POWER ON THE FARM 



397 



piston so that it will not allow gas to leak past it. If well 

 lubricated the rings will spring closely against the cylinder 



HHffiHBBHBBBBBBI^HHHHBBB^HHBMii^ 



FIG. 250. Tractor running a silage cutter and blowing the cut corn into a very 

 high concrete silo. (Tennessee Power Farming Review.) 



and prevent leaks. They will become worn and should then 

 be replaced with new ones. 



Spark System. This is often called the ignition system. 

 By it the compressed gas in the cylinder is lighted and caused 

 to explode. This explosion throws the piston toward the 



