THE CYLINDER, CONCAVES AND BEATER 163 



The Beater. In threshing very heavy, tough grain, 

 if the straw be inclined to wrap the beater or if it tends 

 to follow the cylinder around too far, the beater may be 

 raised by taking out the blocks from between the beater 

 boxes and the girt to which they are fastened on wood sep- 

 arators or by moving the girts to the upper holes on steel 

 machines. There is also provision in the girts for moving 

 the beater back to give more room between beater and 

 cross-piece, but it is very seldom necessary to move it. The 

 speed of the beater is four hundred revolutions per minute 

 and as its bearings are provided with hard-oil cups, a little 

 attention will keep them in good running order. 



The Grates. A large percentage of the grain is sep- 

 arated from the straw by the grates through which it is 

 thrown with all the force acquired from the cylinder. The 

 grate under the beater is adjustable and should usually be 

 kept as high as possible for the separation is better when it 

 is high. It should never be lowered unless absolutely 

 necessary. 



The Check Board should usually be kept quite low to 

 prevent the grain from being thrown to the rear of the ma- 

 chine on top of the straw, where it might be carried out 

 of the machine without being separated. In damp grain 

 and especially damp rye or oats the check board should be 

 raised to allow the straw to pass freely through the ma- 

 chine, for if left down, it will retard the straw too much, 

 and may cause the cylinder to wind. 



