24 CIRCULAR NO. 119, BUREAU OF PLANT INDUSTRY. 



to the axis. The matting is secured by tacks and staples and can 

 easily be replaced when worn. The cylinder of the machine shown 

 in figure 1 is 8 inches in diameter and 12 inches long. This will 

 serve to give the approximate dimensions of the apparatus. 



An essential feature of the machine is the adjustable apron of 

 rough canvas or similar material having an abrading surface. The 

 apron is held against the cylinder by springs, the tension of which 

 can be regulated by means of the wing nuts at the top of the machine. 

 As the grain is fed into the machine the compression of these springs 

 affords the necessary clearance between the cylinder and the apron. 



A second convenient feature of the machine is the ease with which 

 it can be cleaned. By pressing down on the upper crossbar, the rod 

 supporting the lower end of the apron will slip out from between the 

 guides, thus completely exposing both apron and cylinder to view. 



[Ch\ 119] 



