50 SCIENCE OF THRESHING. 



at the rear of the machine to return the unbroken 

 balls through the tailings elevator. 



In threshing barley, plenty of concave teeth and a 

 high cylinder speed break off or "nub" the beard 

 effectually. 



The grate, as before indicated, which lies back of 

 the cylinder, should have its rear edge raised so that 

 the straw and grain, as it comes from the cylinder, 

 should strike its face at a slight angle. This keeps it 

 clean and prevents it from loading up with thick or 

 brittle straw. 



The beater should be in a position for the straw 

 and grain, as it comes from the cylinder, to pass it 

 without changing its course too much; that is, it 

 should be so adjusted that the straw will not strike it 

 near its center, as the straw would then have to 

 change its course to pass around it. 



If the beater is arranged to allow the straw to pass 

 under it, the wings of the beater or beater boards 

 should have just sufficient contact with the straw to 

 keep it moving. 



In the scheme of separation, the first essential 

 feature is to have the threshing members deliver the 

 straw to the separating devices with the kernels all 

 threshed from the heads and the straw unbroken. 

 Whole straw will not pack as closely and hold the 

 kernels in consequence as does broken or cut straw. 

 Stalks that are heavily loaded with leaves form a com- 

 pact, homogeneous mass which retains the kernels, 

 and are consequently hard to separate. 



Oats are frequently hard to separate. In some 



