Note: Images of the original pages are available through Internet Archive. See http://archive.org/details/asteroidsorminor00kirkrich Transcriber's note: Text enclosed by underscores is in italics (_italics_). Every effort has been made to replicate this text as faithfully as possible, including non-standard spelling and punctuation. Some apparent typographical errors in the indices and names of asteroids in Tables I and II have been corrected. THE ASTEROIDS, Or Minor Planets Between Mars and Jupiter. by DANIEL KIRKWOOD, LL.D., Professor Emeritus in the University of Indiana; Author of "Comets and Meteors," "Meteoric Astronomy," etc. Philadelphia: J. B. Lippincott Company. 1888. Copyright, 1887, by Daniel Kirkwood. [Illustration] PREFACE. The rapid progress of discovery in the zone of minor planets, the anomalous forms and positions of their orbits, the small size as well as the great number of these telescopic bodies, and their peculiar relations to Jupiter, the massive planet next exterior,--all entitle this part of the system to more particular consideration than it has hitherto received. The following essay is designed, therefore, to supply an obvious want. Its results are given in some detail up to the date of publication. Part I. presents in a popular form the leading historical facts as to the discovery of Ceres, Pallas, Juno, Vesta, and Astræa; a tabular statement of the dates and places of discovery for the entire group; a list of the names of discoverers, with the number of minor planets detected by each; and a table of the principal elements so far as computed. In Part II. this descriptive summary is followed by questions relating to the origin of the cluster; the elimination of members from particular parts; the eccentricities and inclinations of the orbits; and the relation of the zone to comets of short period. The elements are those given in the Paris _Annuaire_ for 1887, or in recent numbers of the _Circular zum Berliner Astronomischen Jahrbuch_. DANIEL KIRKWOOD. BLOOMINGTON, INDIANA, November, 1887. CONTENTS. PART I. PAGE PLANETARY DISCOVERIES BEFORE THE ASTEROIDS WERE KNOWN 9 DISCOVERY OF THE FIRST ASTEROIDS 11 TABLE I.--ASTEROIDS IN THE ORDER OF THEIR DISCOVERY 17 NUMBERS FOUND BY THE RESPECTIVE DISCOVERERS 23 NUMBERS DISCOVERED IN THE DIFFERENT MONTHS 25 MODE OF DISCOVERY 25 NAMES AND SYMBOLS 25 MAGNITUDES OF THE ASTEROIDS 26 ORBITS OF THE ASTEROIDS 28 TABLE II.--ELEMENTS OF THE ASTEROIDS 29 PART II. EXTENT OF THE ZONE 37