Mechanics.

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7. Thus for the Living Force, if on the proportionalBalance you place 4 Ib. at the Distance of 6 Inches onone Side, and 2 Ib. at the Distance of 12 Inches on theother Side, and if the Balance be put into Motion, theywill each of them have a Vis Viva , or an active Force,because they will keep the Beam in Motion for someTime, till, by militating, they murder or kill eachother ; and then surely enough they become Vires Mor-tuæ, or Dead Forces.

8. But let us see how they exerted their Powerwhile living. One (A) acted against the other (B),with the Gravity of every Particle in a Mass of 4 Ib.and with the Velocity in each Stroke that 6 InchesDistance could give ; but since all allow the Weight tqbe as the Mass of Matter, and the Velocity as the Dis-tance from the Centre of Motion, therefore all theForce which A exerted was as 4 X 6 — 24. In thefame Manner it is shewn the whole Force of B actingagainst A, was as 2 X 12 — 24; that is, in eachCafe, the Force was as the Velocity into the Mass ofMatter. And because they were equal they destroyedeach other.

9. But had those Combatants A and B been armedwith Forces proportioned to the Squares of the Velo-cities, that of A would have been but 4X6 X 6=144;whilst B would have had a Force equal to 2 X 12 X 12 =288; by which he would have demolished A at onesingle Stroke, and been the surviving Conqueror.

10. Let us now consider those two Bodies A and Bas dead, and fee what Forces they exert (Verbo deturVenia) in that State. In order to this they must behung upon the Arms of the Balance, one on eachSide, till they are dead, i. e. motionless ; but this willnot happen till their Distances from the Centre of Mo-tion become reciprocally proportional to their Masses ofMatter ; and then it is plain the Cafe is the fame as be-fore ; for the dead Force of A will be as 4 X 6 = 24 = 2X 12 = dead Force of B. Whereas if these Force? wero-as the Masses into the Square of the Velocities, A of4 Ib. and B of 2 Ib. ought to die at the Distances 6 and8,4 Inches from the Centre respectively; but if the Ex-periment be tried there, such strong Symptoms as Life

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