RECENT ADDITIONS.

ANDERSON—The Prospector's Hand-Book:

A Guide for the Prospector and Traveler in Search of Metal Bearing or other Valuable Minerals. By J.W. Anderson. 52 Illustrations. 12mo. $1.50

BILGRAM.—Slide-Valve Gears:

A new, graphical method for Analyzing the Action of Slide-Valves, moved by Eccentrics, Link Motions, and Cut-off Gears, offering easy means for properly designing Valves and Valve-Gears, and for establishing the comparative merits of their various constructions. By Hugo Bilgram, M.E. Illustrated. 16mo. $1.00

CREW.—A Practical Treatise on Petroleum:

Comprising its Geographical Distribution, its Geology, Chemistry, Mining, Refining, Preparation, and Uses. Together with a Description of Gas Wells and the Application of Gas as Fuel, etc. By Benjamin J. Crew. Illustrated. 8vo. (In preparation.)

CROOKES.—Select Methods in Chemical Analysis (Chiefly Inorganic):

By William Crookes, F.R.S., V.P.C.S. 2d edition, re-written and greatly enlarged. Illustrated by 37 wood-cuts. 725 pp. 8vo. $9.50