54 SCIENCE OF THRESHING. 



is all the better, as the upper part of the movement 

 will do the throwing and agitating, while the slow 

 part of the stroke will allow the sieve time to come to 

 rest for an instant, thereby permitting the kernels to 

 fall through. 



The boxes and connections that operate the shoe 

 should be kept in good order and not permitted to 

 work loose, as the lost motion causes a pounding that 

 jars the sieve, which springs and trembles; this 

 impedes the passage of the grain. 



