l88 SCIENCE OF SUCCESSFUL THRESHING 



and one-quarter-inch lip, E, should be used as a chaffer 

 and the three-eighths-inch lip-sieve, G, in the second notch 

 and fourth hole as a shoe-sieve. Any of the screens men- 

 tioned for wheat are suitable for barley. 



Threshing Flax. The thresherman should devote 

 some study to the peculiarities of flax if he wishes to do 

 a nice job of threshing. Operators of some makes of 

 separators have great difficulty in threshing flax on ac- 

 count of the straw being composed of tow or tough fibres, 

 and therefore having great tendency to wind on every 

 revolving thing it encounters. The "Case" separator, 

 having no rotary parts on which flax straw can wind, has 

 always had an advantage in this respect. Flax is usually 

 unbound, and on separators equipped with feeders, the 

 pitchers are apt to throw it upon the feeder-carrier in large 

 forkfuls. The straw, on the contrary, should be fed even- 

 ly to the cylinder, for if allowed to pass into the machine 

 in large bunches, it is liable to "slug" the motion down 

 and prevent all parts of the separator from doing good 

 work. When green or damp, it requires close work on 

 the part of the cylinder and concave teeth to get the seed 

 out of the bolls. Usually six rows of concave teeth are 

 required, and the speed must be kept fully up to the 750 

 for the twenty-bar or 1075 f r tne twelve-bar, but when 

 dry and in good condition, it is best to run the cylinder at 

 a little less than its normal speed to favor the shoe. Some 

 very good samples of cleaned flax have been taken from 



