve in a horizontal plane, and also in a vertical plane. To plates in these positions the names of horizontal plate and verti- cal plate are given, respectively. The intermittent plate movement is one where the plate is revolved until a hill is counted out, and then remains at rest until put in motion for another hill by the check wire. The movement may belong to full-hill or cumu- lative drops. The argument is set forth that the seed cells are filled to better advantage by this intermittent motion ; the starting and stopping will shake the corn into the cells. To cause the seed cells to fill more perfectly, the kernels are prearranged by the corrugations and the slope of the seed-box bottom. In the continuous plate movement the plates are driven from the main axle usually by a chain and sprockets. While the plates travel continuously, the size of the hill is determined by a valve movement which opens and closes the outlet from the seed plate. To produce this movement, two clutches with double cam attachments, one at each hopper, are used. At each trip of the planter the dog on the clutch is thrown out, and it turns through one-half revolution, allowing one cam to pass ; at the same time the arm of the valve glides over the cam and opens the outlet to the hopper, which allows the corn to drop from - SEEDING MACHINERY 125 each cell until the cam passes and the arm drops, closing the valve. Thus the leni^th of this cam determines the length of time the valve is open, thereby controlling the number of kernels in the hill. Several lengths of cams are furnished with each planter. It is claimed in opposi- tion to the claim set forth for the intermittent movement that the cells are more apt to be filled, for they are in con- tinuous motion and travel a greater distance under the corn. 171. The clutch. — In the early planters the plate was drivenentirelyby thecheck wire. Witheachbuttontheplate Top View FIG. 92 — THE SEED-SHAFT CLUTCH WHICH IS THROWN IN GEAR BY THE CHECK WIRE. THE POWER TO DRIVE THE SEED SHAFT THEN COMES FROM THE MAIN AXLE, NOT THE CHECK WIRE was moved just far enough to deposit one hill in the seed tube. When the cumulative drop was developed, a means had to be provided to rotate the plate long enough to count out the hill. To arrange for this, the button was 126 FARM MACHINERY made to throw a clutch which put the dropper shaft in connection with a chain drive from the main axle. This clutch remained in gear for one revolution of the shaft, which is equivalent to one-fourth revolution of the seed plate. The one-fourth of the seed plate was arranged with enough seed cells to count out one hill. This clutch may be made to operate a valve which will permit a suffi- For Hill Drop Fixed to Drill FIG. 93- -A DOUBLE VALVE MECHANISM SHOWING HOW THE CORN IS RE- LEASED AT THE HEEL OF THE FURROW OPENER cient number of kernels to leave the plate to make a hill as described above. The clutch has relieved the check wire of a large portion of its work. It is only required to put the clutch in gear and to open the valves in the shank. The clutch is one of the vital parts of the planter, and is often the first part to wear out and give trouble. Fig. 92 illustrates a planter clutch. 172. Valves are divided into two classes: single and double valves. The single valve is placed in the heel of SEEDING MACHINERY I27 the furrow opener. The corn may be either caui^ht here a sin.yle grain at a time or a full hill at a time. When the check wire throws the valve open to let a hill out, it closes in time to catch the next hill. With the double valve, the hill is caught twice in its transit from the seed bo.x to the ground. Fig. 93 shows one style of double-valve arrangement. The lower valves are made quite close to the ground and arranged to discharge backward and downward FIG. 94 — THE STUB-RUNNER FURROW OPENER into the furrow to overcome the tendency to carry the hill on and make uneven checking. 173. Furrow openers. — The curved runner is used on a large majority of planters as a furrow opener. It is easy to guide, but will not penetrate trash or hard soil as well as some others. The curved runner is illustrated in Fig. 89. The stub runner has good penetration and will hook under trash and let it drag to one side out of the way. 128 FARM MACHINERY There is less tendency for the stub runner to ride over trash than the curved runner. Fig. 94 shows a stub runner. The stub runner cannot be used in stony or stumpy land. The single-disk furrow opener has good penetration and is desired in some localities for that reason. It is also better adapted to trashy ground, the disks cutting their way through. The disks may or may not reduce draft; FIG. 95 — THE SINGLE-DISK FURROW OPENER at any rate, the planter is not a heavy-draft implement. Penetration is not often needed ; more often the planter has a tendency to run too deep. The single-disk planter throws the soil out one way, and it is difficult for the wheels to cover the seed. The disk has a bearing to wear out, which the runner has not. The double disk cuts through trash to good advantage, but does not have the penetration of the single disk. It SEEDING MACHINERY 129 has two bearings to wear out to each furrow opener. It is claimed dry dirt falls in behind the disks on the corn, preventing early germination. All disk planters are very hard to guide. They do not follow the team well. FIG. 96 — A CORN PLANTER WITH DOUBLE-DISK FURROW OPENERS, OPEN WHEELS, AND HORIZONTAL CHECK HEADS 174. Planter wheels may be had in almost any height, from very low wheels to those high enough to straddle listed corn ridges. The tire may be flat, concave, or open (Fig. 97)- The flat wheel is not used to any extent on planters to-day, but is offered for sale by most manufacturers. It does not draw the soil well over the corn, but leaves this hard and smooth to bake in the sun. and gives the water a smooth course to follow after heavy rains. 130 FARM MACHINERY The concave wheel gathers the soil better than the flat wheel, but leaves the surface smooth. The open wheel is now used to a larger extent than any other type. It has the good gather, covering the corn FIG. 97 — CORN-PLANTER WHEELS WITH CONCAVE, FLAT, AND OPEN TIRE; ALSO THE DOUBLE WHEEL well ; the ground has no tendency to bake over the corn, and the water during rains is carried to one side of the track. The double wheel consists in two wheels instead of one to cover the corn, and may be set with more or less gather, thus being able to cover the corn under all con- ditions. 175. Fertilizer attachment. — In some localities it is necessary to use fertilizer to secure an early and quick growth of corn. An attachment is made to drop fertilizer for each hill, and careful adjustment must be made to drop the fertilizer the right distance from the hill. If too far away, it will not give immediate benefits, and if placed too close, will rot the corn. This adjustment is difficult owing to the difference in speeds at which planters are operated. 176. Marker. — IMarkers are made in two styles, the sliding and the disk. The disk has proved to be a very satisfactory marker. SEEDING MACHINERY I3I 177. Wire reel. — Two types of check wire reels have been developed : one to reel by friction contact to the planter wheel, and one to reel under the seat with a chain to the main axle, using a friction clutch on the spool. It is claimed to be desirable to wind the wire on a solid, smooth drum rather than on a reel, as the former kinks the wire less. 178. Conveniences. — In making a purchase of a planter it is well to have in mind the conveniences which may be had, as well as the matter of strength, durability, and accuracy. Convenience in turning and reeling the wire is first to be considered. Another advantage offered by some planters over others is in the convenience of changing plates. It is very handy to have a seed box which may be tipped over and emptied without picking the seed out by hand. The planter should have an adjustable tongue by which the front may be kept level. Unless the planter front is level, an accurate check cannot be obtained if the heel of the furrow opener is too far ahead or too far to the rear. It is impossible to get an even check if the planter front is not carried level. It is desirable to have the check-rower arms act inde- pendently of each other, as it relieves the wire of some work. Two types of check heads for check rowers are used, the vertical and horizontal, but seem to be equally satisfactory. 179. Draft of planters. — Draft tests gave the following results for the mean draft of two styles of planters : Planter with open wheels 212 pounds Planter with double wheels 237 pounds 180. Calibration of planters. — It is an undisputed fact that high accuracy cannot be secured with any plante' 132 FARM MACHINERY unless the corn be of uniform size and a seed plate chosen to suit the size of corn. Types of corn vary much in size of kernel, and one plate will not suit all types and varie- ties. Makers usually furnish several plates vv^ith their machines, and others may be secured if necessary. It stands to reason that no planter can do good work unless these conditions are fulfilled. The planter should be cali- brated and tested before taken to the field, if accuracy of work is desired. i8i. Corn drills. — Although most planters may be set to drill corn, the corn drill remains a distinct tool and is FIG. 98 — THE SINGLE-ROW CORN DRILL used to a large extent in certain localities of the country. Fig. 98' shows a single-row drill which dififers but little from others except that an extra knife is provided in front of the seed tube. Various covering devices in the way of shovels and disks are provided. Drills are now made to take two rows, and even four, when made as an attach- ment to a grain drill. 182. Listers. — The use of the lister is confined to the semi-arid regions. It can be used in most of the corn- growing sections where the rainfall is not overabundant. SEEDING MACHINERY ^33 It is not adapted to fields that are extremely level, as water will collect in the ditches after rains and drown the corn while small. Neither can it be used in hilly locali- ties, as the corn will in this case be washed out. The lister is simply a double plow throwing a furrow both ways. The seedbed is prepared at the bottom of the furrow with a subsoiler. The planting may be done later or with an attached drill, which plants as the furrow is opened up. Thus plowing and planting are done at one operation. Fig. 99 shows one of the latest styles of walk- FIG. 99 — A SINGLE-KUW WALKING LISTER WITH A CORN DRILL ATTACHED. DISKS ARE USED IN PLACE OF THE COVERING SHOVEL Ing listers with sprocket-wheel-covering attachments. The drill attachment may be used independently as a drill. Fig. 100 is a representative three-wheel riding lister. Riding listers are also made without the furrow wheel, and when so made are termed sulky listers. Even the lister as a single-row machine has not been rapid enough for the Western farmer, and several makes of a two-row lister are to be found upon the market. 183. Loose-ground listers. — Listing of corn has some disadvantages. W'hen listing is practiced, the soil is not all loosened, and when successive crops are grown in the same way an effect upon the yield is noticed. To gain the 134 FARM MACHINERY IS^.^ " — ^" FIG. lOI — A TWO-ROW LISTER SEEDING MACHINERY 135 advantages of listing after plowing, the loose-ground lister has been developed. This tool is a two-row ma- chine provided with disks to open the furrow, instead of right and left moldboards. Moldboards will not scour in loose ground, hence the use of disks. When the loose- ground lister is used, the ground must be plowed as for the planter, thus increasing the cost. The merits of the system consist in having the corn deeper to stand the drought better, and to be better braced to stand the high FIG. 102- -A LOOSE-GROUND LISTER. DISK FURROW OPENERS MAY BE USED ON PLANTER FOR THE SAME PURPOSE winds of the fall and not become "lodged." The fact that the corn is placed in a furrow makes it more easily tended because there is a large amount of soil to be moved toward the corn. In the moving of this dirt, any weeds are easily destroyed. Fig. 102 shows a loose-ground lister. Attachments are provided which may be placed upon corn planters to give the same results. CHAPTER VII HARVESTING MACHINERY Agricultural machinery has done much for the agri- culturist in enabling him to accomplish more in a given time, and to do it with less effort, than before its intro- duction. Although this is true of all agricultural ma- chinery, it is especially true of harvesting machinery. By its use it has been estimated that the amount of labor required to produce a bushel of wheat has been reduced from 3 hours and 3 minutes to 10 minutes. In this brief discussion harvesting machinery will be considered in its broadest sense and will include reap- ers, self-binders, headers, combined harvesters, and corn-harvesting ma- chinery. 184. Development of hand tools, — From the oldest records that remain we find that the people of that early time were pro- vided with crude hand tools for the reap- ing of grain. These primitive sickles, or reaping hooks, were made of flint and bronze, and are found among the remains left by the older nations. Upon the tombs at Thebes, in Egypt, are found pictures of slaves reaping. These pictures were made 1400 or 1500 B.C. The form of the Egyptian sickles varied some- what, but consisted generally of a curved blade with a straight handle. The scythe is a development from the sickle and differs from it in that the operator can use both hands instead of one. The Flemish people developed a tool known as the Hainault scythe. It has a wide blade 2 feet long, having a handle about i foot in FIG. 103 — THE SICKLE, AN EARLY HAND- REAPING TOOL HARVliSTING MACHINERY 137 length. The handle is bent at the upper end and is provided with a leather loop, into which the forefinger is inserted to aid in keeping the tool horizontal. The grain was gathered by a hook in the left hand. This tool was displaced later by the cradle. Development in scythes has consisted in making the blade lighter, lengthening the handle, and adding fingers to collect the grain and to carry it to the end of the stroke. With the addition of the fingers, the tool was given a new name, that of the cradle scythe, or the cradle. And it was in this tool that the first American development took place. The colonists, when they settled in this country, prob- ably brought wMth them all of the European types, and the American cradle was simply an improvement over the old coun- try tools. The time of the intro- fig- 104— the American cradle. duction of the cradle has been ^"^ ^o^^ ^sed for reaping -,,_,. . UNTIL AFTER THE MIDDLE OF fixed by Professor Brewer, of the nineteenth century Yale, in an article written for the Census Report of 1880, as somewhere between 1776 and the close of the eighteenth century. The American cradle stands at the head of all hand tools devised for the reaping of grain. When it was once perfected, its use spread to all countries, with very little change in form. It has been displaced, it is true, by the horse reaper almost entirely; yet there are places in this country and abroad where conditions are such that reaping machines are impracticable and where the cradle has still a work to do. Again, there are parts of the world where the reaping machine has never been intro- duced and where the sickle and the cradle are the only tools used for reaping. It seems almost incredible that any people should be so backward as to be using at the present time these primitive tools, yet it is to be remembered that even the most advanced nations used them for centuries, and apparently did not think of anything in the way of improvement. 185. The first reaper. — History records several early attempts toward the invention of a machine for harvesting, but none 138 FARM MACHINERY reached a stage where they were practical until the eighteenth century. Pliny describes a machine used early in the first cen- tury which stripped the heads of grain from the stalk. The machine consisted of a box mounted upon two wheels, with teeth to engage the grain at the front end. It was pushed in front of an animal yoked behind it. The grain was raked into the box by the attendant as the machine was moved along. It is further stated that it was necessary to go over the same areas several times. i86. English development. — There were several attempts at the design of a reaping machine before 1806, but none were suc- cessful. They need not be considered in this discussion. It was in 1806 that Gladstone invented a machine which added many new ideas. In his machine the horse walked to the side of the grain, and hence the introduction of the side cut. It had a revolving cutter and a crude form of guard. It did, however, have a new idea in an inside and outside divider. The grain fell upon a platform and was cleared occasionally with a hand rake. As a whole, this machine was not successful. In 1808 Mr. Salmon, of Woburn, invented the reciprocating cutter, which acted over a row of stationary blades. This machine combined reciprocating and advancing motion for the first time. The delivery of the grain was unique in the fact that a vertical rake actuated by a crank swept the grain from the platform upon which the grain fell after being cut. In 1822, Henry Ogle, a school- master of Remington, in connection with a mechanic by the name of Brown, designed and built a machine which is worthy of mention. The use of a reciprocating knife had been hinted at by Salmon, but Ogle made it a success. This machine also had the first reel used, and was provided FIG. 105 (Kil.E S REAPING . , , ' MACHINE (ENGLAND, 1822) With a droppcr. Accouuts are not specific, but it is thought that the operator for the first time rode upon a seat. The next machine was the most successful up to that time (1826). Patrick Bell, a minister of Canny ville, Forfarshire, has HARVESTING MACHINERY 139 the honor of designing it. His machine had oscillating knives, each of which were about 15 inches long and about 4 inches broad at the back, where they were pivoted and worked over a similar set of knives underneath like so many pairs of shears. The rear ends of the movable blades were attached to an oscillating rod connected with a worm flange on a revolving shaft. It pre- sented a new idea in having a canvas moving on rollers just behind the cutting mechanism, which carried the grain to one side and deposited it in a continuous swath. Bell also provided his machine with a reel and inside and outside dividers. His FIG. 106 — bell's reaping MACHINE (ENGLAND, 1828) machine marks the point when the development of the reaping machine was practically turned over to Americans. It never was very practical because it was constructed upon wrong prin- ciples, but nevertheless it was used in England for several years until replaced with machines built after the inventions of the Americans, Hussey and ?*lcCormick. 187. American development. — Beginning with the year 1803. a few patents were recorded before Hussey's first patent, which was granted December 31, 1833. These were not of any impor- tance, since they did not add any new developments and were not practical. The only one which gave much encouragement was the invention of William Manning, of New Jersey, patented in 1831. Manning's machine had a grain divider and a sickle which were similar to those used later in the Hussey and McCor- mick machines. It was in 1833 when Obed Hussey, of Baltimore, Maryland, was granted his patent which marks the beginning of a period I40 FARM MACHINERY of almost marvelous development. Though Cyrus B. McCor- mick was granted his first patent June 2i, 1834, it is claimed that his machine was actually built and used before Hussey's, whose machine had the priority in the date of patents. Hussey's first machine was indeed a very crude affair. It con- sisted of a frame carrying the gearing, with a wheel at each side and a platform, at the rear. The cutter was attached to a pitman, which received its motion from a crank geared to the FIG. 107 — hussey's reaping MACHINE (AMERICA, 1833) I main axle. The cutter worked in a series of fingers or guards, and perhaps approached the modern device much closer than any reaper had up to this time. McCormick's machine was provided with a reel and an outside divider. The knife had an edge like a sickle and worked through HARVESTING MACHINERY 141 wires which acted for the fingers or guards of Hussey's machine. The machine was of about 4^/2 feet cut and was drawn by one horse. The grain fell upon a platform and was raked to one side with a hand rake by a man walking. Of the two machines, perhaps Hussey's had the more valuable improvement and it was nearer the device which proved to be successful later. Friends of both these men claim for them the honors for the first successful reaper. Hussey did not have the energy and the perseverance, and hence lost in the struggle for FIG. 108 — M'cORMICK RE.A.PING MACHINE (aMERICV, 1834) supremacy which followed. At first the honors were evenly divided. In 1878 McCormick was elected a corresponding mem- ber of the French Academy of Sciences upon the ground of his "having done more for the cause of agriculture than any other living man." Palmer and Williams, July i. 1851, obtained a patent for a sweep rake which swept the platform at regular intervals, leav- ing the grain in bunches to be bound. The next invention of importance was that of C. W. and 142 FARM MACHINERY W. W. Marsh, of Illinois. A patent for this was granted August 17, 1858, and gave to the world the Marsh harvester. This carried two or more attendants, who received the grain from an elevator and bound it into sheaves. The two Marsh brothers, in connection with J. T. Hollister, organized a company which built 24 machines in 1864 and increased the output each year until in 1870 over 1,000 machines were built. This company was finally merged into the Deering Harvester Company. George H. Spaulding invented and was granted a patent on the packer for the modern harvester, May 31, 1870. This inven- tion was soon made use of by all manufacturers. John P. Appleby developed the packer and added a self-sizing device. He has also the honor of inventing the first successful twine knotter. The Appleby knotter, in a more or less modified form, is used on almost every machine to-day. Jonathan Haines, of Illinois, patented, March 27, 1849, a ma- chine for heading the grain and elevating it into wagons driven at the side of the machine. In certain parts of the West, notably California, where con- ditions are such that grain will cure while standing in the field, a combined machine has been built which cuts, threshes, sep- arates, and sacks the grain as it is drawn along either by horses or by a traction engine. The first combined machine was built in 187s by D. C. Matteson. Benjamin Holt has done much to perfect the machine. The development of the grain harvester may be summarized as follows : Gladstone was the first to have a side-cut machine. Ogle added the reel and receiving platform. Salmon gave the cutting mechanism, which was improved by Bell, Hussey, and McCorniick. To Rev. Patrick Bell must be given credit for the reel and side- delivery carrying device. Obed Hussey gave that which is so important, the cutting ap- paratus. For the automatic rake credit must be given to Palmer and Williams. For a practical hand-binding machine the Marsh brothers should have the honor. To Spaulding and Appleby the world is indebted for the sizing, packing, and tying mechanisms. Jonathan Haines introduced the header. Many other handy and important details have been added by a multitude of inventors, but all cannot be mentioned. HARVESTING MACHINERY U3 i88. The self-rake reaper. — The modern self-rake re- sembles the early machine very much, and improvement has taken place only along- the line of detail. The machine has a platform in the form of a quarter circle, to which the grain is reeled l)y tlie rakes, as well as removed to one side far enough to permit the machine to pass on the next round. The cutting mechanism is like that of the FIG. 109 — A MODERN SELF-RAKE REAPER harvester. The machine is used to only a limited extent owing to the fact that the grain must be bound by hand. The reaper is preferred by some in the harvesting of certain crops, like buckwheat and peas. It is usually made in a 5-foot cut, and can be drawn by two horses, cutting six to eight acres a day. MODERN HARVESTER OR BINDER 189, The modern self-binding harvester consists essen- tially of (i) a drive wheel in contact with the ground; 144 FARM MACHINERY (2) gearing to distribute the power from the driver to the various parts ; (3) the cutting mechanism of the ser- rated reciprocating knife, driven by a pitman from a FIG. 1 10 — A MODERN SELF-BINDING HARVESTER OR BINDER crank, and guards or fingers to hold the grain while being cut; (4) a reel to gather the grain and cause it to fall in form on the platform; (5) an elevating system of endless FIG. Ill — ANOTHER MODERN HARVESTER webs or canvases to carry the loose grain to the binder; and (6) a binder to form the loose grain into bundles and tie with twine. HARVESTING MACHINERY I45 Some of the more important features and individual parts will now be discussed in regard to construction and adjustment. Parts are numbered to correspond with numbers in Figs, iio and iii. 190. Canvases (i) Should be provided with tighteners by which they may be loosened when not in use. Tighteners also make it more convenient to put canvases on the machine. The elevator rollers should be driven from the top, thus placing the tight side next to the grain. The creeping of canvases is due to one of two things, either the canvases are not tight enough or the elevator frame is not square. If the elevator is not square, the slats will be torn from the canvases. This trouble may be over- come by measuring across the rollers diagonally or placing a carpenter's square in the corner between guide and roller, and adjusting. The method of adjustment varies with different makes, but the lower elevator is usually adjusted with a brace rod to the frame, and the upper elevator with a slot in the casting attaching the guide to the pipe frame. 191. Elevator chains (2). — Two kinds of chains are found in use, the steel chain and the malleable. The steel chain is claimed to be the most durable, but has the disadvan- tage of causing the sprocket teeth to cut away faster. This wear is often the greatest upon the driving sprocket, as it has the most work to do. It is thought that the steel chain is the most desirable chain to have. 192. The chain tightener (3). — The chain tightener may have a spring or slot adjustment. The spring adjustment is very handy and an even tension is maintained on the chain. The elevator chain should not be run with more tension than needed, as it produces wear and adds to the draft. 193. Twine box (4). — The location of the twine box is 146 FARM MACHINERY the principal thing to be considered in order to secure the greatest convenience in watching the twine, and also in adding new balls. 194. Reel (5). — Convenience and strength are the prin- cipal things to be considered in a selection of a reel. It should have the greatest range of adjustment and permit this adjustment to be made easily. The making of a good bundle and the handling of lodged grain depend largely upon the manipulation of the reel. This may mean that the reel must be adjusted several times during a single round of a field. The reel slats or fans should be adjusted to clear the dividers equally at each end, and also to travel parallel to the cutter bar. 195. Grain dividers (6). — It is an advantage to have the outside divider adjustable not only for different-sized grain, but also for making the machine narrow when mounted upon the transport trucks. 196. Grain wheel (7). — The weakpointof thegrain wheel is the bearing, and it is often necessary to replace the axle and boxings several times during the life of a machine. In order to prolong the life of the grain-wheel axle, it is made, by some manufacturers, with a roller bearing. 197. Elevators (8). — The elevator should extend well to the front of the platform in order that the grain may not be hindered in the least in starting upon its path up the elevator. The guides should be hollowed out slightly on the side next the grain, giving the canvases a chance to expand and not drag heavily upon the guides. It is also an advantage to have the lower end of the upper guide flexible in order that it may pass over extra large bunches of grain. The open elevator, permitting the handling of long grain, as rye, is now almost universally adopted. HARVESTING MACHINERY I47 The sprockets by which the elevator rollers are driven should always be in line. Adjustment may be made by sighting across their face. 198. Deck (9). — The steeper the deck, the better; but makers have made it rather flat in order to reduce the height of the machine. The deck should be well covered by the packers to prevent clogging. 199. Main frame (lo). — Main frames are shipped either separate or fastened to the platform. In the latter case, if there is a joint, it is riveted and very seldom gives any trouble in becoming loose. In the first case, bolts must be used ; but they do not give any trouble if care is used in assembling the binder. 200. Platform (ii). — The platform is now universally provided with an iron bottom, which is more durable and smoother for the platform canvas to pass over. It is made of painted iron, and it might be improved if it should be made of galvanized iron, as it often rusts out before the machine is worn out. 201. Main wheel (12). — Themainwheelisoneof theparts which usually outwear the rest of the machine. The tendency is now to make the main wheel too small. The larger wheel is more desirable, as it carries the load better and is able to give a greater driving power. Main wheels have now attained a standard size of 34 and 36 inches in the side-cut machine. The steel wheel is now used almost universally, the wooden wheel and the wooden- rimmed wheel having gone out of use entirely. Three types of spokes are used : the hairpin, the spoke cast in the hub, and the spoke fastened to a flange of the hub with nuts. The main wheel shaft or axle should be pro- vided with roller bearings, and also a convenient and sure method of oiling. The bolt in the lower part of the quad- rant should always be in place. When the bolt is out 148 FARM MACHINERY it is possible to run the machine up too far and let the main axle start into the quadrants crosswise. 202. Main drive chain (13). — Two common types of drive chains are to be found upon the market : the all-malleable link and the malleable link with the steel pin. The lat- ter is perhaps the more desirable, but not so handy for replacing broken links. The main chain should not pass too close to the tire of the main wheel, or it will clog with mud badly. 203. Cutterbar(i4). — Twokinds of cutter bars are found, the Z bar and the angle bar. One seems to be as good as the other, but some little difference is to be found be- tween the angle given to the guards, enabling some machines to cut closer to the ground than others. 204. Main drive shaft (15) . — The main drive shaft should be given good clearance from the main wheel to prevent clogging. This shaft is now generally provided with roller bearings, and often self-aligning bearings, which prevent any possible chance for the shaft to bind and thus increase the friction. 205. Butter or adjuster (16). — The canvas butter has always been very satisfactory, except it was short- lived. Often it was the first part of the binder to be re- placed. This led several makers to build an adjuster which had oscillating parts or board. The single board seems to be just as satisfactory, as the upper half- of the two-board adjuster does very little good. The all-steel belt as now commonly used upon push binders is no doubt the most satisfactory butter made. It is durable and efficient, but not generally adopted, probably on ac- count of its cost. 206. Packers (17). — The packers should practically cover the deck, reaching within an inch or so of the deck roller. This will prevent any tendency to clog in heavy grain. HARN'ESTING MACIIINKRY I49 The third packer is considered an advanta4- or 4-foot cut, and is used principally in the mowing of lawns, parks, etc. 229. The two-horse mower is commonly made in 4^- ahd 5-foot cuts, although 6-, 7-, and 8-foot machines are FIG. 122 — A MODERN TWO-HORSE MOWER manufactured. The latter are spoken of as wide-cut mowers and are usually of heavier construction than the standard machines (Fig. 122). From 8 to 15 acres is an average day's work with the 5- or 6-foot machines. 230. Mower frame. — Mower frames are usually made in one piece of cast iron. The openings for the axle and l66 FARM MACHINERY the shafting are cored out, but where the bearings are to be located enough extra material is provided for boring out to size. Roller bearings are usually provided for the main axle. 231. The crank shaft is usually provided with a plain bearing at the crank and a roller bearing at the pinion end. A ball bearing is provided at the end of the small bevel pinion to take the end thrust. It is not possible to use a ball or roller bearing at the crank end, due to the vibratory action of the shaft tending to wear the bearing out of round. This bearing is either provided with an adjustment or an interchangeable brass bushing to take up the wear. The crank should be well protected from the front and under sides. The crank and pitman motion seems to be the most satisfactory device to transmit a reciprocating motion to the knife. A wobble gear was tried a few years ago, but has been given up. A mower is manufactured with a pitman taking the motion from the face of the crank wheel instead of the side. It is not known how successful this machme is. 232. Main gears. — The driving gears should be liberal in size and always closed in such a way as to be protected from dust, and also to facilitate oiling. It might be an advantage in mowers as in some other machines to have the gears run in oil. 233. Wheels should be high and have a good width of tire. The common height is 32 inches, and 3^ and 4 inches the common width of tire. It is some advantage to have several pawls to engage the ratchet teeth in the wheels, because this feature, in connection with a clutch with several teeth for throwing the machine in and out of gear, will make the machine more positive in its action. That is, the sickle will start to move very shortly after the main wheels are set in motion. Mowers driven by I HAYING MACIIINKRY 1 67 large gear wheels in the drive wheels are more positive in their action and hence are preferred in foreign coun- tries where very heavy swaths are to be cut. 234. The pitman in the mower corresponds to the con- necting rod in an engine. Its function is to change cir- cular motion into rectilinear motion, the reverse of the connecting rod. The crank pin and sickle should always be at right angles with each other, but this feature is not so essential when the pitman is connected to the sickle with a ball-and-socket joint. Pitmans are made of wood and steel. Wood rods are the most reliable, because steel, due to the excessive vibration, becomes crystallized and weak. The steel pit- man, however, may be so constructed as to be adjustable, and enables the operator to adjust the length until the knife acts equally over the guards at each end of the stroke. The pitman should be protected from being struck by any obstruction from the front. 235. The cutter bar is the cutting mechanism, exclusive of the sickle. It has a hinge coupling at one end and a divider and grass board at the other. The bar proper to which the guards are bolted should be stiff enough to prevent sagging. It is the practice in some machines to make the bar bowed down slightly and to straighten it by carrying the greater part of the weight at the hinge end, the weight of the bar itself causing it to straighten. Some arrangement should be provided to take up the wear of the pins of the hinge joints in order that the cutter bar may be kept in line with the pitman. 236. Wearing plates. — Best mowers are now equipped with wearing plates where the sickle comes in contact with the cutter bar. They may be renewed at a small cost. The clips to hold the sickle in place are now made of malleable iron and are bolted in place to facilitate l68 FARM MACHINERY their replacement when worn. If slightly worn, they may be hammered down until the proper amount of play be- tween the clip and the sickle is obtained. Under normal conditions, this is about i/ioo of an inch. In no case should it be so open as to permit grass to wedge under the clips, but at all times should hold the knife well upon the ledger plates so as to give the proper shearing action. 237. Mower guards are fitted with two kinds of ledger plates, one with a smooth edge and the other with a serrated edge. The serrated plate holds fine grasses to better advantage than the smooth ledger plate, and in this way aids with the cutting. 238. Shoes. — The cutter bar should be provided with an adjustable shoe at each end, by means of which the height of cut may be varied to some extent. A weed at- tachment is often provided which will enable the cutter bar to be raised 10 inches or more. A shoe is better than a small wheel at the outer end of the bar because the wheel will drop into small holes, while the runner will bridge them. 239. The grass board. — The purpose of the grass board and the grass stick is to rake the grass away from the edge of the sWath to give a clean place for the inside shoe the next round. The grass board should be provided with a spring to make it more flexible and less apt to be broken in backing and turning. 240. Foot lifts. — Nearly all modern mowers are now provided with a foot lift, which enables the operator to lift the cutter bar over obstructions, and also makes easier work for the team by lifting the bar while turning. A spring is necessary to aid in the lifting. Certain mowers, known as vertical lift mowers, permit the cutter bar to be lifted to a vertical position by a lever, to pass obstructions, and at the same time the mower is HAYING MACHINERY 169 automatically thrown out of gear. When the bar is lowered the mower is as^ain put in gear. 241. Draft connections. — The hitch on mowers is usually made low and below the tongue. A direct con- nection is sometimes made to the drag bar with a draft rod. This is styled a draw cut, and may have some ad- vantage in applying the power more directly to the point where it is used. 242. Troubles with mowers. — If a mower fails to cut the grass and leave a clean stubble, there may be several things wrong: (i) the knife or sickle may be dull; (2) it may not fit well over the ledger plates, losing the advan- tages of a shear cut; (3) the knife may not register, or, in other words, it travels too far in one direction and not far enough in the other. The first of these troubles may be remedied by grinding, the second by adjusting the clips on top of the knife. There should be but a very slight clearance under these clips, and the exact amount has been given as i/ioo inch. To make the knife register in some makes, the pitman must be adjusted, while in others the yoke must be adjusted. If the mower leaves a narrow strip of grass uncut, it indicates that one of the guards has been bent down, a common thing to happen to mowers used in stony fields. Mower guards are now uni- versally made of malleable iron and may be hammered into line with a few sharp blows with a hammer. The guards may be lined up by raising the cutter bar and sighting over the ledger plates and along the points of the guards. 243. A windrowing attachment consists in a set of curved fingers attached to the rear of the cutter bar, which rolls the swath into a windrow. It is useful in cut- ting clover, peas, and buckwheat. The attachment may be used as a bunchcr with the addition of fingers to hold the swath until tripped. 170 FARM MACHINERY FIG. 123 — A VVINDROWING ATTACHMENT FOR A MOWER. IT MAY ALSO BE USED AS A BUNCHER 244. Knife grinder. — The knife grinder is a handy tool which may be attached to a mower wheel or to a bench. FIG. 124 — A SlCKl.E UK MOWER KNIFE GRINDER II HAYING MACHINERY 171 It is used for sharpening the mower knives. Usually it has a double-beveled emery wheel which will L;rind two sections of the knife at the same time. The emery wheel is given a high rotative speed by means of gearing or sprocket wheels and chain (Fig. 124). RAKES 245. Development. — The introduction of the mower created a demand for something better and with a greater capacity than the ordinary hand rake. As long as hand methods prevailed in the cutting of the grasses there was little need for anything better than the hand rake. The first horse rake was revolving. It did very satisfactory work when carefully handled. But later in the steel tooth rake there was found a much better tool. To Walter A. Wood Company, of Hoosick Falls, New York, is given the credit for bringing out the first spring-tooth rake. Differing from the modern tool, it was made almost entirely of wood except the teeth. The early rakes were dumped entirely by hand, but later an internal ratchet was provided on the wheels, which engaged a latch operated by the foot, and which carried the rake teeth up and over, thus dumping the load. The early rakes were almost universally provided with thills. FIG. 125 — A STEEL SELF-DUMP RAKE FOR TWO HORSES. THE TONGUE MAY BE SEPARATED INTO THILLS FOR ONE HORSE. THE TEETH HAVE ONE COIL AND CHISEL POINTS 172 FARM MACHINERY Finally arrangements were made whereby the thills could be brought together and a tongue made for the use of a team instead of one horse. 246. The steel dump rake or sulky rake. — Althotigh the first rakes were made of wood, there are now upon the market rakes made almost entirely of steel. The rake head to which the teeth are fastened is usually made of a heavy channel bar with a minimum of holes punched through it so as not to impair its strength. In the selection of a rake considerable variance is offered in the choice of teeth, which may be constructed of 7/16-inch or i/2-inch round steel, may have one or two coils at the top, be spaced 3^2 inches to 5 inches apart, and have either pencil or flat points. The choice depends somewhat upon the kind of hay to be raked. The rake is always provided with a set of cleaner teeth to prevent the hay from being carried up with the teeth when the rake is dumped. The outside teeth are some- times provided with a projection which prevents the hay from being rolled into a rope and scattered out at the ends when the hay is very light. Sometimes an extra pair of short teeth is provided to prevent this rolling. 247. Self-dump rakes are always provided with a lever for hand dumping. Rakes are made from 8 to 12 feet in width. In the purchase of a rake the important things to look for are ease in operation, strength of rake head and wheels. Often the wheels are the first to give way. Some wheels are very bad about causing the hay to wrap about the hub. The wheel boxes should be interchange- able so they may be replaced when worn. 248. Side-delivery rakes. — The side-delivery rake was brought about by the introduction of the hay loader, the loader creating a demand for a machine which would HAYING MACHINERY 173 place the hay in a light windrow. The first of these ma- chines was manufactured by Chambers, Bering, Quinlan Company, of Decatur, Illinois. 249, One-way rakes. — Practically all of these machines consist of a cylinder mounted obliquely to the front. They carry flexible steel-wire fingers, which revolve under and to the front. These fingers roll the hay ahead, and also FIG. 126 — ONE-;'AY SIDE-DELIVERY R.^KE to one side. Some variance is to be found in the methods employed to drive the cylinder. Both gears and chain- and-sprocket drives are used. 250. Endless apron, reversible rakes. — There are other machines upon the market with a carrier or endless apron upon which the hay is elevated by a revolving cyl- inder and carried to either side. This machine does very satisfactory work and will place in one windrow as many as six swaths of the mower. By manipulation of the clutch driving the apron, this machine may be made to deposit the hay in bunches to be placed in hay cocks or loaded to a wagon by a fork. The side-delivery rake takes the place of the hay tedder 174 FARM MACHINERY to a large extent. The method of curing- hay, especially clover, by raking into light windrows shortly after being mown, has proved very successful. A first-class quality of hay is obtained and in an equal length of time. It is claimed that if the leaves are prevented from drying up, they will aid very greatly in carrying ofif the moisture from the stems. Green clover contains about 85 per cent of water. When cured, only about 25 per cent is left. The leaves draw this moisture from the stems, and if free circulation of air is obtained the hay will dry quicker than if this outlet of the moisture for the water was cut FIG. 127 — THE ENDLESS APRON OR REVERSIBLE SIDE-DELIVERY RAKE ofif by letting the leaves dry up. Many of the one-way side-delivery rakes may be converted into tedders by re- versing the forks and the direction of their movement. The standard width for side-delivery rakes is eight feet. They are drawn by two horses. HAY TEDDERS 251. Hay tedders. — Where a heavy swath of hay is ob- tained, some difficulty is experienced in getting the hay thoroughly cured without stirring. To do this stirring the hay tedder has been devised. Grasses, when cut with HAYING MACIIINF.RY 175 a mower, are deposited very smoothly, and the swath is packed somewhat to the stubble by the passing of the team and mower over it. The office of the tedder FIG. 128 — AN EIGHT-FORK HAY TEDDER is to reverse the surface and to leave the swath in such a loose condition that the air may have free access and thus aid in the curing. The hay tedder consists of a number of arms with wire tines or fingers at the lower ends. These are fast- ened to a revolving crank near the middle and to a lever at the other end. The motion of the cranks causes the tines to kick backward under the machine, thus engaging the mown hay, FIG. I29-TYPES OF TEDDER FORKS tOSsiug it Up aud Icaviug it WITH COIL AND FLAT RELIEF in a vcrv loosc conditiou. SPRINGS. D SHOWS THE SPRING t^, 1" 1 • ^ „^^ OF C SPRUNG ^ "^ modern machme, made 176 FARM MACHINERY almost entirely of steel, is illustrated in Fig. 128. The size of tedders is rated by the number of forks. Tedders constructed of wood are still upon the market. The fork shaft may be driven by a chain or by gearing. HAY LOADER 252. Development. — The hay loader has been upon the market for some time, but only during recent years has there been any great demand for the tool. The Keystone Manufacturing Company, of Sterling, Illinois, began ex- KIG. 130 — .^ FORK HAY LO.\DER perimenting with the hay loader as early as 1875. The machine is designed to be attached to the rear of the wagon, to gather the hay and elevate it to a rack on the wagon. HAYING MACHINERY I77 253. Fork loader. — In all of the early machines the hay was placed upon the elevating apron by tines or forks attached to oscillating bars extending up over the load. The hay was pushed along this apron by these oscillating bars with the tines on the under side. This form of loader worked very satisfactorily, but had one disadvantage in w^orking in clover and alfalfa. The oscillating bars were unsatisfactory, as they shook the leaves out of the hay. This led to the introduction of an endless apron, which works very satisfactorily in this respect. The loader equipped with oscillating forks is of much more simple construction than the other type. It also has an advan- tage in being able to draw the swath of hay together at the top, and force it upon the wagon. Loaders of this kind are made without gears by increasing the throw of the forks. These machines have not as yet demonstrated their advantages. 254. Endless apron loaders. — The hay is elevated in this type of loader on an endless apron or carrier after it has been gathered by a gathering cylinder. The main advantage of this type of loader is that it does not handle the hay as roughly as the fork loaders. This is an im- portant feature in handling alfalfa and clover, as there is a tendency to shake out many of the leaves, a valual)le part of the hay. Due provision must be made, however, to prevent the hay from being carried back by the carrier returning on the under side. The apron or carrier usually passes over a cylinder at the under side, which has teeth to aid in starting the hay up the carrier. Provision must be made to enable the gathering cylin- der to pass over obstructions and uneven ground. For this reason the gathering cjdinder is mounted upon a separate frame and the whole held to the ground by suit- able springs. The loader has a great range of capacity. 178 FARM MACHINERY All modern machines will load hay from the swath or the windrow, and the carrier will elevate large bunches of hay without any difficulty. FIG. I3I^AN ENDLESS APRON OR CARRIER HAY LOADER MACHINES FOR FIELD STACKING 255. Sweep rakes. — Where a large amount of hay is to be stacked in a short time, the sweep rake and the hay stacker will do the work more quickly than^ is possible by any other means. The sweep rake has straight wooden teeth to take the hay either from the swath or windrow, and is either drawn between the two horses or pushed ahead. When a load is secured the teeth are raised, HAYING MACHINERY 179 the load hauled and placed upon the teeth of the stacker and the rake backed away. 'inhere are three j^eneral types of sweep rakes: (i) the wheelless, with the horses spread to each end of the FIG. 132 — A TWO-WHEEL SWEEP RAKE. THE TEETH ARE RAISED BY THE DRIVER SHIFTING HIS SEAT rake; (2) the wheeled rake, with the horses spread in the same manner ; and (3) the three-wheel rake, with the horses directly behind the rake and working on a tongue. FIG. 133 — A THREE-WHEEL SWEEP RAKE. THE DRIVER IS AIDED IN LIFT- ING THE LOADED TEETH BY THE PULL OF THE HORSES The latter are the more expensive. They oiTer advan- tages in driving the team, but are a little difficult to guide (Figs. 132 and 133). 256. Hay stackers are made in two general types : the overshot and the swinging stacker. In the overshot the i8o FARM MACHINERY n FIG. 134 — A PLAIN OVERSHOT HAY STACKER FIG. 135 — THE SWING HAY STACKER. NOTE THE BRAKE AT THE REAR END FOR HOLDING THE ROPE HAYING MACHINERY lOI teeth carrying the load are drawn up and over and the load is thrown directly back upon the stack, the work being done with a horse or a team of horses by means of ropes and suitable pulleys (Fig. 134). The swinging stacker permits the load to be locked in place after it has been raised from the ground to any height and swung to one side over the stack. When over the stack, the load may be dumped and the fork swung back and lowered into place. The latter stackers are very handy, as they may be used to load on to a wagon. They have not as yet been built strong enough to stand hard service. 257. Forks. — A cable outfit may be arranged with a carrier and fork for field stacking, the cable being stretched between poles and supported with guy ropes. This outfit works the same as the barn tools to be de- scribed later. Very high stacks may be built by this method. A single inclined pole may be used in stacking by raising the fork load to the top and swinging over the stack. This is usually a home-made outfit, with the ex- ception of fork and the pulleys. BARN TOOLS 258. Development. — The introduction of the field hay- ing tools created a demand for machinery for the unload- ing of the load of hay at the barn, and this led to the development of a line of carriers and forks, the first of which was a harpoon fork, a patent for which was issued to E. L. Walfer, September, 1864. In 1873 a Air. Nellis patented a locking device, which has given to this fork the name of Nellis fork. J. E. Porter began the manufacture of a line of carriers FARM MACHINERY FIG. 136— TYPES OF STEEL AND WOOD HAY CARRIER TRACKS HAYING MACHINERY 183 and hay tools at Ottawa, Illinois, in 1868. This firm is still doing business. P. A. Meyers was another pioneer in the hay tool business, and in 1866 patented a double track made of two T-bars. In 1887, J. E. Porter placed upon the market a solid steel rail. 259. Tracks. — A large variety of tracks is to be found upon the market to-day — the square wooden track, the two-piece wooden track, the single-piece inverted T steel track, the double steel track made of two angle bars, and various forms of single- and double-flange steel tracks. Wire cables are used in outdoor work. Various forms of track switches and folding tracks are to be found upon the market. By means of a switch it is possible to unload hay at one point and send it out in four different directions. In circular barns it is possible to arrange pulleys in such a way that the carrier will be carried around a circular track. 260. Forks are built in a variety of shapes and are known as single-harpoon or shear fork, double-harpoon fork, derrick forks, and four-, six-, and eight-tined grapple forks. To replace the fork for rapid unloading of hay, FIG. 137 — A, DOUBLE- HARPOON HAY FORK. B, SINGLE-HAR- POON HAY FORK FIG. 138 — C, A GRAPPLE FORK. RICK FORK FOUR-TINED D, A DER- 1 84 FARM MACHINERY the hay sling is used. The harpoon forks are best adapted for the handling of long hay, like timothy. For handling clover, alfalfa, and the shorter grasses, the grapple and derrick forks are generally used. The der- rick fork is a popular style for field stacking in some localities. Harpoon forks have fingers which hold the hay upon the tines until tripped.. The tines are made in lengths varying from 25 to 35 inches, to suit the condi- tions. The grapple fork opens and closes on the hay like ice tongs. The eight-tined fork is suitable for handling manure. The hay sling consists of a pair of ropes spread with wooden bars and provided with a catch, by which it may FIG. 139 — A HAY SUNG. THE SPRING CATCH BY WHICH THE SLING IS PARTED IS ABOVE E be separated at the middle for discharging a sling load. The sling is placed at the bottom of the load, and after sufficient hay has been built over it for a sling load, another sling is spread between the ends of the hay rack and another sling load is built on, and so on. Four slings are usually required for an ordinary load ; however, the number has been reduced to three, and even two. The sling is a rapid device, but is some- what inconvenient in the adjusting of the ropes and placing in the load. It is very convenient at the finish. If the standard sling carrier is used, it is necessary HAYING MACHINERY 1^5 rack, requiring little hand labor. The most popular method at the present time is to use forks to remove all the load but one slingful, which is removed by a sling placed in the bottom of the load. This method circum- vents the necessity of building slings into the load or hand labor in cleaning up the load for the fork at the finish. If the standard sling carrier is used, it is necessary FIG. 140 — A TWO-WAY FORK HAY CARRIER. TO WORK IN THE OPPOSITE DIRECTION, THE ROPE IS SIMPLY PULLED THROUGH UNTIL THE KNOT ON THE OPPOSITE END IS STOPPED BY THE CARRIER to use two forks ; however, a special fork and sling carrier will permit the use of a single fork. 261. Carriers. — Carriers are made to suit all of the various forms of tracks and are made one-way, swivel, i86 FARM MACHINERY ^ and reversible. In order to work the one-way from both ends of a barn it is necessary to take it off the track and reverse. The swivel needs only to have the rope turn to the opposite direction, while in the reversible the rope is knotted at each end, and when it is desired to work FIG. 141 — A DOUBLE-CARRIAGE REVERSIBLE SLING CARRIER. DESIGNED FOR HEAVY SERVICE from the other end of the barn all that is necessary is simply to pull the rope through the other way. There are numerous devices to be used with barn outfits, carrier returns, pulley-changing devices, which are very handy, but need only be mentioned here. HAYING MACHINERY BALING PRESSES 187 262. Development. — Many patents were granted on baling presses during the early half of the past century, indicating the rise of the problem of compressing hay into a form in which it could be handled with greater facility. It was not, however, until 1853 that H. L. Emery, of Albany, N. Y., began the manu- FIG. 142 — A LIGHTER SLING CARRIER LOADED WITH A SLING LOAD OF HAY facture of hay presses. It is stated that this early machine had a capacity of five 250-pound bales an hour and required two men and a horse to operate it. It made a bale 24 X 24 X 48 inches. The next man to devote his efiforts toward the development of a hay press with any success was P. K. Dederick, who began his work about i860. He produced a practical hay press. l88 FARM MACHINERY George Ertel was the pioneer manufacturer of hay presses in the West. His first efforts were in 1866, and from that time he devoted practically his entire time to the manufacture of hay presses. His first machine was a vertical one operated by horse power. Now both steam and gasoline engines are used to furnish the power. 263. Box presses are used very little at present, being superseded by the continuous machijies of larger capacity. The box press consists in a box through which the plunger or compressor acts vertically, power being fur- nished either by hand or by a horse. The box, with the plunger down, is filled with hay ; the plunger is then raised, compressing the hay into, usually, the upper end, where it is tied and removed. The machine is then pre- pared for another charge. 264. Horse-power presses are either one-half circle or full circle. In the half-circle or reversible-lever presses 1 FIG. 143 — A FULL-CIRCLE HORSE HAY PRESS ON TRUCKS FOR TRANSPORTATION the team pulls the lever to one side and then turns around and pulls it to the other side. The hay is placed loose in a compressing box, compressed at each stroke and pushed toward the open end of the frame, where it is held by tension or pressure on the sides. When a bale of sufficient length is made a dividing block is inserted and the bale tied with wire. In the full-circle press the team is required to travel in a circle. Usually two strokes are made to one round HAYING MACHINERY 189 of the team. Various devices or mechanisms are used to obtain power for the compression. It is desired that the motion be fast at the beginning of the stroke, while the hay is loose, and slow while the hay is compressed during the latter part of the stroke. The cam is the most com- mon device to secure this; however, gear wheels with a FIG. 144 — A HAY PRESS FOR ENGINE POWER AND EQUIPPED WITH A CON- DENSER TO THRUST THE HAY INTO THE HOPPER cam shape are often used. The rebound aided by a spring is usually depended upon to return the plunger for a new stroke ; but a cam motion may be made use of to return the plunger. It is to be noted that some machines use a stiff pitman and push away from the powder, while others use a chain and rod and pull the pitman toward the power or reverse the direction of travel of the plunger. A horse- power machine has an average capacity of about 18 tons a day. A cubic foot of hay before baling weighs 4 or 5 pounds when stored in the mow or stack. A baling press increases its density to 16 or 30 pounds a cubic foot. Specially designed presses for compressing hay for export secure as high as 40 pounds of hay a cubic foot. 265. Power presses make use of several variable-speed devices and a flywheel to store energy for compression. Power machines are often provided with a condenser to igO FARM MACHINERY thrust the hay into the hopper between strokes. The common sizes of bales made are 14 X 18, 16 X 18, and 17 X 22 inches in cross-section, and of any length. A new baler has appeared which is very rapid, making round bales tied with twine. The machine can readily handle the straw as it comes from a large thresher. Plunger presses are built with a capacity up to 90 tons a day. CHAPTER IX MANURE SPREADERS 266. Manure as a fertilizer. — Although the manure spreader has been a practical machine for some time, it is only recently that its use has become general. This is especially true in the Middle West, where for a long time the farmer did not realize the need of applying manure, owing to the stored fertility in the soil when the native sod was broken, and cultivated crops grown for the first time. It has been proved that manure has many advan- tages over commercial fertilizer for restoring productive- ness to the land after cropping. It has been estimated by experts of the United States Department of Agricul- ture that the value of the fertilizing constituents of the manure produced annually by a horse is %2y, by each head of cattle $19, by each hog $12. The value of the manure a ton was also estimated at $2 to $7. It is not known from what data these estimates were made. The value of manure as a fertilizer does not depend solely upon the fact that it adds plant food to the soil, but its action renders many of the materials in the soil available and improves the physical condition of the soil. 267. Utility of the manure spreader. — As it was with the introduction of all other machines which have dis- placed hand methods, there is much discussion for and against the use of the manure spreader. The greatest advantage in the use of the manure spreader lies in its ability to distribute the manure economically. Experi- ment has shown that, in some cases at least, as good 192 FARM MACHINERY results can be obtained from eight loads of manure to the acre as twice that number. It is impossible to dis- tribute and spread by hand in as light a distribution as by the spreader. The manure is thoroughly pulverized and not spread in large bunches, which become fire-fanged and of little value as a fertilizer. It is a conservative statement that the manure spreader will make a given amount of manure cover twice the ground which may be covered with hand spreading. Since a light distribution may be secured, it can be applied as a top dressing to growing crops, such as hay and pasture, without smother- ing the crop. The manure spreader also saves labor. It is capable of doing the work of five men in spreading manure. With a manure loader or a power fork it is possible to handle a large amount of manure in a short time. 268. Development. — The first attempts at the development of a machine for automatically spreading fertilizer were contem- poraneous with a machine for planting or seeding. In 1830 two brothers, by the name of Krause, of Pennsylvania, patented a machine for distributing plaster or other dry fertilizer. This machine consisted of a cart with a bottom sloping to the rear, where a transverse opening was provided with a roller under- neath. This roller was driven by a belt passed around one of the wheel hubs. It fed the fertilizer through the opening. The first apron machine was invented by J. K. Holland, of North Carolina, in 1850. The endless apron was attached to a rear end board and passed over a bed of rollers and around a shaft driven by suitable gearing at the front end of the cart. After the box had been filled with fertilizer and the apron put in gear, it drew the fertilizer to the front and caused it to drop little by little over the front end. The first spreader of the wagon type was produced by J. H. Stevens, of New York, in 1865. His machine had an apron which was driven rearward by suitable gearing to discharge the load and was cranked back into position for a new load. The later machines were provided with vibrating forks at the rear end, MANURE SPRKADERS 193 which fed the manure to fingers extending to each side, and securing in this way a better distribution of the fertilizer than the former ways. Thomas McDonald, in 1876, secured a patent on a machine much like the Stevens machine, except that it was fig. 145 — the j. s. kemp machine of 1877. (from a patent office drawing) provided with an endless apron passing around the roller at each end of the vehicle. Many of the ideas of the modern spreader made their appear- ance in the patent of J. S. Kemp, granted in 1877. The objects of the invention read as follows : "To provide a farm wagon or cart with a movable floor composed of slats secured to an end- less belt or chain. To the foremost slat an end board is secured, 194 FARM MACHINERY which, when the machine is in forward motion, moves by a suitable gearing slowly to the rear, thus propelling the material that may be loaded in the vehicle against a rotating toothed drum, which pulverizes and evenly spreads the load on the ground behind." A spreader with a solid bottom to the box over which the manure was drawn by chains with slats across and attached to an end board, appeared in 1884. Variable-speed devices for varying the rate of distribution were provided at the same time. An endless apron machine appeared in 1900, with hinged slats which overlapped while traveling rearward, and which hung downward while traveling ahead on the under side, making an open apron. There is a tendency on the part of endless apron machines to become fouled by the manure which passes through the apron on the upper side and lodges on the inside of the lower half. It would be impracticable to mention all of the improvements to manure spreaders along the line of return motions, variable- feed devices, safety end boards, and almost countless details in the construction of bed, apron, and beater. THE MODERN SPREADER The modern manure spreader consists essentially in (a) a box with flexible apron for a bottom, (b) gearing to move the apron to the rear at a variable speed, and (c) a toothed drum or beater to pulverize and spread the manure evenly behind. 269. Aprons. — Three types of aprons or box bottoms are to be found in use on the modern spreader: (a) a return apron (Fig. 146), with an end board which pulls the load to the beater by being drawn under the box; (b) the endless apron (Fig. 147), which is com- posed of slats or bats passing continuously around reels at each end of the box; and (c) bars or a push board, moved by chains, thus moving the load to the beater over a solid floor. 1 MANURE SPREADERS 195 The endless apron spreader is perhaps of more simple construction than the others, as no return motion is needed to return the apron for another load. It will not distribute the load well at the finish because it does not FIG. 146 — A RETURN APRON SPREADER, SHOWING THE APRON UNDER- NEATH, AND ALSO A GEAR AND CHAIN DRIVE TO BEATER have the end board to push the last of the load to the beater. There is also some difficulty in preventing the inside of the apron from being fouled with manure. One make overcomes this difficulty by hinging the slats in a 777771 V\ i i ^^y,'':^- FIG. 147 — AN ENDLESS APRON way that they may hang vertically while on the lower side. To prevent fouling, the endless apron may be cov- ered with slats for only half its length. The chain apron without doubt requires much more power than the others, since the weight is not carried upon rollers. Some 196 FARM MACHINERY spreaders have an advantage over others in the arrange- ment of rollers and the track on which they roll. The rollers may be either attached to the bed or to the slats. 270. Main drive. — The main drive to the beater varies with different machines. The power may be taken from the main axle with a large gear wheel or by means of a large sprocket and a heavy chain or link belt. It is % FIG. 148 — A CHAIN DRIVE TO THE BEATER. NOTE THE METHOD OF REVERSING THE MOTION almost universal practice to use a combination of a chain and a gear in the drive. The speed of the beater must be such that the power must be increased twice, while the direction of rotation must be reversed. To reverse the direction of the motion, the gear is used. The heavy chain or link belt offers some advantage in case of breakage. A single link may be replaced at a small cost, while if a tooth is broken from a large gear the entire wheel must be replaced. MAXURE SPREADERS 197 The use of "ears is avoided entirely in at least one make by passing;' the drive chain over the top of the ■main sprocket and back instead of around it. This re- verses the direction of rotation (Fig. 148). Some spreaders are so arranged that a large part of the main drive must be kept in motion even when the machines are out of gear. The gearing must be well protected, or it FIG. 149 — A CHAIN AND GEAR DRIVE TO THE BEATER. THE BEATER IS PLACED IN GEAR BY MOVING BACK UNTIL GEARS MESH will become fouled in loading. The main axle must be very heavy on a spreader, as a large share of the load is placed upon it, and it must not spring or it will increase the draft greatly. Large bearings should be provided with a reliable means of oiling and excluding dirt. 271. Beaters. — The beater is usualh^ composed of eight bars filled with teeth or pegs for tearing apart and pul- 198 FARM MACHINERY verizing- the manure (Fig. 150). Some variance is noticed in the diameter of the beater and its location as to height. It is claimed by certain manufacturers that much power FIG. 150 — A MANURE SPREADER BEATER may be saved by building the beater large and placing it low ; in this way there is no tendency to compress the manure on the lower side of tHe beater, as it is not neces- sary to carry the manure forward and up. When a FIG. 151 — A MANURE SPREADER WITH AN END BOARD TO BE PLACED IN FRONT OF THE BEATER beater is so placed it does not have the pulverizing effect it would have otherwise. When a load is placed upon a spreader it is usually much higher and more compact in MANURE SPREADERS 199 the center. If due pro\-ision is not made, the spreader will spread heavier at the center than at the sides. One beater has the teeth arranged in diagonal rows, tending to carry the manure from the center to the sides. Sev- eral have leveling raV:es in front of the beater, and at least one a vibrating rake, to level and help pulverize the manure. If no provision is made, the front of the beater will be filled with manure while loading, and the •4 6,500 2% 6,500 4 8,500 2H 9,000 434 10,000 3 15,000 4/2 12,000 356. Draft of wagon. — The draft of a wagon is the resistance encountered in moving the wagon with its load. It is often called tractive resistance, and is worthy of careful consideration, for a reduction in the draft of wagons not only means increased efficiency on the part of the draft animals, but also a reduction in the cost of transportation. The draft of wagons is made up of three elements : (a) axle friction, (b) rolling resistance, and (c) grade resistance. WAGONS, BUGGIES, AND SLEDS 249 357. Axle friction is the resistance of the wheel turn- ing about its axle similar to the resistance of a journal turning" in its bearing, independent of the other elements of draft. Axle friction is usually a small part of the total draft. The power required to overcome it diminishes as the ratio between the diameters of the wheel and axle increases. Thus in Fig. 183 if R be the radius of the wheel, r the radius of the axle, from the principle of the wheel and axle — Power Power = Axle friction : : / Axle friction R R/t In the standard farm wagon R/r has a value of from ii to 20, or an average of about 15. Morin found in his experiments, which have been con- sidered a standard for years, that with cast-iron axles in cast-iron bearings lubricated with lard, oil of olives or tallow gave a co- efficient of friction of 0.07 to 0.08 when the lubrica- tion was renewed in the usual way. Assuming 0.08 to be the coefficient of fric- tion and 15 to be the ratio between wheel and axle diameters, the force re- quired per ton to overcome friction would be between 10 and II pounds. Another authority* states that the tractive power required to overcome axle friction in a truck wagon which has medium-sized wheels and axles is about 3yi to 4>< pounds a ton. The use of ball and roller *1. O. Baker, "Roads and Pavements." FIG. I S3 250 FARM MACHINERY bearings would tend to reduce the axle friction and man ufacturers trying to introduce these bearings claim a great reduction in draft. No doubt there are other ad- vantages in the use of ball and roller bearings beside a reduction in draft. It is not thought that the dished wheel and bent axle are of a construction that tends to reduce axle friction to a minimum. It is hoped that ex- periments will be conducted at an early date to deter- mine accurately the axle friction of wagons. 358, Rolling resistance. — Rolling resistance corre- sponds to rolling friction in that it is due to the indenta- tion or cutting of the wheel into the road surface, which really causes the wheel to be rolling up an inclination or grade. The softer the road bed the farther the wheel will sink into it, and hence the steeper the inclination. The height of wheel influences the rolling resistance in that a wheel of large diameter will pass over an obstruction with less power, as the time in which the load is lifted is lengthened. There is also a less tendency upon the part of a large wheel to cut into the surface, due to the larger area presented at the bottom of the wheel to carry the load. Elaborate experiments have been conducted by T. I. Mairs, of the Missouri experiment station, in re- gard to the influence of height of wheel upon draft of wagons. Three sets of wheels were used with six-inch tires and a net load of 2,000 pounds was used in all cases. The total load for the high wheels was 3.762 pounds, for the medium wheels 3,580, and for the low wheels 3.362. The high wheels were 44-inch front wheels and 56-inch hind wheels, medium " " 36 " " " " 40 " " " low " " 24 " " " " 28 " " 1 WAGONS, BUGGIES, AND SLEDS 251 EFFECT OF HEIGHT OF WHEELS ON DRAFT * Draft in Pounds per Ton Description of Road Surface Macadam; slightly worn, clean, fair con- dition Dry gravel road ; sand i inch deep, some loose stones Earth road— dry and hard " — thawing '/<-inch sticky mud. Timothy and bluegrass sod, dry, grass cut. " " " wet and spongy. . . Corn; field flat culture across rows, dry on top Plowed ground, not harrowed dry and cloddy HiKh Wheels Medium Wheels 57 61 84 69 lOI 90 75 119 132 173 145 203 178 201 252 303 Low Wheels 70 IIO 99 139 179 281 265 374 The width of tire also infltiences the rolling resistance to a great extent. The wide tire on a soft road bed is able to carry the load to better advantage and prevent the wheel ctitting in as far as it would otherwise. The rolling resistance as indicated in the above re- marks depends largely upon the condition of the road sur- face. The harder and smoother the road surface the less will be the rolling resistance. It is for this reason that much larger loads may be hauled upon good hard roads than upon poor soft ones. Prof. J. H. Waters, at the Missouri experiment station, has conducted extended ex- periments to determine the influence of the width of tire upon the draft of wagons when used on various road surfaces. The wheels used were of standard height and were provided with ij^^-inch and 6-inch tires. The sum- mary of the results of these experiments states that the wide tires gave a lighter draft except under the follow- * Missouri Agricultural Experiment Station, Bulletin No. 52, 1901. 252 FARM MACHINERY ing conditions: (a) When the earth road was muddy, sloppy and sticky but firm underneath, (b) when the mud was deep and adhered to the wheels, (c) when the road was covered with deep loose dust, and (d) when the road was badly rutted with the narrow tire. INFLUENCE OF WIDTH OF TIRE UPON DRAFT* Draft in Pounds per Ton Description of Road Surface Width of Tire ii^-Inch 6-Inch Broken stone road — hard, smooth, and no dust Gravel road — hard and smooth 121 182 246 QO 149 497 286 825 466 98 134 " " — wet, loose sand, i to 2^ inches deep. Earth road loam, dry dust, 2 to 3 inches deep " " " dry and hard, no dust " " " stiff mud, dry on top, spongy underneath 254 106 109 307 406 551 323 " clay, sloppy mud, 3 to 4 inches hard below " " clay, stiff, deep mud Plowed land harrowed smooth and compact Besides the reduction of draft attained in the majority of cases with the use of wide tires, there is another im- portant advantage from their use, as there is less ten- dency to rut and destroy the road surface. It is be- lieved that this feature should be placed before all others. There is a slight increase in draft with an increase in speed. Morin, who conducted experiments to determine the relation between draft and speed, found that the draft increased about as the fourth root of the speed. The draft upon starting a load is greater than after motion has been attained, and is due to the settling of the load into the road bed, the increased axle friction of rest, and * Missouri Agricultural Experiment Station, Bulletin No. 39, 1897. WAGONS, BUGGIES, AND SLEDS 253 the extra force required to accelerate the load. Springes tend to reduce draft, as they reduce the shocks and con- cussions due to the unevenness and irregularities of the road surface. Their effect is greater at high speeds than at lower. 359. Grade resistance. — Grade resistance involves the principle of the inclined plane, and may be explained as the force required to prevent the load from rolling down the slope. It is independent of everything except the angle of inclination. In Fig. 184 if IV be the load and P the grade resistance, AB the height of the grade and CB the length, by com- pleting the force diagram similar triangles are obtained, from which it is seen : P : AB :: IV : AC, or P = IV X 4^ A C As AC is very nearly equal to BC for ordinary grades, no great error will be accrued by substituting BC for AC. Grades are usually expressed in the number of feet rise and fall in 100 feet, or in the number of per cent the total rise is of the length of the grade. Then for practical purposes the Fit;. 184 grade resistance is equal to the per cent of the total load, which expresses the grade. For example, if the grade is 5 per cent and the load 2,000 pounds, the grade resistance will be 100 pounds. The foregoing analysis does not take into account the way the load is placed on the wagon or angle of hitch, which may lead to error. 360. Handy wagons. — The name handy wagon is given to a low-wheeled, broad-tired wagon used about the farm for hauling implements, grain, and stock. They are used 254 FARM MACHINERY to a limited extent in road transportation. Two styles of wheels are used, the metal with spokes cast in the hub and riveted into the tire, and a solid wooden wheel bound with a tire and provided with a cast hub. The metal wheel may be had in any height from 24 inches up. The wheel with staggard oval spokes is con- sidered stronger than the straight spoke wheel, as it is able to resist side hill stresses to better advantage. The solid wooden wheel is very strong and there is no tendency for the wheel to fill with mud above the tire. The fact that the wheel proper is made of wood requires an occasional setting of tires, but this is not often, as the wheel is filled with circular wooden disks with the grain of the sections at right angles, and there is little shrink- age on account of the small diameter of the wheel. Four- or 5-inch tires are common widths used on handy wag- ons, although almost any width may be obtained. Some handy wagons are made very cheaply and sold at a very low price. These wagons are poorly ironed, do not have any front or rear hounds, and are poorly fin- ished. Others are made with as much care as the stand- ard farm wagon and are as well finished. Care should be used in the selection of a handy wagon. Although boxes may be used upon handy wagons the wagon used about the farm is usually equipped with a rack or a flat top which readily permits the loading of implements, fodder, etc. BUGGIES AND CARRIAGES 361. Selection. — Light vehicles for driving have been in use since the introduction of springs and good roads. The points which make a buggy or a carriage popular are lightness, neatness of design, excellent and durable fin- ish, good bracing, a reliable fifth wheel, well-secured WAGONS, BUGGIES, AKD SLEDS 255 clips, and a body sufficiently braced and stayed and, if SO provided, with a neat leather or at least leather ciuar- ter top. Leather quarter is the name given to tops made with leather sides above the curtains, while the roof is made of the cheaper material, rubber or oil cloth. It is very hard to detect c|uality in a buggy and the re- liability and guarantee of the manufacturer must be de- pended upon to a large extent. As in the construction of wagons and implements, poor (piality may be detected by poor workmanship used in the construction. Only the best materials, carefully cured, should be used in the construction. The wheels and other wood parts of the FIG. 185 — A LONG-I)IST.\NCE BUGGY AXLE. NOT£ THE PROVISION MADE TO EXCLUDE DUST AND DIRT gear should be made of best hickory. This is especially true of the wdieels, which must meet with very hard service. The rims of the wheels should be well clipped and screwed. 362. The body or box should be made of the very best yellow poplar and should be well screwed and braced. The plain top Ijuggy has two common styles of bodies: the piano box, which is narrow and has the same height of panel all around, and the corning body, which has low panels just back of the dashboard. 363. Hubs. — Two styles of hubs are in general use, the compressed hub with staggard spokes and the Sarven patent hub. The former is perhaps the stronger but more difficult to repair. There are many other parts which might be men- 256 FARM MACHINERY tioned, as the st3des of springs, spring bars, box loops, etc., but it is not deemed wise to take up space, 364. The painting of a buggy is of great importance and should be done only by an expert. Several coats of filler should be used, and between coats it should be ^ FIG 186 A COMPRESSED WHEEL HUB FIG- I.S7 - A SAKVEN WHEEL HUB well sandpapered. In all, there should be 20 to 24 coats applied. It is stated that the varnish for the body should be first-grade copal, and for the gears second-grade copal, which should be very carefully rubbed between coats and the final coat should be rubbed with the palm of the hand. SLEDS 365. Utility and selection. — Sleds were the first means of conveyance known to man, and among the uncivilized they are still the only conveyance. There has probably been as great a change made in the sled as in the wagon since man commenced to improve his machinery. Due to the variety of work required of sleds and the climatic conditions, there is almost invariably a different type of sled required in every locality. In heavily tim- bered countries where there is an extended season of snow, sleds are made with as much care as wagons, while WAGONS, BUGGIES, AND SLEDS 257 in communities where sleds are used only at intermittent times of the year and then only as a substitute for a wagon with light loads, they are very much more cheaply built. \\'here the runners of a sled are bent they should be of either ash or hickory. If the natural curve of a tree is used, good hard wood will do. If the curve is sawed, white oak is better. All other parts should be of oak. The knees should be fastened by means of two bolts on each end. This will prevent splitting. All connec- tions are better if made flexible, and it is more convenient to have the front bob connected so it can turn under the load. The shoes are more economical when made of cast iron and removable. In communities where there is no continued season of snow a cheaper type of sled is sufficient. In such cases the shoes can be made of wrought iron, the bobs connected directly by a short reach and eyes, and the flexil:)le parts dispensed with. 366. Capacity. — A bob sled with two knees in each bob ought to have a capacity of about 4,000 pounds, and one with three knees, of 6,000 pounds. There is practically no limit to the load a team can handle on a sled provided they can start it. In most cases it is better to carry a bar to assist in starting the load and thus avoid the troublesome lead team. In hilly countries it is essential to have some method for holding the load back in descending and to keep it standing while the team breathes upon ascending a hill. A short chain attached to the runner and dropped be- neath it will hold the load back when descending a hill. In some localities a curved spike extending to the rear is bolted to the sled in such a manner as to prevent the sled from sliding backward when pressed to the snow by the teamster. CHAPTER XIV PUMPING MACHINERY 367. Early methods of raising water. — The oldest method of raising water was by bailing. The vessel and the water it contained were raised either by hand or by machines to which power might be applied. The buck- ets were provided with a handle or a rope when it was desired to draw water from some depth. To aid in draw- ing water from wells, the long sweep or lever weighted at one end was devised. This sweep is often seen illustrated in pictures of an old home- stead and similar pictures. Fol- lowing the sweep, a rope over a pulley with two buckets, one at each end, was used. Later, one bucket was used and the rope carried over a guide pul- ley and wound around a drum. This latter method of raising has not entirely disappeared and is still in use in many places. For raising water short distances and in large quantities, swinging scoops and flash wheels are used. The scoop is provided with a handle and is swung by a cord long enough to permit it to be dipped into the water. The water is simply pitched to a higher elevation much like grain is elevated. Flash wheels are the reverse of the undershot water wheel; the paddles or blades ascend- ing a chase or waterway carry the water along with I FIG. 188 — THE WELL SWEEP AN OLD METHOD OF RAIS- ING WATER PUMPING MACHINERY 259 them. If operated by hand the paddles are hinged Hke valves and are rocked back and forth in the waterway. Flash wheels are used extensively in Holland in draining low lands. The Chinese devised at a very early time scoop wheels which have buckets on the periphery. These buckets dip into water and are set at such an incline that they carry almost their full capacity to the upper side, and there they pour their contents into a trough. They are sometimes hinged and are made to discharge their contents by strik- ing against a suitable guide. Wheels of this nature may now be used profitably where a large quantity of water is to be elevated for only short distances. One of the oldest water-raising devices made famous by history is the /\rchimedean screw. It consists essen- tially of a tube wound spirally around an inclined shaft and taking part in the rotation of this shaft. The pitch of the screw and the inclination of the shaft are so chosen that a portion of each turn will always slope downward and form a pocket. A certain quantity of water will be carried up the screw in these pockets as it is rotated. At the upper end of the inclined screw the water is discharged from the open end of the tube. 368. Reciprocating pumps. — As advancement came along other lines of machinery, the early devices for raising water gave way to the introduction of more effi- cient machines to which may properly be given the name of pumps, the most common of which is the reciprocating pump. A reciprocating pump consists essentially of a cylinder and a closely fitting piston. 369. Classes. — Reciprocating pumps may be divided into two classes : I. Pumps having solid pistons or plunger pumps. 26o FARM MACHINERY 2. Pumps having valves in the piston or bucket pumps. Plunger pumps will not be considered in this discus- sion, for, at the present time, their use is confined almost entirely to steam and large power pumps. Pumps used for agricultural purposes are almost universally of the latter type. Pumps may further be divided into tv;o distinct classes : 1. Suction or lift pumps. 2. Force pumps. Suction pumps do not elevate the water above the pump standard. The pump standard is the part which is above the well platform when, speaking of pumps for hand or windmill power. A pump will then necessarily include the standard, cylinder, and pipes. 370. Pump principles. — Before continuing the discus- sion it will be well to take some of the principles con- nected with the action of pumps. The action of a plain suction pump when set in operation is to create a vacuum, and atmospheric pressure when the lower end of the suc- tion pipe is immersed in water causes the vacuum to be filled. Atmospheric pressure amounts to about 14.7 pounds per square inch. Water gives a pressure of .434 pound per square inch for each foot of depth, or each foot of head, as it is usually spoken of. Thus atmospheric pressure will sustain a water column only about 33.9 feet, above which a vacuum will be formed. Pumps will not draw water satisfactorily by suction more than 25 feet, and it is much preferred to have the distance less than 20 feet. It is often an advantage to have the cylinder submerged. 371. Hydraulic information. — The following informa- tion will be useful in making calculations involving pumping machinery : 1 k PUMPING MACHINERY 261 A United States gallon contains 231 cubic inches. A cubic foot of water weighs 62.5 pounds. A gallon of water weighs Syi pounds. A cubic foot contains approximately yYj gallons. The pressure of a column of water is equal to its height multiplied by .434. Approximately the pressure is equal to one-half of the height of water column or head. Formulas for pump capacity and power: D = diameter of pump cylinder in inches. N 1= number of strokes per minute. H = total height water is elevated, figuring from the surface of suction water to highest point of discharge. S = length of stroke in inches. Q = quantity of water in gallons raised per minute. D" X .7854 X S = capacity of pump in cubic inches per stroke. D^ X S — — -— capacity of pump per stroke in gallons. 294 D^ X S ,^ — capacity of pump per stroke in pounds of water. 35-206 D'XSXN . , . , . „ — —: capacity of pump per mmute m gallons. 294 D' X S X H X N 35-268 number of foot-pounds of work per minute. A rule which may be used to calculate roughly the capacity of a pump is as follows : The number of gal- lons pumped per minute by a pump with a lo-inch stroke at 30 strokes per minute is equal to the square of the diameter of the cylinder in inches. From this rule it is easy to calculate the capacity of a pump of a longer or shorter stroke and making more or less strokes per min- ute. 372. Friction of pumps. — Pumps used to pump water from wells are of rather low efficiency; on an average, 35 per cent of the power is required to overcome friction 262 FARM MACHINERY -HAT SLIDE BAR HANDLE PIN FULCRUM PIM ^SnII fig. 190 — A CAST-IKON PUMP STANDARD, PIC_ 189— A SUCTION PUMP IN WITH THE COMMON NAMES FOR A WELL ITS PARTS PUMPINC. iMACIIINKRY 263 alone. Often as much as one-half or even more of the power is required for this purpose. A common rule in use to determine approximately the power rc(|uired to operate a farm pump is that one horse power is required to lift 30 gallons 100 feet per minute. From this rule it is easy to calculate for different capacities at more or less head. The rule assumes a mechanical efficiency of 68 per cent on the part of the pump. The friction of water Mowing in pipes is also very great. The loss of head due to friction is proportional to the length of the pipe and varies about as the square of the velocity of the flow. It is greatly increased by angles, valves, roughness, and obstructions in the pipe. The following table given by Henry N. Ogden indi- cates the loss of head due to friction in pipes : LOSS OF HEAD DUE TO FRICTION* Flow in Gallons per Loss of Head by Friction in each loo Feet of Length Minute J'^-Inch Pipe 1-Inch Pipe 0.5 4 I.O 7 0.3 2.0 17 0.7 4.0 54 1.6 7.0 140 5.3 10. 224 9-3 The importance of choosing a pipe of sufficient size for the flow per minute and the length of pipe is shown by this table. For instance, suppose it is desired to de- liver seven gallons a minute at a distance of 500 feet. The 3^-inch pipe would require an impractical head of * The Installation of Farm Water Supplies— Cyclopedia of American Agri- culture, Vol. I., page 294. 264 FARM MACHINERY ' 1 700 feet, while i-inch pipe would need only about 26 feet of head to secure the desired flow. 373. Wells. — The type of pump used will often depend upon the kind of well. Wells are divided into four classes : (a) dug or bored wells, (h) driven wells, (c) tubu- lar wells, and (d) drilled wells. Dug wells are those from which the earth is removed by a bucket, rope, and windlass. These wells are either walled with stone or brick or cased with wooden or tile curbing. Bored wells belong to the same class except the earth is removed from the well with an auger. Pumps for dug or bored wells are independent of the casing, and any common type may be used provided the cylinder is placed within the proper distance of the water. Driven wells are made by attaching a point with a screened opening to permit of a flow of water to the casing, usually i^-inch galvan- ized pipe, and the whole driven to sand or gravel strata bearing water. A driven well does not extend through rock strata. Tubular wells are made by attaching a cutting edge to the well casing, which is usually made of pipe 2 inches in diameter, and which is sunk into the opening made by a drill which operates inside of the casing. The earth and chips of stone are removed by a stream of water which flows out through the hollow drill rod in the form of a thin mud. A screened sand point similar to those used in driven wells is placed in the bottom of the well after it has been finished. A turned flange is provided wdiich prevents the point from pass- ing beyond the casing. A pit 6 feet deep and 4 feet square, walled with brick, stone, or cement, should be placed around driven and tubular wells to permit of the use of underground pumps, or to provide a vent hole to prevent water freezing in the pump standard during cold weather. It is an advantage to have the well at least 6 PUMPING MACIIINKRY 265 inches from one side of the pit wall, as this will permit the use of pipe tools to better advantage. Drilled wells are much like tubular wells except that they are larger, usually 6 or 8 inches in diameter, cased with wrought-iron pipe or galvanized-iron tubing. The pump is independent of the casing and may be removed w'ithout molesting it in any way. Pump cylinders or barrels usually form a section of the casing in driven and tubular wells. The lower check valve is seated below the barrel by expanding a rubber bush against the walls of the well casing in such a way as to hold it firmly in place. It is to be noted that wooden pump rods should be used for deep-driven and tubular wells, for wooden rods may not only be lighter, but displace a large amount of water, reducing the weight on the pump rod during the up stroke. 374. Wooden pumps. — The first pumps were made of wood, simply bored out smoothly and fitted with a piston. The wood used was either oak, maple, or poplar. Later an iron cylinder was provided for the piston to work in. The better pumps of to-day belonging to this class have porcelain-lined or brass cylinders. These lined cylinders are smoother and are not acted upon by rust. Wooden pumps are nearly all lift pumps and can be used only in shallow w^ells. The cylinder is fitted in the lower end of the stock and no provision is made for lowering it. Wooden pumps are used with wooden piping, the ends of the pipe being driven into the lower end of the stock so as to form an air-tight joint. 375. Lift pumps. — Lift pumps include all pumps not made to elevate water above the pump standard. For this reason the top of the pump is made open and the pump rod not packed, as is the case in force pumps. Lift pumps, in the cheaper types, are cast in one piece, the 266 FARM MACHINERY handle and top set in one direction, which cannot be changed. Another style of light pump is made in which the lower part of the standard is a piece of wrought-iron pipe. The cast standard has one advantage in cold cli- mates, as it permits warm air from the well to circulate around the pipe where it extends into the standard and prevents freezing to a certain extent. 376. Pump tops. — Pump tops are divided into two classes, known as hand and windmill tops. The former permits the use of hand power only, while with the latter the pump rod is extended so as to permit windmill con- nection. At least two methods are to be found for fasten- ing the pump top in place : set screws and ofifset bolts. The latter seem to give the best satisfaction, as they give more surface to support the top and are not apt to work loose from the jerky motion given to the pump handle. Windmill tops should be provided with interchangeable guides or bushes, which may be replaced when worn. This is not important, however, as very little wear comes upon the bushes, the forces being transmitted in a vertical direction only. 377. Spouts. — Spouts are either cast with the pump standard or made detachable. They are styled by the makers plain, siphon or gooseneck, and cock spouts. The object of the siphon spout seems to be the securing of a more even flow of water from the pump. If the pump is a force pump, the spout should be provided with some means of making a hose connection. The cock spout is for this purpose, but a yoke hose connection or clevis may be used for the same purpose with a disk of leather in the place of the regular washer. 378. Bases. — Like the spout, the base may be cast with the rest of the pump standard. However, there are two other types found upon the market: the adjustable and PUMPING MACHINERY 267 split or ornamental. It is a great advantage in fitting the standard to a driven well to have the base adjustable, doing away with the necessity of cutting the pipe an exact length in order to have the base rest upon the pump platform or having to build the platform to the pump base. 379. Force pumps. — Force pumps are those designed to force water against pressure or into an elevated tank. In order to do this the pump rod must be packed to make it air tight. Force pumps are also provided with an air chamber to prevent shocks on the pump.' It is common practice to use the upper part of the pump standard for the air chamber. It has a vent cock or a vent screw to permit the introduction of air when the pump becomes waterlogged. With tubular wells it is an- advantage to have a pump standard with a large open- ing its entire length and a removable cap to permit the withdrawal of the plunger or cylinder. The two most common methods of providing for this are to have the pump caps screwed on and to have the cap and the pump top in one piece. In the latter case the entire top is made air tight by drawing it down on a leather gasket or washer on the top of the standard. 380. Double-pipe pumps or underground force pumps. This class of pump is used where the water is to be forced underground, away from the pump to some tank or reser- voir. These pumps are built with either a hand or a windmill top. A two-way cock is provided, manipulated from the platform to send the water either out of the spout above the platform or through the underground pipe. As the piston rod of these pumps has to be packed below the platform where it is not of free access, we find in use a method of packing known as the stufiing- box tul)e to take the place of the ordinary brass bush. 268 FARM MACHINERY R^ FIG. 191 — A DOUBLE PIPE OR UN- DERGROUND PUMP WITH STUFF- ING-BOX TUBE AND ADJUSTABLE BASE MP $AnTY V*LVe FIG. 192 — AN UNDERGROUND PUMP WITH ORNAMENTAL BASE AND EQUIPPED WITH A WINDMILL REGULATOR PUMPING MACHINERY 269 The stuffing-box tube is nothing- more nor less than an auxiliary piston fitted with the regular leathers. The tube is always made of brass, and does not need attention as often as the regular stuffing box. 381. Pump cylinders.— Three classes of pump cylin- ders are found upon the market: Iron, brass-lined, and brass-body. Iron cylinders are used mostly in shallow wells. Brass-lined and brass-body cylinders are the most desirable, as they work very smoothly and will not corrode in the least. Iron cylinders are often galvanized to prevent rusting. Brass-body cylinders have the cylin- drical portion between the caps made entirely of brass. Brass cylinders are easily damaged by being dented, and when so damaged cannot be repaired to good advantage. Brass being a soft metal, some difficulty is encountered in making a good connection between the cylinder and the caps by screw threads. In order to strengthen the brass-body cylinder at this point, the caps are often fitted on the cylinder by rods at the sides. Cylinders to be used inside of tubular or drilled wells are made with flush caps to enable a larger cylinder to be put into the Avell. 382. Valves. — The valves of a pump are a very vital part. IMost valves are made of iron in the piston and leather in the cylinder cap. Brass often makes a better valve than iron, as it will not corrode. The valve com- monly used is known as a poppet valve, and may have one or three prongs. The single-pronged valve is not interfered with by sand to the same extent as the three- pronged. Ball valves are used in deep-well pumps, but it is very difificult to keep these valves tight. Various ma- terials are used out of which to make the valve seats. One large manufacturer manufactures valve seats of glass and makes many claims for their superiority. 270 FARM MACHINERY Pump pistons are usually provided with only one cap leather for the piston. For high pressures more are needed, and in the better makes of deep-well pumps the pistons are provided with three or even four leathers. 383. Pump regulators have a hydraulic cylinder at- tached, into which the pump forces water when the con- nection with the tank is cut oft by a float valve. The hydraulic cylinder is provided with a piston and a stuffing box and a piston rod. Connection is made by a chain to a quadrant on a weighted lever above the platform. This lever is also attached to the pull-out wire of the mill. All the water being forced into the hydraulic cylin- der, enough pressure is created to pull the mill out of gear. Safety valves are provided to prevent too great pressures coming on the hydraulic cylinder, which might cause breakage. 384. Chain and bucket pumps. — Chain pumps have the pistons or buckets attached to a chain running over a sprocket wheel at the upper or crank end, and dip in the water at the lower. The buckets are drawn up through a tube, into which they fit and carry along with them the water from the well. The chain pump is suited only for low lifts. Another type of pump similar to the above and some- times styled a water elevator has buckets open at one end, attached to the chain. These are filled at the bottom and are carried to the top, where they are emptied. It is claimed the buckets carry air into the water and this has a beneficial effect. 385. Power pumps are not used very extensively about the farm except for irrigation and drainage purposes. W hen the power is applied with a belt the pump is known as a belted pump. If provided with two cylinders, it is known as duplex; if three, triplex. The cylinders may I i I PUMPING MACHINERY 271 be single or double actin.q-. In double-acting- pumps the water is discharged at each forward and backward stroke. The capacity of a doul)le-acting' pump is twice that of a single-acting- pump. A direct-connected pump is on the same sb.aft with the motor or engine, or coupled thereto. riG. 193 — A ROTARY TUMP 386. Rotary pumps are used to some extent in pump- ing about the iarn-i. They are not suited for high lifts, as there is too much slippage of the water past the pistons. They are not very durable, and it is doul)tful if they will ever come into extensive use. 387. Centrifugal pumps are used where a large quan- 272 FARM MACHINERY tity of water is to be moved through a short lift, as in drainage and irrigation work. They are efficient machines FIG. 194 — SECTION OF A ROTARY PUMP SHOWING PISTONS for low lifts at least, and will handle dirty water better m than any other kind of pump. Centrifugal pumps are ' 1 FIG. 195 — CENTRIFUGAL PUMP made with either a vertical or a horizontal shaft. The pumps with a vertical shaft are called vertical pumps and PUMPING MACHINERY 273 may be placed in wells of small diameter. This class of pump gives but little suction and works the best when immersed in the water. 388. The hydraulic ram. — Where a fall of water of sufficient head and volume is at hand, it may be used to elevate a portion of the flow of water to a higher eleva- tion. The action of a hydraulic ram depends upon the intermittent flow of a stream of water whose momentum when brought to rest is used in forcing a smaller stream to higher elevation. The ram consists essentially of (a) a drive pipe leading the water from an elevated source to the ram ; (b) a valve which automatically shuts ofif the flow of water from the drive pipe through the overflow, after sufficient momentum has been gathered by the water; (c) an air chamber in which air is compressed by the moving water in the drive pipe in coming to rest; and ((/) a discharge pipe of smaller diameter leading to the elevated reservoir. TABLE OF PROPORTIONATE HEAD, GIVING HIGHEST EFFICIENCY IN OPERATION OP HYDRAULIC RAM* To Deliver Water to Height of Place Ram under ConSucted Through 20 feet above ram 40 " 80 120 " " " 3 feet Head of Fall 5 " 10 " " " 17 " 30 feet of Drive Pipe 40 " 80 " 125 " Under the foregoing conditions about 12 times as much water will be required to operate ram as will be dis- charged. Hydraulic rams are manufactured in sizes to discharge from I to 60 gallons a minute, and for larger capacities ♦ The Gould Companj', Chicago. 274 FARM MACHINERY rams may be used in batteries. To replenish the air in the air chamber, a snifting valve is placed on the drive pipe. In freezing" weather it is necessary to protect the ram by housing, and often artificial heat must be supplied. 389. Water storage, — Owing to the fact that water must in nearly all cases be pumped at certain times which HYDRAULIC RAM IN OUTLINE may vary greatly in the intervals between each other, some form of water storage must be had in order to secure at all times an adequate supply to meet the con- stant needs. It is not only necessary to have a supply to furnish water for stock and household needs, but also for fire protection. 390. Amount of water needed. — The amount of water required for household purposes with modern conven- iences has been found to be about 20 gallons a person, large or small. A horse will drink about 7 gallons a day and a cow 5 to 6 gallons. From this data the amount of water used a day may be estimated. If a windmill is PUMPING MACHINERY 275 used to pump the water, three to four days' supply should be stored to provide for a calm. If a gasoline engine is used, it will not be necessary to store for so long an in- terval. Two systems of storing water are now in use : the elevated tank and the pneumatic tank. 391. Storage tanks. — The elevated tank may be placed outside on a tower, or in the building ui)()n an upper floor. The objection to placing a tank in a building is the great weight to be supported. It has the advan- tage of being protected from dirt and the weather. The elevated tank on a tower is exposed to freezing in winter and to the heat of the sun in summer. Further- more, a tower and a wooden tank are not very durable. The elevated tank is cheaper than the pneumatic system where a large amount of storage is desired. A reservoir located on a natural prominence, when such a location can be secured, offers many advantages in the way of capacity and cheapness. The pneumatic or air-pressure system has an inclosed tank partly filled with air and partly with water. When filled the air is under pressure, and, being elastic, will give the same kind of pressure to the water as an elevated tank. One of the principal advantages of the air-pressure system is that the tank may be buried in the ground or placed in the cellar in a cool place. The disadvantage is a limited capacity for the cost. If water be pumped into a closed tank, until the tank is half full, the air contained will give a pressure of about 15 pounds a square inch, which is sufficient to force the water to a height of 2)?^ feet. Air in the tank follows the well-known law of gases known as P>03de's law — pressure X volume = constant. If the air be pumped to a pressure of 10 pounds before the introduction of the water, the maximum discharge from the tank will be had at the 276 FARM MACHINERY common working pressures. The water capacity of a tank will not be more in any case than two-thirds the total capacity of the tank. As the water continually dis- solves a certain amount of the air, or, rather, carries the air out with it, it is necessary to supply air to the tank from time to time. Pumps are now arranged with an auxiliary air cylinder to supply this air. It is not advisable to pump air to pressure because it is very slow work, as each cylinderful must be compressed before any is forced into the tank. Air-pressure tanks must be very carefully made, as air is very hard to contain, much more difficult than steam. 4 CHAPTER XV THE VALUE AND CARE OF FARM MACHINERY 392, Value and cost. — Few realize the enormous sums spent annually by the farmers of the United States for machinery. Of the $2,910,138,663, the value of all crops raised in 1899, about 3.4 per cent was spent for machinery. The total amount of money invested in ma- chinery was $749,775,970. The following is the census report of the value of machinery manufactured each census year since 1850: Year Total for U. S. Year Total for U. S. 1850 $6,842,611 1880 $68,640,486 i860 20,831,904 1890 81.271,651 1870 42,653,500 1900 101.207,428 In closing, it is fitting that the subject of the care of farm machinery be considered, for one reason at least. The American farmers buy each year over $100,000,000 worth of machinery, which is known to be used less effi- ciently than it should be. The fact that farm machinery is poorly housed may be noticed on every hand. Even the casual observer will agree that if machines were housed and kept in a better state of repair they would last much longer and do more efficient work. It has been stated by conservative men that the average life of the modern binder is less than one-half what it should be. The care of farm machinery readily divides itself into three heads : First, housing or protecting from the weather; second, repairing; third, painting. 278 FARM MACHINERY 393. Housing. — Many instances are on record where farmers have kept their tools in constant use by good care for more than twice the average life of the machine. The machinery needed to operate the modern farm represents a large investment on the part of the farmer. This should be considered as capital invested and made to realize as large a dividend as possible. The following is a list of the field tools needed on the average 160-acre farm and their approximate value : I grain binder $125.00 I mower 45-00 I gang plow 65.00 I walking plow 14.00 I riding cultivator 26.00 I walking cultivator 16.00 I disk harrow 30.00 1 smoothing harrow 17.00 2 farm wagons 150.00 ' I corn planter 42.00 I seeder 28.00 I manure spreader 130.00 I hay loader 65.00 I hay rake 26.00 I light road wagon 60.00 I buggy 85.00 Total $924.00 In addition to the above, miscellaneous equipment will be needed which will make the total over $1,000. If not protected from the weather, this equipment would not do good work for more than five years. If well housed, every tool ought to last 12 years or longer. It is obvious that a great saving will accrue by the housing of the implements. An implement house which will house these implements can be built for approximately $200, and it is THE VALUE AND CARE OF FARM MACHINERY 279 to be seen that it would prove to be a very good invest- ment. Sentiment ought to l)e such that the man who does not take good care of his machinery will be placed in the same class as the man who does not take good care of his live stock. 394. Repairing. — Repairs should be made systemati- cally, and. as far as possible, at times when work is not rushing. It is necessary to have some system in looking after the machines in order that when a machine is to be used it will be ready and in good repair. In putting a machine away after a season's work, it is suggested that a note be made of the repairs needed. These notes may be written on tags and attached to the machine. During the winter the tool may be taken into the shop, with wdiich every farm should be provided, and the machine put in first-class shape, ready to be used upon short notice. It is often an advantage not only in the choice of time, but also in being able to give the implement agent plenty of time in which to obtain the repairs. Often repairs, such as needed, will have to come from the factory, and plenty of time should be allowed. 395. Painting. — Nothing adds so much to the appear- ance of a vehicle or implement as the finish. An imple- ment may be in a very good state of repair and still give anything but that impression, by the faded condition of its paint. Paint not only adds to the appearance, but also acts as a preservative to many of the parts, especially if they are made of wood. As a rule, hand-mi.xed paints are the best, but there are good brands of ready-mixed paints upon the market, and they are more con\-enient to use than the colors mixed with oil. It is the practice. in factories, where the pieces are not too large, to dip the entire piece in a paint vat. 28o FARM MACHINERY After the color coat has dried, the piece is striped and dipped in the same way in the varnish. This system is very satisfactory when a good quality of paint is used. It is not possible here to give instructions in regard to painting. It might be mentioned, though, that the sur- face should in all cases be dry and clean before applying any paint. FARM MOTORS PART II INTRODUCTION 396. Motors. — The application of power to the work of the farm largely relieves the farmer from mere physical exertion, but demands of him more skill and mental ac- tivity. At the present time practically all work may be performed by machines operated by power other than man power. This change has been important in that it has increased the efficiency and capacity of one man's work. Farm Machinery has been a discussion of the machines requiring power to operate them, while Farm Motors will be a discussion of the machines furnishing the power. The number of machines requiring power to operate them is increasing very rapidly. They re- quire the farmer to understand the operation and care of the various forms of motors used for agricultural pur- poses. 397. Energy may be defined as the power of producing change of any kind. It exists in two general forms : 1. Potential or stored energy, an example of which is the energy contained in unburned coal. 2. Kinetic or energy of motion, an example of which is the energy of a falling body. Sources of energy. — Following are some of the sources of energy available for the production of power. 282 FARM MOTORS Potential : 1. Fuel. 2. Food. 3. Head of water. 4. Chemical forces. Kinetic or actual : 1. Air in motion, or the wind. 2. The waterfall. 3. Tides. The energy found in the forms just mentioned must be converted into a form in which it may be applied to machines for doing work. This change of the energy from one form to another is spoken of as the transforma- tion of energy. The law of transformation of energy holds that when a definite amount of energy disappears from one form a definite amount appears in the new form, or there is a quantivalence. Prime movers are those machines which receive energy directly from natural sources and transmit it to other machines which are fitted for doing the various kinds of useful work. 398. Forms of motors: 1. The animal body. 2. Heat engines — Air, Gas or vapor, Steam, Solar. 3. Water wheels. 4. Tidal machines. 5. Windmills. 6. Electrical motors. Of the above all are prime movers except the last named, the electrical motors. The energy for the animal 1 INTRODUCTION 283 body is derived from the food eaten. This undergoes a chemical change during the process of digestion and assimilation, and is transformed into mechanical energy by a process not fully understood. Heat engines make use of the heat liberated by the chemical union of the combustible constituents of fuel and oxygen. Water wheels, tidal machines, and windmills utilize the kinetic energy of masses of moving water or air. Electrical motors depend either upon chemical action or a dynamo to furnish the energy, it being necessary to drive the lat- ter with some form of prime mover. Only such motors as are well adapted to agricultural purposes will be considered in this treatise. CHAPTER XVI ANIMAL MOTORS 399. The animal as a motor. — Although the animal dif fers from other forms of motors, being an animated thing, it is possible, however, to consider it as a machine in which energy in the form of food is transformed into me- chanical energy, which may be applied to the operation of various machines. The animal as a motor is excep- tionally interesting to those who have made a study of the transformation of heat energy into mechanical energy, for this is really what takes place. Combustible matter in the form of grain and other foods is consumed with the resultant production of carbon dioxide or other products of combustion in various degrees of oxidation, and, as stated before, mechanical energy is made available by a process not clearly understood. Viewed from the standpoint of a machine, the animal is a wonderful mechanism. Not only is it self-feeding, self-controlling, self-maintaining and self-reproducing, but at the same time is a very efficient motor. While the horse is like heat engines in requiring carbonaceous fuel, oxygen, and water for use in developing energy, it is necessary that combustion take place in the animal body at a much lower temperature than is possible in the heat engine, and a much smaller proportion of the fuel value is lost in the form of heat while the work is being done. The animal is the onl}^ prime mover in which combustion takes place at the ordinary temperature of 98° F. For this reason the animal is one of the most efficient of prime n \ ANIMAL MOTORS 285 movers. That is, a large per cent of the energy repre- sented by the food eaten is converted into work, a larger per cent than is possible to realize in most motors. Pro- fessor Atwater in his recent experiments found the average thermodynamic efficiency of man to be 19.6 per cent. Experiments conducted by the scientist Hirn have shown the thermodynamic efficiency of the horse to be about 0.2. The best steam engines give an efficiency equal to this, but the average is much below. Internal- combustion engines will give a thermal efficiency from 20 to 30 per cent. 400. Muscular development. — It is possil)le to consider the animal as a motor, but the animal is made up of a great number of systems of levers and joints, each sup- plied with a system of muscles which are in reality the motors. Muscles exert a force in only one way, and that by shortening, giving a pull. For this reason muscles are arranged in pairs, as illustrated by the biceps and tri- ceps, which move the forearm. It is not clearly under- stood just how muscles are able to exert forces as they do when stimulated by nerve action. The theory has been advanced that the shortening of the muscles is due to a change of the form of the muscular cell from an elongated form to one nearly round, produced by pressure obtained in some way within the cell walls. There is no doubt but there is a transformation of heat energy into mechanical energy. While at work and producing mo- tion there is but little change in the temperature of the muscles, but when the muscles are held in rigid contrac- tion, there is a rise in temperature. Another author* has likened this to a steam plant, which while at work con- verts a large portion of the heat generated in the fire box into mechanical energy, but as soon as the engine is *F. H. King, in "Physics of Agriculture." 286 FARM MOTORS Stopped and the flow of steam from the boiler stopped the temperature rises rapidly. 401. Strength of muscles. — All muscles act through ver}- short distances and upon the short end of the levers composing the animal frame. Acting in this way speed and distance are gained with a reduction m the magnitude of the force. A striking example of the strength of a muscle is that of the biceps. This muscle acts upon the forearm, while at a right angle with the upper arm. as a lever of the second class, with a leverage of i to 6. That is. the distance from the point of attachment of the mus- cle to the elbow is but one-sixth of the distance from the hand to the elbow. A man is able to hold within the hand, with the forearm horizontal, as explained, a weight of 50 pounds, necessitating an exertion of a force of 300 pounds by the mitscle. Attention may also be called to the enormous strength of muscles of a horse as they act over the hock joint while the horse is exerting his maxi- mum effort, in which case the pull of the muscles may amount to several thousand pounds. It is because muscles are able to act only through very short distances that it is necessary- for them to act upon the short end of the levers in order to secure the proper speed or sufficiently rapid movement. 402. Animals other than horse and mule used for power. — Dogs and sheep are used to a very limited extent in the production of power by means of a tread power similar to the one shown in Fig. 200 for horses. These may be used to furnish power for a churn or some other machine requiring little power. The use of cattle for power and draft has been practically discontinued in America. An ox at work will travel only about two- thirds as fast as a horse. 403. Capacity. — A man working a crank or winch can I ANIMAL MOTORS 287 develop power at his maximum rate. It is also possible to develop power at very nearly the maximum rate while pumping. A large man working at a winch can exert 0.50 horse power for two minutes and one-eighth horse power by the hour. It is stated that an ox will develop only about two-thirds as much power as a horse, owing to the fact that he moves at a much slower speed. 404. The horse is the only animal used extensively at present as a draft animal or for the production of power. As reported in the Twelfth Census, the number of horses and mules on the farms in the United States was 15,517,- 052 and 2,759,499, respectively, making a total of 18,- 276,551 animals. If it be assumed that each animal de- velop two-thirds horse power, the combined horse power while at work would be 12.184,366, an excess of 184,285 horse power over that used for all manufacturing pur- poses during the same year, 1900. From a consideration of the skeleton and muscular development, it is perceived that the horse is an animal specially well adapted to dragging or overcoming hori- zontal resistances rather than for carrying loads. With man it is different. Although greatly inferior in weight, man is able to bear a burden almost as great as that of a horse, while at dragging he is able to exert only a small horizontal effort, even when the body is inclined well for- ward. The skeleton of man is composed of parts super- imposed, forming a column well arranged to bear a burden. The horse is able to d;'aw upon a cart a load many times his own weight, while he is unable to carry upon his back a load greater than one-third his weight. It is to man's interest that his best friend in the brute world should be strong, live a long life, and waste none of his vital forces. Much attention has been given to the 288 FARM MOTORS development of breed in horses. The result is a great improvement in strength, speed, and beauty. But while attention has been turned to developing horses capable of doing better work, few have tried to improve the con- ditions under which they labor. That the methods are often unscientific can be pointed out. In England, T. H. Brigg, who has made a study of the horse as a motor, and to whom we must give credit for the preceding thought, states that the horse often labors under conditions where 50 per cent of his energy is lost. It is a very strange thing that men have not studied this thing more, in order that people might have a better understanding of the conditions under which a horse is required to labor. The amount of resistance which a horse can overcome depends on the following conditions : First, his own weight ; second, his grip ; third, his height and length ; fourth, direction of trace ; and fifth, muscular develop- ment. These will be taken up in the above order. 405. Weight. — The heavier the horse, the more ad- hesion he has to the ground. The tendency is to lift the forefeet of the horse from the ground when he is pulling, and thus a heavier horse is able to use his weight to good advantage. It is to be noted that often a horse is able to pull a greater load for a short time when he has upon his back one or even two men. Experienced teamsters have been known tO make use of this method in getting out of tight places with their loads. 406. Grip. — That the weight adds to the horse's grip is self-evident, but cohesion is not the same thing as grip. Grip is the hold the horse is able to get upon the road surface. It is plain that a horse cannot pull as much while standing on ice as on solid ground unless his grip is increased by sharp calks upon his shoes. A difiference is ANIMAL MOTORS 289 to 1)6 noticed in roads in the amount of ^viy) which a horse may get upon the surface while pulling a heavy load. Under ordinary circumstances the improved stone road will not provide the horse with as good a grip as a com- mon earth road. 407. Height and length. — A low, rather long-bodied horse has much the advantage over a tall, short horse for heavy draft work. He has his weight m a position jsStttl^M h',-.^ .■/^■M\ F mmMm ) ii,. HJ7 — OllTAIMNf; THE WORK OF A HORSE WITH A REC0R1IIX(, DYNAMOMETER where he can use it to better advantage. It is an ad- vantage to have the horse's weight well to the front, since there is a tendency, as mentioned before, to balance his weight over his rear foot as a fulcrum. Horses heavy in the foreshoulder have an advantage in pulling over those that are light, as weight in the foreshoulder adds greatly to the ability of the horse to pull. To prove that this is true, it is only necessary to refer to the fact that horses when pulling extend their heads well to the front. 408. Direction of trace. — A heavy load may be lifted by a common windlass if the pull be vertical, but if the pull be transferred over a pulley and carried off in a horizontal direction the machine must be fastened or it will move. It must be staked and weighted to prevent slipping. This 290 FARM MOTORS same principle enters into the discussion of the draft of a horse. As long as the trace is horizontal, the horse has to depend upon his grip and his weight only to furnish enough resistance to enable him to pull the load. But if the trace be lower than horizontal the tendency is then to draw the horse on to the ground and thus give him greater adhesion. If the horse has sufBcient adhesion to pull a load without lowering the trace it is to his ad- vantage because the draft is often less in this case than any other. 409. Line of least draft. — When the road bed is level and hard, the line of least draft to a loaded carriage is nearly horizontal because the axle friction is but a small part of the weight. Thus in Fig. 198, if AO represent by direction and mag- nitude the weight upon the axle, and OB in like manner the resistance of friction, the direction of the least force required to produce motion will be perpendicular to AB, a line joining the two forces. The angle that the line of least draft makes with the horizontal is named in me- chanics, the angle of repose. If the resistance of friction be that of sliding friction and not that of axle friction, the angle of repose will be much greater. ANIMAL MOTORS 29 1 If the road surface be inclined, it will be found that the line of least draft is nearly parallel to the road surface. If the trace is inclined upward from the line of least draft there is a tendency to lift the load ; if the line of draft is inclined downward there is a tendency to press the load on the surface. Furthermore, it is found that roads are not perfectly level and there are obstructions over which the wheels of vehicles must pass, or, in other words, the load at times must pass up a much greater in- cline than a general slope indicates, and hence this calls for a greater angle of trace than will be needed for level or smooth road. Teamsters find in teaming over roads in one locality that they need a different angle of trace than they find best in another, because the grades of the roads are dififerent. 410. Width of hock. — As mentioned before (405) prac- tically all of the pull a draft horse exerts is thrown upon his hind legs and for this reason the form and strength of this part must be considered in the selection of a horse for draft purposes. If the hock is wide or, in other words, if the projection of the heel bone beyond the joint is large, the muscles will be able to straighten the limb under a greater pull than if the projection is small; thus the ability of the horse to overcome resistance will be increased. Thus there are many things to be considered in the selection of a draft horse. The general make-up of a horse built for speed is notably different from one built for draft purposes. 411. The horse at work. — \\hen a horse is required to exert the maximum effort, it is necessary to add to his adhesion or grip so that he may be able to exert his strength to a limit without any slipping or without a tendency to slip. But if the horse is loaded all the time, either by a load upon his back or a low hitch, he is at 292 FARM MOTORS times doing more work than necessary. In fact, a certain amount of efifort is required for the horse to stand or to walk even if he does no work at all. This has led men to think that if the hitch could be so ar- ranged as to relieve the horse entirely of neck weight at times or even raise his trace the horse would be able to accomplish more in a day of a given length. In fact, it might be even an advantage to carry part of the weight of the horse. Although not a parallel case, it is some- times pointed out that a man can go farther in a day when mounted on a bicycle than when walking. Walking in itself, both for man and beast, is labor, and in fact walk- ing is like riding a wheel polygonal in form, and each time the wheel is rolled over a corner, the entire load must be lifted only to drop again as the corner is passed. Whether or not there are any possibilities in the development of a device along this line to conserve the energy of the horse we do not know; however, the argument seems very good. Mr. Brigg, of England, has devised an appliance for applying to vehicles with thills which will in a meas- ure accomplish the result referred to; that is, the horse on beginning to pull will be gradually loaded down,. thus per- mitting him to overcome a greater resistance. 412. Capacity of the horse. — The amount of work a certain horse is able to do in a day is practically a con- stant. Large horses are able to do more work than smaller ones, but a given horse can do only about so much work in a day even if he is given a long or a short time in which to do it. Not only is the ability to do work dependent upon the size, but also upon the natural strength, breed, health, food, environment, climate, adap- tation of the load, and training of the horse. A horse with maximum load does minimum work, when traveling at maximum speed he can carry no load, so at some inter- i i ANIMAL MOTORS 293 mediate point the horse is able to do the maxinuini amount of work. 413. Best conditions for work. — The averaj^e horse will walk from 2 to 2}^ miles an hour, and at the same time overcome resistance equal to about one-tenth or more of his weight. Work may be perfoi^ied at this rate for ten hours a day. Assuming the above to be true, a 1,500- pound horse will perform work at the rate of one horse power. As 1,500 pounds is much above the average weight of a farm horse the average horse whose weight is not far from 1,100 will do continuous work at the rate of about 2/^ to 4/5 horse power. 414. Maximum power of the horse. — Entirely different from other motors, the horse, for a short time at least, is able to perform work at a very much increased rate. A horse when called upon may overcome resistance equal to one-half his weight, or even more. The horse power developed will be as follows, assuming that he walk at the rate of 23/2 miles an hour (see Art. 20) : „ ^ 1,500 x^ X 21^X5,280 Jrl. r. = 5 33,000 A horse will be able to do work at this rate for short intervals only. The fact that a horse can carry such a heavy overload makes him a very convenient motor for farm purposes. The maximum effort or power of traction of a horse is much greater than one-half his weight. A horse weigh- ing 1,550 pounds has been known to overcome, when pull- ing with a horizontal trace, a resistance of 1,350 pounds. With the point of hitch lowered until the trace made an angle of 27° with the horizontal, the same horse was able to give a draft of 1.750 pounds. It is believed, however, that this horse is an exception. 294 FARM MOTORS 415. Effect of increase of speed. — As stated before, a horse at maximum speed cannot carry any load, and as the speed is increased from the normal draft speed, the load must be decreased. It is stated that the amount of work a horse is capable of doing in a day is constant within certain limits, varying from one to four miles an hour. Assuming this, the following equation holds true : 2^/2 X traction at 2Y2 miles = miles per hour X traction. 416. Effect of the length of working day. — Within certain limits the traction a horse is able to exert varies inversely with the number of hours. When the speed re- mains constant the traction may be determined approxi- mately by the following equation, provided the length of day is kept between five and ten hours. 10 hours X i/io weight of horse := number of hours X traction. 417. Division of work. — It may not be absolutely true that the ability of a horse to do work depends largely upon his weight, nevertheless it is not far from correct. It is not advisable to work horses together when differing much in size, but it is often necessary to do so. When this is done the small horse should be given the ad- vantage. In determining the amount of the entire load each horse should pull when hitched to an evener it may be considered a lever of the second class ; the clevis pin of one horse acting as the fulcrum. From the law of me- chanics (see Art. 24) : Power X power arm := weight X weight arm. Example: Suppose two horses weighing 1,500 and 1,200 pounds respectively are to work together on an evener or doubletree 40 inches long. If each is to do a share of the work proportionately to his weight, it will be possible to substitute their combined weight for the total I ANIMAL MOTORS 295 draft and the weight of the larger horse for his share of the draft in the general equation and consider the smaller horse hitched at the fulcrum : 2,700 X long arm of evener = 1,500 X 40, , f 60.000 , . , long arm 01 evener = •:= 22 2/9 inches, ^ 2,700 short arm of evener —40 — 222/9 = 177/9. That is, to divide the draft proportionately to the weights of the horses, the center hole must be placed 2 2/9 inches from the center toward the end upon which the heavy horse is to pull. ■r.,.,'*( •! •.>7-..li. .!.--.'Si ••• ■■•J'"<'!i ■* FIG. 200 — TREAD POWER FOR THREE HORSES 418. The tread power, — Tlic tread power consists in an endless inclined plane or apron carried over rollers 296 FARM MOTORS and around a cylinder at each end of a platform. Power is derived from a pulley placed upon a shaft passing through one of the cylinders. Fig. 200 illustrates a tread power for three horses with the horses at work. Some aprons are made in such a way that each slat has a level face. This tread is thought to enable the horse to do his work with less fatigue because his feet are more nearly in their normal attitude. Owing to the large number of bearings, the matter of lubrication is an important feature in the operation of a tread power. Lubrication should be as nearly perfect as possible in order that little work will be lost in friction and the efficiency of the machine may be increased. The bearings should not only have due provision for oiling, but they must be so constructed that they will exclude all dirt and grit. 419. The work of a horse in a tread power. — A horse at work in a tread power lifts his weight up an incline against the force of gravity. The amount of work ac- complished depends upon the steepness of the incline and the rate the horse travels. If the incline has a rise of 2 feet in 8, the horse must lift one-fourth of his weight, which is transrnitted to the apron and travels at the same rate the horse walks. Working a 1,000-pound horse in a tread power with a slope of i to 4 is equal to a pull of 250 pounds by the horse. This is much greater than is ordinarily required of a horse, but it is not uncommon to set the tread power with this slope. If a horse weighs 1,600 pounds and walks at the rate of two miles an hour, work will be done at the rate of 2.13 H.P. At the same speed a 1,000-pound horse will do 1.33 H.P. of work. It is often true that a horse will be able to develop much more power when worked in a tread power than when worked in a sweep power, but he will be overworked. ANIMAL MOTORS 297 Often horses are overworked in. tread powers without the owner intending to do so, or even knowing it. 420. Sweep powers. — In the sweep power the horses travel in a circle, and the power is transmitted from the master wheel through suitable gearing to the tumbling rod, which transmits the power to the machinery. Sweep powers vary in size from those for one horse to those for 14 horses. Attention is often called to the fact that a considerable part of the draft is lost because the line of draft cannot be at right angles to a radius of the circle in which the horse walks. For this reason a considerable portion of the draft is lost in producing pressure toward the center of the power, often adding to the friction. The larger the circle in which the horse travels, the more nearly the line of draft will be at right angles to a radius to the center of the circle. 1 CHAPTER XVII WINDMILLS If the horse is excepted, the windmill was the first kind of a motor used to relieve the farmer of physical exertion and increase his capacity to do work. With the exception of the horse, the windmill is still the most extensively used. To prove that the windmill is an important farm motor, it is only necessary to cite the fact that many thousand are manufactured and sold each year. 421. Early history — Prof. John Beckmann, in his "History of Inventions and Discoveries," has given everything of special interest pertaining to the early history of the windmill. As it is conceded by all that his work is exhaustive, the following notes of interest have been taken from it. Prof. Beckmann believes that the Romans had no windmills, although Pomponius Sabinus affirms so. He also considers as false the account given by an old Bohemian annal- ist, who says that before 718 there were windmills nowhere but in Bohemia, and that water mills were then introduced for the first time. Windmills were known in Europe before or about the first crusade. Mabillon mentions a diploma of 1105 in which a convent in France is allowed to erect water wheels and windmills. In the twelfth century windmills became more common. 422. Development of the present-day windmill. — It was about the twelfth century that the Hollanders put into use the noted Dutch mill. These people used their mills for pumping water from the land behind the dikes into the sea. Their mills were constructed b> having four sweeps extending from a common axle, and to these sweeps were attached cross pieces on which was fastened canvas. The first mills were fastened to the tower, so that when the direc- tion of the wind changed the owner would have to go out and swing the entire tower around ; later they fastened them so that only the top of the tower turned, and in some of the better mills they were so arranged that a smaller mill was used to swing the wheel to the wind. The turning of the tower was no small matter when one learns that some of these mills were 140 feet in diameter. i WINDMILLS 299 John Burnham is said to be the inventor of the American wind- mill. L. H. Wheeler, an Indian missionary, patented the Eclipse in 1867. The first steel mill was the Aermotor, invented by T. O. Perry in 1883. The windmills still most common in Europe are of the Dutch type, with their four long arms and canvas sails. These sails usually present a warped surface to the wind. The degree of the angle of the sails with the plane of rotation, called the angle of weather, is about 7° at the outer end and about 18° at the inner. The length of the sails is usually about 5/6 the length of the arms, the width of the outer end 1/3 the length, and the width of the inner end 1/5 the length. It is seen that the total projected area of sails is very small compared to the wind area or zone carrying the sails. Quite often these wheels are 120 feet in diameter and occa- sionally 140 feet. In comparing these mills with the close, compact types of American makes a very great contrast is to be drawn. Among the men who have done the most experimenting in windmill lines are Smeaton, Coulomb, Perry, Griffith, King, and Murphy. The names are given in order of date of experimenting. The more prominent among these are Smeaton, Perry, and Murphy. Probably Perry did more for the windmill than any of the others. Prof. E. H. Barbour is noted for his designs and work with home- made windmills. 423. Home-made windmills. — Professor Rarbotir made an extensive study of home-made windmills and has had a very interesting bulletin published on the subject. He has classified them as follows : 1. Jumbos (Fig. 202). This type consists of a large fan- wheel placed in a box so the wind acts on the upper fans only. 2. Merry-go-rounds. Merry-go-round mills are those in which the fans in turning toward the wind are turned edgewise. 3. Battle-ax mills (Fig. 203). These are mills made with fans of such a shape as to suggest a battle-ax. 4. Holland mills. Somewhat resembling the old Dutch mill. 5. Mock turbines (Fig. 204). Resembling the shop-made mill. 6. Reconstructed turbines (Fig. 205). Shop-made mills rebuilt. These mills, although of low power, are used exten- sively in the West Central States. Most of them are fixed 300 FARM MOTORS in their position and consequently have full power only when the wind is in the direction for which they are set. In those States in which these mills are used the wind i FIG. 202 — HOME-MADE JUMBO has the prevailing" directions of south and northwest, and for that reason the mills are generally set a trifle to the west of north. To the casual observer the Jumbo mill (Fig. 202) seems a very feasible means of obtaining power, but when one considers the massiveness of the whole affair and that only one-half of the sails is exposed to the wind at one time, also that full power is developed from the wind only when the latter is in the proper direction, it will immedi- ately be seen that only in cases of dire necessity should one waste much time with them. I WINDMILLS 301 The cost of this type of mill is very slight. It is stated by Professor Bar- bour that a gardener near Bethany, Nebraska, con- structed one which cost only $8 for new material, and with this he irrigates six acres of vegetables. If the water-storage ca- pacity for such mills is enough, they will often furnish sufificient water for 50 head of stock. One farmer has built a gang of Jumbo mills into the cone of a double corn crib and connected them to a small sheller. The Merry-go-round is not nearly as popular as the Jumbo, in that it is very much harder to build and the only advantage it has over the latter is that a vane may be attached in such a manner that the wind wheel is kept in the wind. In some parts of Kansas and in several localities of Nebraska the Battle-ax mill is used probably more than any other type of home-made mill. The stock on large ranches is watered by using such mills for pumping pur- poses. Where one has not sufficient power, two are used. The cheapness of these mills is a consideration ; very sel- dom do they cost more than $1.50 outside of what can be FIG. 203. — BATTLE-AX WINDMILL 302 FARM MOTORS 1 FIG. 204 — MOCK TURBINE WINDMILL picked up around the farm. The axle can be made of a pole smoothed up at the ends for bearings, or a short rod can be driven in at each end. The tower can be made of three or four poles and the sails of pole cross pieces and old boxes. One of these mills 10 feet in diameter will pump water for 75 head of cattle. Near Verdon, Nebraska, a farmer uses one of these mills in the summer to pump water for irrigation, and in the winter for sawing wood. 424. Turbine windmills. — The term windmills as it is commonly used refers only to the American type of WINDMILLS 303 205 — RECONSTRUCTED TURBINE shop-made mills. They may be classified by the form of the wheel and the method of governing. 1. Sectional wheel with centrif- ugal governor and independ- ent rudder (Fig. 206). 2. The solid-wheel mill with side- vane governor and inde- pendent rudder (Fig. 207). 3. Solid wheel with single rud- der. Regulation depends upon the fact that the wheel tends to go in the direction it turns. To aid in governing. the rudder is often placed outside of the center line of wheel shaft (Fig. 208). 4. Solid or sectional wheel with no rudder back of tower, the pres- sure of the wind being depended upon to keep the mill square with the direction of the wind. Regulation is accomplished with a centrifugal governor (Fig. 209). 425. The use of the windmill. — The windmill receives its power from the kinetic energy of the moving atmos- phere. Since this is supplied without cost, the power ftirnished by a windmill must be very cheap, the entire cost being that of interest on the cost of plant, deprecia- tion and maintenance. Where power is wanted in small units the windmill is a very desirable motor, provided — 1. The nature of the work is such as to permit of a suspension during a calm, as pumping water and grinding feed. 2. Some form of power storage may be used. 426. Wind wheels. — T. O. Perry btiilt a frame on the end of a sweep which revolved in an enclosed room in such a manner that he could fasten different wheels on it with- out making any change in the mechanism. By this lueans 304 FARM MOTORS he was able to make very exhaustive experiments with- out being retarded by atmospheric conditions. He made FIG. 206 — SECTIONAL WHEEL WITH CEXTKIi UGAL GOVERNOR AND INDEPENDENT RUDDER tests with over 60 different forms of wheels, and it was' the result of these experiments which brought out the steel wheel. From Mr. Perry we learn that in wood wheels the best angle of weather is about 30°, and that there should be a space of about one-eighth the width of the sail between the sails. By angle of weather is meant the angle made by the blade and the plane normal or perpen- dicular to the direction of the wind. With the tower in WINDMILLS FIG. 207 — SOLID-WHEEL MILL WITH SIDE-VANE GOVERNOR AND INDE- PENDENT RUDDER FIG. 208 — SOLID WHEEL WITH SINGLE RUDDER FARM MOTORS FIG. 209. — SECTIONAL WHEEL WITH NO RUDDER front of the wheel there is a loss of efificiency of about 14 per cent ; with it behind the wheel there is a loss of only about 7 per cent. 427. Regulation. — Wind wheels of this country are made to regulate themselves automatically, and by this means of regulation they do not attain a very high rate of speed, nearly all of them cutting themselves out when the wind has reached a velocity of about 25 miles an hour. This is principally due to the fact that our mills are gen- erally made for pumping purposes and the pumps do not work well when the number of strokes becomes too great. It is for this reason that the direct-connected wooden wheels do not give as much power as the back-geared Steel wheels. As a result of the wind wheels being WINDMILLS 307 thrown partially out of gear when the wind velocity is only about 25 miles an hour, many wheels are kept from doing- the amount of work which they might be able to do. Any mill should stand a velocity of at least 40 miles an hour. It is understood that as the wind increases, the strain on the working parts decreases. For any given velocity of wind the speed of the wheel should not change, but the load should be so arranged that the work can be done to sviit the wind. 428. The efficiency of a wind wheel is very greatly af- fected by the diameter. This is due to the fact that wind is not the same in any two places on the wheel. The smaller the wheel, the greater efficiency. Experiments were attempted to get the efficiency of a 22-foot wheel, but because the wind did not blow at the same velocity on any two parts of the wheel they were given up. 429. Gearing. — At one time the wind wheel seemed to be the most vital part of a windmill, but from the results of tests and experiments this belief has been obliterated, and now the vital part seems to be the gearing. On all the old standard makes the gearing seems to be as good as ever, even if the mills have run for several years. However, on the new designs, and this is mostly the steel mill, the gears are wearing out. The fault lies with no one but the manufacturers. Competition has been so strong that they have reduced the cost of manufacture at the expense of wearing parts. For this reason the steel wheel, which is far the more powerful, is going out of use in some localities, and the old makes of wooden wheels are coming back. In direct-connected mills the main bearings should be long and so placed that they will carry the wheels in good shape, and the guide should be heavy and designed so that it can be lubricated easily. The bumper spring 308 FARM MOTORS should be well placed, not too close in, so that as the wheel is thrown out of the wind there is not too much jar. Rubber should never be used for this spring, as the continual use and exposure to the weather will cause it to harden or flatten so that it is of no use. Generally weights are better to hold the wheel in the wind than springs. In support of back or forward geared mills there is not much more to say than has been said about direct con- nected. The most vital parts of these mills other than named above are the gearings. They must be well set and well designed so that when they wear there is not a very great chance for them to slip. 430. Power of windmills. — Probably there is no other prime mover which has so many variables depending upon it as the windmill, when we undertake to compute the power by mathematical means. It is also hard to distinguish between the greatest and the least of these variables, so the author gives them promiscuously. Vari- able velocity of wind ; velocity greater on one side of wheel than on the other ; angle of weather of the sails ; thickness of sails ; width of sails ; number of sails ; length of sails; obstruction of tower either behind or in front of wheel ; diameter of wheel ; velocity of sails ; variation of load, and location and height of tower. In all the tests of windmills which have been carefully and completely carried out it is shown that as the wind velocity increases or decreases the load should increase or decrease accord- ingly ; as the velocity of the wheels increases, the angle of weather should decrease, and vice versa. Wide sails give more power and a greater efficiency than narrow sails. A. R. Wolff gives the following table as results for wood-wheel mills : WINDMILLS 309 i$- Gallons of Water raised per J linute t( an Elevatir in of 25' 5c.' 75' 100' 150' 200* 10' 60-65 19-2 9.6 6.6 4-7 0.12 12' 5S-6o 33-9 17.9 11.8 8.5 5-7 0.21 14' 50-55 45-1 22.6 15-3 1 1.2 7.8 5-0 0.28 16' 45-50 64.6 31.6 19-5 16.1 9.8 8.0 0.41 :8' 40-45 97-7 52.2 32.5 24.4 175 12.2 0.61 20' 35-40 124.9 63.7 40.8 31.2 19-3 15-9 0.78 25' 30-35 212.4 107.0 71.6 49-7 37-3 26.7 1-34 The above table is given where the wind velocity is such that the mill makes the number of revolutions a minute given; of course, if the velocity increases, the R.P.M. will increase likewise and consequently the power. Smeaton drew from his experiments that the power in- creases as the cube of the wind velocity and as the square of the diameter of the wheel. Murphy did not check this result, but found that the power increases as the squares of the velocity and as about 1.25 of the diameter of the wheel. This latter conclusion is probably the more re- liable, as the instruments which Smeaton used were more crude than those of Murphy. The former determined the velocity of the wind by taking the time which it would take a feather to travel from one point to another as the velocity. The latter used a Thompson anemometer. 431. Tests of mills. — The following tests were made by E. C. Murphy to determine what windmills actually did in the field, also to see whether mills in practice carried cut the rules made by previous experimenters. Perry found by his experiments in a closed room that the power of a wheel increases as the cube of the velocity, while Murphy found that it varied from this. It will be noticed from the following table that some steel wheels as well as wooden gave much more power 3IO FARM MOTORS Name Kind Diameter in Feet Number Sails Angle of Weather Velocity of Wind in Miles per Hour Horse Power Monitor Wood 12 96 34° 20 .357 Challenge " 14 102 39° 20 .420 Irrigator II l6 10 39° 20 .400 Althouse " l6 130 32° 20 .600 Halliday* li 22.5 144-100 25° 20 .890 Aermotor Steel 12 18 31° 20 1.050 Ideal " 12 21 32° 20 .606 Junior Ideal " 14 24 ■29° 20 .610 Perkins " 14 32 31° 20 .609 Aermotor " i6 18 30° 20 1-530 *This wheel was made up of two concentric circles of sails, the outer having 144 sails and the inner 100. than others. This is due to workmanship and angle of weather. It is very clearly shown that the steel wheel is much more powerful than the wooden. Another important factor noticed from the above table is that the i6-foot mill develops only about 50 per cent more power than the 12-foot. Taking the shipping weights of the 12-foot and 16- foot mills with 50-foot steel towers, it is found that they are about 2,000 pounds and 4,200 pounds, respectivel}^ and since a 16-foot mill is much more liable to be damaged by a storm than a 12- foot, it is better in a great many cases to put up two 12-foot mills instead of one 16-foot. Mr. Murph}^ miade tests of a Little Jumbo mill 7^ feet in diameter with eight sails, each 11X16 feet, and found that in a 20-miIe wind he got 0.082 H.P. and in a 25-mile wind he got o.ioo H.P. He also made tests of a Little Giant mill and by computation found that the lat- ter mill, having the same dimensions as the former, would start in a slov^-er wind and when at full speed would develop about 2.5 times as much power. Other advan- WINDMILLS 311 tages of this mill over the former arc that it is always in the wind and is much less liable to be injured by storms. By a comparison of tables from different manufacturers of windmills the following table has been compiled of the size of steel windmills required for various lifts and size of cylinder. Although it cannot be said that the table is accurate, it conforms very closely to the general practice. T3 C V u u u u *^ -a «ti •a a -a w -a ^ •a vti c c c s ^*j J »j "^ hJ hJ •^ ►J 1"^ ">, V V4_, ">. W-. >> ^*-l ">. wi >- vu. «5 >. <^-s U y *o "0^ X .C .s s .s be _M .£? .y _M V c V 0) c75 X w X w a in K cH K 6 IS 2" 100' 3" 50' 4" 25' 8 15 2 100' ^%" ICXj' 3" 75' 4" 35' 10 '5 2" 300' 2!^" 200' 3" I so' 4" 70' 12 IS 2 500' ^H" 37S' 3" 250' 4" 125' 16 15 2^" 800' 3" 500' 3^" 400 4" 300' 5" 200' 30 IS 3^' 800' M" 500' 5" 400' 7" 200' 8" 135' The above table is for mills back-geared about 10 to 3. Since wood-wheel mills are generally direct-stroke, they require a much larger wheel to accomplish the same work as the steel wheels. 432. Towers. — The Hollanders built their towers in the form of a building which either had a revolving roof or the tower itself revolved. Within the tower they kept mills and grain. Often to-day we see the towers of American mills housed in a similar way, with the excep- tion that they do not revolve. This is not an economical way of providing room, for it requires much more ma- terial in the construction than a low building does to withstand the excessive wind pressure which it receives. Since the top of the tower vibrates greatly, the tower needs to be very stifi". Probably a wood tower is stififer ;i2 FARM MOTORS « Pieces lSJi"lim ««eoaSV""6V"«S (rie<<>ik'>ck">iiiJ 1 llil'!ll l'.:\ ill Sriet FIG. 210 — DIMENSIONS FOR 50-FOOT TOWER Srie«i5\ <:.■;• iC:i WINDMILLS 313 than steel when new, but owin^ to the variation in wind velocity and direction it is only a short time before the continual vibration has worked the tower loose at all joints and splices. At every joint in the wood tower there is a chance for the rain to run in and cause decay. Therefore as an offset to the greater rigidity of the wood tower one must consider the time for tightening bolts, labor for painting, and money for replacing the tower every few years. Steel towers, as a rule, are not as rigid when new as the wood, but they do not present as great a surface to the wind as the latter, and since all parts are metal there is no chance for a loosening of the joints. The steel tower not only saves all of the labor and expense required to keep the wooden tower in repair, but it is practically indestructible. In a cyclone the steel tower will often become twisted before the wooden one will be broken. However, the latter will generally become so racked and splintered that it cannot be repaired. 433. Anchor posts can be made by setting strong fence posts in the ground their full length and nailing some strips across them to hold beneath the earth ; but a bet- ter method is to insert an angle iron in a concrete base, which will support the tower posts. The dimensions of the base should be about 18 X 18 inches X 4 feet for small mills, and proportionally larger for large mills. 434. Erecting mills. — Windmills over 60 feet high should be assembled piece by piece, but low towers can be assembled on the ground, including windmill head, sails, and vanes, then raised in a manner similar to Fig. 211. After the tower has been raised it should be exam- ined and all braces and stays given the same tension and all nuts tightened. It is also well before the pump 314 FARM MOTORS rod is put in place to drop a plumb bob from the center of the top of the tower to the intersection of cords stretched diagonally from the corners of the tower at FIG. 211 — RAISING A TOWER the base. If the plumb bob does not fall on this inter- section, either the braces do not have equal tension or the anchor posts are not level. 435. Economic considerations of windmills. — Many- manufacturers claim much more power than the wind- mills really develop. This erroneous claim is probably due to the fact that early experimenters worked with small wheels and figured the power of larger ones from the law of cubes, which does not seem to hold true in actual practice. It is wrong to say that a good 12- foot steel mill will furnish i H.P. in a 20-mile wind and that a good 16-foot mill will furnish 1.5 H.P. The economic value of a windmill depends upon its first cost, its cost of repairs, and its power. The com- petition in manufacture at present is so great that often the initial cost is kept down at the expense of the other two. A mill should have as few moving parts as possible. The power of a mill is so small that if there is much to retard its action there will be very little power left for use. WINDMILLS 315 In power mills very often the shafting" is much heavier than need be. This is proliably clue to the fact that the mill was designed for much more power than it will actually develop. Often poor workmanship in manufac- ture as well as in erection is the cause of so many mills having such small power. Trees, buildings, and embankments cause the wind velocity to be so variable that for good work it is de- sirable that the wind wheel be placed at least 30 feet above all obstructions. This would cause the towers to be at least 60 or 70 feet high. It is better to put a small wheel on a high tower than a large wheel on a low tower. An 8-foot wheel on a 70-foot tower will probably do more work in a given length of time than a 12-foot wheel on a 30-foot tower. The pumping mill is ordinarily constructed so the work is nearly all done on the up stroke. This is hard on the mill, as it produces a very jerky motion and ex- cessive strain on the working parts. By placing a heavy weight on one end of a lever and connecting the plunger rod to the other this strain is reduced, since when the plunger rod goes down it raises the weight, and when it comes up, lifting the pump valve and water, the weight goes down and thus assists the mill. 436. How the wind may be utilized. — In a country where there is such an abundant supply of wind as in the Central and Western States there is no doubt that a windmill is the cheapest and most feasible power for the farmer. In certain localities water power is a great opponent of the wind, but it has the disadvantage to the farmer of being in the wrong location, causing water rights to be looked after and dams to be kept in repair, while in utilizing the wind all that is required is some simple device which will turn wind pressure into work. 3l6 FARM MOTORS The windmill without doubt is the best machine for this, but since we cannot depend on the wind at all hours of the day, we must devise some scheme whereby we can store the work when the wind blows so that we may use it when there is no wind. For this means four ways come to mind : One is to connect a dynamo to the mill and store the electricity in storage batteries. This is not a feasible plan at present, since the expense of storage batteries and the cost of repairs is too great. Another plan is to run an air compressor by means of the wind and then use the compressed air for power purposes. This again is not satisfactory owing to the cost of keep- ing air machines in repair and also of conveying the air. Another scheme, and probably the best, is to pump water into a tank on a tower, and then let this water which has been stored up during the time of wind run down through a water motor and from thence to the yards, or, if there is more water than is desired for the stock and house use, run it into another tank below the tower and then pump it back. Another scheme which is similar to that named last is to pump the water into a pressure tank in the cellar and then let it pass out the same as in the tank on the tower. By this latter scheme the ex- pense of the tower and the danger of freezing are obvi- ated, but a more expensive tank and also an air pump are added. 437. Power mills. — The same discussion, which has been given more especially to pump mills, will apply to power mills. As a rule, power mills are larger than pump mills, and require more skill in keeping the bearings in repair. Care should be taken in erecting power mills that the shaft is in perfect alignment. A great deal of power can be lost by not having the shaft running in a perfect Ime. ^ CHAPTER XVIII STEAM BOILERS 438. Principle. — A kettle over the fire filled with water is a boiler of small proportions. When fuel is burned be- neath the kettle heat is transferred to the metal of the kettle and from the metal to the water at the bottom. Thus the water in direct contact with the bottom is heated, and, since warm water is lighter than cold, the warmer water rises to the top and the cold settles in its place. In physics this action of the water rising and falling- in the kettle, conveying the heat from one part to another, is known as convection. In the steam boiler it is known as circulation. When sufficient heat has been transferred to the water to raise the temperature to 212° F. it will commence to boil and throw ofif steam. The reason why the water had to be heated to 212° before the particles of water would be thrown ofif as steam was because the atmosphere, having a pressure of 14.7 pounds to each scpiare inch, pressed upon it so hard that the steam could not be thrown ofif until this tem- perature had been reached. If the kettle were up on a mountain where the atmospheric pressure is not nearly as great, steam would have been thrown ofif at a lower temperature. The same process which takes place in a steam boiler also takes place in a kettle, only under less economical conditions. A fire is maintained within the furnace of the boiler and the heat is transferred to the metal of the boiler shell and tubes, thence to the water, w'hich is con- 3i8 FARM MOTORS verted into steam. The water of a low-pressure boiler, i.e., one which carries a pressure of only about 5 pounds gauge, is heated to only about 228° when steam is given off, while in a high-pressure boiler which carries about 200 pounds gauge pressure it has to be heated to about 385°. The first boilers were simply large cylindrical shells. They did the work required of them, but were very in- t irir' 1 kV/T. -^"^"4^ FIG. 212 — VERTICAL BOILER FIG. 213 VERTICAL BOILER WITH SUBMERGED FLUES efficient. The next was merely a shell with one tube or flue, as it is often called. Multitubular, return tubular, internally fired, water-tube, sectional boilers, etc., have come in in succession until we have the present-day types. 439. Classification, — Steam boilers may be classified ac- cording to their "form and use. Thus we have locomotive, STEAM BOILERS 319 marine, portable, semi-portable, and stationary boilers, according" to use ; and according to form we have hori- zontal and vertical boilers. Further, the horizontal class may be subdivided into internally and externally fired, shell, return-flue, fire-tube and water-tube boilers. For FIG. 214 — WATER-TUBE VERTICAL BOILER rural use the marine type is very seldom used, and the sectional only in rare cases. 440. Vertical boilers. — Boilers of this type (Fig. 212) are not ver}^ economical. They require little floor space and are easily installed. In construction they consist of a vertical shell, in the lower end of which are the fire box and ash pit; extending up from the furnace and reaching the top are the fire flues. 320 FARM MOTORS Since the shell of the fire box is under external pres- sure, it must be stayed to avoid collapsing. The blow- off cock and frequent hand holes are near the base for EXTERNALLY FIRED BOILER AA, boiler setting; BB, boiler front; CC, boiler shell; Z?A flues; E, flue door; F, handhole; G, flue sheet; //, bracket; /, steam dome; /, safety valve; A', steam pipe; L, steam gauge; M, steam gauge syphon; NN, try cocks; O, water glass: PS, blow-off pipes; Q, blow-off valve; TT, fire door; [/, fire door lining; V, ash door; IV, grates- X, bridge wall; V, ash pit; Z, britchen; A, damper. convenient cleaning. A water glass and try cocks are near the top. Heating surface in this type of boiler con- sists of the fire box and the fire tubes up to the water STEAM nOlLERS 321 line ; as the water does not completely cover the tubes, the upper part forms a superheater. When the exhaust steam is released into the stack, the tubes have a tendency to leak. To avoid this, some manufacturers sink the tube sheet below the water level (Fig. 213). This form reduces the superheating surface, and moreover, since the conical smoke chamber is sub- jected to internal pressure, it is likely to be weak. Fig. 214 is a special type of vertical boiler in which are water tubes laid up in courses. The boiler shell can be removed from the caisson of tubes so that all parts are accessible for cleaning and repairing. 441. Externally fired boilers (Fig. 215) are generally of the C3-lindrical tubular type and can be used for sta- tionary work only. These are probably the most simple as well as most easily handled and kept in repair of all, but they are very bulky, requiring a great amount of floor space. The furnace for such boilers is a part of the set- ting and is made under the front end. The flames sur- round the lower part of the shell and pass to the rear, where they enter the tubes and return to the front, thence up the stack. When setting externally fired boilers, care should be taken that one end or the other, generally the rear, be free to move forward or backward, since the variation of temperature will cause the boiler to contract and expand enough to crack the masonry upon which it rests. 442. Internally fired boilers. — This class comprises several types, the locomotive type (Fig. 216), the return- flue type (Fig. 217), and the Lancashire. The first two of these types are the most used for traction or portable work, while the latter is adapted only to stationary use. 443. Locomotive type. — The locomotive fire-tube type was probably the first of the modern boilers to come into 322 FARM MOTORS 1 STEAM BOILERS 323 general use. With only a few changes, it is the same now. By referring to hig. 218, it will be noticed that the fire box is practically built into the rear end of the boiler barrel. Extending from the rear tube sheet and through the entire length of boiler barrel arc the fire tubes, which are generally about two inches in diameter. Surrounding the lire box and fire tubes is the water. This gives abundance of heating surface, also freedom of circulation. As the sides of the fire box are nearly flat, they will easily collapse under the pressure of the steam flt^aj- -^ aJTSiSa; FIG. 217 — RETURN-FLUE TYPE OF INTERNALLY FIRED BOILER unless supported by stay bolts at intervals of every few inches. The steam dome can be located anywhere, but it is generally placed about midway between front and rear ends. A pipe takes the steam from the top of the dome, carries it down through the steam space, where it is dried, then out wherever convenient. Generally the blow-off is at the bottom and in front of the lire box. The water glass is placed about on a 324 FARM MOTORS level with the crown sheet, since this is the place where the water must not get low. 444. Round-bottom types. — The principal variation from the original type of this class of boilers is in the de- sign of the rear or furnace end. The common practice is to have the water pass completely around the fire box, including the under side. Such boilers are generally known as the round- or enclosed-bottom type (Fig. 218). As a rule, the draft can enter at front or rear of the fire box. This method of draft frequently aids the fireman in firing up, for when there is but one ash door the direc- tion of the wind may be such as to blow away from the door, retarding the draft. 445. The open-bottom type (Fig. 219) is so constructed that ash pan and grates can be removed and a complete new fire-box lining put in. The draft can enter at either end of the fire box. There is not as free circulation in this type as in the round-bottom boilers, providing the latter are kept clean. When a portable boiler of the locomotive type is setting with the front end low, unless there is an abundance of water, the crown sheet will be exposed and, if not at- tended to at once, will become overheated and collapse. To aid in avoiding this, some manufacturers are making the rear end of the crown sheet (Fig. 220) lower than the front. This mode of construction reduces the size of the rear end of the fire box to a certain degree, but it is done where the space is not essential. Fig. 220 also shows a device which further aids in protecting the crown sheet by displacing" the water in the front end of the boiler. 446. Return-flue boilers of the internally fired type have one main flue, which carries the gases from the fire box through the boiler to the front end. Here they STEAM BOILERS 325 »> 'X !S te ^ c E ■' ^ « t: "^ s i < ^ v; "^ ^ -S ^ a •' ^ •- •- C te , < OS 326 FARM MOTORS are divided and enter several smaller flues, then return to the rear end and pass up the stack. This, without doubt, is a very economical type. By referring- to Fig. 221, which is an end view of a return-flue boiler, it will be noticed that the smaller tubes are above the main flue. By this arrangement the smaller and cooler parts will become exposed first, thus giving FIG. 219 OPEN-BOTTOM FIRE-BOX BOILER the engineer a chance to save the boiler from collapse or explosion. 447. Wood and cob burners. — Most boilers upon the market have interchangeable grates so that by placing a grate with smaller openings in place of the coarser one for coal, wood and cobs may be burned. Since the most economical firing can be accomplished by refraining from poking the fire on top, a great many factories are making a rocker grate (Fig. 222), which is STEAM BOILERS ZV 328 FARM MOTORS worked by a lever in such a manner that all fine ashes will drop through. 448. Straw burners. — For burning straw there must be special arrange- ments within the fire box. The fuel is light and generally chaffy, and as a result flashes up very quickly, and un- less prevented will be carried by the draft some distance through the tubes before it is all aflame. Not only this, but straw must be burned rapidly in order to produce heat enough to make steam as fast as needed'. To handle straw under these conditions, the return-flue boilers are generally constructed similar to the type shown in Fig. 223 : a is an extended fire box with a drop- hinge door ; b is the upper grate ; and c is the lower grate, where as much of the straw as is not burned in the upper grate, or as it falls from it, is consumed ; d d are deflectors which hold the flames next to the upper side of the flue. -END VIEW OF RETURN-FLUE BOILER FIG. 222. — ROCKER GR.\TES STEAM BOILERS 329 FIG. 223. — STRAW BURNER RETURN-FLUE BOILER 449. Direct-flue boilers, (Fig. 224), can be more easily changed from coal burners to straw burners. This is generally done by adding a feeding tube with an enclosed drop-hinge door, by removing the grates and inserting a dead plate with short grates in front of it, and by placing a deflecting arch composed of firebrick in the fire box. FIG. 224. — STRAW BURNER DIRECT-FLUE BOILER 330 FARM MOTORS By means of the shorter grates the draft opening is re- duced, and by the aid of the deflector a combustion chamber is produced where all of the light particles are consumed and the gases are heated to an incandescent state before entering the tubes. The direction of draft in this type is nearly always toward the straw, thus caus- ing the heat as it passes the unburned straw to prepare it for better combustion. BOILER ACCESSORIES 450. Supply tank. — Boilers used for traction purposes require a small supply t'tank to which the boiler pump or the in- _. A. jector is connected. This tank is gener- ally placed in some position where it is convenient, yet out of the way. 451, Siphon or ejector — When the supply tank is placed so high that it can- not be filled from a stock tank or other similar source, a siphon (Fig. 225) is generally used. The construction of this is such that a jet of steam is passed into a water pipe leading from the tank or cistern to the supply tank. As the steam comes in contact with the water it is condensed ; this produces a vacuum such that the water rushes in to fill, and the inertia due to the velocity of the steam sends it along into the supply tank. Care must be taken in regard to the amount of steam used, since if too much steam be used the water will be- come so warm that the feed pump or injector will not work. 452. Feed pumps. — There are three types of pumps now in use : the crosshead pump, the independent direct- FIG. 225 — SYPHON FOR FILLING SUP- PLY TANK STEAM BOILERS 331 FIG. 226— CROSSHEAD PUMP FIG. 22"] — INDEPENDENT DIRECT-ACTING PUMP 332 FARM MOTORS FIG. 228- -INDEPENDENT PLUNGER PUMP acting (Marsh) pump, and the independent phinger pump (Figs. 226, 22^, and 228). The crosshead type is the simplest and most economical, but can be run C-^*^)f^\ //W4l\w\^ °"^^ when the engine is 'K/^JmA'l/nX^vX' running. The Marsh inde- pendent pump is simple and economical, but the action of its steam valve is deli- cate and' should be molested only by an expert. The in- dependent plunger pump is very satisfactory in that it can be run at any time and by any one. The initial cost of this is more than that of other types. 453. The injector i s probably the most gen- erally used means o f feeding boilers. It was invented in 1858 by M. Giffard, and large num- bers of the same types are still made. The ac- tion of the injector will be understood by refer- (J^^e ring to the sketch (Fig. 229). Steam is taken from the boiler and passes through the nozzle A to the injector; ,, 1. r i. • FIG. 229 — PRINCIPLE OF THE the amount 01 steam is injector STEAM BOILERS 333 regulated by the valve B. In the tube C the steam is combined with the slowl}^ moving" water, which is drawn up from the tank D. The swiftly flowing steam puts sufficient momentum into the water to carry it into the boiler. The delivery tube E has a break in it at F where the surplus steam or water can overflow. An injector should 1)e chosen with reference to the special work required of it. Some will lift water, others will not. Some will start under low-pressure steam and ST£AM FIG. 230 — COMMERCIAL INJECTOR refuse" to act under high, while with others the reverse is true. There are also injectors which will operate with exhaust steam. Such an injector is not essential, since the efficiency of one of high pressure is practically 100 per cent. Locomotives are equipped with self-starting injectors. Every traction engine should be equipped with two systems of boiler feeds. Some have two injectors, while 334 FARM MOTORS some have two pumps, but the most common method is a pump and injector. 454. Feed-water heaters. — The sudden change in tem- perature of boilers puts them under a great deal of strain. One of the principal reasons for this change in tempera- ture is the admitting of cold feed water. This water may- be easily heated by passing the exhaust steam through it. There are two methods of such heating : one is to allow the exhaust steam to mingle with the water, thus bemg condensed and carried back to the boiler, and the other is to pass the feed water through pipes surrounded by steam. By the former method the steam is returned FIG. 231 — FEED-WATER HEATER to the boiler, and unless a filter is used all the cylinder oil is carried into the boiler, to which it is detrimental. In the latter case the steam does not return to the boiler, but is sent up the stack, thus producing a forced draft. Fig. 231 shows a heater of this type. As pumps and injectors will not operate with hot water, and since the water from a heater is nearly as hot as the exhaust steam, the heater must be located between pump and boiler. 455. Water columns. — The purpose of the water col- umn is to support the gauge glass and try cocks; it is STEAM BOILERS 335 used only in stationary boilers. The water column should be located so that the center of the column will come to the point where the level of the water should be above the tubes, or crown sheet. The column is gen- erally of a casting- about 3J^ inches in diameter and 15 inches long. Into this casting are secured the try cocks and water glass. Some builders connect the steam gauge to the upper end. By referring to Fig. 232 it will be noticed that the lower end of the glass, the lower try cock, and the crown sheet are on a level with each other, hence when the water is out of sight in the glass and also will not flow from the try cock the crown sheet is ex- posed. The water should be kept about in the middle of the glass, and likewise even with the center try cock. It should not be above the upper try cock, or there will be trouble from wet steam. 456. Steam gauge. — The mechanism of a steam gauge (Fig. 233) usually consists of a thin tube bent in a circle. One end of the tube is connected to the boiler, and the other, by means of a link, to a small pinion which works a needle indicator. Air is kept in the tube by means of the siphon, and a cylmdcr of water lies between the air and the boiler. When there is zero pressure in the boiler the needle should set at o. As pressure begins to rise in the FIG. 232 — WATER COLUMN, GAUGE GLASS, TRY COCKS AND STEAM GAUGE 336 FARM MOTORS FIG. 233 — STEAM GAUGE boiler the air will tend, to straighten the tube, and hence the tube acts upon the needle. If it is found by comparison with another gauge that the needle does not indicate the actual steam pressure it can be regulated by sliding the link up or down in the slot at the end of the pinion, thus chang- ing the throw o f t h e needle. 457. Fusible plug. — As a safeguard against low water a fusible plug is put in the boiler. In fire-box boilers it is placed in the crown sheet directly over the fire, and in return-flue boilers it is placed in the back end just above the upper row of flues. The plug is generally made of brass about one inch in diameter and with a tapered hole bored through its center (Fig. 254). The tapered hole is filled with some metal, generally Banca tin, which will fuse at a low tem- perature, so that when the water has become so low that the metal melts and runs out the steam will flow through the opening and put out the fire. 458. Safety or pop valve. — It is essential that in every boiler there be a safety valve so that the steam may be released before too high pressure has been reached. There are two distinct types of these valves, the ball and lever valve and the spring 1 'nt- i /T7- ^ -\ • FIG. 234 — FUSIBLE pop valve. Ihe former (rig. 235) is vivQ STEAM BOILERS 337 FIG. 235 — BALL AND LEVER SAFETY VALVE the least expensive, also the less reliable. It is generally used upon stationary boilers. To increase the pressure in the boiler before it blows off, the ball must be moved farther out on the lever, and inversely to de- crease the pressure. The ball should be set at the proper point to blow off at the desired pressure, and then the lever marked so that the point can be seen distinctly. Spring safety valves are generally used on traction en- gines and the better class of boilers. They are more re- liable and also act much more quickly. If properly constructed they will allow the pressure to fall about 5 pounds before clos- ing, while the ball and lever type only falls to a trifle less than the blow-off pressure. By referring to Fig. 236 fig. 236-pop valve 338 FARM MOTORS it will be noticed that there is a groove B in the valve such that when the valve starts to open, the steam rushes into it, thus increasing" the area of the valve and causing it to open more quickly and remain open longer. To increase the pressure at blow-off, screw down on the pin G ; to lower the pressure, screw up on the pin G. Care must be taken not to tighten the spring down too far, or it will not allow the valve to lift off its seat. 459. Blower and exhaust nozzle. — In all traction en- gines there nuist be some mctliod of increasing the draft. The most simple method and the one universally used is the blower when the engine is not running, and the ex- haust when it is. The blower (Fig. 218) consists of a small pipe with a valve which leads from the boiler to the stack. After the pressure has reached 5 or 10 pounds the valve in this pipe is FIG. 237 — EXHAUST NOZZLE OpCUCd aud a JCt OI s t e a m is allowed to blow into the stack. The momentum of the steam pro- duces a vacuum and the air rushing through the grates and coal to fill this space increases the rate of combus- tion. When the engine is running the exhaust steam from the heater takes the place of the blower and the lat- ter is closed. Fig. 237 shows an exhaust nozzle which can be made to give a sharp or sluggish exhaust, as desired. 460. Blow-off pipe. — Wherever there is a chance for sediment of any kind to collect in a boiler there should be some means of cleaning it. This is almost always accomplished by means of a blow-off pipe and valve. In vertical boilers this is located at the lower end of the water leg. In return-flue boilers this is either at the front STEAM BOILERS 339 or the rear end. and in fire-box l)oilers it is l)eneath the fire box or in the water lej^s. 461. Spark arrester. — Where some method of forced draft is used in a boiler there is danger of sparks being carried out and causing fires. Traction engines guard against this by means of a spark arrester. This may con- sist of a screen which catches the sparks and allows them to fall into the stack, or it may be accomplished by turn- ing the smoke around a sharp corner and, as the sparks are heavier than the smoke, they will be thrown out and are caught in a receptacle for that purpose. The smoke box or front end of the boiler may be long for the purpose. BOILER CAPACITY 462. The capacity of a boiler depends upon the amount of heat generated and the proportion of that heat trans- ferred to the water. The amount of heat generated de- pends upon the quantity of coal, the draft, and area of grate surface. The amount of heat transferred from the coal to the water depends upon the amount and position of the heating surface. There is no entirely satisfactory method of stating the capacity of a boiler or its economy, but they are com- monly stated as boiler horse power and the pounds of steam evaporated per pound of coal. This method of rating is on the assumption that the steam is all dry saturated steam and that there is no priming or super- heating. When water is carried along with steam from the boiler it is called priming. Very seldom is a boiler designed which does not prime at least 2 per cent, but if it primes over 3 per cent it is improperly designed. When steam passes over a hot surface after leaving the boiler it will absorb additional heat and become superheated. That 340 ^ FARM MOTORS part of the tubes which is above the water line in a vertical boiler is superheating surface. In other styles of boilers the steam in order to be superheated generally passes through a coil of pipe within the fire box or a furnace made purposely for it. 463. Steam space. — The surface for the disengagement of steam and the steam space should be of sufficient size so that there is no tendency for the water to pass off with the steam. It has been found by experiment that if the steam space has capacity to supply the engine with steam for 20 seconds, there will be no trouble with prim- ing. To determine whether the boiler has sufficient steam space, find the volumes of the engine cylinder, less the volume of the piston, and multiply this by twice the number of revolutions that the engine makes in 20 sec- onds. This should be about equal to the volume of the steam space, which is the space above the water in the boiler, plus that in the dome. 464. Boiler horse power. — There are two common methods of approximately determining the horse power of a boiler, and a third one which is sometimes resOrted to. One of the common methods is by test, and the other is by heating surface, while the third method is by grate sur- face. 465. Horse power by test. — A committee of the Ameri- can Society of Mechanical Engineers has recommended that one horse power be equivalent to evaporating 30 pounds of water at 100 "^ F. under a pressure of 70 pounds gauge. This is equivalent to 33,320 B.T.U. an hour. Example. — If a 15 H.P. boiler evaporate 15 X 30 or 450 pounds of water in one hour with feed water at 100° and under a gauge pressure of 70 pounds, it would be doing its rated horse power. To make the test, fill the boiler to its proper level and tie a string around the glass at this point, then keep the water in the boiler at this level. If the feed water is below 100°, turn steam into it until STEAM nOILKRS 34I the proper temperature has Uecn reached. Use just steam enough to keep the pressure at 70 pounds. Vv cigh the feed water supply be- fore starting, then weigh again at the close of the run. If the run has been of one hour's duration, divide the number of pounds of feed water by 30, and this will give the horse power developed. If the run has been only one-half hour, multiply by 2, then divide by 30. 466. Power by heating surface. — The heating surface of a boiler consists oi the entire area of those parts of the surface which have fire on one side and water on the other. In the horizontal tubular boiler it is all of the shell which comes beneath the boiler arch, also the inside area of all the tubes and about two-thirds the area of the tube sheets less the area of the titles. In the vertical boilers it is the total inside area of the fire box and as much of the tubes as is below the water line. In the fire-box boilers it is the inside area of the water legs, the crown sheet, and the flues and a portion of the tube sheets. The common rating of boiler horse power 1)y heating surface is 14 square feet for each horse power. This varies with the boiler, some styles requiring a little less and some a little more. As an example, let it be desired to find the heating surface of a horizontal tubular boiler, h'ind the total area of the outside of shell and take about one-half of this. The brickwork covers about one-half of the shell, hence, one-half of it is all the heating surface there is in this part. Now meastire and compute the inside area of one of the flues and multiply this by the number of flues. Add this surface to the heating surface of the shell and divide the sum by 14. This gives the horse power of the boiler. 467. Power by grate surface. — This method is not very often resorted to. In any case it can be only a rough 342 FARM MOTORS estimate. It is generally conceded that from one-third to one-half square feet of grate surface is equivalent to one horse power. STRENGTH OF BOILERS 468. Materials used. — The materials used in the con- struction of boilers are mild steel, wrought iron, cast iron, copper, and brass. In order that a boiler have proper strength for the severe work required of it, sample pieces of all the ma- terials used in its construction are selected and given a test, and those which fail to have the proper require- ments are discarded. They are tested in tension, com- pression, and shear. (See Chap. Ill, Part I.) Steel. — All present-day boilers are made up of mild-steel plates. This steel is a tough, ductile, ingot metal, with about one-quarter of i per cent of carbon. It should have a tensile strength of about 55,000-60,000 pounds. Some- times a better grade of steel plate is used for the lire box and tube sheets of the boiler than for the shell. This is because flanging for riveting and the variations of tem- perature due to the fire require a better grade of steel. Blue heat. — All forms of mild steel are very brittle when at a temperature corresponding to a blue heat. Plates that will bend double when cold or at a red heat will crack if bent at a blue heat. WroiigJit-iron parts. — All welded rods and stays should be of wrought iron. About 35 per cent of the strength of the bar is lost because of the weld. Boiler plates made of wrought iron are considered more satisfactory than of steel, but are used only in exceptional cases because of the greater cost. VVrought-iron plates should have a tensile strength of 45,000, and bolts should have 48,000. Rk'ets. — Boiler rivets are either of wrought iron or mild steel. The rods from which rivets are made should have a STKAM liOILKRS 343 tensile strength of 55,000 j^ounds for steel and 48,000 for iron. When cold they should l)cnd around a rod of their own diameter, and when warm bend double without a fracture. The shearing strength is about two-thirds of the tensile strength. Cast iron is used in boilers for those parts where there are no sudden changes of temperature and where there is no great tens,ile strength required. Couplings, elbows, etc., are better of cast iron, for when they become set and can be removed in no other way they can be l)roken. 469. Stay bolts and stay rods. — In some parts of the boilers the flues act as stays. In horizontal tubular boilers the flues hold the ends of the shell together. In the fire box and in vertical boilers they act in the same way between the flue sheets. Wherever there are flat surfaces and no other means of supporting them, special stay bolts or braces must be put in. In nearly all boilers above the flues stay rods are used to support the ends. Around the fire box stay bolts are put in. These bolts are threaded full length, then screwed through the outer shell and through the water leg and into the fire-box lining, then they are riveted on both ends. Their size and distance apart depends upon the pressure to be carried. Example.— If tlie stay bolts are 4 inches apart and the maximum pressure to be carried is 120 pounds they should be large enough to hold 4 X 4 X 120 = 1,920 pounds. If we use a factor of safety of 10 — that is, make it ten times as strong as necessary to avoid accidents — it will have to be large enough at the base of the thread to hold 1,920 X 10 = 19,200 pounds. If a wrought-iron bolt is used it would have to have 19,200 -^ 48,000 = 0.40 square inches area at the base of threads. A %-inch bolt has about this area. 344 FARM MOTORS 470. Strength of boiler shell. — To determine the ten- sion upon one side of a boiler shell, let p = pressure in pounds per square inch, / ^ thickness in inches, r =: radius, J = stress in pounds per square inch; then Example. — A boiler has a diameter of 3 feet, a thickness of 7/16 inch and the steam pressure is 125 pounds. How many pounds per square inch pull is there on each side? pr 125 X 3 X12 7 pounds. This is about one-tenth the tension which boiler plate will stand, hence we have a factor of safety of 10, which is greater than need be. 471. Riveted joints. — If a boiler shell could be made of one continuous piece, the above tension would be the safe working- load, but since the steel has to be riveted and a riveted joint is not as strong as the original plate, we must consider the ratio of this strength of the whole plate. This ratio is commonly called the efficiency of a riveted joint. There are three general ways that a riveted joint may give way : 1. By tearing the plate between the rivets. 2. By shearing the rivets. 3. By crushing the rivets or plate at the point of contact. Since only single-riveted and double-riveted lap joints are used in small boilers, these styles will be considered only. 472. Single-riveted lap joint. — in the joint shown by Fig. 238, let t be the thickness of plate, d the diameter of rivet, p the distance between rivets, commonly called pitch, the tensile strength STEAM nOILERS 345 of the plate 5*(=: 45.000, and resistance to crushing 5,.. =: 90,000. Assume t = 7/16 inch, d = 1 inch, and p = 2yi inches. A strip of the joint equal in width to the pitch is sufficient to be considered. 1. Tearing between the two rivets. — In this case there is a strip to be torn in two, equal in width to the distance between the rivets less the diameter of the rivet, i.e., p — d, and it has a thickness equal to t, i.e., the strip has a cross-section of an area (p — d)t; this cross-section in square inches times the tensile strength will give the pull required to fracture the joint: (p — d)tSt= (2i/i — i) X 7/16 X 55,000 = 36,095. 2. Shearing one rivet. — Since there is only one rivet in each 2j/2-inch strip, we have to consider the shearing of it only. FIG. 238 — SINGLE-RIVETED LAP JOINT 239 — DOUBLE-RIVETED LAP JOINT The area to be sheared is the area of a cross-section of the rivet, or 3.1416 rtfi' 4 The pull which it will take to shear this rivet is the area times the shearing strength : 3.1416^'' ^ 3.1416 ^-^ X Ss= -" X 45.000 = 35.343- 3. Crushing. — In this case it is common to consider that the area to be crushed is the diameter of the rivet times the thickness, hence dtSc= I X 7/16 X 90.000 = 39,375. The number of pounds it will take to fracture a strip of plate 2^2 inches wide and 7/16 inch thick by tension is 2K- X 7/ 16 X 55.000 = 60,155. 346 FARM MOTORS Hence the ratio of the strength of the joint to the strength of the plate is 35.350-^60,155 = 088; hence 0.588 X 100 = 58.8 per cent = the efficiency. Now, if the original shell on page 344 is referred to, it will be seen that instead of having a boiler with a factor of safety of 10 it will have only 58.8 per cent of this factor, or approximately 6, which is about the usual factor. 473. Double-riveted lap joint (Fig. 239). 1. Tearing between two rivets. — The resistance to tearing is (p — d)tSt = (214 — I ) X 7/16 X 55-000 = 36,095. 2. Shearing two rivets. — Instead of shearing one rivet as in the single-riveted lap joint, two are sheared. Hence 4 4 is equal to 70,686. 3. Crushing two rivets. — Here again two rivets are considered instead of one, hence 2dtSc = 78,750. The efficiency of this joint would then be 100 X 36,095 -i- 60,155 ^60 per cent. The same dimensions have been used in this joint as in the pre- vious one for simplicity and comparison. By using a smaller rivet this joint can be made much more efficient. 474. Test of boilers for strength. — There are two dis- tinct methods of testing boilers for strength. The one which is generally conceded to be best is the hydravilic test ; and the other, which is about as safe and sure, and in some cases more so, is the hammer test. Hydraulic test. — This test consists in filling the boiler full of cold water and then putting pressure upon it to the desired point. This pressure is generally about one and one-half times the working pressure. Since some boilers are designed with a factor of safety of only four or five, if twice the working pressure be put on it there will be danger of rupture to the boiler. With new boilers this STEAM BOILERS 347 test shows all leaks around stays, tubes, joints, etc.; while in old boilers, if they are carefully watched as the pressure increases, it will disclose weakness by bulging in some places and distortion of joints in others. Hammer test. — The inspector who conducts this test should go over the boiler before it has been cleaned inside and out and carefully note all places where there is corrosion or incrustation. At the same time he should carefully strike all suspicious places a sharp blow with the hammer to detect weaknesses. A good plate will give a clean ring at every blow of the hammer, while a weak one has a duller sound. Although a boiler may be carefully inspected and tested by both methods, it does not insure it against failures. The greatest strain upon a boiler is due to un- equal expansion, and neither of these methods takes this into account. Some authorities recommend hot water to be used in the test, but there seems to be no advantage in this, since it is the unequal expansion of boilers and not the rise in temperature which causes the failure of certain parts and consequently so much destruction. FUELS 475. The fuels most commonly used for making steam are coal, coke, wood, ])eat, gas, oil, boggasse, and straw. Those used for traction engines and threshing purposes are coal, wood, straw, and occasionally cobs. Anthracite coal. — Anthracite coal, commonly known as hard coal, consists almost entirely of carbon. It is hard, lustrous, and compact, burns with very little flame, and gives an intense heat. It has the disadvantage when being fired of breaking into small pieces and falling through the grates. 348 FARM MOTORS Semi-anthracite coal. — This variety has properties that make it to be considered a medium between anthracite and soft coal. It burns very freely with a short flame. Bituminous or soft coals. — These burn freely and with all gradations of character. Their properties are so varied that they will not permit of classification. Some burn with very little smoke and no coking. This class is gen- erally used m traction engines. Others which coke very freely are good for gas making. Wood is used only where it is more plentiful than coal. It requires a finer meshed grate than coal and more atten- tion in feeding. Oil. — In localities where oil is plentiful or where it is cheaper to freight oil than coal, furnaces are fitted for it as a fuel. It has been found that oil burns the best when atomized and mixed with steam. For this purpose a nozzle is constructed so that both steam and oil can flow from it, the steam forming an oily vapor of the oil, which when ignited burns with a very intense heat. Straw. — In localities where straw is practically worthless and coal and wood are scarce, straw is used as a fuel. It must be handled with care, since too much in the fire box at once is as harmful as not enough. 476. Value of fuels. — Anthracite and semi-anthracite coals have about the same heating value. Bituminous has a trifle lower value. A cord of hard wood has the same amount of heat in it as a ton of anthracite coal, while a cord of soft wood has only about half that value. COMBUSTION 477. The term combustion as ordinarily used means the combining of a substance in the shape of fuel with oxygen of the air rapidly enough to generate heat. . In all fuels there are hydrogen and carbon, and some mineral matter. STEAM BOILERS 349 The carbon and hydrogen unite readily with the oxygen of the air, generating heat and Hght, but the mineral matter remains and forms the ash. When the carbon of the coal mixes with the oxygen of the air and the mixture is at or above the igniting temperature, combustion takes place and either carbon monoxide (CO) or carbon dioxide (COo) is formed, de- pending upon the amount of air supplied. If the air is insuflficient in quantity to furnish enough oxygen to form COo, CO will be formed. If the mixture is not hot enough to form complete ignition a great deal of free carbon in the form of smoke is thrown ofif and is a loss. 478. Heat of combustion. — Carbon will not unite with oxygen when in the free state until a certain temperature is reached. This temperature is known as the igniting temperature. Wlien the igniting temperature has once been reached and the carbon of the fuel combines with the oxygen of the air, they in turn throw ofif heat. By experiment it has been found that one pound of carbon burned to carbon monoxide (CO) produces 4,400 B.T.U., and if burned to carbon dioxide (COo) 14,650 B.T.U. are produced. One pound of hydrogen united with sufficient oxygen produces 62,100 B.T.U. 479. Air for combustion.* — By weight, 12 pounds of carbon unite with 16 pounds of oxygen ; hence i pound of carbon forms 28 ^ 12 = 2I/3 pounds CO, or if it be burned to COo it will require twice as much oxygen for each pound of carbon ; hence 12+ (2 X 16) ^12 = 35^ pounds COo for each pound of carbon. Since in the 3 2/3 pounds CO2 there is one pound of *A good discussion of this will be found in Peabody and Miller's "Steam Boilers." 350 FARM MOTORS carbon, there must be 2 2/2^ pounds of oxygen ; hence one pound of carbon requires 2 2/3 pounds of oxygen. As we must have 4 1/2 pounds of air to get one pound of oxygen to burn one pound of carbon to CO,, it requires pounds of air. ,. ^ ,, ^ 23/3 X aVz — 12 As there are impurities in all fuels, so that a pound of fuel is not necessarily a pound of pure carbon, there are variations which have to be considered. 480. Volume of air for combustion. — As before stated, an insufficient amount of air burns the carbon only to CO, while a sufficient amount burns it to CO2. Instead of having the exact 12 pounds of air for each pound of carbon, as previously computed, it requires an excess for complete combustion. This excess varies from one-half the quantity required for combustion to an equal quan- tity. Roughly, for each pound of carbon there should be from 18 to 24 pounds of air. By experiment it has been found that it requires 10 pounds of air for each pound of certain coals, and since 13 cubic feet of air at the temperature it generally enters the fire box weighs i pound, for each pound of coal it requires 10 X 13= 130 cubic feet of air without excess. If the excess is 50 per cent, it requires about 200 cubic feet. Loss from improper amount of air. — If one pound of car- bon be burned to CO, there will be 4,400 B.T.U. liberated. If it be burned to CO^, there will be 14,650 B.T.U. set free. Hence there will be a loss of 14,650 — 4,400 = 10,250 B. T. U. 100 X 10,250 -^ 14,650 = 70 per cent. This would be a case too rare to be considered and is used only for simplicity. If due caution is practiced in STEAM BOILERS 351 regard to handling drafts, there is very seldom a loss of over 5 to 8 per cent due to lack of air. On the other hand, if there be too great an excess of air, it would not only furnish oxygen for combustion in sufficient quantities, but the excess would be heated as it passes through the boiler from a temperature of the outside air to a temperature of the flue gases, thus taking up part of the heat which would be transferred to the water. This loss generally amounts to from 4 to 10 per cent. 481. Smoke prevention. — Black smoke is caused by in- complete combustion. It is generally noticed when start- ing a fire or when fresh coal is put on. To avoid as much of this as possible, keep the fire hot and feed the coal in small quantities. Do not have the door open longer than is absolutely necessary, as the excess of air cools the fire and instead of burning the CO to COo, it passes ofY as CO or free carbon, which causes the smoke. HANDLING A BOILER 482. The flues are made of a soft, tough iron or steel. They are put in place, then expanded with a tube ex- FIG. 240 — FLUE EXPANDED WITH PROSSER EXPANDER FIG. 241 — KLUE EXPANDED WITH DUDGEON EXPANDER 352 FARM MOTORS pander to a steam-tight joint. The Prosser and Dudgeon expanders are the two types in common use. The Prosser makes a shoulder on the inside of the sheet as well as on the outside, but permits the tubes to touch only at the outer edges (Fig. 240), while the Dudgeon expander enlarges the end of the tube and causes it to fit the full thickness of the sheet (Fig. 241). Owing to the construction of this type of expander, it is preferable for repair work. 483. Manholes and handholes. — These are openings in the boiler to permit of cleaning and examining. The use of a manhole is confined to stationary boilers and is generally placed near the top in an opening about 11X15 inches. Handholes are generally in the water legs or near the bottom of the boiler. Their accustomed size is about 3X5 inches. The plate used to cover these holes is held in place by a bolt passing through a yoke. To secure a tight joint, a yi-inch gasket is placed between the plate and the boiler shell of the handholes. The same style of gasket is used for the manholes, but it should be about ^4 inch thick. 484. Safety valves and steam gauges. — The safety valve should be placed in a pipe by itself, and this pipe should be inspected often for stoppages, etc. The safety valve and steam gauge should be set for the same pressures; that is, if the valve blows oft at no pounds, the gauge should not read 100 or 120. In case this should happen, do not set the valve to blow ofl according to the gauge until the gauge has been tested by some gauge known to be correct. During freezing weather the gauge should be taken off every night and put where it will not freeze. Every morning before starting up the safety valve should be tried to see that it neither leaks nor sticks. 485. Water glass. — There is a cock at each end of the STEAM BOILERS 353 glass tube. When these cocks are both open the water will pass from the boiler into the glass and stand at the same level as in the boiler, but if either one of the cocks be closed or the pipes leading to the cocks be stopped, the water would rise in the glass and give a false water level. If it is the upper one that is closed, the pressure in the boiler will cause the glass to fill, and if the lower one is closed, the glass will fill with condensed steam. Below this glass is another cock, which is used to drain the glass or blow out the other cocks. By opening this cock when there is pressure and closing the lower one leading to the glass, the upper one will blow out, or if the upper one is closed and the lower opened it will blow out. It is best to try the cocks every morning and see if they are open or free from stoppage. Always have some extra glasses along, for they are likely to break at any time. 486. Leveling the water column. — Before firing up a boiler a new man should always determine the level of his water in the boiler as compared to the water column. If it is a stationary boiler, take ofif the manhole cover and fill until the water has reached the lowest limit in the glass. Then continue to fill until the proper height of water has been reached and again note the level in the glass. A good way to mark these points is to file notches in the guard wires which protect the glass. Should the boiler be traction or portable, it should be set on level ground and leveled up with a level. Then the water column should be leveled the same as in a stationary boiler. 487. Feed pipe. — There is difference of opinion in re- gard to the place where the feed pipe should enter the boiler. In horizontal tubular boilers it generally enters near the front end and passes back through the boiler to 354 PARM MOTORS near the back end before it discharges. In this way the feed water reaches nearly the temperature of the boiler water before it conies in contact with the shell or the tubes. In threshing boilers it generally enters on the side. Sometimes it enters near the bottom through the blow-ofif pipe. There should always be a hand valve in the feed pipe near the boiler and a check valve outside of this. The hand valve is placed close to the boiler so that in shut- ting down in cold weather the water can be shut ofif. Also if anything happens to the check valve, the hand valve can be closed while the former is being repaired. Where bad water is being used the feed pipe is likely to become choked with scale, and if the pump or injector fails to work it is often well to look in this pipe for the trouble. 488. Firing. — Before firing up a boiler always see that there is plenty of water. Do not simply look at the glass, but clean the glass and see if it fills immediately. Try the try cocks and see if the water stands the same in them as in the glass. Notice the tubes and grates and see if they are clean. 489. Firing with soft coal. — Soft coal should not be thrown in in chunks ; it should be broken into pieces about the size of a man's fist. Put the coal in quickly and scatter it over the fire as you throw it in. Keep the door open as short a time as possible, so that no more cold air will enter than can be helped. Keep the grates well covered with burning coal so that no cold air will come through them. If the boiler has more grate capacity than needed, do not keep fire on only a part of the grates, but check the fire by closing the drafts. When the fire cannot be kept down in this way without causing incomplete combustion, bricks may be placed over the STEAM nOlLERS 355 back end of the grate and to a height equal to the bridge wall. Some furnaces and fuels require different depths of fire than others. The proper depth can be determined only by trial. Fine coal and a poor draft require a thinner fire than coarse coal and a strong draft. Engineers differ in regard to the best methods for keeping up a fire. Some suggest that it is best to keep the fresh coal near the door, and when it has become coked push it back to the rear, and again throw fresh coal in the front. By this method there is an intense fire maintained at the back of the furnace, and as the partially burned gases pass back they are completely burned. The advantage of this method lies in the fact that complete combustion is se- cured ; consequently there is less smoke, but there is a corresponding disadvantage in keeping the fire door open so long and allowing the furnace to cool slightly. 490. Cleaning. — Do not clean oftener than necessary. Keep the clinker loosened from the grates between clean- ing times. Wdien cleaning large furnaces, rake all the iire to one side and then clean the grates. Rake a part of the live coals back on this side and put on fresh coal. When this is burning well clean the other side in the same manner. To clean small furnaces, crowd the fire back, clean the grates, then rake the fire forward again. 491. Banking the fire. — Fires are banked to keep the steam from rising when there is a good fire, and also to hold the fire over night. Banking a fire consists in cover- ing the glowing coals with fresh coal or ashes. When banking a fire for the night, crowd the coals to the rear, then fill the front of the furnace with fresh coal, and open the damper over the fire enough to carry off the gases. • All drafts should be kept closed. By banking a fire this way it will gradually burn back toward the door, thus 356 FARM MOTORS ^^ ' keeping the boiler warm, and in the morning there will be a good bed of coals which will start up readily. When a boiler is being used daily, it is considered more econom- ical to bank a fire than to let it go out and then rekindle it in the morning. 492. Drawing a fire. — Fires are drawn when it is de- sired to cool the boiler down very quickly or when the water is dangerously low. A fire should never be drawn without first smothering it with ashes, dirt, or fresh coal. Drawing a fire without first doing this causes it to glow up, and for a moment become much hotter than before it was stirred. Never put water in a furnace, as it is liable to crack the grates. It will also produce so much steam that it will either blow back or else blow the fire out the door and make it too hot to work around. 493. Priming. — When water is carried over from the boiler with the steam the boiler is said to be priming. Priming can always be detected by the click in the engine cylinder, which shows that there is water there. Taking too much steam from the boiler at once, carrying too much water, or not having enough steam space will cause priming. If the cause is too much water, blow out some and then slowly start the engine. Carrying a high steam pressure and keeping the water as low as possible will retard priming to a certain extent. 494. Foaming is similar to priming, but it is generally caused by dirty or impure water. It can be detected by the rising and falling of the water in the gauge glass and by the engine losing power or speed ; also by the clicking in the cylinder. When a boiler foams, the engine should be shut down at once and the water in the boiler allowed to settle. So much water is carried over in the steam that the glass does not show the true level. If after settling down it is found that there is plenty of water over J STEAM BOILERS 357 the flues, it will be safe to pumj) in more, but if the water is low, let the boiler cool down somewhat before filling. A boiler is more likely to foam with a high-water level than with a low. It is also more likely to foam with low pressure than high. A sudden strain on an engine will sometimes cause the boiler to foam. If a boiler is likely to foam, it is advisable to carry low water and high pres- sure. Then if it still persists in foaming, shut down and pump in a cjuantity of water and allow some to run out. This will change the water. If this does not remedy it, the boiler must be cleaned. 495. Low water. — Should the water happen to get be- low the danger line in a boiler, immediately cover the fire with ashes, dirt, or even fresh coal, and as soon as it can be drawn without increasing the heat do so. But never draw the fire until it is in this condition. Do not start the feed pump, or start or stop the engine, or open the safety valve. Simply let it cool down. After it has be- come cool, then examine it for injuries. If a failure of the injector or pump has caused the water to become low and there is still an inch over the flues or crown sheet, the engine should be shut down and attention given to the feed supply. W' hen the water has become so low as this, do not try to repair the injector or pump with the engine still running, as it will run the water below the crown sheet before it is anticipated and thus make the boiler more dangerous. 496. Corrosion and incrustation. — It is practically im- possible for an engineer to get for his boilers water which does not have some detrimental ingredients. Nearly all hard waters will form some sort of scale. W^hile soft waters do not do this, they do contain acids which act on the boiler and fittings in a harmful manner. The general impurities to contend with are the car- 35^ FARM MOTORS bonates and sulphates of lime. These vary with the loca- tion and can be dealt with properly only after experiment. Generally, however, they are thrown down in the boiler in the form of a soft mud and can then be disposed of by blowing out and washing the boiler with a strong stream from a hose. The presence of other impurities, such as oils or organic matter, or even sulphates of lime, makes these lime scales hard and adhesive. Removing the water from the boiler while still hot will cause these scales to bake or dry on the parts, in which case it is very difificult to remove them. Wherever it is possible, run some soft water through the boiler for a few hours before cooling down to clean. The acids will act upon the limes and loosen them from the tubes, etc. Since the lime impurities of water are thrown down at a temperature of about 200° F., there are devices on the market which allow the feed water to mingle with the exhaust steam. This heats the former to a temperature sufficient to throw out the lime parts. 497. Boiler cleaning. — It is essential that a boiler be kept clean both inside and out. Authorities have stated that one-tenth inch of scale will require 15 per cent more fuel. Boiler scale is a non-conductor of heat ; conse- quently, the flues must be kept hotter to affect the water as much with scale as without. The frequency of washing a boiler can only be deter- mined by experience with the water used and the sur- rounding conditions. Usually a traction boiler should be cleaned once a week, but there are wide variations from this rule. Often when there is considerable mud in the water it can be blown out by means of the lower blow-off valve. It is good practice to fill the boiler extra full at night; then in the morning when the sediment has settled and STEAM BOILERS 359 there is about 20 pounds of steam, blow ofif through the lower valve until the proper water level has been reached. \A'hen the boiler is in operation the circulation keeps the dirt mixed and it does not avail much to blow off then. A good way to wash a boiler is to allow it to cool down until one can bear his hand in it; then open the blow-off valve and let the water run out. Remove the manhole and handhole plates and scrape all tubes and the shell with a scraper made for the purpose, then wash well with a hose and force pump. 498. Cleaning the flues. — Fire tubes should be cleaned at least once a day, and sometimes oftener. This is done by means of a scraper or a steam jet. Scraping should always be done in the morning before firing up. Never do it just after the fire is started, for then the tubes are wet and pasty. If they have to be cleaned while running, do it as quickly as possible and let as little cold air as possible get into them. 499. Boiler compounds. — Often there are cases where the impurities in boiler waters are such that they form a hard scale. In these cases it is nearly always advisable to use a boiler compound. If the proper compounds are used, they will dissolve the scale and throw it down in the form of a mud. Then it can be blown out. Wherever the scale does not become hard it is very seldom advisable to use a compound. Wherever a compound is necessary it is best to have a chemist analyze the water and make a compound to suit the case, giving directions as to use and quantity to be used. For traction and small creamery service this is not practical. Soda ash gives very good results for creamery service. It has no offensive odors and is com- paratively cheap. Sal soda has also been used with good results. For boilers where steam is used only for en- 360 FARM MOTORS gines, kerosene is largely used. Kerosene is also good to remove scale already formed. Where a sight-feed lubri- cator is available, kerosene may be fed through it, but when not the kerosene may be put into a boiler before filling. The kerosene floats, and as the water rises it adheres to the sides and tubes. Avoid using a compound except when absolutely necessary. 500. Blister. — A blister in a boiler is identical with a blister on the hand. On account of imperfect material or dirt, the metal will separate and one part will swell. Wherever there is a blister it is best to cut this part out and patch. If the blister is around the fire, a new half sheet should be put in. 501. Bag in a boiler. — A boiler is likely to bag if dirty, or if a quantity of oil has found its way into it. The oil will stick in one place and keep the water away. Then the fire will overheat this place and the inside pressure force it out. In forcing out the place it breaks the oil scales and allows the water to run in and cool it ofT. Sometimes it is best to put in a new half sheet where a bag is formed, but often it can be repaired by heating the place and driving it back. 502. Cracks sometimes form in the flue sheet because the flues are expanded too much. They are often formed in riveting. Whenever a crack is discovered it can be mended by drilling a hole in the end of the crack and putting in a rivet. This keeps the crack from getting larger; then the crack can be filled in. 503. Laying up a boiler. — In laying up a boiler, always clean it thoroughly. Scrape and wash it inside and out, and then paint the outside with black asphaltum or graphite and oil. CHAPTER XIX STEAM ENGINES 504. Early forms. — Hero of Alexandria is given credit for being the first man to use steam as an agent to con- vert heat energy mto mechanical energy. He produced an aeopile which operated with steam upon the same principle that our present-day centrifugal lawn sprinklers work with water. History gives us ideas which were advanced by certain men, but nothing of importance after Hero's machine until 1675, when, con- jointly, Newcomen, Calley, and Savery invented what has been known as the Newcomen engine. Fig. 242 is a drawing of this engine as it was used for pumping water. A is the pump plunger and is always held down by the weights B. The steam, after being generated in the boiler C, is passed through valve D to the cylinder F. The piston H, which is up as the steam enters, is connected with the pump by means of the walking beam /. When the cylinder F is filled with steam, the valve D is closed and the valve E opened, letting in a jet of water from the previously filled tank G. As the water enters the cylinder it condenses the steam F, thus producing a vacuum in the cylinder, consequently the atmosphere will act upon the piston H and force it down. As it forces the steam piston down it raises the piston A, and with it the water. After Newcomen, Watt produced probably the most important im- provement of the steam engine. It was in 1769 that he got out an engine which would not condense the steam in the working cylinder, and by so doing cool off the walls, but he condensed it in separate vessels, which produced a continuous vacuum. The same principle as that of Watt is in use in the condensing steam engine of to-day, the only changes being in the mechanism for admitting and releasing the steam, in mechanical make-up and methods whereby labor in the machine shop is reduced. 505. The present engine. — The working parts of the present engine are .all of the same general plan, with dif- 362 FARM MOTORS I ferent designs for carrying out the actions. The prin- ciple is that of a cylinder separated into two parts by a piston. There is a valve connected with the cylinder by FIG. 242 — NEWCOMEN S ENGINE means of which the steam is thrown from one side to the other. This valve also conducts the exhaust steam out of the cylinder. In Fig. 243, A is a steam chamber which receives the steam from the boiler. B is the valve which slides back and forth on the valve seat /. The valve B, situated as it is in this figure, allows the steam to pass STEAM ENGINES 363 from the steam chest A, through the steam port C, into the front end of the cylinder D, and press against the piston E. This forces the piston through the cylinder toward the end P. At the same time the steam which FIG. 243 — CYLINDER AND VALVE OF STEAM ENGINE has been previously admitted to the end of the cylinder F is forced out through the cylinder port G into the ex- haust chamber H, and out through the exhaust port / into the air. By the time the piston E has reached the end of the stroke the valve B has reversed its position so that the steam chest A is connected with the end of the cylinder F by way of the steam port G. The exhaust port / is now connected with the exhaust end of the cylinder C, hence as the steam enters the cylinder at the end F it drives the piston toward the end D. 364 FARM MOTORS FIG. 244 I. Base. 10. Wrist pin. 2. Cylinder. II. Crank pin. ^■ Steam chest. 12. Crank shaft. 4- Piston. 13- Eccentric. S- Valve. 14. Eccentric strap. 6. Piston rod. '5- Crank disk. 7- Crosshead. 16. Flywheel. 8. Connecting rod. 17- Valve rod guide 9- Crosshead shoe. 18. Eccentric rod. 19. Valve rod. 20. Steam inlet pipe. 21-22. Steam ports. 23. Exhaust pipe. 24. Cylinder head. 25-26. Packing boxes. 27. Guides. 506. Classification of steam engines. — Sneed -^ ^^^^ T^• •^- r c. ( Condensing: Disposition of Steam ] Non-Condensing Simple Number of Expansions j Single i Double i Tandem Compound -| Cross ( Twin ( Throttling Governor Speed Regulation -. Automatic ( Corliss Stationary Kind of Work ■{ Marine Locomotive \ Rail ] Traction Pressure on Piston \ ^'"^'^ Acting pressure on riston j j^^^^^^ Acting I i STEAM ENGINES 365 The classes of en,^ines j^^enerally used in agricultural pursuits would be known as high-speed, non-condensing, either simple, single or double, or conii)oun(l tandem or cross, throttling governed, either stationary or loco- motive traction and double-acting. 507. Generation of steam. — Enclose i pound of water at a temperature of 32° F. in a cylinder under a movable frictiotdess piston. Suppose the piston to have an area of I square foot, but no weight other than the atmos- pheric pressure. Apply heat to the water and the follow- ing results will be noted : 1 gAJl l iMCi*. ft ;le at the FIG. 316 — SIDE-MOUNTED PORTABLE ENGINE rear end of the boiler and is known as rear mounting. As a rule, the return tul:)ular boilers are mounted on an axle which passes beneath the boiler. This style of mounting is given no special name, but might be called under-mounted boilers. There is now on the market a type of mounting which might be known as frame mount- ing; that is, there is a frame to which the drive wheels are attached, and it also supports the boiler. 582. Side mounting. — Fig. 316 shows the method of side mounting a portable engine. This is similar to a great many side-mounted traction engines. Fig. 317 438 FARM MOTORS shows a similar side-mounted traction engine. This is done by means of an axle for the drive wheel, which is FIG. 317 — SIDE-MOUNTED TRACTION ENGINE substantially fixed to a casting. This casting, which is known as the bracket, is then riveted to the side of the fire box. Fig. 318 shows this principle very well except- ing that the bracket is strengthened by means of a couple of rods which pass under the fire box and are correspondingly attached to the bracket on the other side. This is a very simple method, but has some disadvantages. The side bracket is at- tached only to the water leg of the boiler, while the total weight of the engine FIG. 318 — BRACKET FOR SIDE- i i M • ^i MOUNTED ENGINE ^nd boilcr IS throwH TRACTION RNCINKS 439 upon it. It is ob\'ioiis that this puts undue strain upon the boiler shell at a point where it is the weakest. The weight of the boiler and the engine is thrown upon these brackets and in such a manner that it has a tendency to throw the inside of the axle down and the outside up. This will tend to throw the tops of the drive wheels to- gether and the bottoms apart. The weight is also throw^n upon these axles so that that part of the hub of the fly- wheel next to the engine will wear faster than the -middle, and as a result the wheels will tend to become wobbly in action and wear the teeth of the transmission gearing unevenly. A truss bar similar to that of Fig. 318 re- moves a great deal of the strain from the water leg, and FIG. 319 also tends to hold the axles in line with each other, and thus keep the drive wheels more nearly vertical. An- other method of side mounting an engine is shown in 440 FARM MOTORS Fig. 319. By inspection it will be noticed that this style of mounting is similar to that of Fig. 317, but in addition to this there is a heavy curved axle which passes from the bracket down beneath the fire box and up to the bracket on the opposite side. Although this style of mounting is considered superior to the one previously described, in order to prevent springing of the axle and the consequent wobbling of the wheels it will be neces- sary to make the axle too heavy for practice. Although the bad efifects of the strain on the boiler are practically all removed by passing the axle beneath the fire box, the effect of the wearing of the boxings in the hubs is still uncared for. This al- lows the wheels to travel out of a vertical plane and wear the gearing irregu- larly. Fig. 320 shows an end view of this style of mounting, with the addi- tion of springs. These springs are a benefit to a traction engine in that they take the jar off the parts as the engine travels over rough roads or pavements. 583. Rear mounting. — Rear mounting, as a rule, is not as simply done as side mounting. However, it has some advantages over the other. Fig. 321 shows one type of rear mounting which has its merits. The brackets which support the boiler and the engines are attached to the corners of the water leg, thus removing the strain from a weak point to one which is stronger. By having the en- gine rear-mounted the axle upon which the drive wheels FIG. 320 — SIDE-MOUNTED ENGINE WITH SPRINGS AND TRUSS BAR TRACTION ENGINES 441 travel is allowed to revolve in the bearings instead of the wheels revolvino upon the axle. By having the axle re- volve in this manner the wear is all in a straight line and on the top of the boxing, hence there is no reason for the wheels to become wobbly and cut the transmission gear- FIG. 321 — REAR-MOUNTED ENGINE ing unevenly. By referring to Fig. 2^22 it will be seen that the use of springs becomes impossible on a rear- mounted engine as shown in Fig. 321. Assuming that there are springs in this type of mounting, and that the 442 FARM MOTORS springs are so adjusted that when a jar comes upon the engine the teeth will mesh as shown in Fig. 322, then if there were no jar upon the engine and the springs were carrying it in its normal position, the gears A and B would not mesh, or else they would mesh just enough so that the teeth would catch and strip. If a spring could be placed so the combination of gears A, B, and C would 1 FIG. 322 rise and fall together in a circle whose radius is equal to the sum of the radii of the wheels C and D, it would be as efiective and the wheels C and B would mesh. Fig. 323 shows the type of mounting which has this desired effect, but it has the additional complication of radius and cross links. As the springs respond to the jars of rough roads, these links keep the gear wheels the proper distance apart, so that they are always in proper mesh. TRACTION ENGINES 443 FIG. 323 — REAR-MOUNTED ENGINE WITH RADIUS AND CROSS LINKS FIG. 324 — UNDER- MOUNTED ENGINE 444 FARM MOTORS 584. Under-mounted boilers. — Fig. 324 shows a type of mounting where the axle is straight and fastened directly beneath the boiler. By inspecting Fig. 325, this method of mounting will be more clearly understood. A is the '^'I^Txir^ FIG. 325 FIG. 326— FRAME- MOUNTED ENGINE TRACTION ENGINES 445 main axle upon which the drive wheels operate. Althousi^h made of a square bar, it is round at the bearing B. and revolves in it. Althou.qh the brackets for this type of mounting are attached to the boiler, the boiler itself, being- round, is probaljly strong enough so that the ex- cessive strain will cause very little trouble. This type of mounting ver}^ seldom contains springs. 585. Frame mounting. — To remove as much of the strain as possible from the boiler, some engines are now coming upon the market with a frame which supports engine, transmission gears, and boiler. Or else the frame supports the boiler and the boiler supports the engine. FIG. Ti2/ — FRAME-MOUNTED VERTICAL TRACTION ENGINE Fig. 326 shows the frame for this type of engine with the boiler and transmission gears removed. Fig. 327 shows 446 FARM MOTORS a vertical traction engine and boiler complete. For a cer- tain class of work there is a call for a style of frame mounting such as is seen in Figs. 328 and 329. In this style of mounting all the strain is thrown upon the frame, allowing the boilers to be freely suspended as shown. FIG. 328 — FRAME-MOUNTED ENGINE OF THE LOCOMOTIVE TYPE FIG. 329 — LOCOMOTIVE TYPE OF TRACTION ENGINE WITH STEAM- OPERATED PLOW 586, Engine mounting. — Where the engine is not mounted upon the frame as shown in Figs. 326, 327, 328, and 329, it is mounted upon the boiler. This is not con- l! TRACTION ENGINES 447 sidered the best nietliod. However, it is commendable for its simplicity and possibly counterbalances the evil ef- fects of the extra strain upon the boiler. Fig. 330 illus- A "" B FIG. 330 — ILLUSTRATING METHOD OF MOUNTING ENGINE ON BOILER FIG. 331 trates the method which most engine builders utilize in attaching- their engines to boilers. The brackets A, B, C are riveted directly to the boiler shell. 448 FARM MOTORS Fig. 331 shows the main bearing A, which is a part of the frame, also the bearing B, which is commonly known as the pillow block bearing. These bearings are both riveted to the boiler. 587. Clutch. — When the separator is being driven by the engine the traction part must not move. Conse- quently, there must be some method for throwing the power from the drive wheel which drives the pulley to the transmission gearing that runs the traction part of the engine. The device for transferring the power is a clutch generally located on the engine shaft. It acts upon the belt wheel of the engine. Fig. 332 shows a sim- ple. 332 — CLUTCH pie clutch in parts. A is the belt wheel upon which trav- els the belt that drives the separator. It is fixed to the engine shaft so that whenever the engine moves this wheel moves also. The clutch blocks and arms are seen at D, and the pinion is engaged with the transmission gearing at C. This part of the mechanism is not fixed to the shaft, and revolves with it only when the clutch is TRACTION ENGINES 449 locked. In other words, \Yhen the clutch locks, the blocks all are forced out against the rim of the belt wheel tight enough so they stick to it and the whole mechanism re- volves with the wheel. The clutch is a very important part of the traction engine and requires very careful ad- justment and care. Since the blocks DDD are continually wearing off, the arms EE have to be constantly adjusted. They should be so carefully adjusted that when thrown in, the clutch will lock and hold itself in position. They should also be adjusted so there will be no slip between the clutch blocks and the clutch shoe. Fig. 333 shows another type of clutch, which has a metal clutch block instead of wood. 588. Transmission gear- ing. — The steam engine for traction engine work gen- erally has a speed of 200 to 225 revolutions a min- ute. If the drive wheels were connected directly to the engine shaft such a speed would drive the out- fit over the ground nearly as fast as a locomotive travels. This is something that could not be conceived of on country roads, hence the speed has to be reduced to one which is permissible. For this purpose a chain of gears such as is shown in Fig. 334 is utilized. Not only are these gears used to reduce the speed of rotation from that of the drive wheel to that of the engine, but since the engine is generally located some distance from the traction wheel shaft, these gears con- duct the power from the engine shaft to the shaft of the FIC,. ^23 — CLUTCH WITH METAL BLOCKS 450 FARM MOTORS traction wheel. The intermediate gears are generally attached to the boiler by means of brackets as shown in Fig. 322. If the engine were ahvays to travel straight ahead or straight backward the matter of trans- mission gearing would be very simple, but since it has to turn and often on a very small circle one wheel is compelled to travel faster than the other; consequently they cannot be both attached rigidly to the same shaft. FIG. 334 — GEARS CONNECTING ENGINE WITH TRACTION WHEELS If one wheel were attached to the shaft and the other were allowed to go free then one wheel would do all of the traction work. This would not do, since the engine would have only half of the tractive pov/er and for road work it is necessary that every pound possible of trac- tive pull be developed. To arrange the drive wheels of a traction engine so that both will pull when the engine is traveling in a straight line and also so they will travel TRACTION ENGINES 451 r in a curve without slipping, a compensating gear is in- serted in the chain of transmission. 589. Compensating gears. — Fig. 335 shows a simple, very effective compensating gear. The large pinion A carries the small pinions CCC. The shaft F is connected to the flywheel on the opposite side of the engine by means of a small pinion. The pinion G is connected to the other main gear. The power is transmitted from the en- gine shaft to the pinion A. As pinion A revolves in the di- rection of the arrow, pinions CCC will be driven, and they in turn will propel the drive wheels. But if the drive wheel attached to pinion G happens to travel faster than that attached to shaft F the ^^^^. , pinion C will revolve and ^9^^EB^^^£.^^SJliL ^^^^^ ^^^ pinion A will propel ^^^^S»^BSi^rtF«»c the gearing. Often there are some very severe jerks on the transmission gearing of an engine and some com- panies are now inserting in their compensating gears a set of springs which take this jar off the gearing. 590. Traction. — Any traction engine has power enough to propel itself over the road and through the fields pro- vided the drive wheels do not slip. Consequently the matter of the wheels adhering to the ground is an im- portant part. Where the road surface is firm there is no difficulty ; but in a soft field great trouble is experienced due to the fact that the lugs of the drive wheels tear up the earth and allow the drive wheels to move without moving the engine. It is a common belief that the driv^e wheel which has the sharpest lug is the one which will FIG- 335 — COMPENSATING GEARS 452 FARM MOTORS adhere to the ground the best. In nearly all cases this is not true, since the lug which is sharp is very apt to cut through the earth, while one which is dull or round and does not have such penetrating effect will pack the earth down and thus make more resistance for itself while passing through the earth. Nearly every engine builder has a style of lug of his own. Fig. 338 shows a new style of traction wheel which seems to be giving very good results. The more weight that can be put on to the drive wheels of an engine the better it will adhere to the ground, providing the surface is firm enough to support the load. This makes the matter of location of the main axles upon the boiler an important factor. When the boiler is rear- mounted it is obvious that more of the weight is thrown upon the front wheels, which act as a guide, than when the Pjg ^,g boiler is side-mounted. Hence one would be led to believe that the side-mounted traction engine will have better tractive power than the rear-mounted. It is also in- dicative of better tractive power when the pivot of the front axle is as far ahead as possible. For this reason some builders are now attaching a frame to the boiler and crowding the front trucks ahead. Fig. 336 is an illus- tration of this type of mounting. 591. Width of tires. — Where traction engines such as are used for harvesting and threshing grain simultane- ously are used for plow work or in the field an excep- tionally wide tire is required. If an engine is to be used for this work exclusively the wheels are made with the i TRACTION ENGINES 453 proper width of tires at the factory. But where an en- gine is to be used for job threshing a part of the time and for plowing a part of the time the wheels should be made so an extra width of tire can be attached to support the engine for plowing. 592. Road rollers. — For road rolling purposes traction engines as a rule, especially the gearing and bearings, are made much heavier. The tires are wider, and the front truck instead of being made of two wheels is made into one broad wheel. HANDLING A TRACTION ENGINE 593. Moving an engine. — ^^llen moving an engine it is best to carry more water than when doing stationary work. This is especially true in hilly fields or hilly roads. The gauge glass and water cocks should be care- fully watched. The steam pressure should be maintained near the blow'-off point. Upon approaching a hill judg- ment should be exercised in regard to the fire and amount of water and pressure. As much water should be car- ried as is permissible without priming. If possible there should be sufficient fire when starting up a hill to carry the engine to the top. Judgment should also be exercised in regard to the speed. Taking an engine up a hill too fast is apt to cause priming. Also there is danger of reducing the steam pressure so that a stop will have to be made to raise it. When the summit of the hill has been reached, the fire can be started up, more water put in the boiler, and the engine allowed to travel faster. As much and probably more care should be exercised in descending a hill than in ascending. If possible the engine should be taken from the top of the hill to the foot without a stop. If this is not possible turn the en- gine around so that it sits as near level as possible while 454 FARM MOTORS the stop is being made. Every engineer knows the dan- ger of having the front end of a fire box boiler the lowest. If the engine is inclined to run too fast in going down a hill the reverse should be thrown. If then it still travels too fast, while the engine is still in the reverse, open the throttle and let in a little steam. 594. Guiding an engine. — Traction engines are guided by means of the hand wheel, which operates through a worm gear. This in turn acts upon chains which are attached to the ends of the front axle. Turning the hand wheel to the right will turn the engine in that direction, while in turning the hand wheel to the left the engine will turn to the left. Do not turn the steering wheels too often or too far. Watch the front axle and act accord- ingly. It is much easier to steer an engine when moving than when standing. If possible always move the engine a trifle when steering. The steering chains should be moderately tight ; if they are too tight they will cause undue friction, while if they are too loose the engine cannot be guided steadily. 595. Mud holes. — The best way to get out of a mud hole is not to get into it. An engineer should go out of his way a considerable distance rather than to take his engine into a mud hole. A\ hen an engine is once in a mud hole and the drive wheels commence to slip without propelling, the engine should be shut down at once. When the drive wheels are run in the mud without moving the engine they soon dig up a hole out of which it is very hard to raise the engine. When drive wheels commence to slip, straw, boards, rails, posts, or anything at hand should be put under them so they may get a grip. In getting out of a mud hole do not start the en- gine quickly, but ver}' slowly. If the wheels will stick at all they will gradualh^ move the engine by starting it 1 TRACTION EXGIN'ES 455 slowly, while if starting it quickly the grip of the wheels gives away before momentum can be put into the engine. If stuck in a mud hole always uncouple the separator or Avhatever load the engine is hauling, move the engine out, then by means of a rope or chain pull the separator across. If the engine is stuck in a soft place like a plowed field often the hitching of a team in front will take it out. 596. Bridges. — Before crossing a bridge or culvert the engineer should make inspection to see if it will carry the weight of his engine and the separator. If there be any doubt and it is impossible to move the engine around the bridge heavy planks should be placed across it to dis- tribute the load. Always move slowly while crossing a bridge. If the engine has once broken through it can sometimes be removed by winding a rope around the belt wheel several times, then setting the friction clutch and hitching a team upon the rope. As the rope gradu- ally unwinds, it will move the engine by means of the transmission gearing. 597. Gutters. — In road work often one drive wheel of an engine will strike a soft place in the gutter. Owing to the principle of the compensating gear this wheel will then slip in the mud and revolve while the other wheel will remain stationary and the engine not move. In a case like this the compensating gear should be locked and both wheels be made to revolve together. 'I'he wheel which is on the solid ground will move the engine out of the hole. To lock the compensating gear there is generally some scheme, as in Fig. 335, whereby a pin can be inserted in the pinion A and lock the pinion D by means of the projection //. 598. Reversing the engine on the road. — \\ hen it is de- sired to reverse a traction engine moving on the road 456 FARM MOTORS the throttle valve should be closed, the engine reversed, then the throttle opened. Traction engines are usually made strong enough so they will stand the strain of being reversed without closing the throttle. This, how- ever, is hard on the bearings, and the engineer should always close the throttle before reversing the engine, especially if the engine is running at full speed. 599. Setting an engine. — A new engineer will expe- rience some difficulty in setting an engine so it is prop- erly lined with the separator. On a still day the belt wheel of the engine should be in line with the separator. This is also true when the wind is blowing in line with the engine and the separator. But if the wind is at an angle allowance will have to be made for the amount which it will carry the belt to one side. Often the en- gine will have to be set a few feet out of line with the separator and toward the wind. If the engine has been set when there is no wind and enough wind comes up to throw the belt over, it is not necessary to .stop the en- gine and move, but a jack screw can be set against the end of the front axle and the engine worked over toward the wind. Also the front end of the separator should be crowded in a similar manner until the belt runs in the proper position on the pulley. The friction clutch should always be used in backing the engine into the belt. 600. Gasoline traction engines. — Since the gasoline traction engine requires no boiler, the engine with its necessary accessories, such as water tanks, gasoline tanks and battery boxes, is mounted upon a frame. Conse- quently the mounting of a gasoline engine is more simple than that of a steam engine. However, it has a disad- vantage which the steam engine does not have ; that is, the engine itself cannot have its direction of rotation reversed without a great deal of trouble, consequently TRACTION ENc;iNES 457 there has to be connected into the transmission gear a reversing gear. The simplest of the reversing gears for gasoline engines now on the market is a system of fric- tion pulleys, such that when the engine is in one posi- tion on the frame the traction wheels will move for- ward. When it is in another position another set of wheels is connected in and the traction wheels will move backward. It will be noticed from this that the engine, which generally weighs 2,000 or 3,000 pounds, has to be slid backward or forward on the mounting frame. Fig. 337 shows a type of engine which reverses as above FIG. 337— GASOLINE TRACTION ENGINE WITH FRICTION GEARING described. This engine is operated by means of a set of friction v/heels, instead of a set of gearing as steam traction engines are run. Fig. 338 illustrates an engine which utilizes pinions for its transmission gearing similar to a steam traction engine. Rating. — Gasoline traction engines are all rated upon 458 FARM MOTORS the horse power they will develop at the brake. Conse- quently when one speaks of a 15 H.P. gasoline engine he refers to an engine which will develop only about the same horse power which a commercially rated 7 H.P. steam engine will develop. For this reason when com- paring the powers of the two engines it is always well at least to double the size of the gasoline engine to do the work which a commercially rated steam traction engine has been doing. 1 FIG. 338 — TRACTION ENGINE WHICH REVERSES IN THE CLUTCH Regulation of speed. — A gasoline traction engine oper- ated by means of friction gearing, as illustrated in Fig. 337, can have any speed required of it at the expense of slippage between the gears. But a positively driven traction engine must have other methods of changing the speed. These methods generally amount to changing I TRACTION liNGlNES 459 the point of ignition in the engine in order to reduce the power at low speed, or else shifting the power from one set of gears to another. Generally in an engine where the power is shifted there are only two speeds, a high and a low. On the road. — About the same caution should be exer- cised in handling a gasoline traction engine through soft and muddy places and over bridges as in handling a steam engine. But there is practically no caution to be taken in climbing hills other than that taken on level ground. Upon descending a hill a strong and efTective brake should always be at the control of the operator. Traction. — As a rule gasoline traction engines are much lighter than steam traction engines. Consequently their tractive power is correspondingly less. And for heavy traction work the size of the engine must be increased in order to add to the tractive power. 1 CHAPTER XXII ELECTRICAL MACHINERY 6oi. Natural magnets. — The name magnet was given by the ancients to a brown-colored stone which had the property of attracting certain metals. Later the Chinese found that when free to move this stone always pointed in one direction, and they named it loadstone (meaning to lead). The commercial name for it is magnetite (Fe304). This mineral is found in such quantities in sev- eral localities that it is a valuable ore for producing iron. WSm'^^W*'' FIG. 339 — NATURAL AND ARTIFICIAL MAGNETS ATTRACTING IRON FILINGS 602, Artificial magnets. — The ancients learned by stroking pieces of steel with natural magnets that the steel would become magnetized. Magnets produced in this manner are known as artificial. They are now made by stroking bars of steel with another magnet or an electromagnet, which will be described later. 603. Poles. — If a magnet is sprinkled with tacks or iron filings, it will be noticed that the filings attach them- selves to the ends of the magnet but not to the middle of it. The name poles has been given to these places where the filings adhere. A suspended magnet will swing so that one of its poles points toward the north. This pole is then known as the -f- or north-seeking pole, or simply the north pole (N), and the other end is known as the — ELFXTRICAL MACHINERY 461 or south pole (S). The mariners' and the engineers' compasses work upon the same principle. 604. Magnetic lines of force, — Again, if a sheet of paper be placed over a magnet and some filings then dropped upon the paper, and if the paper is slightly jarred, the filings will assume the position shown in Fig. 340. From this it is gathered that the magnet has lines of force and that these lines are of the form indicated in Fig. 341. For convenience it is assumed FIG. 340 that the lines of force leave the magnet at the N pole and enter at the S pole. 605. Laws of magnets. — If the north and the south poles of two magnets are determined and marked it will be noticed that when one of the magnets is suspended so it is free to move in any direction and the north pole of the other is brought close to the south pole of the sus- pended one, these two ends attract each other. If, on the other hand, the N ends be brought together it will be — ^HSh \ \ \ \ >-w- -5- FIG. 341 — DIRECTIONS OF LINES OF FORCE noticed that they repel. Hence the general law of mag- nets is deduced : Like poles repel and unlike poles attract. The force of this attraction is found to vary inversely as the square of the distance, i.e., increasing the distance 462 FARM MOTORS between the poles two times reduces the force acting between them 2X2^4 times. In other words, the force is one-fourth as strong. 606. Magnetic materials. — Steel and iron are the only common substances which show magnetic properties to any appreciable degree. STATIC ELECTRICITY 607. Static electricity. — If a hard rubber rod be rubbed with flannel and then brought close to a suspended pith ball the ball will jump toward the rod. By rubbing the rod has been electrified and the action of the charge is to attract the ball. This charge of electricity is not within the rod but is on the surface and is known as stationary or static electricity. Another example of this is rubbing a glass rod with silk. 608. Laws of electrical attraction and repulsion. — If a rubber and a glass rod be excited and suspended as shown I Gloss FIG. 342 in Fig. 342 and brought close together it will be noticed that they attract each other, but if two rubber rods be suspended in the same way and brought together, they will repel each other. Hence the following law is ad- vanced : Electrical charges of a like kind repel each other and those of an unlike kind attract. 6og. Density of charge varies with form of surface. — ELECTRICAL MACHINERY 463 Since all of the little particles of a charged substance, because of their mutual repulsion, tend to get as far away from each other as possible, the density of a charge is very much greater on the ends of an oblong body than in the middle. If the ends be drawn to a point the charge will become so intense that the point cannot hold it all and some of it will be given off to the air. 610. Lightning and lightning rod. — In 1752 Franklin with his famous kite and key learned that there is elec- tricity in the clouds. He also showed that lightning is only a huge electric spark and that by means qf points like lightning rods these mammoth sparks may be dissi- pated into the earth. As the cloud which is charged with electricity approaches it induces an opposite charge in the points and the charge is then quietly conducted away, while if the points are not there the electric charge will assume such a volume that when the cloud does give it up it will strike the building in such a great bolt that damage is done. From this it will be seen FIG. 343 that lightning rods do not protect the building by conducting the whole charge of the stroke away at once, but by diffusing and thus preventing the charge collecting in large quantities. 611. Potential difference (P.D.). — If water is placed in a tank A, Fig. 343, it will run through the pipe C into tank B. We attribute the running of the water from tank A to tank B to the difference in pressure between the two tanks. In exactly the same way will a positive charge of electricity flow from one body to another. Thus, just as water tends to flow from higher pressure to lower, does electricity of a higher potential flow to a c e : z ^ 464 FARM MOTORS lower. Moreover, if the tank A is not continuously sup- plied with water the tank B will soon be filled to an equal level ; likewise if current is not supplied to the body having the greater potential, the potential will become the same in the two bodies. 612. Volt or unit of potential difference. — To measure the amount of work required to transfer a charge from one body of a high potential to one of a low potential there must be a unit. This unit is called the volt in honor of the great physicist Volta. It is roughly equal to the P.D. between one of Volta's cells and the earth. CURRENT OR GALVANIC ELECTRICITY 613. Current electricity. — Electricity is an invisible agent and is detected only by its effects or manifestations. Current electricity is generally detected by its magnetic effects. That is, near all currents of electricity there are indications of magnetism, while in stationary or static electricity there are none. 614. Shape of magnetic field about a current. — If a wire carrying a heavy cur- rent of electricity be run through a cardboard and filings be sprinkled upon the board they will form them- selves into concentric rings about the wire (Fig. 344). A compass placed in this field and at several positions will show that the lines of force are all in one direction. Re- verse the current and the _-„ -., needle will also reverse. This FIG. 344 ELECTRICAL MACHINERY 465 shows that there is a direct relation between the direction of the current in the wire and the direction of the magnetic hnes which encircle it. 615. Right-hand rule. — Ampere devised a rule in which the right hand is used as a means to indicate this rela- tion in all cases. Let the right hand grasp the wire ( Fig. 345) so that the thumb points in the direction in which the cur- rent is flowing and the fingers will then point in the direc- tion of the magnetic lines of force. Ampere being the investigator who made quantitative measurements of cur- rent electricity, the unit of measurement was named am- pere in his honor. Owing to the peculiarity of electricity it cannot be measured in pints and gills as liquids but can be measured by the chemical effect it will pro- ^^^- 345 . duce, i.e., one ampere will deposit in one second 0.0003286 gram of copper in a copper voltmeter. 616. The ammeter is an instrument used for the measurmg of amperes. Commercial ammeters do not FIG. 346 — AMMETER FIG. 347— VOLTMETER measure them by means of chemical deposits, but by means of a needle enclosed in an electrical coil in such a 466 FARM MOTORS manner that as the current varies the magnetic force of the coil will vary, and cause a deflection of the needle. 617. Voltmeter. — To measure the electrical pressure or potential difference requires an instrument similar to the ammeter excepting that instead of having a few coils of wire it often has several thousand coils of very fine wire. Only a very small amount of current will pass through these numerous coils. Electromotive force. — The total electrical pressure which an electrical generator is able to exert is called its electromotive force, commonly abbreviated to E.M.F. 618. Electrical power. — The unit of electrical power is a unit of electrical work performed in a unit of time and is called a watt. The product of volts into amperes gives watts, i.e., volts X amperes = watts. Example. — An incandescent lamp is fed by a current having a voltage of 220 and requires 0.3 ampere of current. The electrical power consumed is then V X A =: W, 220 X 0.3 =. 66.0 watts. Kilowatt. — The watt is such a small quantity that it has become the custom to use a larger unit known as the kilowatt. „^ I kilowatt = 1,000 watts, or, I watt = 1/1,000 kilowatt. Horse pozuer. — By experiment it has been found that •7375 foot pound per second = i watt. Now, since 550 foot pounds a second is the equivalent of one mechanical horse power, an equivalent rate of electrical working would be: 550 ^ , . , , z= 746 watts = one electrical horse power. •7375 619. Resistance, — If two pipes of the same di'ameter but (lift'erent lengths lead from a tank of water, the water I ELECTRICAL MACHINERY 467 will flow very nuicli faster from the short pipe than from the long one. l'"roni this we learn that the pressure de- creases as the water passes through the pipes and the longer the pipe the more it falls. The friction between the water and the inside of the pipe retards the flow and is known as resistance. Electricity flowing over a wire is an analogous case. The current meets with re- sistance in the wire and there is a fall in potential. Comparative resistance. — To measure comparative re- sistance, silver is the unit of comparison, it having the lowest resistance of any substance. Specific resistance of some metals : Silver, i.oo; Copper, 1.13; Aluminum, 2.00; Soft iron, 7.40; Hard steel, 21.00; Mercury, 62.70. Laivs of resistance. — As the lengths of wire increase the resistance increases and as the diameter increases the re- sistance decreases. Hence the following law is deduced : That the resistance of conductors of the same materials varies in direct proportion to length and inversely to the area of the cross-sections. The resistance of iron increases with rising tempera- ture, likewise with nearly all metals, while the resistance of carbon and liquids decreases as the temperature in- creases. Unit of resistance. — A conductor maintaining a P. D. of one volt between its terminals and carrying a current of one ampere is said to have a resistance of one ohm. The ohm is the unit of resistance and is named in honor of George Ohm, the great German physicist. Ohm's laiv. — The current existing in a circuit is always 468 FARM MOTORS ^1 directly proportional to the E.M.F. in the circuit and in- versely proportional to the resistance. Hence if C = current, E = E.M.F.. R = resistance, Likewise, — _, or R current _ E.M.F. Resistance Amperes =r Volts Ohms 620. Rheostats. — The common method for controlling the current required for various electrical purposes is either to insert or to remove resistance. By Ohm's law 1 -=l (A) If E is kept constant and R is varied, C will also be varied but with an inverse ratio. Any instrument which' will change the resistance in a circuit without breaking it is known as a rheostat. A rheostat can be constructed FIG. 348— PRINCIPLE OF RHEOSTAT FIG. 349 — COMMERCIAL RHEOSTAT of various substances : coils of iron wire, iron plates or strips, carbon, columns of liquids, etc. Fig. 348 illus- trates a commercial rheostat. The current enters at A, ELECTRICAL MACHINERY 469 A ohms 4 ohms 4ohma FIG. 350 — SERIES CONNECTIONS passes through the resist- ance B, which can be in- creased or decreased as the metalHc arm C is moved from point to point, and out through the arm C and pivot D. The rheostat absorbs energy and throws it off as heat instead of doing useful work with it. 621. Series connections. — When lines are connected up as in Fig. 350, so that tliC same current flows through each one of them in succession, they are said to be con- nected in series. In this case the total resistance is the sum of the several resistances. 4-1-4+4 = 12. 622. Parallel connection. — If instead of connecting these lines up as in Fig. 350 they be connected as in Fig. 351 they will be in parallel and the total resistance will be only one-third of the resistance of one of them. This is obvious, for in this connection there is three times as much cross-section of wire carrying the current as in the previous case, and by formula (A) the resistance varies inversely with the sectional area. 623. Shunts. — One line connected in parallel w-ith an- other is said to be a shunt connection to the other. In Fig. 35 lA, 6" is shunted across the resistance R. If R has a greater resistance than S it will carry less of the current, since the currents carried are inversely proportional to the resistance. Hence if R has a resistance of 5 ohms and 5" a resistance of i ohm, R will carry one-fifth as much current as 6" or one-sixth of the total current. FIG. 351 — PARALLEL CONNECTIONS FIG. 35IA — SHUNT 470 FARM MOTORS 624. Cells. — If a strip of copper be connected to one end of a strip of zinc and the free ends of the two metals be immersed in dilute sulphuric acid (Fig. 352) a cur- rent of electricity will manifest itself in the wire. If the circuit is broken and tlie plates carefully watched, bubbles will be seen to collect on the zinc plate and none on the copper. As soon, however, as the circuit is com- pleted again a current will be noticed, also a great number of bubbles will appear about the copper plate. These last bubbles are bubbles of hydrogen and always appear when a current is being produced. The bubbles which form about the zinc are also of hydrogen, but they are caused by the zinc being impure and by a current starting up between these particles of impurities and the particles of zinc. This action is detrimental to the cell and should be stopped by covering the zinc with mercury. By permitting the current of this cell to run for some time it will be noticed that the zinc is being gradually eaten away, and that the copper plate does not change. From this it is learned that when the cur- rent of a simple cell is formed the zinc is eaten away and hydrogen collects on the copper. The cur- rent passes out from the FIG. 352 — CELL copper plate and in on the zinc. In other words, the copper plate is the positive ter- minal and the zinc is the negative. 625. Polarization. — After the current has run for some time in the cell as previously described the strength will KUXTRRAI. MACllINKRY 47I become very much weaker, hut if the copper plate be removed and wiped, then reinserted, the current will be as strong as ever. From this it is learned that the hydro- gen bubbles collect on the copper and form an insulator, so that the chemical action is retarded. This forming of hydrogen bubbles is known as polarization, and in a good cell there must be some means to check it. The various forms of cells now in use differ from the above only by using different electrodes and having some method for checking polarization.* 626. Dry cells. — Dry cells differ from liquid cells only in that the exciting fiuid is formed into a jelly or held in suspension by some absorbent such as sawdust or pith. In the common commercial type the zinc element is in the form of a cylinder and holds the exciting fluid and carbon. The ends of the cylinder are generally sealed with wax. The following proportions by weight will make a very good cell : i part zinc oxide ; i part sal ammoniac ; 3 parts plaster ; i part zinc chloride ; 2 parts water. 627. Heating effect of an electric current. — Owing to the resistance to an electric current passing through a conductor, heat is developed. If the current is small and the cross-section of the conductor large the amount of heat developed will hardly be noticeable, but if the cur- rent is strong and the conductor small in cross-section, the latter will soon become hot, often red hot, and some- times melt down. It is due to this heating effect that many machines are burned out, and it is also due to this same effect that more machines are saved. 628. Fuse. — If a piece of copper wire is connected in series with one of lead and a current sent through them the lead will melt down at a little over 600° F., but it *For discussion of commercial cells see any text book on physics or elementary electricity. 472 FARM MOTORS will require a temperature of nearly 2,000° to melt the copper. Because lead melts at such a low temperature it is used as a fuse. A fuse consists of a leaden wire connected in series with the circuit it is to protect, and when the current becomes too excessive the lead melts out and thus opens the circuit. Fuse wires, as they are called, are always labeled with the number of amperes they are supposed to carry. 629. Magnetic properties of coils. — Let a wire carry- ing a current be formed into a small single coil and bring a compass close to it. When the compass is on one side of the coil it will be noticed that the N pole is attracted and the S pole repelled. Change the compass to the other side and the reverse will be found true. Now re- verse the direction of the current and it will be found that the needle acts in just the opposite manner. From this it is learned that the electric coil is simply a flat disk magnet with a N and a S pole, the same as any other magnet. 630. Electromagnet. — When instead of forming the wire which carries the current into a single loop the wire is formed into several loops in the shape of a helix, a com- pass brought into its field will produce the same actions of the needle as in the single loop, only they will be much more violent. Now, if a soft iron bar, commonly known as a core, be placed within the helix, a very strong magnet known as an electromagnet will be formed. The lines of force of such a magnet are identical with those of the bar magnet. Hence, if the electromagnet is con- structed so that the lines of force can remain in iron throughout their entire length, the magnet will be much stronger. For this reason electromagnets are made in the horseshoe form as shown by Fig. 353. ELECTRICAL MACHINERY 473 631. Electric bell. — The electric bell is a simple applica- tion of the electromagnet. The current enters at A (Fig. 354), passes through the horseshoe magnet B, over the closed circuit breaker C, and out at D. The instant the circuit is completed through the coils a magnet is formed, which attracts the armature E, and rings the gong F. But as soon as the armature is drawn down FIG. 353 — ELECTROMAGNET FIG. 354 — ELECTRIC BELL against the poles of the magnet the circuit is broken at C, hence the current stops flowing and the magnet becomes nil. As soon as the magnet has no strength the force of the spring G draws the armature back and makes contact at C again, and the operation is repeated. 632. Electromagnetic induction. — In a previous para- graph it has been shown that there is a magnetic field sur- rounding all electric currents. If a wire be arranged so as to form a closed circuit and then moved across a mag- netic field a reverse action of that explained above will take place. In other words, if a closed circuit be moved 474 FARM MOTORS through a magnetic field a current will be set up. This is the most important part of electricity, for upon it ii> based the operation of nearly all forms of commercia* electrical machinery. 633. Currents induced in a coil by a magnet. — A sensi- tive galvanometer is connected in a circuit with a wire (Fig. 355) in such a manner that the galvanometer is not afifected by the magnet and yet the wire can come into the magnetic field. If that part of the wire between A and B be very quickly moved down across the field the galvanometer needle will be deflected. When the needle comes to zero and the wire is moved across the field in the opposite direction the needle is again deflected, but the opposite way. If the wire be moved into the mag- netic field and held still the needle will come to zero and remain there until the wire is set in motion. Again, if the wire is moved back and forth across the magnetic field the needle will vibrate back and forth across zero, showing that there is a current but an alternating one. When the backward and forward motions of the wire have become fast enough the needle of the galvanometer will practically stand at zero, only giving enough vibration to show that there is an al- ternating current afTecting it. By trial the following re- sults will be obtained : I. When the magnet is moved and tiie wire held sta- tionary the same results are noted. PjQ ^cc 2. When the position of 1 4 ELECTRICAL MACHINERY 475 the poles of the magnet is reversed the current is also re- versed. 3. When an electromagnet is used in place of the per- manent one the same results are noticed. 4. The induced current is produced by the expenditure of muscular energy and does not weaken the magnet. 5. \Mien the wire is moved so as to cut the magnetic lines of force at right angles the momentarily induced current is greatest. 6. The direction of the lines of force is at right angles to the direction of the current in the wire. 634. Factors upon which the value of induced E.M.F. depends. — If the wire in Fig. 355 be very quickly moved across the magnetic lines of force the galvanometer needle will deflect farther than when the wire is moved slowly. Also, if two magnets with their similar poles together are used instead of one and the wire is moved at the same velocity as previously the needle will have a greater deflection. Again, if a coil of wire be used in- stead "of a single one the deflection of the needle will be greater. Hence it is obvious that the induced E.AI.F. is dependent upon and proportional to the number of ■magnetic lines cut, the speed or rate at which they are cut and the number of wires cutting them. 635. Currents induced in rotating coils. — Instead of cutting the magnetic lines of force of a strong magnet with a single wire let them be cut with a coil of 400 or 500 turns. Let the coil be small enough so it will rotate between the poles of a horseshoe magnet. With the coil at right angles to the plane of the poles rotate it 180'' and note the direction of deflection of the galvanom- eter needle. Rotate the coil the other 180° and bring it to the position from which it started and again note the direction of the deflection of the galvanometer needle. 476 FARM MOTORS The needle shows that a current has been induced which has two directions of flow during each revolution of the coil. This induced current is produced in exactly the same manner in which currents are produced by dynamos. 636. Dynamos are machines for converting mechanical into electrical energy. They cannot develop energy but simply change the form of the energy delivered to them. Since they cannot develop energy, the amount of current delivered by them is wholly dependent upon the amount of me- chanical energy supplied. In principle the dynamo consists of two parts : a magnetic field made up of electromagnets and a number of coils of wire wound upon an iron core forming an armature. 637. Simple alternating-current dynamo. — Consider the single loop of wire ABCD (Fig. 356) as the armature and the poles N and S as the magnets of a dynamo. With the armature in the position it is shown there is no cur- rent developed. The armature is for the instant moving parallel to the magnetic lines of force and consequently is cutting none of them. As the armature moves from a position perpendicular to the lines of force to a position parallel to them, the number of lines it cuts increases until it reaches the perpendicular position, and from then on until it has traversed 180° the number of lines cut de- creases until none are cut. From this it is obvious that with the armature in the first and last positions no cur- FiG. 356 ELECTRICAL MACHINERY 477 rent is produced and when the armature is cutting the greatest number of lines of force the current is at a maximum. When the armature is turned through the remaining i8o° of the revokition the same action takes place. As the side AD moves down the current flows in the direction indicated, but as the side BC moves down it is reversed. Hence for one half of the revolution the cur- rent flows in one direction and for the other half it flows in the opposite direction. One end of the coil is attached to the metal ring E, and the other end is attached to the ring F. Both rings are fixed to the shaft, so they rotate with it. Brushes C a.nd H a.re in continual contact with the rings, so the current is taken from them and carried over the circuit. Armature. — It might be assumed that the iron part of an armature of a dynamo is only to carry the numerous wires which are used for cutting the magnetic lines of force, but this is not the only use for the iron core. The iron carries the magnetic lines of force very much bet- ter than they travel through air, and for this reason the FIG. 357 FIG. 358 — MAGNETO ARM.\TURE air space between the fields is as nearly filled with the armature as possible. Fig. 357 shows the path of the magnetic lines through a ring armature. 478 FARM MOTORS FIG. 359 — SYSTEM OF WIRING FOR MULTIPOLAR ALTERNATOR 638. Magneto alternator. — Fig. 358 shows a magneto armature with the wires off. This is probably the most simple commercial electrical- current generator used. It is only applicable for such uses as cigar lighters, tele- phone calls and line testers. For large purposes it is too inefficient. 639. Multipolar alternator. — The numberof alternations in a dynamo as just described is 4,000 a minute with a speed of 2,000 revolutions a minute. This speed is as high as advisable, but the number of alternations is only about half as high as is considered good practice. For this reason large commercial dynamos are built with several poles, as shown by Fig. 359, and the number of revolutions reduced. The dotted lines in Fig. 359 represent the directions and paths of the lines of force. The full lines indicate the windings, and the arrowheads the direction of current. By carefully following out the direction of the induced current it will be seen that the coils passing beneath the north poles have a current set up in them which is opposite in direction to that set up in the coils passing under the south poles. By inspecting the windings it will be noted that the direction is reversed between each set of poles, hence the current set up through the system is the, sum of all the currents set up at each pole. As the coils of the armature pass across the points midway between the poles, the direction of current is alternated. The number of alternations to the minute is found by multiplying the number of poles by the number of revolutions to the minute. ELECTRICAL MACHINERY 479 640. Direct-current dynamo. — For a great many pur- poses it is desirable to have a direct current, that is, one which always flows in one direction the same as a cur- rent from a cell. To do this some device must be applied to the dynamo just at the point where the current leaves the armature and before it reaches the external circuit. This device as used in a direct-current dynamo is known as a commutator. Conumitators are practically split rings secured to, but insulated from, the shaft of the armature. They take the place of the accumulating rings of the alternator. Each part of the commutator is insulated from the other parts. FIG. 360 FIG. 361 Principle of the coiiiinittator. — Fig. 360 shows a simple commutator connected to a coil which represents an armature. A and B are the segments of the metal ring, each of which is connected to the armature. As the arma- ture rotates in the direction indicated by the arrow the current passes off through the side C, out over the ex- ternal circuit through the segment .4, and in through the segment B and side D. When the side D has passed into the i)osition of side C, the current goes out over the circuit in a similar manner. The brushes E and F must 480 FARM MOTORS be set so they close contact with each side respec- tively and make contact with the other side at the instant the current in the armature changes direction. 641. Ring armature, direct-current dynamo. — A ring armature may be made for a direct-current dynamo by winding on the iron ring a series of coils, the ending of each coil being connected to tlie beginning of the next. The junction of the two is connected to a section of the commutator. As the number of groups of coils is in- creased the number of sections of the commutator must also be increased. An eight-coil ring armature is shown in Fig. 361 ; the direction of current is indicated by the arrows. The induced current from both halves of the armature flows up toward the positive brush B, out over the external circuit, back in through the negative brush C and through each half of the armature to B again. As each coil passes from the field of the N pole and enters the field of the S pole, commutation takes place and the direction of current is reversed. The brushes are located at this point and the current from both sides is con- ducted ofif on the same wire. When the brushes pass from one of the commutator bars to another there is an instant when the armature sections are short-circuited ; but this is at the instant when these coils are moving parallel to the lines of force, hence there is no current passing through them. 642. Drum armature, direct-current dynamo. — Instead of winding the armature coils upon an iron ring some- times they are wound upon a drum. Fig. 362 shows the principle of the drum-wound armature suitable for a bipolar field. Like the windings of the ring armature the coils are in series and both halves are parallel with the external circuit. 643. Comparison of the drum and ring armature. — By ELECTRICAL MACHINERY 481 reference to Fig. 357 of a ring- armature it will be noticed that the inside parts of each coil on the armature do not cut lines of force, hence these lines conduct only the cur- rent and may be known as so much dead wire. In the drum-wound armature both sides of the coil cut lines FIG. 362^DRUM ARM.A.TURE of force and the only dead wire is across each end. Al- though the drum-wound armature has less dead wire than the ring-wound, it is not as convenient to repair. For this reason high-voltage direct-current arc-lighting dynamos are generally constructed with ring armatures. A combination of the two, which is known as a drum- wound ring armature, is extensively used in practice. 644. Self-exciting principle of dynamos. — In the earlier types of dynamos the field magnets were always sepa- rately excited by either a battery or a magneto. Later it was learned that the soft iron of the field magnet after once being excited retains some of the magnetism. Since then all direct-current dynamos are built on this principle. There is sufficient magnetism remaining in the fields so that when the armature is up to speed it cuts enough 482 FARM MOTORS lines of force to induce a small current into the circuit around the field coils. This current more highly excites the field magnets until the dynamo soon picks up or establishes its rated E.M.F. 645. Shunt dynamo. — In the so-called shunt-wound dynamo a small portion of the current is led ofT from the brushes bb (Fig. 363), and through a great many turns of very fine wire which encircle the core of the magnet. In such a dynamo, as the load increases the E.M.F. slightly decreases, and as the load decreases the MAIN CIRCUIT FIG. 363 — SHUNT-WOUND DYNAMO FIG. 364 — SERIES-WOUND DYNAMO E.M.F. increases. Hence, if the current fluctuations are great and quite frecjuent it would keep an attendant oc- cupied to keep the field resistance regulated for the load. (See Fig. 368.) 646. Series-wound dynamo. — In the so-called series- wound machines the whole of the current is carried through a few turns of very coarse wire which encircles the field mag- nets (Fig. 364). Since every change of current alters the field magnetizing current, consequently in the current in- duced in the armature the E.M.F. at the brushes will vary with every change of resistance in the external circuit. 647. Compound-wound dynamo. — In the compound- ELECTRICAL MACHINERY 483 wound machines there is both a series and a shunt coil surrounding- the cores of the field magnets. This style of machine is designed to give automatically a better regulation of voltage on constant-potential circuits than is possible on the shunt-wound machines, and yet pos- sesses the characteristics of both the series and shunt ma- chines. Like the shunt machine a part of the current ic shunted from the brushes and around the magnet cores, also the external circuit is thrown around these cores. These machines are designed especially for conditions in which the load is very variable, as street car work, in- candescent lighting and for commercial power purposes. 648. Classification of dynamos. — Dynamos may be classified according to their mechanical arrangement as follows : 1. Stationary field magnet with revolving armature. 2. Stationary armature with revolving field magnet. 3. Stationary armature and stationary field magnet with re- volving core. They may also be classified by mechanical designs as follows : 1. Direct-current machines. 2. Alternating-current machines. And by electrical arrangement as 3. Shunt-wound. 4. Series-wound. 5. Compound-wound. 649. Armatures. — The armature core introduced into the magnetic circuit to lielp lower the reluctance is also an electrical conductor, and when rotated in a magnetic field will have currents set up within itself. These cur- rents are independent of the external circuit, hence are 484 FARM MOTORS i FIG. 365 — BIPOLAR DIRECT-CURRENT DYNAMO a loss. They are known as eddy currents and the loss is termed eddy current loss. Fig. 366 shows a section of a solid armature and the direction of these currents. Not only do these currents create a loss themselves but they heat the armature windings and thus increase the armature resistance. If these large eddy currents can be broken up into smaller ones the loss will not be so great. To break up these eddies armatures are now generally built up of a large number of sheets of iron with insula- tion between the sheets. The insulation used for this ELECTRICAL MACHINERY 485 purpose is generally a coat of rust or a sheet of tissue paper. 650. Hysteresis. — Another source of loss in an arma- ture is due to the fact that every time the current alter- nates the polarity of the magnetism is reversed. If the armature is making 2,000 revolutions a minute and there are two alterations in each revolution there would be 4,000 alterations of the magnetism. This causes heat in the armature which is not accounted for in the external circuit, hence is a loss. Not onl}^ is there loss by heat in the armature, but the heat acts on the coils and in- creases the resistance in them and creates another loss. The loss in an armature due to these alterations of mag- netism and the heat produced thereby is known as hysteresis loss. 651. Insulation of an armature. — The insulation of an armature is probably the most essential part of a dynamo. After it is put on in the various places where it is needed it must be baked and all moisture evaporated out of it. After an arm.ature is thoroughly prepared for use it is generally tested for poor insulation. The potential dif- ference for the test is about eight times as much as the armature is expected to carry, if there is any place where the electricity breaks through the insulation it is detected by means of a sensitive galvanometer. 652. Capacity of dynamos. — It would seem that the amount of current that a dy- namo could produce might be indefinite if enough power be supplied. This is true in a certain sense, but there is a limit and this will appear in fiG. 366 one of the following ways : 486 FARM MOTORS 653. By poor regulation of voltage. — An overload will cause an excessive drop of the E.M.F. at the machine This will decrease the potential difference at the brushes and cause a weak current over the line. By excessive heating. — The heat from an armature increases four times for each doubling of the cur- rent. At this rate the armature would soon become red hot. It would work at a little less than red heat, but even this much heat would break down the insulation. The armature should not become warmer than 212° F., and the general custom is not to run it at a higher tem- perature than 70° above the surrounding air. 654. Commercial rating of dynamos. — Dynamos are rated according to the number of kilowatts they will carry" in the external circuit without excessive heating. For example, a person calls for a 60 K. W. iio-volt generator. This means that he desires a machine which will deliver 60 K. W. to the external circuit and maintain a potential difl'erence of no volts across the brushes. Owing to losses in the machine such a machine may develop 63 K. W. and still have only 60 K. W. available for use in the external circuit. 655. Efficiency of dynamos. — The efficiency of a dyna- mo is the ratio of its electrical output to the mechanical energy exerted upon it. For a i K. W. machine it is only about 50 per cent, and in generation of several thousand kilowatts it is about 95 per cent. 656. Sparking at the commutator. — Sparking at the commutator is the most serious trouble the attendant will have with a dynamo, provided he keeps all other parts clean, and the insulation does not break down or the machine become short-circuited. There are several causes for a dynamo to spark, some of which are : I, Brushes not set at neutral point. This can be remedied by 'ill |l ELECTRICAL MACHINERY 487 working the brushes back and forth until the proper position is located. 2. Brushes not spaced according to commutator bars. The com- mutator bars should be carefully counted and the brushes accurately set between them. 3. Brushes do not bear against commutator with sufficient pressure. 4. Brushes do not bear on the commutator with a perfect surface. 5. Collection of dirt and grease which prevents good contact of the brushes on the commutator. 6. A high or low commutator bar which causes poor contact. 7. Commutator not worn perfectly round, consequently poor con- tact with the brushes. 657. Repairing a dynamo. — If the insulation breaks down, a wire burns out or the commutator becomes worn out of round, an expert should be called in, and generally the defective part will have to be sent to the factory for repairs. Sometimes a good machinist can put the arma- ture in a metal lathe and turn it down round. A good man with a file can work down a high bar, and holding a piece of sandpaper on the commutator while it is in motion will clean it of all oil and dirt. MOTORS. 658. Comparison with a dynamo. — A dynamo is a ma- chine for converting mechanical energy into electrical. An electrical motor is just the reverse; it is a machine for converting electrical energy into mechanical. Any machine that can be used as a dynamo can when supplied with electrical power be used as a motor. Dynamos and motors are convertible machines ; thus the various dis- cussions will apply as well to the motor as to the dynamo. 659. Principles of the motor. — It has been shown that when a coil of wire is placed in a magnetic field and ro- tated an electrical current is produced. If the oppo- site of this is done, i.e., if a current is passed through the 488 FARM MOTORS I coil, the coil will tend to rotate. This is the principle of the electric motor: instead of taking a current off of the armature, one is put into it and at the same time sent through the fields. The current passing through the FIG. 367 — MULTIPOLAR MOTOR fields induces magnetism in them ; the lines of force pro- duced by this magnetism draw on the armature and cause it to revolve. By stud3nng Fig. 356 it will be noticed that the coil will revolve until the plane of the coil is parallel to the lines of force, and then stop. This same condition would take place in the motor if it were not for the commutator. Just at the instant the coil is brought to the position to stop, the commvitator changes the di- ELECTRICAL MACHINERY 489 rection of the current and the turning efifect is thrown to the other side and the armature moves on. Counter electromotive force of a motor. — The armature wires of a motor rotating in its own magnetic field cut the lines of force as if the motor were being driven as a dynamo, consequently there is an induced E.M.F. in them. The direction of this induced E.M.F, is op- posite to that of the applied pressure. Such an induced E.M.F. is known as counter electromotive force and is an important property of the motor. A motor without load will run with sufficient speed that its counter electro- motive force will very nearly equal the applied pressure. The counter E.M.F. will never be as great as the ap- plied force. There will always be a difiference between these, equal to the loss due to resistance in the motor armature. The power of a motor increases as the counter E.M.F. decreases until the counter E.M.F. is one-half of the applied E.M.F., then the power of the motor decreases. The maximum power of a motor is reached when the counter E.M.F, is one-half of the applied E.M.F. Losses of a motor. — The losses of a motor, like those of a dynamo, are due to resistance in the armature fric- tion, eddy currents and hysteresis. 660, Operating motors. — The resistance in the arma- ture of a motor is so low that if a motor were directly con- nected to the supply mains, too great a current would flow through it before a counter E.M.F. could .be set up, consequently the machine would be practically short-cir- cuited and the windings damaged. For this reason a rheostat known as a starting rheostat is inserted into the armature circuit of a shunt motor. To start the motor, switch A (Fig. 368) is closed, and this throws the cur- rent into the fields and excites them; then the arm is moved over the starting box to point one, and when 490 FARM MOTORS ^nnnr\ romnn STARTING RHEOSTAT OrNAMO MOTO FIG. 368— WIRING SYSTEM FOR DYNAMO AND MOTOR the motor has attained its speed for this point it is moved on up to point two, then three, and so on until the last point is reached and the motor is directly con- nected to the feed wire. To stop the motor, switch A should be opened, and if the arm B is not an automatic shifter, it should be thrown back to its original position ready for starting the next time. Most of these arms are now made so they work against a spring, and when the last point is reached an electromagnet attracts the arm sufficiently to hold it in position ; then when the circuit is broken the magnet loses its attraction for the arm, and the spring draws it back. 661. The electric arc. — When a current of from 6 to 10 amperes under a pressure of about 45 volts is passed through two rods of carbon with their ends first in con- tact, then gradually drawn apart to a distance of about 1/8 inch, a brilliant arc of flame is established between them. This arc, known as the electric arc, is made of a vapor of carbon. As the current passes across the con- tact points the high resistance produces enough heat to ELECTRICAL MACHINERY 491 ES FIG. 369 COMMERCIAL SWITCHBOARD disintegrate the carbon and cause it practically to boil ; this boiling throws off a vapor which is a conductor of electricity and as a consequence conducts the current across the gap. The temperature of the arc at its hottest point is about 3,500° C, which is about twice the tem- perature required to melt platinum, the most refractory of metals. Arc lamps are rated according to the watts consumed. They generally range from 6 X 45 = 270 watts to 10 X 45 = 450 watts. About 12 per cent of the energy supplied to an arc light really appears as light; the rest goes to produce the heat evolved. 1 492 FARM MOTORS Since the carbons of the arc lights are constantly wast- ing away there must be some device to regulate the dis- tance they are from each other and to work automatically to keep them at this distance. An ingenious appliance of electromagnets and clutches accomplishes this action and is explained in any book upon electric lighting. 662. Incandescent lamps. — It is on the principle of the heated wire that we get light from the in- candescent lamp. Referring to Fig. 370, connections are made with the lamp at A and B. At CC are bits of platinum wires attached to the carbonized filament D. E is the highly exhausted globe. If the car- bonized filament were in the air, the intense heat created within it due to the resistance of the current would immediately burn it up, but since it is in almost perfect vacuum, it will last from 600 to 800 hours. Even at the end of this period the filament does not always break, but it becomes so disinte- grated that the candle power is low and further use is not satisfactory. 663. Commercial rating of incandescent lamps. — Before a lamp is put upon the market it is compared with a lamp of known brilliancy. While it is being com- pared with the standard lamp, measurements of its voltage and current are made. After this is done the lamp is labeled with the voltage it carries, its candle power and watts consumption. A 16 C.P. 60-watt iio- volt lamp will require W FIG. 370 — INCAN- DESCENT LAMP ,55+ amperes. _ 160 E "~ no Lamps are usually made for circuits of 50 to 60 volts. no to 115 volts and 220 volts with constant potential. ELECTRICAL MACHINERY 493 A i6 C.P. lamp requiring 55 watts on a 50-volt circuit will take about one ampere; on a iio-volt circuit it will take 0.5 ampere ; on a 220-volt circuit about 0.25 ampere. A lamp should not be subjected to a voltage higher than its rating ; the filament is not made for it and will soon give out. The efficiency of a lamp is proportional to the ratio of the number of candles it will produce to the number of watts it absorbs. A high efficiency is 3 watts per candle power, and the average efficiency is 3.5 watts candle power. High-efficiency lamps are used where the pressure is very closely regulated or cost of power is high, and low- efficiency lamps are used where there is not such close regulation and power is less expensive. 664. Potential distribution in lamp circuits. — Incandes- cent lamps are usually operated from low-voltage con- stant-potential circuits. Where lamps are supplied with current from a street car circuit, which generally has a potential of 500 volts, they are grouped in multiple series ; i.e., 5 loo-volt lamps or 10 50-volt lamps will be connected across the mains. In a series circuit the drop on the lead wires does not interfere with the regulation of the vol- tage at the terminals, but in a parallel circuit this drop is an important factor and requires that the lamps be dis- tributed and the size of wire proportioned so that each lamp receives about the same voltage. For example, con- sider 100 220-volt lamps to be connected at distances along a pair of mains which extend 500 feet from a gen- erator which has a potential dift"erence of 225 volts at the brushes. The lamps nearest the dynamo will receive a greater potential than their rated capacity and will often burn out, while those farthest from the d3mamo will not receive potential equal to their capacity, hence will burn dimly. In order to overcome this, centers of distribution 494 FARM MOTORS are laid out in wiring construction and groups of lamps are fed from these centers Fig. 371. Feed wires are run from the generators to these centers and a constant po- tential is kept in them by regulation at the generator. Sets of mains are run from these centers, and then sub- mains are led off from these mains to supply subcenters of distribution. To these subcenters lead wires to the lamps are connected. In this system of wiring it does not matter if there is a fall of potential of 20 per cent, between lamps and genera- tors, for the fall is alike in all. For example, a voltmeter across the brushes of a generator shows 225 volts, one at the main center of distribution shows only 218 volts, one at the subcenters shows only 212 volts and one across the terminals of the lamp shows only 210 volts. But since there has been the same number of divisions and subdivis- ions the P.D. of all of the lamps is the same. 665. Calculations for incandescent wiring. — To find the size of wire for carrying a certain current, let C. M. := circular mil area of wire, K = 10.79 = resistance i mil foot of copper wire. L = length of circuit in feet, C = current in amperes, E = volts drop on the line. In the formula, CM -^ ^^ X L X C ^ 10.79 X L X C E ~ E After obtaining the circular mil area, this must be compared with a wire table to get the number of wire to use. Example. — Fifty 55-watt no-volt lamps are connected in parallel to a center of distribution located 100 feet from a dynamo which generates 112 P.D. By measurement the potential at the point of distribution is no volts. What size wire is required for the feeder? FIG. 371 — PARALLEL CIRCUIT WIRING ELECTRICAL MACHINERY 495 To find amperes to be conducted. ^ W 55 , C = ~=- = =0.5 per lamp. E no ^ 0.5 X 50 = 25 amperes for all lamps. 112—110 = 2 volts drop on line. „ . . KXLXC io.7qX(iooX 2)X 25 = E = ■ 2 ~ 26,975. C. M. = circular mil area. K = 10.79. L = 100 X 2 r- 200 feet. C = 25. By comparison with the wire table (670) the next larger size than 26.975 is B. & S. No. 5. Wiring calculations for a motor. — To find the size of wire to transmit any given horse power any distance when the voltage and efficiency are known. _ HP. X 746 X LX IP. 79 E X e X ^M ■ E = voltage required by motor, e = drop on line. H. P. ^ horse power of motor. % M = efficiency of motor in decimals. Example. — What size of wire is required to conduct current to a 220-volt 6 H.P. motor located 175 feet from the dynamo? The drop on the line is to be 6 volts and the efficiency of the motor 80 per cent : r M -HP- X 74 6 X L X 10.79 '-'^^■- ExeX^M 6 X 74O X 175 X 2 X 10.79 ~ 220 X 6 X -So = 15,984 C. M. = No. 8 B. & S. To find the current required by a motor when the horse power, efficiency and voltage are known. H. P. X 746 E X ^ M ■ Example. — What current is furnished to the motor in the previous problem? H. P. X 746- C = E X^M 6X 746 220 X .80' = 25.4 amperes. 496 FARM MOTORS INDUCTION COILS AND TRANSFORMERS 666. Self-induction. — Self-induction is defined as the cutting of a wire by the lines of force flowing through the wire. When a current begins to flow through a wire magnetic whirls spring outward from the wire and cut it. This cutting of the wire with only its own magnetic lines of force induces an E.M.F. for an instant. But the E.M.F. which it does induce has an opposite direction to the E.M.F. which causes the current to flow. Hence the E.M.F. will be retarded for an instant by its own induced E.M.F. and will not flow until this is overcome. When the current flowing through the wire is stopped the lines of force again cut the wire but in an opposite direction, hence this time they tend to retard the cessation of flow of the current. The effects of self-induction are rarely noticeable in a straight wire, but when the wire is wound into coils in the form of a helix the magnetic field of every turn cuts many adjacent turns and the E.M.F. is greatly increased, being proportional to the current, the number of turns and the magnetic lines through the coil. If an iron core is placed within the coil the effects of self-induction are very much greater. By snapping the wires from a battery after passing through such a coil as described above a brilliant spark will be produced. This is the simple coil (Fig. 372) used in make-and-break ignition on gasoline engines. 667. Induction coil. — If two coils entirely separate from each other be wound around an iron core and con- nected up as in Fig. 373 every time the current is started in coil a there will be a deflection of the galvanometer needle in b. If the current is broken in a the needle b will again be deflected, but in an opposite direction. From this it is seen that the magnetic lines of force which surround the wire in coil a induce a current in the coil h. ELECTRICAL MACHINERY 497 This is the principle of the induction coil, a diagram of the connections being shown in Fig. 374. The circuit leading from the batteries to the inside of the coil is known as the primary and the circuit wound on the out- '"mfp] r^f^RPi-^ HiH FIG. 372 FIG. 373 side of this is known as the secondary. The primary in- duces the current in the secondary, and if the secondary circuit has more turns of wire than the primary it will have a correspondingly greater E.M.F., in other words, the difference in E.IM.F. of the two circuits varies directly with the difference in the number of turns in the wire of the two. Since the induced E.M.F. is set up only as the current is made or broken, an automatic device A is connected into the pri- mary, whose action is iden- tical with the circuit break- er of an electric bell. In induction coils this, how- ever, is generally known as a buzzer. The induction coil is used with jump-spark igni- tion, on gasoline engines. For this work the spark requires such a high E.M.F. that the primary consists of only a few turns of coarse wire, while the sec- ondary consists of several thousand turns of fine wire. FIG. 374 — I'RINCIPLE OF THE INDUC- TION CFII. 498 FARM MOTORS 668. Transformers. — Where alternating currents are used for electric lighting, to make the cost of transmission a minimum a voltage of i,ioo to 2,200 or even higher is used ; this is far too high to be taken into houses and so a transformer is connected into the circuit. A transformer is identical with the induction coil with the automatic circuit breaker removed. A transformer, however, usually decreases the E.M.F. instead of increasing it. This is done by having the primary enter the coil on a large num- ber of turns and the secondary pass off on a few turns. Since the current is alternating in action, it takes the place of a circuit breaker. 669. Copper wire table. Gauge, A. VV. G. Diameter, Inches Area, Circular Weight Pounds per Length, Feet Ohms Resistance B. & S. Mils 1,000 Feet per Pound per 1000 Feet 0.3249 105,500 319-5 3-I3O . 09960 I 0.2893 83,690 253-3 3-947 0.1256 2 0.2576 66,370 200.9 4-977 0. 1584 3 0.2294 52,630 159-3 6.276 0.1997 4 . 2043 41,740 126.4 7-914 0.2518 5 O.1819 33JOO 100.2 9.980 0.3176 6 0.1620 26,250 79.46 12.58 . 4004 7 0.1443 20,820 63.02 15.87 0.5048 8 0.1285 16,510 49.98 20.01 0.6367 9 O.II44 13,090 39-63 25-23 0.8028 10 0. IOI9 10,380 31-43 31-82 I. 012 II . 09074 8,234 24-93 40. 12 1.276 12 0.08081 6,530 19.77 50.59 I. 610 13 0.07196 5,178 15.68 63-79 2.029 14 . 06408 4,107 12.43 80.44 2.559 15 0.05707 3,257 9.858 101.4 3.227 16 0.05082 2,583 7.818 127.9 4.070 CHAPTER XXIII THE FARM SHOP 670. Necessity. — There is no farm so small but a farm shop would be of value. For small farms there should not be m.any tools, but there is seldom a year when a small investment in a bench with a vise and a few tools would not return to the user a good dividend. It is not alone the amount of money which can be saved by doing a large per cent of one's own repairing, but it is the time saved in emergencies. Often breakages occur with farm machinery which, if the tools are at hand, may be repaired in much less time than is required to take the broken parts to a repair shop where the job must wait its turn with others equally urgent. There are times when farm work is very press- ing and a delay of a few hours means a loss of many dol- lars in wasted crops. Not only is there a loss by not having a shop for urgent repairs, but there are rainy and disagreeable days, when men do not relish working outside, that can very profit- ably be put in working in the shop. 671. Use. — The idea is prevalent that only skilled me- chanics can do work in a shop. Of course this is true in a great many instances where the work is difficult, but there are more times when the work is such that a man with only ordinary mechanical ability can do it. The farmer should not attempt to point plows, weld mowing machine pitmans and do such work until Jie has achieved skill. However, he can tighten horseshoes, re- pair castings, etc., as well as do carpentry work. =^oo FARM MOTORS 672. Location. — The location of the shop depends greatly upon circumstances and taste. If the shop is equipped with only a work bench and the tools which go with it, it can be built in the barn, or a part of the ma- chine shed be used. In fact a suitable place can be ar- ranged almost anywhere. To locate a shop with a forge in the equipment is a little more trouble. It should be a separate building and far enough away from the other buildings so that in case it should catch fire the other buildings could be saved. Should the owner of a farm shop be fortunate enough to I Bencn H Tool Cose h FIG. 375 — ARRANGEMENT OF A SMALL SHOP possess a gasoline engine or some similar source of power, the engine can very handily be placed in a room adjoining the shop and a shaft run one way into the shop and another way into the granary where the sheller and grinder may be located. 673. Construction. — That part of the shop floor about the forge and anvil should be of earth or concrete, and if concrete be used in this part it might as well be ex- tended over all the floor space. The material and design of the outside of the shop should conform to the style of the other buildings about the place. 674. Size. — The size of the shop should conform to the size of the farm and a man's ability as a mechanic. A small farm does not require as well equipped a shop as a large one. A farm close to town does not require as large *a shop as one several miles in the country. A man who is inclined to handle tools more or less will make very much more use of a shop than a man who will TIIK FAUM SHOP 501 Forgo Tool Case. V\5Q Bench ^- Outside Dirnensions 1 6-0 X (6-0 RaKes, forks ond other hand tools hang on Thi5 woU FIG. 376 — ARRANGEMENT OF A LARGE SHOP use it only when dire necessity requires, consequently the man who uses the shop frequently needs a larger one than the man who very seldom enters it. A shop with a floor space of 8 X 10 is large enough for a bench with a few hand tools and a small portable forge. If one desires to have his shop large enough so that a wagon can be nm in for repairs it should be about 16 X 16 feet. It might seem that this would be a waste of space, but that part of the shop where the wagons stand for repairs can be used for a wagon shed all the rest of the time. 502 FARM MOTORS 675. Equipment. — The following is a list of tools sug- gested for a farm of 160 to 320 acres. The cost of the wood tools is from $15 to $20, according to grade, and the cost of the forge tools from $25 to $35. The anvil re- ferred to in this list is cast iron with steel face ; if a wrought-iron anvil with a steel face be substituted for .! it an addition of about 5 cents for each pound weight *' should be added. LIST Wood Tools I rip saw, 5-point. I panel saw, lo-point. I 12-inch compass saw. I steel square. I 8-inch sliding tee bevel. I set bits. I each %-, 3/8-- H-< and i-inch socket firiner chisels. I 20-inch fore plane. I 8-inch smooth plane. I rachet brace, lo-inch sweep. I marking gauge. I 8-inch screw driver. I ^-inch socket firmer gouge. I 2 X I X 8-inch oil stone. I 8-inch try square. I i/^ X 15-inch bench screw. I pocket level. I drawing knife. I expansive bit. 14X6 lignum-vitse mallet. I pair 12-inch carpenter's pincers. Forge Tools I forge. I pair 20-inch straight-lipped blacksmith tongs. I 80-pound cast-iron anvil with steel face. I 1%-pound ball pein hammer. I bardie to fit anvil. I 12-pound steel sledge with handle. I 55-pound solid box vise. I Champion post drill. I set dies and taps. LITERATURE WHICH HAS BEEN CONSULTED IN THE PREPARATION OF "FARM MACHINERY AND FARM MOTORS" The Influence of Farm Machinery on Production and Labor. By N. W. Quaintance. 1904. Publication of the American Eco- nomic Association, Vol. V., No. 4. Theoretical Mechanics. By L. M. Hoskins. 1900. Stanford. Mechanics of Engineering. By I. P. Church. John Wiley & Sons, New York. General Physics. By C. S. Hastings and F. E. Beach. 1900. Ginn & Company, Boston. Text Book of the Mechanics of Materials. By Mansfield Merriman. 1901. John Wiley & Sons, New York. The Materials of Construction. By J. B. Johnson. 1903. John Wiley & Sons, New York. Experimental Engineering. By R. C. Carpenter. 1902. John Wiley & Sons, New York. The Book of Farm Implements and Machines. By James Slight and R. Scott Burn. 1858. William Blackwood & Sons, Edm- burgh. Bulletin No. 103, Evolution of Reaping Machines. By M. F. Miller. 1902. U. S. Department of Agriculture. Physics of Agriculture, Chapters XL, XVI., XX., XXII. and XXIII. By F. H. King. 1901. Madison. Farm Implements and Farm Machinery. By J. J. Thomas. 1869. Orange Judd Co., New York. Cyclopedia of American Agriculture, Vol. I., pp. 203-231, 387-398. 1907. Macmillan Co., New York. Farm Engineering. By John Scott. 1885. Crosby Lockwood & Co., London. The Fertility of the Land. By I. P. Roberts. 1904. The Macmillan Co., New York. Kent's Mechanical Engineers' Pocket-Book. By William Kent. 1906. John Wiley & Sons, New York. Architects' and Builders' Pocket-Book. By F. E. Kidder. 1905. John Wi ey & Sons, New York. Twelfth Census of the United States. Science of Threshing. By G. F. Conner. The Thresherman's Re- view, St. Joseph, Michigan. Bulletin No. 6, Trial of Sleds and Tillage Tools, and Bulletin No. 7. Draft of Mowing Machines. By J. W. Sanborn. Utah Experiment Station. Bulletin No. 39, Influence of Width of Tire on Draft of Wagons. By H. J. Waters. 1897. Bui etin No. 52, Influence of Height of Wheel on the Draft of Farm Wagons. By T. I. Mairs. 1901. Missouri Experiment Station. Bulletin No. 68, One Year's Work Done by a 16-Foot Geared Wind- 504 FARM MOTORS mill, and Bulletin No. 82, Experiments in Grinding with Small Steel Feed Mills. By F. H. King. 1898 and 1900. Wisconsin Experiment Station. Mechanics of Pumping Machinery. By Julius Weisbach and Gustav Herrmann. 1897. Macmillan Co., New York. Science of Successful Threshing. By Dingee and MacGregor. 1907. J. I. Case Threshing Machine Co., Racine, Wis. The Animal as a Machine and Prime Mover. By R. H. Thurston. 1894. John Wiley & Sons, New York. Haulage by Horses. By Thomas H. Brigg. 1893. Transactions of the American Society of Mechanical Engineers, Vol. XIV. The Windmill as a Prime Mover. By Alfred R. Wolff. 1900. John Wiley & Sons. Bulletin No. 59, The Homemade Windmills of Nebraska. By E. H. Barbour, Nebraska Experiment Station. Steam Boilers. By C. H. Peabody and E. F. Miller. 1902. John Wiley & Sons. Modern Steam Engineering. By Gardner D. Hiscox. 1907. The Norman W. Henley Publishing Co., New York. The Steam Boiler. By Stephen Roper, 1897. David McKay, Pub- lisher, Philadelphia. The Traction Engine Catechism. Compiled by the Thresherman's Review. 1906. St. Joseph, Mich. Instructions for Traction and Stationary Engineers. By William Boss. 1906. The Author, St. Anthony Park, Minn. The Traction Engine. By J. H. Maggard. 1902. David McKay, Publisher, Philadelphia. Rough and Tumble Engineering. By J. H. Maggard, Iowa City. Farm Engines and How to Run Them. By J. H. Stephenson. 1903. Frederick J. Drake & Co., Chicago. The Gas and Oil Engine. By Dugald Clerk. 1899. John Wiley & Sons, New York. The Gas Engine. By F. R. Hutton. John Wiley & Sons, New York. The Practical Gas and Gasoline Engineer. By E. W. Longanecker. 1903. The Acme, Publisher, Chicago. Bulletin No. 93, Comparative Values of Alcohol and Gasoline for Light and Power. By J. B. Davidson and M. L. King. 1907. Iowa Experiment Station. Bulletin No. 191, Tests of Internal Combustion Engines on Al- cohol Fuel. By C. E. Lucke and S. M. Woodward. 1907. U. S. Department of Agriculture. Dynamo Electric Machinery. By Samuel She'don. 1902. D. Van Nostrand Co., New York. Lessons in Practical Electricity. By C. Walton Swoope. Fourth Edition. D. Van Nostrand Co., New York. First Course in Physics. By R. A. Millikan and H. G. Gale. Ginn & Co., New York. Elementary Lessons in Electricity and Magnetism. By Silvanus Thompson. The Macmillan Co., New York. Steam Engine Theory and Practice. By William Ripper. 1899. Longmans, Green & Co., New York. INDEX PAGE Absorption dynamometers 18 Action of valves 430 Adjusting the walking plow 75 sulky plow 75 Advantage, giving one horse the. 14 of the gasoline engine as a farm motor 432 Agricultural engineering — defini- tion 9 Air cooled, the 420 Air for combustion 347 Alcohol 434-435 Alfalfa harrow 85 Alfalfa mills 237 Alternator, magneto 478 multipolar 478 Ammeter 465 Amperes 27 Anchor posts 313 Angle of advance 372 Angularity of connecting rod. ... 38 J Animal as a motor, the 281 Animals other than horse or mule used for power 286 Anthracite coal 347 Arc. electric 490 Armature 476483 insulation of 485 Arrester, spark 339 Artificial magnets 460 Attaching indicator to engines. . . 383 Attachments, threshing machine.. 214 self feed and band cutter 214 stackers 215 weighers 216 wind stackers or blowers 215 Attraction and repulsion, laws of electrical 462 Automatic cut-off governor 389 Bag in a boiler 360 Balanced valve 373 Baling presses 187 box presses 188 development 187 horse power presses 188 power presses 189 Banking the fire 355 Bar share 56 Barn tools 181 Base 407 Batteries 419 connection 419 Battle-ax mills 299 Bean and pea threshers 218 Bearings . . .40, 398 PAGE Bearing surface at wing of share. 70 Bell, electric 473 Belting 28 canvas 30 care of leather 29 ■ dressing 29 lacing of 30 leather 29 link 31 Best conditions for work 293 Bevel gears 37 Binders 143 draft of 153 Bituminous or soft coals 348 Blister 360 Blow-off pipe 338 Blower and exhaust nozzle 328 Blue heat 342 Boilers, bag in 360 capacity 339 classification 318 cleaning 358 compounds 359 direct flue 329 externally fired 319 horse power 340 internally fired 320 laying up 360 locomotive type 321 open bottom type 324 principle 317 return flue 324 round bottom type 324 steam 317 strength of 342 vertical 318 Boiler shell, strength of 344 Boiling point 365 Bolts, stay 343 Bottom, plow 59 types of 63 Boxes, heating of 41 enclosed wheel 65 Bridges 455 British thermal unit 26 Brushes 477 Buggies and carriages 252 selection 252 Burners, wood and cob 326 straw 328 Burr 46 Cable transmission 34 Calculations for incandescent wir- ing 494 Canvas belting 30 5o6 INDEX PAGE Capacity 286 boiler 339 dynamos 485 of the horse 292 Carburetion 430 Carburetors 414 constant level 415 float feed 416 Care of gasoline engines 427 Cassady, W. R 56 Cast iron 44, 343 Cells 470 dry 471 Center, dead 374 Centrifugal pumps 269 Changes, physical and mental.... 3 Chilled iron 44 plow 65 Classification of dynamos 483 of steam engines 364 of windmills 303 Cleaning the fire 355 the boiler 358 the flues 359 Clover hullers 219 Clutch 448 Coal, bituminous or soft 348 anthracite 347 semi-anthracite 348 Coefficient of friction 39 Coils, magnetic properties of 472 induction 496 Columns, water 334 Combustion 348 air for 349 heat of 349 volume of air for 350 Commercial rating of dynamos. .. 486 incandescent lamps 492 steam engines 394 Commutators 479 principle of 479 Comparative resistance 467 Comparison of the drum and ring armature 480 motor with dynamo 487 Compensating gears 451 Compound, boiler 359 engine 392 wound dynamos 483 Compression 428 Connecting rod 410 angularity of 381 Connections, series 469 parallel 469 Constant level carburetors 415 Construction 407 Cooling of gasoline engines 420 Copper wire table 498 Corn crushers 238 Corn drills. 132 Corn harvesting machinery 155 sled harvesters 157 types of 158 Corn machinery 221 feed and ensilage cutters 221 PACE Corn machinery, development 221 buskers and shredders 224 Corn shellers 227 development 227 types of modern 227 Corn planters 120 calibration of 131 development 120 development of check rower... 120 draft of 131 hand planters 121 the modern planter 122 Corrosion 357 Cost of production 5 Coulter 57 Cracks 360 Crank shaft 410 Cultivators 91 classification 91 development 91 features of, with suggestions in regard to selection 92 listed corn 99 one-horse 91 seats 93 hammock 93 straddle 93 single and double shovel 91 wheels 96 pivotal 97 boxes 96 Current electricity 464 Currents induced in a coil by a magnet 474 rotating coil 475 Cylinder 408 head 408 Davenport, F. S 56 Dead center 374 locating 375 Deere, John 55 Density of charge varies with form of surface 462 Development, muscular 285 of the present-day windmill.... 298 Die for cutting threads 16 Differential pulley 16 Direct flue boilers 329 current dynamo 479 ring armature 480 drum armature 480 comparison 480 Direct-reading dynamometer 20 Direction of trace 289 Disk harrows 83 cutaway 84 orchard 85 plow cut 87 tongueless 87 Disk plow 66 Division of work 294 Double-cylinder engine 391 Double-eccentric reverse 378 Double-riveted lap joint 346 Double-ported valves 373 INDEX 507 PAGE Draft of plows 73 Draft, line of least 291 Drawing tlie fire 356 Drills no classification of 110 construction 118 disk 112 draft of 118 the hoe no the shoe 1 1 1 Drum armature direct-current dynamos 480 Dry cells 47 ' Dynamometers 18 absorption 18 direct-reading 20 Giddings 2i self-recording 20 traction 19 transmission 19 Dynamos 476 armature 477 brushes 477 capacity of 485 classification of 483 commercial rating 486 compound-wound 483 direct-current 479 efficiency of 486 multipolar alternator 478 repairing a 487 self-exciting, principle of 481 series 482 shunt 482 simple alternating-current 476 Early forms 361 Early history 298 Eccentric 372 Economic considerations of wind- mills 314 Effect of increase of speed 294 Effect of length of working day. 294 P^ffectual tension on belt 28 Efficiency of dynamos 486 of a lamp 493 of a machine 12 thermal 26 of a wind wheel 307 Ejector, siphon or 330 Electric bell 473 Electric current, heating effect of 471 Electrical energy 26 power 466 transmission 42 Electricity 462 current 464 static 462 Electromagnet 472 Electromagnetic induction 472 Electromotive force 4^6 End-gate seeder 105 Energy 28 1 kinetic 282 law of transformation of 282 potential 282 sources of 28 ( PAGE Engines, internal combustion 401 gasoline traction 401 mounting 446 steam 361 traction 43^ Erecting mills 3^3 Eveners 14 two-horse 13 E,\haust 430 nozzle and blower 338 Expansion of steam 367 work done during 368 Externally fired boilers 319 Factor of safety 49 Factor upon which the value of induced E.M.I", depends... 475 Farm machinery, value and care of 275 Farm shop, construction 500 equipment 575 location 500 necessity 499 size 500 use 499 Feed and silage cutters 221 development 221 Feed mills 234 development 234 power mills 235 alfalfa mills 237 capacity of feed mills 237 corn crushers 238 sacking elevators 236 the selection of a 236 Feed pipe 353 Feed pumps 452 Feed water heaters 334 forks 18 hay stackers 179 sweep rakes 178 Fire, banking the 355 drawing the 35^ Firing 354 with soft coal 354 Float-feed carburetors 416 Flues, the 35' cleaning the 3 5'> Flywheels 410 Foaming 35 > Force 10 electromotive 4^'> magnetic lines of 4 o Force pumps 2^5 double pipe or underground.... 2 -, Forks if"' Forms of motors 29 ? Four-cycle engines 4' ' strokes of . 40? Frame mounting 44 '> Friction mounting 38 coefficient of 39 rolling 39 Frog 5; Fuels 347 value of 348 purley, M 56 5o8 INDEX I PAGE Fuse 471 Fusible plug 335, 336, 337 Future of the gasoline engine.... 434 Gasoline engines, care 427 construction 407 cooling 420 four-cycle 402 future of 434 indicator diagram 423 losses in 424 lubrication 427 parts 403 setting 431 strokes of 403 testing 426 troubles 428 action of valves 430 carburetion 430 compression 428 ignition 429 two-cycle 404 types of 402 wiring 419 Gauge, steam 335, 336, 337, 352 Gearing 37, 307 transmission 449 Gears, reversing 378 compensating 451 Generation of steam 365 Giddings's dynamometer 23 Glass, water 353 Goldswait. E 56 Governors 385 automatic cut-off 389 Corliss 391 hit-or-miss type 411 racing 388 throttling 386, 41 1 Grate surface, power by 341 Gray iron 44 Grip 288 Guiding an engine 454 Gutters. 455 Hammer test 346 Handholes 351 Handling a boiler 351 Hand methods change to modern metliods I Hand planters 121 Hand seeder 104 Handy wagons 251 Harrows, classification 82 curved knife tooth 78 development 79 disk 83 orchard disk 85 smoothing 78 spading 84 spring tooth 81 Harrow cart 82 Harvesting machinery 136 combined harvester and thresher 154 development 138, 139 modern harvester or binder. . . . 143 draft of binders 153 Haying machinery , , 1 62 Haying machinery, baling presses 187 box presses 188 development 187 horse-power presses 188 power presses 1 89 barn tools 181 development 181 field stacking, machines for. ... 178 forks 181 hay stackers 179 sweep rakes 178 hay loader 176 development 176 endless apron 177 fork loader 177 the mower 162 rakes 171 hay tedders 1 74 Heat 26 of combustion 349 latent 366 of the liquid 366 Heaters, feed water 334 Heating effect of an electric cur- rent 471 Heating of boxes 41 Heating surface, power by 341 Heel plate 70 Height and length 289 Hillside plow 65 Hit-or-miss governors 411 Hock, width of 291 Hoe drill no Home-made windmills 299 battle-ax windmills 299 Holland mills 299 Jumbos 299 merry-go-rounds 299 mock turbines 299 reconstructed turbines 299 Hooking up an engine 378 Horse, the 287 at work 291 capacity of 292 grip 288 height 289 length 289 maximum power of 293 resistance he can overcome. . . . 288 weight 288 Horse power 466 brake 25 definition of 11 indicated 25, 425 of belting 28 of shafting 38 of steam engines 394 Horse power presses 188 Howard, P. P 52 Hot tube ignitor 417 How the wind may be utilized. . . 315 Huskers and shredders 224 Hydraulic test 346 Hysteresis 485 Ignition 429 Ignitors 417 INDEX 509 \ PAGE Igniters, contact spark 417 jump spark 418 Incandescent lamps 492 Inclined plane 15 Increase in production 2 Increase in wages 3 Incrustation 357 Indicated horse power 425 Indicator, steam and gas engine.. 24 cards 25 Indicator diagram 382, 423 from a tlirottling-governed en- gine 388 reading an 384 to read for pressures 385 Induction coil 496 Injector, the 332 Insi^"\' .'?• •0- , -^y v-^ OO' .0 o t^ ' .-' ^■'vO?-' .0- / c- -../ *1^ ,,?' %. / %'^-' ■> ^p ' ■"^.-. v^' ' ^ " " . ■ ^ nO°.. v>0 .0^ O V 00 S 1