*SODDY, F. Radio-Activity; an Elementary Treatise from the Standpoint of the Disintegration Theory.* Fully Illustrated. 8vo., cloth, 214 pp Net, $3.00
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*THIESS, J. B. and JOY, G. A. Toll Telephone Practice.* 273 illustrations. 8vo., cloth, 433 pp Net, $3.50
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