RAILWAY ELECTRIC TRACTION. By F. W. CARTER, M.I.E.E., HEAD OF THE TRACTION DEPARTMENT OF THE BRITISH THOMSON HOUSTON COMPANY, RUGBY. 400 pages, with 204 diagrams, photographs and plates. Demy 8vo. Cloth. About 25s. net. The author, a well-known authority on this subject, starts with a survey of the different systems of electrification and with a comparison between steam and electric working under various conditions. He then deals with the locomotive, distribution systems, etc., in detail and develops the mathematical calculations necessary for dealing with the various problems which arise. Finally the characteristics of the principal types of electrical locomotives throughout the world are given with photographs of certain of these locomotives. ELEMENTARY HYDRAULICS FOR TECHNICAL STUDENTS. By F. C. LEA, D.Sc., M.INST., C.E., PROFESSOR OF CIVIL ENGINEERING IN THE UNIVERSITY OF BIRMINGHAM. Crown 8vo. About 8s. 6d. net. Professor Lea, who is well known as the author of "Hydraulics for Engineers and Engineering Students," has here written a shorter book suitable for the courses taken in Technical Schools. Certain of the more elementary portions of the original book are included in this volume, but much of the material is new. IONS ELECTRONS AND IONIZING RADIATIONS. By J. A. CROWTHER, M.A., Sc.D., UNIVERSITY DEMONSTRATOR IN EXPERIMENTAL PHYSICS IN THE UNIVERSITY OF CAMBRIDGE. Third Edition. Demy 8vo. 12s. 6d. net. This book, originally published in November, 1919, has been thoroughly revised. Many portions have been entirely rewritten and of these the Chapter on "The Electron Theory of Matter" should be especially mentioned. The tables of constants have been revised in accordance with the best data available and the book is in all respects abreast of the progress in this fast developing branch of modern Physics. London: EDWARD ARNOLD & Co., 41 & 43 Maddox Street, W. 1. End of Project Gutenberg's A New Medley of Memories, by David Hunter-Blair