418 THE SMALL GRAINS 



Also, of the many instances of thrashing-machine explo- 

 sions in recent years, a very small percentage has occurred 

 in combined machines. 



On the other hand, it is maintained by the millers that 

 the quality of wheat is impaired by the delay in harvest- 

 ing caused by the use of the combined machine. Weed 

 seeds are also distributed by this machine. 



The percentage of nitrogen in the wheat kernel increases 

 as the length of the fruiting period decreases (see Thatcher, 

 1913, pp. 42-46). Therefore, grain cut by the binder, and 

 slightly under ripe, should have a higher percentage of 

 nitrogen than grain cut and thrashed by the combined 

 machine. The latter method may, however, give a better 

 yield by weight. Stewart (1915) also investigated this 

 subject and concluded that grain in Utah is not injured 

 by harvesting with the combined machine. In determin- 

 ing the change in weight of thrashed grain during storage, 

 Harris and Thomas (1914, p. 310) found that this process 

 was not affected by any method of harvesting or thrashing. 



444. The treatment of the grain after harvesting or 

 thrashing is very simple. Shocking or stacking (362, 

 363, 400, 401) requires little or no care to prevent spoiling 

 from moisture in this area of summer drought, unless the 

 thrashing be done very late. Stacks should be protected 

 from fires by plowing around them. For similar reasons, 

 the thrashed grain requires no attention the remainder of 

 the summer. The bags are piled in long ricks out doors, 

 often in the field. 



445. Thrashing. In the main, the discussion of this 

 subject here would add nothing to what is given in other 

 chapters (364, 402). One serious condition, however, 

 must be mentioned, rarely encountered in the other 

 areas. It is the occurrence of thrashing-machine fires, 



