434 Directions for Working Portable Steam- Engines. 



adopted, for by this means the formation of steam is rendered 

 irregular, and much fuel wasted. 



Mode of Firing. 



The fire must be kept constantly bright and clear ; the bars must 

 be covered, but never more than three inches thick ; and the coals 

 must not be heaped up against the mouths of the tubes ; coal 

 must be put on the fire in small quantities, and frequently, and 

 not all at once, and then allow the fire to burn quite low ; ex- 

 perience will show how often the fire must be supplied with coal, 

 as it much depends upon the quality of the coal and the amount 

 of work that the engine is doing. 



Water low in Boiler. 



There should never be less than two inches of water visible in 

 the glass gauge-tube when the engine is at work ; if, by accident 

 or neglect, the water should become so low as only to show about 

 half an inch in the glass tube, the fire should instantly be dropped ; 

 by lifting the fire-bars from their places by means of the tools 

 furnished for the purpose, the burning coals will fall into the 

 water in the ash-pan, and be extinguished ; water should never 

 be thrown into the fire-box to put out the fire — it is apt to scald 

 those who do so, and to injure the fire-box ; the fire must on no 

 account be again lighted until the boiler has been filled up. 



Bearings to be oiled and examined when Engine is at 



work. 



The bearings and guide-bars should be carefully examined 

 from time to time to see tliat they are properly supplied with oil 

 from the lubricators attached to them ; it is a good plan to put a 

 little extra oil upon the guide-bars, in addition to filling the 

 lubricators upon tliem. Whenever the engine is stopped, all the 

 bearings should be felt, to make sure that they have not heated ; 

 if there be any disposition to heat, the bearings having such a ten- 

 dency may be loosened a little, but they must not be too slack, 

 or it will occasion a disagreeable knocking, which is very injurious ; 

 sometimes it becomes necessary to take the top brasses quite off 

 to free them from grit, which will cause heating in the brasses ; 

 the parts requiring most attention are the two ends of the con- 

 necting rod, and the bearings of the crank-shaft ; the eccentrics 

 also should be oiled occasionally when the engine is working ; 

 the brass rings should be slackened a little if they become Avarm ; 

 after taking the cap off a bearing, care must be taken that, on 

 replacing it, it is not screwed down too tightly, or it will be 

 sure to cause friction, and increase the mischief sought to be 

 avoided. 



