Excerpt from An Introductory Treatise on Dynamic Astronomy This book is intended to provide an introduction to those parts of Astronomy which require dynamical treatment. To cover the whole of this wide subject, even in a preliminary way, within the limits of a single volume of moderate size would be manifestly impossible. Thus the treatment of bodies of definite shape and of deformable bodies is entirely excluded, and hence no reference will be found to problems of geodesy or the many aspects of tidal theory. Already the study of stellar motions is bringing the methods of statistical mechanics into use for astronomical purposes, but this development is both too recent and too distinct in its subject-matter to find a place here. Nevertheless the book covers a wider range of subject than has been usual in works of the kind. Thereby two advantages may be gained. For the reader is spared the repetition of very much the same introductory matter which would be necessary if the different branches of the subject were taken up separately. But in the second place, and this is more important, he will see these branches in due relation to one another and will realize better that he is dealing not with several distinct problems but with different parts of what is essentially a single problem. In an introductory work it therefore seemed desirable to make the scope as wide as was compatible with a reasonable unity of method, the more so on account of the almost complete absence of similar works in the English language. The first six chapters are devoted to preliminary matters, chiefly connected with the undisturbed motion of two bodies. These are followed by five chapters VII to XI dealing with the determination of orbits. This section is intended to familiarize the reader with the properties of undisturbed motion by explaining in general terms the most important and interesting applications. It is in no sense complete and is not intended to replace those works which are entirely devoted to this subject. Otherwise it would have been necessary to describe in detail such admirably effective methods as Professor Leuschner's and to include fully worked numerical examples. 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.