rendering Platina malleable. 



101 



contents to allow of the barrel being laid horizontally in a 

 forcible press. 



The press which I have generally used for this purpose 

 consists of a flat iron bar AB, set edgeways, and screwed 

 down by a hook E, near its middle, where it would other- 

 wise be liable to bend, to a strong wooden bench CD. The 

 bar is connected by a pivot at its extremity A, with the lever 





AFG. An iron rod F H, which turns at its two extremities 

 upon the pivots F and H, proceeds from the lever at F^ and, 

 as the lever descends, propels forward the carriage I, which 

 slides along the bar. A stopper or block being placed in the 

 vacant space I k, the carriage communicates motion to the 

 cradle klm, which is also made to slide along the bar, and 

 carries the barrel N, which lies upon the cradle, straight 

 against the piston O, which rests by its end against P, a pro- 

 jection in the further extremity of the bar. 



The weight, which in this machine, when the angle of the 

 lever's elevation is small, will keep the power, applied ver- 

 tically at the extremity of the lever, in equilibrio = that 



power x . _ r k ~ — =77^- X cotan of the angle of the lever's 

 AF [AF + FHJ 



elevation ; which expression, in the case of the press actually 

 used, becomes, Power x 5. cotan of the angle of the lever's 



