THE STONE CRUSHER. 



225 



piece I, stands upon the lever, against the top of which piece 

 the toggles J, J, have their bearings, forming an elbow or tog- 



gle-joint. K, is the fixed jaw against which the stones are 

 crushed. This is bedded in zinc against the end of the frame, 

 and held back to its place by cheeks L, that fit in recesses in the 

 interior of the frame on each side. M, is the movable jaw. 

 This is supported by the round bar of iron N, which passes freely 

 through it and forms the pivot upon which it vibrates. 0, is a 

 spring of india-rubber, which is compressed by the forward move- 

 ment of the jaw and aids its return. 



Every revolution of the crank causes the lower end of the 

 movable jaw to advance toward the fixed jaw about \ of an inch 

 and return. Hence if a stone be dropped in between the con- 

 vergent faces of the jaws, it will be broken by the next succeed- 



29* 



