he
process have been received.

* * * * *

Recent Books.

* * * * *

ELECTRO-METALLURGY. Electric Smelting and Refining: The Extraction
and Treatment of Metals by means of the Electric Current. Being the
second edition of Elektro-Metallurgie by Dr. W. Borchers. Translated,
with additions, by Walter G. McMillan. With 3 plates and numerous
illustrations in the text. 8vo, cloth. 416 pages. London and New York,
1897 $6.50

ELECTRO-TECHNICAL SERIES. By Edwin J. Houston, Ph.D., and A.E.
Kennelly, D.Sc. Ten volumes: Alternating Electric Currents, Electric
Heating, Electro-Magnetism, Electricity in Electro-Therapeutics,
Electric Arc Lighting, Electric Incandescent Lighting, Electric
Motors, Electric Street Railways, Electric Telephony, Electric
Telegraphy. Each $1.00

ENGINEERS. The Practical Management of Engines and Boilers,
including Boiler Setting, Pumps, Injectors, Feed Water Heaters, Steam
Engine Economy, Condensers, Indicators, Slide Valves, Safety Valves,
Governors, Steam Gages, Incrustation and Corrosion, etc. A Practical
Guide for Engineers and Firemen and Steam Users generally. By William
B. Le Van. 12mo, cloth. 267 pages. 49 illustrations. 1897 $2.00

EXPERIMENTAL SCIENCE. By George M. Hopkins. This book treats on the
various topics of Physics in a popular and practical way. It describes
the apparatus in detail, and explains the experiments in full, so that
teachers, students and others interested in Physics may readily make
the apparatus without expense and perform the experiments without
difficulty. The aim of the writer has been to render physical
experimentation so simple and attractive as to induce both old and
young to engage in it for pleasure and profit. A few simple
arithmetical problems comprise all of the mathamatics of the book.
Many new experiments are here described for the first time. It is the
most thoroughly illustrated work over published on Experimental
Physics. 840 pages. Over 790 illustrations. Seventeenth edition.
Revised and enlarged. 8vo, cloth $4.00

EXPLOSIVES. Lectures on Explosives. A course of Lectures prepared
especially as a Manual and Guide in the Laboratory of the United
States Artillery School. By Willoughby Walke, First Lieut. Fifth
United States Artillery. Second edition. Revised and enlarged. 8vo,
cloth. 435 pages. New York, 1897 $4.00

FEEDS AND FEEDING. A Handbook for the Student and Stockman. By