5O SCIENCE OF SUCCESSFUL THRESHING. 



of the engine or of the separator should be done while the 

 belt is running. The friction-clutch should always be used 

 in tightening and in backing the engine into the belt. 



Ascending Hills. In coming to a steep hill the engineer 

 should see that he has about the right amount of water in 

 the boiler, that is, enough to show two inches in the glass 

 when the boiler is level. With the boiler too full there may 

 be danger of priming, which should be especially avoided on 

 a hill. It is also necessary to exercise judgment in regard 

 to the fire. It should be hot enough to insure sufficient steam 

 pressure to climb the hill without stopping. On the contrary, 

 the engine should not be allowed to blow off when pulling 

 hard on a hill, as this is liable to cause priming, necessitating 

 stopping. In short, when approaching a steep hill, prepare 

 for it so that you know you can ascend without stopping. 

 In ascending a hill, avoid running fast, as a moderate rate 

 of speed gives best results. If the engine shows a tendency 

 to prime, the speed should be limited by means of the throttle 

 so that the engine may run just fast enough to pass its dead- 

 centers. 



Descending Hills. Important as it is to ascend the hill 

 without stopping, it is doubly important in descending to 

 reach level ground before stopping. Every man in charge 

 of a boiler of the locomotive type should know the danger 

 of stopping with the front end low. In descending a very 

 steep hill leave the throttle partly open to admit a little steam 

 and if the engine runs too fast control the speed with reverse 

 lever. 



