Mr . smeaton on Mechanic Power . 467 
the firft, and hereby a double velocity is given to the bo- 
dies; for they make 20 revolutions in 14", which is a 
fin all matter lefs than half the time taken up in making 
20 revolutions in the firft experiment. It alfo appears, 
that the velocity acquired is fimply as the impelling 
power compounded with the time of its a&ion ; for a 
quadruple impulfion afting for 7" inftead of 14" gene-* 
rates a double velocity, while the mechanic power em- 
ployed to generate it is quadruple, for 32x25^=808. 
And here the mechanic power employed being four 
times greater than the firft, it holds here alfo, that the 
mechanic power, to be neceflarily employed, is as the 
fquare of the velocity to be generated ; that is,in the fame 
proportion as turned out in the third experiment, where 
the mechanic power employed was only a quarter part 
of the firft. 
j 
5thly, The fifth and fixth experiments were made 
with a mechanic power four times greater than thofe 
employed in numbers 2 and 3 refpecftively ; and fince 
the fame deductions refult from hence as from numbers 
2 and 3, they are additional confirmations of the con- 
clufions drawn from them and from the laft article. 
6thly, In the feventh experiment, the difpofition of 
the apparatus is the fame as number 1, only here the 
bodies are placed upon the arms at the half-length ; from 
whence it appears, that the fame mechanic power ftill 
produces the fame velocity in the fame bodies; for though 
20 revolutions were performed in 14I" (fee column 7) 
Vol. LXVL Q q q which 
