44 SCIENCE OF SUCCESSFUL THRESHING 



the thinner oils, and therefore, its higher price is not nec- 

 essarily an objection. Then, too, it is convenient to have 

 but one kind of oil for the entire engine. 



Cylinder Lubrication. Use a good quality of Valve or 

 Cylinder Oil in the lubricator or the oil-pump, as it is very 

 important that the piston and valve should be well lubri- 

 cated with an oil that will stand the high temperatures' of 

 the steam. Do not imagine that cheap oil, no matter in 

 what quantity, will do in the cylinder. Nothing but first- 

 class cylinder oil will answer, and it must be used in suf- 

 ficient quantities. 



An expert is often called to an engine because of the 

 valve being "off" when the trouble is only poor cylinder 

 lubrication. In the early days of the steam engine, tallow 

 was generally used as a cylinder and valve lubricant. Ex- 

 cept that it contains some acid, it was suitable for the pres- 

 sures then used. However, tallow or ordinary machine oil 

 will not do for the modern steam engine, as they volatilize 

 and lose their lubricating properties at the high pressures 

 and corresponding high temperatures now used. 



The cylinder oil for lubricating the cylinder and the 

 valve should be introduced into the steam-pipe and if pos- 

 sible in. such a manner that the oil passes through the throt- 

 tle and the governor, thus lubricating them. Cylinder oil 

 is quite thick, especially in cold weather, and it is much 

 easier to fill lubricators if the oil be warmed and the cups 

 heated by blowing a little steam through them. A covered 



