218 PHILOSOPHICAL TKANSACTIONS. [aNNO 1746. 



mitted into these secret recesses of science. " Because, says the author, I see 

 you are on our side, I will freely communicate to you my principle of demon- 

 strating a priori the true estimation of forces; which I have sometimes mentioned 

 as in my possession, but have never yet produced. For communicating to you, 

 is committing a seed to a most fruitful soil, that it may grow up to a large 

 plant." 



I cannot but commend the good man for committing his seed to so fruitful a 

 soil ; and yet I cannot think him wholly free from meriting some censure. For 

 though he could work no effect on the Papins, Catalans, and other opposers of 

 his doctrine, who seemed to be incapable of conversion, by any demonstrations, 

 however strong; though he might think them unworthy of this clear light of 

 truth ; yet why begrudge it to the rest of the learned world ? I will not say that 

 it was the part of a good and humane man, and of one who was desirous to in- 

 crease knowledge, to lay open to all an affair of such moment : but if he had only 

 studied his own glory, before every thing else, he should have acted in this man- 

 ner; that those detractors might either have been immediately silenced, or con- 

 demned by all the world. Finally, as great men are not bom for themselves 

 alone, nor for a friend or two ; but for all ; is it not rather unfair that Bernoulli 

 and his disciples only should enjoy this clear light, while we poor wretches are 

 condemned to live in more than Cimmerian darkness. But it is well for us, now 

 that after 50 years of darkness, that light at length shines out upon all. But be- 

 hold the argument ! 



" 1. An action performing double, in a single time, is virtually double of an 

 action performing the same in a double time; or the walking of 2 miles in 1 

 hour, is virtually double of walking 2 miles in 2 hours." 



" 2. An action performing double in a double time, is formally double of an 

 action performing single in a single time; or walking 2 miles in 2 hours, is 

 formally double of walking 1 mile in 1 hour." 



" 3. Therefore an action performing double in a single time, is quadruple of 

 an action performing single in a single time; or the walking of 2 miles in one 

 hour is quadruple of the walking of 1 mile in 1 hour." 



" 4. If for double we had substituted triple, quadruple, quintuple, &c. the 

 action would have come out noncuple, sedecuple, 25ple; and in general it ap- 

 pears that equable equitemporaneous moving actions, are to equal moveable ones, 

 as the squares of the velocities; or, which is the same thing, that in the same or 

 equal bodies, the forces are in the duplicate ratio of the velocities, a. e. d." 



Having read this argument, and, out of regard to the great fame of the author, 

 having considered it with much attention, I must confess I could not discover 

 the least spark of truth in it, or even of common sense. I should have suspected 

 that this had been owing to the weakness of my own eyes, which perhaps might 



