I ml 
h N Qv p And, fomany times i, by ib mmy t> 
qual fpaces, on the fame Bafes, between the fame Paral- 
lels terminated at the Hyperbola: The Aggregate of 
which ishFN Q^. From whence if we fubdu£t the Ag- 
gregate of Ablatives ; the remaining triUnear/^^, 
repreients the Defcent. 
50. If to this of Gravity, be joyned a projefting Force ; 
which is to the impuife of Gravity as h to h F( be it 
greater, left, or equaU taken in the fame line ; the fame 
parallels determine proportional Parallelograms, whofe 
Aggregate is 
51. And therefore if this be a Perpendicular Projection 
downwards; xhmhK^kn ( thefumme of this with the 
former j reprefents the Defcent. 
52. If it be a Perpendicular upwards; then the diffe- 
rence of thefe two reprefents the; Motion ; >vhich jR? long 
K.Q^ is the^greater, is fAic;endent : but Defcendent 
when h becomes greater v and it is; then at the higheft 
when they be equal. T 
5 3. If the Projedion be not in the fanie Perp 
f but Horizontal, or ObUqu^ then /C.^ reprefents the 
Tangent pf the Curve; and 2» thp D^dina^^ to that 
Tangenf, at the given Angle^ / ^ 
5 4 . Buf the Computation |)^fore given I take to be of 
better life than th s reprefenifation in Figure. Becaufe in 
fuch Mathematical enquiries, I choofe to feparate f as 
much as may be ) what purely concerns Proportions ; and 
confider it a'bftraftly from lines or other matter w^here- 
with it is incumbered. 
As to the queftion propofed ; whether the refiflance 
of the Medium do not al ways take olT fuch a proportional 
part of the force moving through it, as is the Specifick 
rravity of the Medium to that of the Body moved in it ; 
for , if fb, it will fave us the trouble of Obfervation. ) 
i think this can by no means be admitted. For there be 
any other things of confideration hereipj befide the In- 
ten- 
