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, 



60,000 

 long arm of evener = = 22 2/9 inches, 



short arm of evener = 40 22 2/9 = 17 7/9. 



That is, to divide the draft proportionately to the weights of tht 

 horses, the center hole must be placed 22/9 inches from the center 

 toward the end upon which the heavy horse is to pull. 



FIG. 200 TREAD POWER FOR THREE HORSES 



418. The tread power. The tread power consists in 

 an endless inclined plane or apron carried over rollers 



