Produced by Brenda Lewis, Scott Marusak, Greg Bergquist and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.) Transcriber's Note The punctuation and spelling from the original text have been faithfully preserved. Only obvious typographical errors have been corrected. The advertisement from the beginning of the book has been joined with the other advertisements near the end of the book. Greek words are spelled out and represented as [word]. Greek letters are represented as [a] "for alpha". ASTRONOMY OF TO-DAY [Illustration: THE TOTAL ECLIPSE OF THE SUN OF AUGUST 30TH, 1905. The Corona; from a water-colour sketch, made at Burgos, in Spain, during the total phase, by the French Artist, Mdlle. ANDRÉE MOCH.] ASTRONOMY OF TO-DAY _A POPULAR INTRODUCTION IN NON-TECHNICAL LANGUAGE_ By CECIL G. DOLMAGE, M.A., LL.D., D.C.L. Fellow of the Royal Astronomical Society; Member of the British Astronomical Association; Member of the Astronomical Society of the Pacific; Membre de la Société Astronomique de France; Membre de la Société Belge d'Astronomie With a Frontispiece in Colour and 45 Illustrations & Diagrams _THIRD EDITION_ LONDON SEELEY AND CO. LIMITED 38 GREAT RUSSELL STREET 1910 PREFACE The object of this book is to give an account of the science of Astronomy, as it is known at the present day, in a manner acceptable to the _general reader_. It is too often supposed that it is impossible to acquire any useful knowledge of Astronomy without much laborious study, and without adventuring into quite a new world of thought. The reasoning applied to the study of the celestial orbs is, however, of no different order from that which is employed in the affairs of everyday life. The science of mathematics is perhaps responsible for the idea that some kind of difference does exist; but mathematical processes are, in effect, no more than ordinary logic in concentrated form, the _shorthand of reasoning_, so to speak. I have attempted in the following pages to take the main facts and theories of Astronomy out of those mathematical forms which repel the general reader, and to present them in the _ordinary language of our workaday world_. The few diagrams introduced are altogether supplementary, and are not connected with the text by any wearying cross-references. Each diagram is complete in itself, being intended to serve as a pictorial aid, in case the wording of the text should not have perfectly conveyed the desired meaning. The full page illustrations are also described as adequately as possible at the foot of each. As to the coloured frontispiece, this must be placed in a category by itself. It is the work of the _artist_ as distinct from the scientist.