302 THE WHEAT CTJLTURIST. 



not knowing that the large kernels were all on the sur- 

 face. The screens are so constructed that they have 

 almost the smoothness of glass, and are made by press- 

 ing common wire screens, rendering the meshes im- 

 movable and always accurate, increasing their durabil- 

 ity, giving them the character of glazed muslin, and 

 allowing the seed to slide over them, when slightly in- 

 clined from a level. The latter quality gives them their 

 preeminent advantage. The seed never falls directly 

 upon them, but first upon a smooth surface, flat with 

 the screen, in passing over which and to the screen, 

 every oblong grain has assumed a horizontal position. 

 If longer than the meshes, it goes over them ; if shorter, 

 it drops through. Such a mixture, therefore, as spring 

 wheat and oats, often so troublesome to the farmer, is 

 perfectly separated. Even barley and spring wheat are 

 separated, the barley grains being slightly longer, and 

 enough lighter to be driven more by the current of wind. 

 Wheat is cleaned from chess in a complete manner. J. 

 J. Thomas says, " For cleaning grass seed, we have never 

 witnessed anything that would compare with this fan. 

 A mixture of clover and timothy was run through once 

 together ; in one drawer was found entirely pure timothy 

 seed, and in another, clover without a single grain of 

 timothy ; the intermediate drawer had a very small quan- 

 tity of imperfect seeds of clover, a very little timothy, 

 and some other seeds of weeds. 



" The current of wind is so completely at command, 

 that all degrees of strength, from the imperceptible breeze 

 to the blast that sweeps away heavy grain, may be readily 

 given. This peculiarity, in connection with the screens, 

 enables the operator to separate any seeds whatever, that 

 differ either in shape, size, or weight. 



