By Sir ROBERT STAWELL BALL, LL.D., F.R.S., author of “The Story of the Sun,” “An Atlas of Astronomy,” “Star-Land,” etc.; Lowndean Professor of Astronomy and Geometry in the University of Cambridge; Director of the University Observatory, etc. With four colored Plates and numerous Illustrations. 12mo. Cloth, $1.80 net; postage, 18 cents additional. This book will make admirable reading for persons of any age. It provides a clear and popular explanation of the great problem of the earth’s beginning. It is believed that no exposition of the nebular theory and its infinitely wide ramifications has been made that is at once so simple, so original, and so comprehensive. Dr. Ball’s success as a lecturer in this country indicates his gift of popular exposition, and this book will rank as one of the most attractive presentations of scientific fact and theory for general readers. =The Sun.= By C. A. YOUNG, Ph.D., LL.D., Professor of Astronomy in Princeton University. New and revised edition, with numerous Illustrations. 12mo. Cloth, $2.00. =The Expanse of Heaven.= By RICHARD A. PROCTOR. A Series of Essays on the Wonders of the Firmament. 12mo. Cloth, $2.00. =Other Worlds Than Ours.= By RICHARD A. PROCTOR. The Plurality of Worlds, Studied under the Light of Recent Scientific Researches. With Illustrations, some colored. 12mo. Cloth, $1.25. =Light Science for Leisure Hours.= By RICHARD A. PROCTOR. A Series of Familiar Essays on Scientific Subjects, Natural Phenomena, etc. 12mo. Cloth, $1.75. =The Story of the Stars.= By G. F. CHAMBERS, F.R.A.S., author of “Handbook of Descriptive and Practical Astronomy,” etc. With 24 Illustrations. (Library of Useful Stories.) 16mo. Cloth, 35 cents net; postage, 4 cents additional. D. APPLETON AND COMPANY, NEW YORK. ------------------------------------------------------------------------ ● Transcriber’s Notes: ○ Missing or obscured punctuation was silently corrected. ○ Typographical errors were silently corrected. ○ Inconsistent spelling and hyphenation were made consistent only when a predominant form was found in this book. ○ Text that: was in italics is enclosed by underscores (_italics_); was in bold by is enclosed by “equal” signs (=bold=) had extra character spacing by “plus” signs (+stretched+). ○ The use of a caret (^) before a letter, or letters, shows that the following letter or letters was intended to be a superscript, as in S^t Bartholomew or 10^{th} Century.