FARM POWER AND MACHINERY 



Farm Motors. 



The sources of energy which are The horse, the steam engine and the 

 used on the farm to drive machinery oil engine each derives its power from 

 are: — (1) animal motors, (2) wind the chemical action of the fuel con- 

 motors, (3) water motors, (4) steam sumed or food eaten, and may there- 

 motors, (5) oil motors, (6) gas mo- fore be called chemical engines; the 

 tors, (7) electric motors. windmill and the water wheel get 



All these motors are machines de- their power by arresting the motion 



signed to utilize the energy of: (1) of wind or water, actuated by the 



chemical action, (2) moving air, (3) force of gravity, and these may be 



running water, (4) and electricity, called gravitation engines. 



The Pull of a Horse. 



It Is estimated that a horse can Pull Required to Move 2000 Lbs. 



pull with a force equal to one-tenth (Load and Wagon). 



of its weight when it Is working ten Pull, Pull, 



hours a day and is moving a load at Kind of 6-in. l^^-in. 



the rate of 2 1-2 miles an hour. For ^.5°^^' , Ji''?^ , H^lw 



.... _». ,, Dirt 100 lbs. 125 lbs. 



example, a horse weighing 1.500 lbs. ^.^.^^^j g4 ^^^ 105 lbs. 



could pull with a force of 150 lbs. Macadam .... 60 lbs. 75 lbs. 



ten hours a day, moving a load at Sod 170 lbs. 255 lbs. 



the rate of 2 1-2 miles an hour. For Plowed 



_ . , . , . Ground . . . 250 lbs. 375 los. 



five or ten minutes a horse can exert 



a force equal to half its weight. It will be noticed that with narrow 



_, . . , , , . tires the pull was greater in each 



Experiments have been made to ^^^^ ^^^^ ^^^^ ^^^ ^j^^ ^j^^^ ^^ 



find the pull required to move a leam from this table: (1) about how 



wagon on different roads. The total large a load can be reasonably, asked 



weight (load and wagon) was 2,000 a horse to haul, and keep it up all 



,, _,, 11 J X day; (2) that the better the road 



lbs. The wagon was pulled at a ^^^ j^^^^^ ^j^^ 1^^^ ^ ^^^^^ ^^^ ^^^^, 



walking pace, about 2 1-2 miles an (3) that with wide tires on a wagon 



hour. The pull was found by means a horse can haul a greater load than 



of a self recording dsmamo-meter. when narrow tires are used. It can 



The wagon was used first with 6-inch ^^"^ one-fourth more, on the aver- 



age, on dirt, gravel and macadam 



tires and then with 1 1-2-inch tires. roads, and half more, on the average. 



The average results were as follows: on sod and plowed ground. 



Units. 



Force is that which causes or tends pounds of work are done, no matter 

 to cause a change of motion in a how long it takes. If a belt Is pull- 

 body. This change may be in the ing 100 pounds and running 1,000 

 velocity in the direction of motion. feet per minute. It does 100,000 foot- 

 In Europe it is measured In kilo- pounds of work each minute, 

 grams, in this country usually in Power Is the rate at which work is 

 pounds. done. It is the amount of work done 



Work is defined as "Force multi- each minute or each second. It is 



plied by the distance through which often expressed in "foot-pounds per 



it acts." That is, if a weight of five minute," "horse-power," "watts." or 



pounds Is lifted 3 feet. 15 foot- "kilowatts." 



