On the various forces of nature and their relations to each other

ON THE VARIOUS FORCES OF NATURE.

_WORKS by RICHARD A. PROCTOR._

EASY STAR LESSONS. With Star Maps for Every Night in the Year, Drawings of the Constellations, &c. Crown 8vo, cloth extra, 6s.

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SATURN AND ITS SYSTEM. Revised Edition, with 13 Steel Plates. Demy 8vo, cloth extra, 10s. 6d.<...