ROUGH-AND-TUMBLE I.NGINEEK 75 



started out by saving i: . new engine you wouM 



most likely firul aboi . hth of an inch between the 



brasses, and we said you would finally get these brasses, 

 or halves together, and would have to take theni 



have taken up one-eighth of an inch 



and the result is, we have lengthened our pitman just one- 



or in other words, the center of the 



o center of the cross-head are just one- 



rnth of an inch further apart than they were before 

 any wear had taken place, and the piston head has onc- 



enth of an inch more clearance at one end, and onc- 



enth of an inch less at the other end than it had be- 

 c take out the boxes and file them so we 

 have another eighth of an inch. by the time we have taken 

 up this wca: .ill then have this distance doubled, 



ar.d we will soon have the piston head striking the 

 of the cylinder, and besides, the engine will not n 

 smooth as it did. Half of the wear comes off of each 

 half, and the half next to the key is brought up to the 



. pin because of the tapering key, while the outside 

 half remains in one place. You must therefore place back 

 of this half a thin piece of sheet copper, or a piece of 

 tin. Now suppose our boxes had one-eighth of an inch 



vear. When we have taken up this much we must 



n one-sixteenth of an inch backing (as it is called). 

 ive reduced the outside half by just that amount. 



have also reduced the front or inside half the same. 



