Comment on, and Defence of, the Principia, BY W. EMERSON. WITI THE LAWS OF THE MOON'S MOTION According to Gravity. a new Edition, the Royal Observatory at Greenwich) W. DAVIS, Editor of the “ Mathematical Companion," &c. &c. &c. IN THREE VOLUMES. VOL. II. London: 1803. Printed by Knight & Compton, Middle Streci, Cloth Fair. Tuo LH 4N48 e 틀 MATHEMATICAL PRINCIPLES THE SECTION 1. Of the motion of bodies that are resisted in the ratio of the velocity. PROPOSITION I. THEOREM I. If a body is refifted in the ratio of its velocity, the motion loft by resistance is as the space gone over in its motion. FOR since the motion loft in each equal particle of time is as the velocity, that is, as the particle of space gone over, then, by composition, the motion loft in the whole time will be as the whole space gone over. Q.E.D. Cor. Therefore if the body, deftitute of all gravity, move by its innate force only in free spaces, and there be given both its whole motion at the beginning, and also the motion remaining after some part of the way is gone over, there will be given also the whole space which the body can describe in an infinite time. For that space will be to the space now described as the whole motion at the beginning is to the part loft of that motion.Vol. II. B |