HOBBS, W. R. P. The Arithmetic of Electrical Measurements.

With numerous examples, fully worked. Sixteenth Edition, revised and edited with six additional chapters by A. R. Palmer. 12mo. cloth, 126 pp 50 cents.

22 illustrations. 5 3/4 x 8 3/4, cloth, 120 pp Net, $2.00

Being a Treatise on the Hydro-Electric Generation of Energy; Its Transformation, Transmission, and Distribution. Second Edition. Illustrated. 12mo., cloth, 350 pp Net, $3.00

INCANDESCENT ELECTRIC LIGHTING.

A Practical Description of the Edison System, by H. Latimer. To which is added: The Design and Operation of Incandescent Stations, by C. J. Field; A Description of the Edison Electrolyte Meter, by A. E. Kennelly; and a Paper on the Maximum Efficiency of Incandescent Lamps, by T. W. Howell. Fifth Edition. Illustrated. 16mo., cloth, 140 pp. (No. 57 Van Nostrand's Science Series.) 50 cents

Eleventh Edition. Illustrated. 16mo., cloth, 123 pp. (No. 53 Van Nostrand's Science Series.) 50 cents

Illustrated with numerous Diagrams, Tables, and Folding Plates. 8vo., cloth, 232 pp Net, $4.00