190 



MECHANICS. 



Fisf. 214. 



This rule will not, however, apply, when the draught 

 of the horse is added to its weight; for it usually happens 

 that the weight alone is not sufficient, without placing the 

 platform in too steep a position for the horse to work 

 comfortably. He is, therefore, attached to a whiffle-tree, 

 and to ascertain the joower requires the use of the dyna- 

 mometer, in connection with the preceding mode. 



Great improvement has been made of late years in 



the appendages of 

 thrashing machines. 

 The large number 

 of laborers formerly 

 employed in raking 

 and separating the 

 straw, and placing it 

 on the stack, is now 

 dispensed with, and 

 the whole done by 

 machinery, working 

 by the same power 

 that drives the 

 thrasher. Among the best and most widely known ma- 

 chinery for this purpose is that invented by H. A. Pitts, 

 and represented in a portable form by fig. 214. It sepa- 

 rates the grain, cleans it, and carries the straw by means 

 of the elevator, (shown folded in the cut,) to the top of 

 the highest stack. 



The tread-jiower is successfully applied to churning, as 

 chown in the cut, (fig. 215.) The employment of a sheep, 

 of one of the larger breeds, has been found better and 

 more convenient than a dog, as it is heavier, more quiet, 

 less averse to the labor, and when the task is done, it is 

 turned into the yard or pasture, where it is readily found 

 next time. 



The cost of horse-powers and thrashers combined, of 

 the different forms, varies from 8225 to 8400. 



Pitts' Thrasher and Straw Carrier. 



