534* Experimental Philosophy/. [Lecture 16. 



ounces. Then, if the power is twelve times as 

 far from the prop as the weight is, they will ex- 

 actly counterpoise ; and a small addition to the 

 power P will cause it to descend, and raise the 

 weight W; and the velocity with which the power 

 descends will be to the velocity with which the 

 weight rises, as twelve to one : that is, directly as 

 their distances from the prop ; and consequently, 

 as the spaces through which they move. Hence 

 it is plain that a man who by his natural strength, 

 without the help of any machine, could support 

 a hundred weight, will by the help of this lever 

 be enabled to support or rather raise twelve hun- 

 dred. If the weight is less, or the power greater, 

 the prop may be placed so much farther from the 

 weight, and then it can be raised to a prpportion- 

 ably greater height. For, universally, if the in- 

 tensity of the weight multiplied into its distance 

 from the prop is equal to the intensity of the 

 power multiplied into its distance from the prop, 

 the power and weight will exactly balance each 

 other ; and a little addition to the power will 

 raise the weight. Thus, in the present instance, 

 the weight W is twelve ounces, and its distance 

 from the prop is one inch ; and twelve multiplied 

 by one is twelve; the power P is equal to one 

 ounce, and its distance from the prop is twelve 

 inches, which multiplied by one is twelve again ; 

 and therefore there is an equilibrium between 

 them. So, if a power equal to two ounces is ap- 

 plied at the distance of six inches from the prop, 



