WILLIAM G. PECK, Ph.D., LL.D.,

PROFESSOR OF MATHEMATICS, MECHANICS, AND ASTRONOMY, IN COLUMBIA COLLEGE.

A. S. BARNES & COMPANY,

PREFACE.

HE following work has been prepare

THE

wants of the Author, but it is hoped of service not only to other teachers of Astr to the general scientific reader.

The book is intended to present, in a com lar form, all the facts and principles of the needed in a general course of collegiate educ end, mathematical formulas and demonstrat avoided as far as possible, and when it ha advisable to introduce them, they have be spicuous by putting them in smaller type. ordinate paragraphs are omitted, it will be remaining ones form a continuous treatise which is as non-mathematical in its chara sistent with a scientific treatment of the sub

It will be found that the order of arrang what different from that which is met with books. The stars have been treated of in