SCIENCE OF THRESHING. 115 



there is in his boiler. The position of the engine must 

 be taken into consideration also, as he will carry a 

 greater depth when the engine is tilted back, so 

 causing the water to run up in the gauge, to insure 

 that the forward or upper end of the crown sheet be 

 covered. Conversely, if the engine be tilted forward, 

 he will carry less, as the gauge glass will be at the 

 higher end of the crown sheet. If the engine be 

 tipped sideways, this must also be taken into account 

 to prevent a burned fire- sheet. If the engine be trav- 

 eling along the road, good watch will have to be kept, 

 as it is difficult to tell, from the agitation of the 

 water, just how much there is. In running down a 

 steep hill, the water is liable to run forward in the 

 boiler and leave the crown sheet bare. Therefore, 

 before reaching the crest of the hill, the boiler should 

 be filled enough to insure the covering of the crown 

 sheet; the fire may also be deadened for a time by 

 putting on a layer of fresh coal. 



When steaming up, the boiler should be properly 

 filled and a fire started in the fire-box with all the 

 drafts open and the spark arrester removed from the 

 stack, when possible, as it impedes the draft. When 

 using natural draft only, the fuel on the grate should 

 be as thin as possible. 



When steam commences to rise, the steam gauge 

 should be watched closely to see if the hand com- 

 mences to move and indicate the pressure. If it stays 

 stationary until a pressure of five to ten pounds is 

 obtained, it should be removed and. tested, as it is 

 inaccurate and not to be relied on. 



