( 5T ) 
1] , A Letter to 2)r. Meadj ColLMeJ. Lond. ^ Soc, 
^eg. S. concerning an Experhnentj whereby it 
has been attempted to [hew the faljity of the 
‘ cotmnon Opinion, in relation to the force of bo- 
dies in Motion^ !By Henry Pemberton, M 2). 
R. S. S. 
4 
■ If ' ■ ' 1 'i • ; ■ 
s / R, • ^ 
P Erufing the Learned Polems's Trac^ de CaftelUs* 
you were pleafed to fend me ; I have found in it 
)ti feveral curious Experiments, among which I reckon that 
:• of letting Globes of equal Magnitude, but of different 
weights, fall upon a yielding Subftance, as Tallow, 
’ Wax, Clay or the like, from heights reciprocally pro- 
portional to the weights of the Globes. This Experi- 
ment, engaged in particular my Attention, as it is 
: brought with defign to overturn one of the firfl: Princi- 
I ples eftablilh’d in Natural Philofophy. And the Know- 
ledge I have of your great Efteem for that part of 
Science, emboldens me to trouble you with my 
Thoughts upon this Experiment; for ! cannot by any 
means admit of the Dedud:ion that is drawn from 
{ thence, that becaufe the Globes make in this Experi- 
J ment equal Impreffions in the yielding Subffance, there- 
: fore they ftrike upon it with equal force.* whereby it is 
) i attempted to prove the Affertion of Mr. that 
^ I the force of the fame Body in defcending is proportional 
j I to the height from whence it falls; or, in all Motion, 
proportional to the Square of the Velocity, and not 
' proportional to the Velocity it felf, as is commonly 
thought. On the contrary, 1 think this very Experi- 
N ment 
