48 SCIENCE OF THRESHING. 



hot, others cold. There may be a hard wind blowing 

 or there may be none. All these various conditions 

 affect the machine, each in a peculiar way. The 

 operator is expected to save every kernel, perfectly 

 cleaned, and do many other things equally well nigh 

 impossible, notwithstanding these varied conditions. 

 The man who best understands the machine and its 

 workings will come the nearest to perfection in 

 managing it. 



As before stated, the cylinder is a vital part and 

 should receive special attention and be kept in good 

 condition. If it is out of balance appreciably, it 

 should be taken from the machine and set on the 

 straight edges, as explained before, and restored to 

 balance by inserting counterbalancing weights in the 

 light side. The boxes should not run too tight, as 

 the extra friction consumes a large amount of power. 



The teeth should not be allowed to become so 

 worn and rounded as not to draw the straw into the 

 machine freely. By replacing the worn by new teeth, 

 evenly distributed around the cylinder, the straw will 

 be readily pulled in and the grain threshed clean. 

 Care should be taken to keep the teeth properly 

 spaced; any bent ones may be trued up with the 

 tooth straightener, or by the use of a heavy hammer. 



The cracking of grain is usually caused by one or 

 more cylinder teeth running so close to the concave 

 bottom, or teeth, as not to permit a whole kernel of 

 grain to pass ; the resultant wedging cracks or breaks 

 the grain. Another cause is the repeated passing of 



