38 



SCIENCE OF SUCCESSFUL THRESHING. 



eighths inch in diameter. Compound engines, (excepting 

 the 25 H. P.), have a slide in place of the rocker-arm, and 

 on these engines the ratchet-rod is attached to the 



eccentric-rod by means of a 

 clamp, provided for this pur- 

 pose. On portable engines, 

 the ratchet-rod must be at- 

 tached to the valve slide, the 

 three-eighth inch hole for 

 the shoulder bolt being lo- 

 cated two and one-half 

 FIG. 9. OIL PUMP ATTACHED, inches from the top and 

 seven-eighths inch from the front edge of the slide. After the 

 pump body is attached, the ratchet-rod may be placed in posi- 

 tion, one end being on the shoulder bolt of the rocker-arm or 

 clamp, an<i the other passing through the knuckle-joint on the 

 sliding ratchet-arm. Having connected the ratchet-rod, screw 

 the gravity check valve into the hole in the throttle, using a 

 bushing to bring it to the right size. The soft one-quarter 

 inch tubing may be bent to bring its ends in proper position 

 in order to make the connections at the unions. 



Instead of placing the oil pump on the steam chest, it may 

 be attached to the cylinder flange of the engine frame. To 

 do this, one of the studs must be replaced by another of suf- 

 ficient length to take the lug on the bottom of the pump body. 

 This avoids the necessity of boring a hole into the steam 

 chest ; but in all cases, it is best to have the pump-body rest 



