THE NEW ASTRONOMY THE NEW ASTRONOMY BY SAMUEL PIERPONT LANGLEY, PH.D., LL.D. DIRECTOR OF THE ALLEGHENY OBSERVATORY, MEMBER NATIONAL ACADEMY, FELLOW ROYAL ASTRONOMICAL SOCIETY, ETC., ETC. Illustrated [Illustration] BOSTON. TICKNOR AND COMPANY 211 Tremont Street 1888 COPYRIGHT, 1884, 1885, 1886, AND 1887, BY THE CENTURY CO.; AND 1887, BY S. P. LANGLEY. _All rights reserved._ University Press: JOHN WILSON AND SON, CAMBRIDGE. PREFACE. I have written these pages, not for the professional reader, but with the hope of reaching a part of that educated public on whose support he is so often dependent for the means of extending the boundaries of knowledge. It is not generally understood that among us not only the support of the Government, but with scarcely an exception every new private benefaction, is devoted to “the Old” Astronomy, which is relatively munificently endowed already; while that which I have here called “the New,” so fruitful in results of interest and importance, struggles almost unaided. We are all glad to know that Urania, who was in the beginning but a poor Chaldean shepherdess, has long since become well-to-do, and dwells now in state. It is far less known than it should be that she has a younger sister now among us, bearing every mark of her celestial birth, but all unendowed and portionless. It is for the reader’s interest in the latter that this book is a plea. CONTENTS. CHAPTER PAGE I. SPOTS ON THE SUN 1 II. THE SUN’S SURROUNDINGS 35 III. THE SUN’S ENERGY 70 IV. THE SUN’S ENERGY (_Continued_) 91 V. THE PLANETS AND THE MOON 117 VI. METEORS 175 VII. COMETS 199 VIII. THE STARS 221 INDEX 253 LIST OF ILLUSTRATIONS. FIGURE PAGE 1. THE SUN’S SURROUNDINGS 4 2. VIEW OF THE SUN ON SEPT. 20, 1870 6 3. THE SUN ON SEPT. 22, 1870 6 4. THE SUN ON SEPT. 26, 1870 7 5. THE SUN ON SEPT. 19, 1870 8 6. THE SUN ON SEPT. 20, 1870 8 7. THE SUN ON SEPT. 21, 1870 9 8. THE SUN ON SEPT. 22, 1870 9 9. THE SUN ON SEPT. 23, 1870 10