202 SCIENCE OF SUCCESSFUL THRESHING 



wind is required, and if the grass be reasonably free from 

 weeds, the lower blinds may be entirely closed and the 

 upper ones opened a little. 



If the grass be damp or dirty, slightly open the lower 

 ones also. From twelve-hundred to fifteen-hundred bushels 

 of orchard-grass have been threshed in a day with a me- 

 dium-sized machine. 



Threshing Brome Grass. This seed can be successfully 

 threshed in the "Case" machine, although it is consider- 

 ably lighter than even orchard grass. In general, the direc- 

 tions for threshing orchard-grass should be followed, but 

 a coarser sieve is necessary. The one-sixth by three- 

 fourths mesh wire, W, is a suitable size. It will be found 

 that the fan blinds must be kept well closed in some cases, 

 it being even necessary to close the opening more than is 

 done by the blinds, as for red-top grass. 



Threshing Red-Top Grass. When threshing red-top 

 grass that is in good condition, the cylinder speed may be 

 considerably below normal, and one filled concave (two 

 rows) usually is sufficient. Should the grass be damp, it 

 may be necessary to use more than two rows of teeth in 

 the concaves and to run the cylinder at normal speed, 1 175 

 r. p. m. for 12-bar and 750 r. p. m. for 2O-bar separators. 



Special attention must be paid to the cleaning apparatus 

 if good results are to be obtained. Set the conveyor-sieve 

 only slightly open, and the conveyor-extension open enough 

 to save what unthreshed seed may pass over the conveyor 

 sieve. The adjustable shoe-sieve should be set in first notch 



