PRINCIPLE OP THE THRESHING-MACHINE. 



219 



made in certain respects, vet in its essential principles, 

 the invention of Meikle has been followed and adopted 

 up to the present day. It is pleasing to learn that the 

 inventor of this important machine was rendered com- 

 fortable in his old age, and enabled to provide for his 

 family, by the voluntary donations of his grateful coun- 

 trymen. Numerous patents have since been taken out, 

 for inventions and improvements, by which this machine 

 has been brought to gi'eat perfection. 



The following wood-cut will make the principle of the 

 threshing-machine quite clear. At A are fluted iron 



rollers between which the uuthreshed corn passes, at 

 rather a slow rate ; B is the cylinder or drum, contain- 

 ing four projections or beaters. These are bars of wood 

 covered with iron, and revolve rapidly. Grain, chaff, and 

 stems, all pass over this cylinder, and are thrown for- 

 ward into the second compartment, where they are acted 

 upon and shaken by four rakes, placed on the hollow 

 cylinder C, and moving rapidly in the direction of 

 the arrow. Here the grain and chaff fall down through 

 the wire meshes into a winnowing-machine, and the 

 straw is carried forward to another cylinder, D, where it 

 is again shaken by rakes, and then thrown out at the 



