A11 technical terms, and all mathematics, except certain simple figures necessary for de scription and comparison, have been omitted, and no signs or symbols have been used except those to be found in the ordinary almanacs. These last do not appear in the text, but are given on a separate page in the back part of the volume. In spite of these omissions, it is hoped that this compilation may have some value as a concise reference book for the general reader or for schools. With a View toward simplicity, the writer has given no exact figures such as would be necessary in an advanced textbook, but has stated all numerical values in the closest approximate terms. There has been added — what the compiler has never happened to see before — a tabulated chronology of the main events in the history of Astronomy, and also a chapter very brie?y de scribing the various instruments now used in the great observatories. In the bibliography at the end of the volume, are listed the titles of all the books used for reference in checking the descriptions, figures, and statements given. To the authors of all of these books, the writer is much indebted. Following each title is a short note, endeavoring to present an idea of the scope of that volume. If, upon reaching this bibliography, the reader is enough interested in the greatest and most ancient of sciences to turn to some of these real books upon the subject, the main purpose of these pages will have been accomplished.