26 SCIENCE OF THRESHING. 



within certain limits, the better will be the results. 



All the separating devices in use are for this 

 purpose of thoroughly agitating the straw and 

 thereby allowing the kernels to fall. This causes a 

 limit to the quantity of straw which any machine can 

 handle, as time must be given for the dislodging and 

 falling of the grain. If the layer of straw travels 

 too fast, the grain is carried along with it. If it 

 moves too slowly, the size of the column will be 

 correspondingly increased. If the straw be damp and 

 pliable, it will form a more compact mass than if dry 

 and elastic. Some kinds of grain have more leaves 

 than other kinds and these mat down closely. 

 Separation is retarded by these conditions, and the 

 feed should be varied in speed to suit them, so that 

 the straw will have a chance to open up and allow the 

 grain to w r ork down through the interstices and fall 

 out of the layer onto the grain rack before the straw 

 reaches the rear of the machine. The intelligent 

 thresher will bear these matters in mind and not 

 crowd his machine beyond its proper capacity, as the 

 result will be unsatisfactory. 



However, any of the separating devices in use will 

 handle very large quantities of grain and straw when 

 operated intelligently, and the aim should be to gain 

 the best results in both quantity and quality of work 

 done. 



Having thus noted the requirements to be met in 

 adjusting and managing the separating mechanism, 

 the different types can be intelligently explained. 



