MCILWAIN, KNOX, AND J. G. BRAINERD. High Frequency Alternating Currents. 1931. MONTESSUS DE BALLORE, R. DE. Probabilit6s et Statistiques. 1931. MOYER, JAMESA., AND JOHN F. WOSTREL. The Radio Handbook. First edition. 1931. NEBLETTE, C. n. Photography: Its Principles and Practice. Second edition. 1931. OMWAKE,JOHN, The Conestoga Six-Horse Bell Teams of Eastern Pennsylvania. 193 ° • Organic Syntheses: an Annual Publication of Satisfactory Methods for the Preparation of Chemicals. Volumes 6-1o. Five volumes. 1926-193o. REYNER, J . H . Testing Radio Sets. 193o. Society of Chemical Industry. Annual Reports on the Progress of Applied Chemistry. Volume I5, 193o. STORY, JOHN P. Elements of Flastic Strength of Guns. 1894. SWAIN, GEORGE FILLMORE. Structural Engineering: Volume I, Strength of Materials; Volume II, Fundamental Properties of Materials; Volume III, Stresses, Graphical Statics and Masonry. Three volumes. 1924-1927 . United States Patent Office. Index of Trade-Marks 193o , 1931. VOGEL, HANS, AND ALFRED GEORG. Tabellen der Zucker und ihrer Derivate. 1931. WEINSTEIN, MICHAEL. Precious and Semi-Precious Stones. Second edition. 193o. Wien-Harms Handbuch der Experimentalphysik. Band 25, 2 Tell. 1931.
BOOK REVIEWS. L'EvOLUTION ET LE DI~VELOPPEMENT DES PRINCIPALES INDUSTRIES DEPUIS CINQUANTE ANS (1880-1930). Numero speciale publi6 a l'occasion du Cinquantenaire du Genie Civii--236 pages quarto, illustrations, paper. Paris, Bureau du Genie Civil. Price 25 frs. The fiftieth anniversary of this widely known journal of industrial arts is fittingly celebrated by a collection of monographs on the evolution and progress of typical industries during that period. There are forty-two papers, all-told, including a short historical account of the journal during its fifty years of existence. The authors are notable specialists in French science or industry: twelve are members of the Institut, seven former presidents of the society of civil engineers and the greater part of the others professors in the foremost engineering schools of Paris. The collection is of rare interest, well illustrated and representative. L. E. P. A TEXTBOOK OF PRACTICAL PHYSICAL CHEMISTRY, by F. Fajans, Professor of Physical Chemistry in the University of Munich and J. Wrist. Translated from the German by Bryan Topley with a preface by F. G. Donnan, LL.D., F.R.S. XV-233 pages, diagrams, 8vo, New York, E. P. Dutton & Company, Inc. Price, $4.95. No doubt many a teacher of physical chemistry will feel that this book is " J u s t what he has been looking for." With aid from some of their colleagues the
[J. F. I.
authors have evolved a text on practical physical chemistry which for its size, would be difficult to surpass in its clarity and detail. In addition to the excellent directions on how to carry out these physical chemistry measurements, each unit of experimental procedure is prefaced by an appropriate theoretical exposition which will give the student a better insight into the laws characterizing the physical and chemical properties of substances as well as teach him the significance of his results and enable a correct evaluation of the data. The book is quite up to date and contains practically all the well established methods universally employed by chemists in their physical-chemistry researches. Among those procedures of more recent development we may list: (I) Coagulation of a Sol by Electrolytes of Different Valencies; (2) The Transformation of RadioElements; (3) Ultra-Violet Spectrography; (4) Preparation of Substances by Electrochemical Means. T. K. CLEVELAND. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS. Report No. 374, The Automotive Ignition Coil, by T. H. Darnell, 28 pages, illustrations, quarto. Washington, Government Printing Office, 1931. Price twenty-five cents. This paper which was submitted by the Bureau of Standards for publication gives the results of an extensive series of measurements on the secondary voltage induced in an ignition coil of typical construction under a variety of operating conditions. These results show that the theoretical predictions hitherto made as to the behavior of this type of apparatus are in satisfactory agreement with the observed facts. The large mass of data obtained is here published both for the use of other investigators who may wish to compare them with other theoretical predictions and for the use of automotive engineers who will here find definite experimental results showing the effect of secondary capacity and resistance on the crest voltage produced by ignition apparatus. Report No. 379. Rolling Moments due to Rolling and Yaw for Four Wing Models in .Rotation, by Montgomery Knight and Carl J. Wenzinger, 27 pages, illustrations, quarto. Washington, Government Printing Office, 1931. Price fifteen cents. Tiais report presents the results of a series of auto-rotation and torque tests on four different rotating wing systems at various rates of roll and at several angles of yaw. The investigation covered an angle-of-attack range up to 9°0 and angles of yaw of o °, 5°, IO°, and 20 °. The tests were made in the 5-foot, closed-throat atmospheric wind tunnel of the National Advisory Committee for Aeronautics. The object of the tests was primarily to determine the effects of various angles of yaw on the rolling moments Of the rotating wings up to large angles of attack. It was found that at angles of attack above that of maximum lift the roiling moments on the wings due to yaw (or side slip) from 5 ° to 20 ° were roughly of the same magnitude as those due to rolling. There was a wide variation in magnitude of the rolling moment due to yaw angle with both angle of attack and with pb/2V. The rates and ranges of stable autorotation for the monoplane models were considerably increased by yaw, whereas for an unstaggered biplane