PHYSIGAL ayn LITERARY. 55 
fuch anieffect ; and. it will be,a hard tafk to 
affign»any juft foundation fora difference in 
this particular, betwixt external and intecnal 
force. », 
¢ We'moft. ala yield to the dificulty, 
cate it is unfurmountable.. It is very true, 
that..a body. ‘has; quam. proxime, the fame 
weight) at the diftance,of ten foot from the 
furface'of the earth, as at the) diftance of 
a-hundred : and the force of gravity is, quam 
proxime, the fame when a body ‘is dropt from 
thethand at thefe'different diftances, But 
then, tho’ gravity ,is {uppofed invariable, 
where the difference of, the diftances is fo 
fmall.; yet this only holds where other ‘cir- 
cumftances are the fame: that is, where the 
body is either at reft, or moves with the fame 
celerity.. For it is'extremely clear, that, °in 
_ the perpendicular defcent -of a‘body, the 
- force of gravity varies every inftant, and 
turns, greater in its. progrefs downwards. 
And indeed gravity cannot otherways produce 
5 acceleration, more than’ the wzs infita does. 
_ Nor is there any thing fingular in this pro- 
_perty of gravity. . The wis infita has a pro- 
_perty fomewhat fimilar: for, tho’ it con- 
‘  -Bnues invariable vafter. the body is fet in mo- 
’ 
vy 
