PHYSICAL AND LITERARY. 73 



The German philofophers, in their ex- 

 periments, have been mifled, by afcribing, 

 to the force of the moving body, effects 

 which obvioufly refult from other caufes. 

 Not to lengthen out this paper too much, 

 I fhall fatisfy myfelf with giving an in- 

 ftance or two. It is a fafl agreed upon, 

 that a pendulum, fwung upwards with a 

 double velocity, will reach a quadruple 

 height. Hence it is inferred by Leibnitz, 

 and his followers, that the forces muft be 

 as the fquares of the velocities ; feeing 

 the efFedls produced by the different for- 

 ces, "uiz, the fpaces gone through, are as 

 the fquares of the velocities. And, could 

 it be juflly maintained that the fpace 

 run through is purely the effedl of the 

 momentum or force with which the body 

 is thrown upwards, the argument would 

 be conclufive. But it is not fo. Laying 

 afide gravity, and the refiftance of the air, 

 a body thrown upwards, with the fmall- 

 eft force, will move on in infinitum. It is 

 by the operation of gravity, and the re- 

 fiftance of the air, that motion ceafes, 

 when the body arrives to a certain 

 Vol. I. K height. 



