Page:The Mathematical Principles of Natural Philosophy - 1729 - Volume 1.djvu/68

24 and of the direct ratio of pH to pN, the weights will have the ame effect towards moving the wheel and will therefore utain each other; as any one may find by experiment.

But the weight p preing upon thoe two oblique planes, may be conidered as a wedge between the two internal urfaces of a body plit by it; and hence the forces of the Wedge and the Mallet may be determin'd; for becaue the force with which the weight p prees the plane pQ is to the force with which the ame, whether by its own gravity, or by the blow of a mallet, is impelled in the direction of the line pH towards both the planes, as pN to pH; and to the force with which it prees the other plane pG, as pN to NH. And thus the force of the crew may be deduced from a like reolution of forces; it being no other than a wedge impelled with the force of a lever. Therefore the ue of this Corollary preads far and wide, and by that diffuive extent the truth thereof is farther confirmed. For on what has been aid depends the whole doctrine of Mechanics variouly demontrated by different authors. For from hence are eaily deduced the forces of Machines, which are compounded of Wheels, Pullies, Levers, Cords, and Weights, acending directly or obliquely, and other Mechanical Powers; as alo the force of the Tendons to move the Bones of Animals. Rh