182 On the Measure of 
In this explanation, however, of the action 
of the spring on C and D, Mr. Maclaurin 
understood a material inconsistency to be in- 
volved, which he stated in a treatise that 
obtained the prize of the Royal Academy of 
Sciences at Paris, in 1724.* Mr. Maclaurin 
supposes two equal bodies like C and D, with 
the compressed spring between them, te be 
situated in a space E FGH, which, together 
with the balls, “ meves uniformly in the direc- 
tion CD with the velocity as 1; and that the 
spring impresses on the equal bodies C and D 
equal velocities, in opposite directions, that are 
each as 1. Then the absolute velocity of D 
(which was as 1) will be now as 2; and accord- 
ing to the new doctrine, its force as 4: whereas 
the absolute velocity and the force of C (which 
was as 1) will be now destroyed ; so that the 
action of the spring adds to D a force as 3, 
and subducts from the equal body € a force as 
Jonly ; and yet it seems manifest, that the 
‘actions of the springs, on these equal bodies 
ought to be equal; (and M. Bernoulli ex- 
pressly owns them to be so): that is, equal 
actions of the same springs upon equal bodies 
* The “ Discours sur le mouvement” of John Bernoulli 
avas offered for the same prize, but was rejected, the 
preference being given to the treatises of Maclaurin and 
Maziere. 
