24 SCIENCE OF THRESHING. 



or under it. It serves as a check to the flying kernels 

 from the cylinder. However, it is not of much 

 benefit as a separating device as its rapid motion 

 tends to carry the grain along and throw a portion of 

 it on top of the moving straw. Consequently, it 

 should be run just fast enough to prevent its catching 

 or winding damp or soft straw, its position being 

 chosen at the proper distance from the cylinder. 



Other devices are used instead of the beater to pass 

 the straw back from the cylinder. One form 

 resembling somewhat the cylinder, comprises a drum 

 set with teeth. Some machines work very well 

 without a beater, the cylinder delivering the straw 

 directly to the separating device. 



THE CHECK BOARD. 



The check board is hung directly behind the beater 

 to arrest flying kernels. It is a sheet iron apron 

 hinged by its upper edge to the separator frame, 

 while its lower edge trails on the top of the stream of 

 moving straw. It should be so adjusted as to prevent 

 any grain passing it and lodging in that part of the 

 straw as it is going through the separator. It also 

 acts as a compressor on the straw, tending to reduce 

 it from the loose, fluffy condition in which it leaves 

 the beater to a more compact layer. 



The check board has an important part in the 

 proper action of the separating devices, and its 

 proper adjustment should be carefully studied. 



THE SEPARATING DEVICES 

 The part of the machine which is of equal import- 



