Excerpt from The Philosophical Transactions of the Royal Society of London, From Their Commencement, in 1665, to the Year 1800, Vol. 6: Abridged, With Notes and Biographic Illustrations; From 1713 to 1723 Kepler himself, who first proposed the problem, had no direct method of computing the planets places, from the time being given: but he was obliged to proceed through the several degrees of the semicircle aqb, from the given are ao, called the excentric anomaly, and both to calculate the time by the area Asa, which is proportional to the mean anomaly, and the angle asp, that is the planet's place, or the coequate anomaly corresponding to this time. Since then the solution of this problem was difficult, astronomers had recourse to other hypotheses, assuming some point for that about which the motion is equable, or proportional to the time, and thence the mean anomaly being given, they determined the coequate anomaly. But computations founded on these hy potheses were found not to agree 'with the Observations. Therefore geometers had recourse to various approximations, by which, from the given area Asa, which is analogous to the time, the angle asp, or the place of the planet, may be had very nearly. Now the easiest of all these, and most ready for practice, seems to be that method which is taught by Mr Newton in his Principia. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.