ſame effect as the weight P, if that weight is to the weight A as the force DC is to the force DA; that is (becauſe of the ſimilar triangles ADC, DOK,) as OK to OD or OL. Therefore the weights A and P, which are reciprocally as the radii OK and OL that lie in the ſame right line, will be equipollent, and ſo remain in equilibrio; which is the well known property of the Balance, the Lever, and the Wheel. If either weight is greater than in this ratio, its force to move the wheel will be ſo much greater.
If the weight p, equal to the weight P, is partly ſuſpended by the cord Np, partly ſuſtained by the oblique plane pG; draw pH, NH, the former perpendicular to the horizon, the latter to the plane pG; and if the force of the weight p tending downwards is repreſented by the line pH, it may be reſolved into the forces pN, HN. If there was any plane pQ, perpendicular to the cord pN, cutting the other plane pG in a line parallel to the horizon, and the weight p was ſupported only by thoſe planes pQ, pG, it would preſs thoſe planes perpendicularly with the forces pN, HN; to wit, the plane pQ with the force pN, and the plane pG with the force HN. And therefore if the plane pQ was taken away, ſo that the weight might ſtretch the cord, becauſe the cord, now ſuſtaining the weight, ſupplies the place of the plane that was removed, it will be ſtrained by the ſame force pN which preſſed upon the plane before. Therefore, the tenſion of this oblique cord pN will be to that of the other perpendicular cord PN as pN to pH. And therefore if the weight p is to the weight A in a ratio compounded of the reciprocal ratio of the leaſt diſtances of the cords PN, AM, from the centre of the wheel,
