ASTRONOMY QB43 i& IX POPULAR ASTRONOMY. BY SIMON NEWCOMB, LL.D., PROFESSOR U. S. NATAL OBSERVATORY, AUTHOR OF " THE A B C OF FINANCE." With One Hundred and Ticdve Engraving*, and Five Maps of the Wars. 8vo. Oloth, $4 GO. The grpo't reputation which the author of this work has merited and enjoys, both in this country and hi Europe, is a sufficient guarantee of its excellence. * * * He has dwelt especially upon those topics which have just now a popular and philosophic interest, carefully employing such lan- guage and such simple explanations as will be intelligible without labori- ous study. Technical terms have as much as possible been avoided. Such as were employed of necessity, and many that occur elsewhere, have been fully explained in a copious glossary at the end of the book. With its abundant aid, the reader cannot fail to derive both pleasure and entertain- ment from the study of what is the most ancient as well as the most ele- vating and inspiring of all the natural sciences. * * * Professor Newcomb, thro^hlWtrthi^^ltqfe' Volume, preserves his well-known character as a writer who, in treating of scientific subjects, fully understands the art of bringing them within the range of popular comprehension. Although his book is a valuable addition to scientific literature, it is fully calculated to hold the attention of the general reader. N. Y. Times. The problem of adapting the facts and principles of a most intricate science to the understanding of the ordinary reader has been earnestly undertaken and successfully solved in this work. * * * The entire volume bespeaks the well-known ability of its author, and furnishes a new title to his world-wide reputation. Boston Transcript. M298784 NewcomVs Popular Astronomy. Professor Newcomb carefully avoids the temptation held out to him bj many parts of the subject to write for effect ; he keeps always faithfully to his purpose, setting forth, with respect to every subject discussed, the history of the investigations made, the positive, certain results attained, and the conjectures which astronomers have founded upon these results, together with the reasoning on which each conjecture rests and the objec- tions that exist to its acceptance. He is, in a word, singularly conscien- tious and perfectly frank ; but the subject itself is so full of wonders that even when treated in this calm, scientific spirit, its discussion is entran- cingly interesting; and Professor Newcomb's work, written as it is in a perfectly clear, simple, and direct style, > likely, we think, to become more than ordinarily popular. N. Y. Evening Post. The book has the great merit of a simplicity that never wearies the reader's attention. It presents the newest as well as the old discoveries, and is free from the errors which mar most of the treatises on astronomy that are designed for non-professional use. Ordinary readers will appre- ciate the circumstance that no mathematical formulas are employed. * * * In each division of the work the history of discovery is made to subserve the purpose of explanation. * * * Step by step the reader is led toward the theories of Copernicus, Kepler, and Newton, and is shown why and how their hypotheses best explained the facts of observation, which have been already detailed. A great advantage is thereby gained o^er ordinary trea- tises of astronomy, which present the recent knowledge first, and either give the facts unsupported, or press their acceptance by means of the stern logic of geometry. In Professor Newcomb's work the great truths grow slowly, and can be measured as they grow. N. Y. Tribune. The author is a master of all the theories and lore of his beloved sci- ence, and he has at command the unrivalled instruments of the United States Naval Observatory at Washington. He is an unwearied investiga- tor and professional enthusiast (in the best sense of the word), and writes an English which all people can understand. Parade and pedantry are wholly absent from this work. jV. Y. Journal of Commerce. Any person of average intelligence can take this volume, and in a month or two become an intelligent observer of the worlds around us. Christian Intelligencer, N. Y. NewcomUs Popular Astronomy. This is one of those books which deserve and are sure to receive a hearty welcome : a full and accurate resume of the subject treated, prepared and brought down to date by one who is a master of the science, and at the same time a clear and vigorous writer. It is a book which ought to be in the library of every intelligent person as a standard authority, safely to be referred to on any topic within its scope ; and yet it is not heavy or dull, but, for the most part, as readable and interesting as a work of fiction. * * * The work is neither abstruse and dry, nor, on the other hand, is it puerile and fanciful, as sometimes happens when savans attempt to popu- larize their favorite sciences, and write down to what they conceive to be the level of the common intelligence. The plan is logical, the due propor- tions of different portions of the subject are observed, and the style is clear, forcible, and sufficiently picturesque and stimulating to keep the attention without effort. Professor CHARLES A. YOCNG, in tfie Independent, N. Y. It is only rarely that a great mathematical astronomer condescends to write books for the people ; and if he does, in four cases out of five, what he writes is unintelligible to all but a very few. Investigators seldom have either the disposition or ability to communicate what they know to the world in general. To this rule, however, there are happy exceptions ; and among them must be counted Professor Xewcomb, whose Popular Astron- omy is undoubtedly the best work of its kind in the English language. Its arrangement is logical, its statements are accurate, its reasonings clear, and its style simple, perspicuous, and sufficiently picturesque. Through- out the book it is everywhere evident that great care has been taken to secure exact and perfect truthfulness of representation: facts are kept distinct from fancies, and theories and speculations stand for just what they are. Sunday School Times, Philadelphia. PUBLISHED BY HARPER & BROTHERS, NEW YORK. Sent by mail, postage prepaid, to any part of tJie Untied States, on receipt of $4 00. THI YXHI THI AFAnHTHI ASTPACTOYSHI KAI ISAITEAQI PREFACE. ALL sciences are making an advance, but Astronomy is moving at the double-quick. Since the principles of this science were settled by Copernicus, four hundred years ago, it has never had to beat a retreat. It is re- written not to correct material errors, but to incorporate new discoveries. Once Astronomy treated mostly of tides, seasons, and telescopic aspects of the planets; now these are only primary matters. Once it considered stars as mere fixed points of light ; now it studies them as suns, determines their age, size, color, movements, chemical constitution, and the revolution of their planets. Once it considered space as empty ; now it knows that every cubic inch of it quivers with greater intensity of force than that which is visible in Niagara. Every inch of surface that can be conceived of between suns is more wave-tossed than the ocean in a storm. The invention of the telescope constituted one era in Astronomy ; its perfection in our day, another ; and the discoveries of the spectroscope a third no less impor- tant than either of the others. While nearly all men are prevented from practical experimentation in these high realms of knowledge, few viii PREPACK have so little leisure as to be debarred from intelligently enjoying the results of the investigations of others. This book has been written not only to reveal some of the highest achievements of the human mind, but also to let the heavens declare the glory of the Divine Mind. In the author's judgment, there is no gulf that separates science and religion, nor any conflict where they stand together. And it is fervently hoped that any one who comes to a better knowledge of God's works through reading this book, may thereby come to a more intimate knowledge of the Worker. I take great pleasure in acknowledging my indebted- ness to J. M. Van Yleck, LL.D., of the U. S. Nautical Almanac staff, and Professor of Astronomy at the Wes- leyan University, for inspecting some of the more im- portant chapters ; to Dr. S. S. White, of Philadelphia, for telescopic advantages ; to Professor Henry Draper, for furnishing, in advance of publication, a photograph of the sun's corona in 1878 ; and to the excellent work on "Popular Astronomy," by Professor Simon New- comb, LL.D., Professor U. S. Naval Observatory, for some of the most recent information, and for the use of the unequalled engravings of Jupiter, Saturn, and the great nebula of Orion. THE CONSTELLATIONS ORION AND TAURUS, NOTES. Star a in Taurus is red, has eight metals ; moves east (page 22T). At o above tip of right horn is the Crab Nebula (page 219). In Orion, a is variable, hao five metals ; recedes 22 miles per second. /3, 3, e, f , p, etc., are double stars, the component parts of various colors and magnitudes (page 212, note). X and are triple ;