76 illustrations. 6 x 9, cloth, 210 pp Net, $2.50

Second Edition, corrected 265 illustrations. 8vo., cloth, 501 pp. Net, $4.00

A simple practical pocket guide on the construction, operation, maintenance, and testing of primary batteries for automobile, motorboat, and stationary engine ignition service. 26 illustrations. 5 x 7, cloth, 79 pp Net, 0.50

Third Edition. Illustrated. 16mo., cloth, 104 pp. (No. 68 Van Nostrand's Science Series.) 50 cents.

WATT, ALEXANDER. Electroplating and Refining of Metals

New Edition, rewritten by Arnold Philip. Illustrated 8vo., cloth, 704 pp Net, $4.50

WEBB, H. L. A Practical Guide to the Testing of Insulated Wires and Cables

Sixth Edition. Illustrated. 12mo., cloth., 118pp $1.00