IOO SCIENCE OF SUCCESSFUL THRESHING 



the same direction as that in which the lever is moved, the 

 pedestal is the proper height. If the pedestal be too 

 high, the "slip" of the valve will be more than one-six- 

 teenth, and if too low, it will be less or none at all, or if 

 very low, the valve stem will move in the opposite direction 

 to that in which the reverse lever is moved. The pedestal 

 may be raised, by placing "shims" of sheet-iron between 

 it and the frame at the place where it is bolted, and lowered 

 by removing the "shims." If there be none, the pedestal 

 must be taken to a machine-shop and planed off in order 

 to lower it. 



Fourth. Dividing the Leads. When you know that 

 the reach-rod is the correct length; that the eccentric is 

 in the proper position, and that the pedestal is the correct 

 height, give the valve three-thirty-seconds of an inch 

 "lead" on the crank-end for the threshing-motion. The 

 "slip" of the valve, in throwing the lever over to the road 

 motion, will reduce this lead by one-sixteenth, so that the 

 leads will be nearly alike for the road motion. The 

 "lead" should be obtained by adjusting the length of the 

 eccentric-rod, allowing the nuts on the valve-stem to 

 remain undisturbed. If the nuts on valve-stem be loos- 

 ened, the "draw-block" is liable to be tilted so that the 

 valve cannot leave its seat (without bending the rod), 

 when necessary to let water out of cylinder. 



It is best, after setting the valve, to go all over it again 

 from the beginning, and if all be found correct, the eccen- 



