WEIGHING MACHINE. 



71 



creased, by the time it reaches the draught-valve, to 

 about one hundred times. 



A more compact arrangement of compound levers 

 is shown in Fig. 51, where the power, P, acts on 

 the lever A, exerting a force 

 on the lever B five times as 

 great as the power, B acts 

 on the lever C with a force 

 increased three times, and 

 this, again, on the weight, 

 W, with a four-fold force. 

 Multiplying 5, 3, and 4 to- 

 gether, the product is 60 ; 

 hence a force of one pound 

 at P will support 60 pounds 

 at W. By graduating (or 

 marking into notches) the le- 

 ver C, so that the distance is measured as the weight 

 is moved along it, a compact and powerful steelyard for 

 weighing is formed. 



Compound levers. 



WEIGHING MACHINE. 



A valuable combination of levers is made in the con- 

 struction of the weighing machine^ used for weighing 



Fig. 52. 



Weighing Machine. 



