



ijlon U generally a cylindrical piece which slid** Uck- 

 wanU and forward* iiuide a hollow cylu..i.-r. The putou may 

 be moved by the action of fluid pressure upon it u 



-engine, or it may be used to give motion to a fluid at in 



A piston ii usually attached to a rod, called a ;***<m rod; 

 i passes Uu-.'i-li the end of the cylinder u.-i.l.- xO.i. h r!.,- 

 kn, and which era* t> Uie motion of the 



uder, or vice 



\ tuntptr U a piston made in one piece with it* piston rod, 

 tin- piston nnd th<> rod beang of the same diameter. 



A j-iston uhii-h is j.n.M.l^l with one or mon valves which 



