IO8 K<>1 uil-AND-TUMBLE ENGINJ 1 KING 



The question as to the advantage of a compound 

 engine is, or would be an interesting one if we cared 

 to discuss it. 



The compound traction engine has come into use 

 within the past few years, and I am inclined to think 

 more for a sort of a novelty or talking point rather than 

 to produce a better engine. There is no question but 

 that there is a great advantage in the compound 

 engine for stationary and marine engines. 



In a compound engine the steam first enters the 

 small or high pressure cylinder and is then exhausted 

 into the larger or low pressure cylinder, where the expan- 

 sive force is all obtained. 



Two cylinders are used because w r e can get better 

 results from high pressure in the use of two cylinders 

 of different areas than by using but one cylinder, or 

 simple engine. 



That there is a gain in a high pressure, can be shown 

 very easily: 



For instance, 100 pounds of coal will raise a certain 

 amount of water from 60 degrees, to 5 pounds steam 

 pressure, and 102.9 pounds would raise the same 

 water to 80 pounds, and 104.4 would raise it to 1 60 

 pounds, and this 160 pounds would produce a large 

 increase of power over the 80 pounds at a very slight 

 increase of fuel. The compound engine will furnish 

 the same number of horse power, with less fuel than 



