MOVING FORCE. 
0<7 :? 
itroyed ; so that thf action of the spring adds to D a force as 3, Cases of diffi- 
and subducts from the equal body C a force as 1 only ; and yet of 
it seems manifest, that the actions of the springs, on these equal movni^ tore*. 
Ixxlies, ought to be equal ; (and M. Bt-moulli expressly owns 
them to be so) that is, equal actions of the same springs upon 
equal bodies would produce very unequal effects, the one being 
triple of the other according to the new doctrine, than which 
hardly any thing more absurd can be advanced in philosophy or 
mechanics*.’’ 
This argument of Mr. Maclaurin has always been considered 
ts the most ingenious and the 'strongest objection that has 
aeen brought against the principle of the vis viva. But we 
tave the following remarks upon it from Dr. Milner : “ I shall 
jnlyjust observe, that if M. Bernoulli expressly owns, that 
r.prings, interposed between two bodies in a space, W’hich is 
'tarried uniformly in the direction in which the springs act, will 
always generate equal forces in the bodies according to his own 
lefinition of the term, he talks more inconsistently than I have 
observed him to do. On the contrary, if I could find that he 
las answered this famous argument (which Dr. Juiin proposed 
wer again in the Philosophical Transactions, vol, xliii. with a 
:onditional promise of embracing the Leibnitzian doctrine) by 
imply saying, that springs he considers as moving forces, or, 
*vhcn the bodies are equal, as accelerating forces ; and that 
heir actions are equal, when in equal times they generate equal 
elocities, but not necessarily equal forces in the equal bodies; 
should not make the least scruple to own, that I thought his 
!*easoning solid and conclusive, and his distinctions a full answer 
O' every objection of that sort.” To this. Dr. Mi’ner has 
lodded the following note : “ No doubt Mr. Maclaurin refers 
3 the following passage of Bernoulli: La force du choc, ou 
l e Paction des corps les uns sur les autres, depend uniquement 
! e leurs vitesses respectives ; or il est visibles que les vi- 
•;sses respectives des corps ne changent pas avant le choc, 
' oil que le plan ou I’espace qui les conlient soit sans mouve- 
• Account of .Sir Isaac Newton's Discoveries, book 2, chapter 2. 
S 2 ment, 
