Produced by Charles Franks, Robert Rowe and the Online Distributed Proofreading Team. HTML version by Al Haines. SIDE-LIGHTS ON ASTRONOMY AND KINDRED FIELDS OF POPULAR SCIENCE ESSAYS AND ADDRESSES BY SIMON NEWCOMB CONTENTS PREFACE I. THE UNSOLVED PROBLEMS OF ASTRONOMY II. THE NEW PROBLEMS OF THE UNIVERSE III. THE STRUCTURE OF THE UNIVERSE IV. THE EXTENT OF THE UNIVERSE V. MAKING AND USING A TELESCOPE VI. WHAT THE ASTRONOMERS ARE DOING VII. LIFE IN THE UNIVERSE VIII. HOW THE PLANETS ARE WEIGHED IX. THE MARINER'S COMPASS X. THE FAIRYLAND OF GEOMETRY XI. THE ORGANIZATION OF SCIENTIFIC RESEARCH XII. CAN WE MAKE IT RAIN? XIII. THE ASTRONOMICAL EPHEMERIS AND NAUTICAL ALMANAC XIV. THE WORLD'S DEBT TO ASTRONOMY XV. AN ASTRONOMICAL FRIENDSHIP XVI. THE EVOLUTION OF THE SCIENTIFIC INVESTIGATOR XVII. THE EVOLUTION OF ASTRONOMICAL KNOWLEDGE XVIII. ASPECTS OF AMERICAN ASTRONOMY XIX. THE UNIVERSE AS AN ORGANISM XX. THE RELATION OF SCIENTIFIC METHOD TO SOCIAL PROGRESS XXI. THE OUTLOOK FOR THE FLYING-MACHINE ILLUSTRATIONS SIMON NEWCOMB PHOTOGRAPH OF THE CORONA OF THE SUN, TAKEN IN TRIPOLI DURING TOTAL ECLIPSE OF AUGUST 30, 1905. A TYPICAL STAR CLUSTER-CENTAURI THE GLASS DISK THE OPTICIAN'S TOOL THE OPTICIAN'S TOOL GRINDING A LARGE LENS IMAGE OF CANDLE-FLAME IN OBJECT-GLASS TESTING ADJUSTMENT OF OBJECT-GLASS A VERY PRIMITIVE MOUNTING FOR A TELESCOPE THE HUYGHENIAN EYE-PIECE SECTION OF THE PRIMITIVE MOUNTING SPECTRAL IMAGES OF STARS, THE UPPER LINE SHOWING HOW THEY APPEAR WITH THE EYE-PIECE PUSHED IN, THE LOWER WITH THE EYE-PIECE DRAWN OUT THE GREAT REFRACTOR OF THE NATIONAL OBSERVATORY AT WASHINGTON THE "BROKEN-BACKED COMET-SEEKER" NEBULA IN ORION DIP OF THE MAGNETIC NEEDLE IN VARIOUS LATITUDES STAR SPECTRA PROFESSOR LANGLEY'S AIR-SHIP PREFACE In preparing and issuing this collection of essays and addresses, the author has yielded to what he could not but regard as the too flattering judgment of the publishers. Having done this, it became incumbent to do what he could to justify their good opinion by revising the material and bringing it up to date. Interest rather than unity of thought has determined the selection. A prominent theme in the collection is that of the structure, extent, and duration of the universe. Here some repetition of ideas was found unavoidable, in a case where what is substantially a single theme has been treated in the various forms which it assumed in the light of constantly growing knowledge. If the critical reader finds this a defect, the author can plead in extenuation only the difficulty of avoiding it under the circumstances. Although mainly astronomical, a number of discussions relating to general scientific subjects have been included.