SCIENCE OF THRESHING. 3! 



jerk and have a tendency to tear the mass or layer of 

 straw apart. The greater part of the separation is 

 done at this point where the straw falls on the raddle. 

 The operation seems to be more effective if the straw 

 is permitted to fall a little distance before it strikes 

 the raddle. The impetus of the falling straw added 

 to the force of the blow given while the direction 

 which the straw takes is changed, also aids in the 

 separation; if the straw is moving in the same direc- 

 tion as the raddle when it comes in contact with it, 

 the jarring and pulling apart motion is eliminated, 

 and the straw passes along quietly without change 

 of direction or change of position of the stalks in 

 reference to each other, so that the kernels are not 

 disentangled. 



THE COMBINATION OF RACK AND RADDLE. 



In the combination of the vibrating rack with the 

 traveling .raddle, the straw usually passes over the 

 rack first and is then delivered to the raddle; the 

 straw is pulled apart and thinned by the rapid motion 

 of the raddle, which disposes of the straw very 

 quickly and usually faster than it is delivered. This 

 pulling apart process greatly aids separation at this 

 point. 



