A CONCISE ELEMENTARY TREATISE ON THE SUN, PLANETS, SATELLITES AND COMETS. 0. M. MITCHEL, LL.D., DIRECTOR OF THE CINCINNATI AND DUDLEY OBSERVATORIES. NEW YORK: PHINNEY, BLAKEMAN & MASON, No. 61 WALKER STREET. Educ T 318.60.570 HARVARD COLLEGE LIBRARY GIFT OF GEORGE ARTHUR PLIMPTON Enterod, according to Act of Congress, in the year 1860, by O. M. MITCHEL, In the Clerk's Office of the District Court for the Southern District of New York. STEREOTYPED BY SMITH & MCDOUGAL, 82 & 84 Beekman-st., N. Y. PRINTED BY J. D. BEDFORD & CO., 115 & 117 Franklin St. CONTINENTAL BANK PREFACE. 20 THE author has no other apology to present for offering to the public the following work on "Popular Astronomy" than the marked favor with which his "Planetary and Stellar Worlds" has been received, both in this country and in Europe. The science of Astronomy is so rapidly progressive that to keep the public advised of its advances new works are required almost every year. This may b offered as an additional reason for the present publica tion. In the preparation of the work I have availed mysel of so many sources of information that it would be quite impossible for me to specify the authors or the volumes to which I am indebted. The plan and the cast are all my own. I have endeavored to follow the path of real discovery, and in every instance to present the facts and phenomena so as to afford to the reader and student an opportunity to exercise his own genius in their discussion and resolution, before offering the explanation reached by ancient or modern science. It is hoped that this method of treating the subject which is new, (so far as I know,) may avail in exciting a greater interest in the examination of those great problems of the universe whose successful solution constitutes the chief honor of human genius. In a few instances I have ventured to present the results of my own observations, and have occupied a short space in exhibiting a sketch of new methods and new instruments, which have been introduced into the observatories at Cincinnati and at Albany. DUDLEY OBSERVATORY, January, 1860. |