The book is intended for class-room use and affords such a preparation as the student needs before entering upon the study of the larger and more elaborate works on this subject. The appendix contains an elementary exposition of the method of least squares. Daniel Carhart, Act. Prof. Mathematics, Western Univ. of Pa., Allegheny, Pa.: "Professor Greene has supplied that which is needed to make the usual course in Astronomy in our colleges more practical." Rodney G. Kimball, Polytechnic Institute, Brooklyn, N.Y.: "The hasty examination which I have given it has left a very favorable impression as to its merits as a judicious compound of the practical work which it professes to cover." SCHEINER'S ASTRONOMICAL SPECTROSCOPY Department of Special Publication.--Revised Edition. Translated, revised and enlarged by E.B. FROST, Professor of Astronomy in Dartmouth College. 8vo. Half leather. Illustrated. xiii + 482 pages. Price by mail, $5.00; for introdoctiort, $4.75. This work aims to explain the most practical and modern methods of research, and to state our present knowledge of the constitution, physical condition alld motions of the heavenly bodies, as revealed by the spectroscope. Edward S. Holden, Director of the Lick Observatory, Mt. Hamilton, California: "I congratulate you on the appearance of this very important book; it is indispensable to all astronomers and students of spectroscopy." ELEMENTS OF PLANT ANATOMY By EMILY L. GREGORY, Professor of Botany in Barnard College. 8vo. Cloth. viii + 148 pages. Illustrated. Mailing price, $1.35; for introduction, $1.25. This book is designed as a text-book for students who have already some knowledge of general botany. It consists of an outline of the principal facts of plant anatomy, in a form available not only for those who wish to specialize in botany but for all who wish to know the leading facts about the inner structure of plants. It affords a preparation for the study of the more intricate and difficult questions of plant anatomy and physiology, while it is especially adapted to the wants of students, who need a practical knowledge of plant structure. ELEMENTS OF STRUCTURAL AND SYSTEMATIC BOTANY For High Schools and Elementary College Courses. By DOUGLAS H. CAMPBELL, Professor of Botany in the Leland Stanford Junior University. 12mo. Cloth. ix + 253 pages. Price by mail, $1.25; for introduction, $1.12. The special merit of this book is that it begins with the simple forms, and follows the order of nature to the complex ones. PLANT ORGANIZATION By R. HALSTEAD WARD, formerly Professor of Botany in the Rensselaer Polytechnic Institute, Troy, N.Y. Quarto. 176 pages. Illustrated. Flexible boards. Mailing price, 85 cents; for introduction, 75 cents. ELEMENTARY METEOROLOGY By WILLIAM MORRIS DAVIS, Professor of Physical Geography in Harvard College. With maps and charts. 8vo. Cloth. xi + 355 pages. Mailing price, $2.70; for introduction, $2.50.