334 SCIENCE PROGRESS 



Airplane Photography. By Herbert E. Ives, Major in Charge of Experi- 

 mental Department, Photographic Branch, Air Service, U.S.A. 

 [Pp. 422, with 210 illustrations.] (Philadelphia and London: J. B. 

 Lippincott Co., 1920. Price 18s. net.) 



Aeroplane photography practically originated in the war, and under the 

 stress of military and naval requirements, it underwent an extraordinarily 

 rapid development and reached a relatively high pitch of perfection. The 

 author of this volume, a scientist who became head of the photographic 

 experimental department of the U.S. Air Service, is convinced that it has 

 equally great possibilities and practical uses in times of peace. The semi- 

 popular treatise under review contains an account of the methods employed 

 in aeroplane photography during the war, the uses to which it was put, 

 and its possibilities for the future. The book is extremely well illustrated, 

 and many of the illustrations, particularly those of war subjects, are of 

 fascinating interest. To some extent the requirements during the war 

 were extreme : in order not to become too easy a target for anti-aircraft 

 gunners, aeroplanes had to fiy at a great speed and generally at a great 

 height ; this necessitated the length of exposures being reduced to a mini- 

 mum and, generally, successive photographs being taken at as short 

 intervals as possible. These requirements to some extent conditioned the 

 types of camera and the brands of plates used, and the methods of develop- 

 ment employed. But, although peace conditions differ somewhat, it is 

 desirable that those who would contribute to future peace-time develop- 

 ment should be acquainted with what has already been done. Major Ives' 

 volume will serve this purpose ; in addition, it will be found of great interest 

 by the large body of amateur photographers. 



The nature of the contents of the volume can be tolerably well indicated 

 by the titles of the sections into which it is divided : Introductory ; The 

 Airplane Camera ; The Suspension and Installation of Airplane Cameras ; 

 Sensitised Materials and Chemicals ; Methods of Developing Plates, Films, 

 and Papers ; Practical Problems and Data ; The Future of Aerial Pho- 

 tography. 



The last section will be found in some ways the most interesting ; the 

 author's views, based on a wide practical experience, must receive great 

 weight, and it appears certain that peace-time aerial photography has a 

 great future before it. Apart from purely pictorial uses, it has undoubted 

 advantages in preliminary surveys for engineering purposes in undeveloped 

 country ; in locating submerged vessels, with a view to estimating the 

 chances of salvage ; in city mapping ; in revealing shifts in channels and 

 shallows ; in making coast and harbour surveys, and in other directions too 

 numerous to mention. 



The most important omission is an account of the method employed in 

 the French Air Service of obtaining a photograph true to scale from an 

 oblique (distorted) photograph : for accurate mapping purposes, the use 

 of such a method of restitution is essential. 



H. S. J. 



MISCELLANEOUS 



Food Inspection and Analysis, for the Use of Pubhc Analysts, Health 

 OflBcers, Sanitary Chemists, and Food Economists. By Albert 

 E. Leach, S.B. Fourth Edition, revised and enlarged by Andrew 

 L. WiNTON, Ph.D. [Pp. xix + 1090, with 120 figures and 40 plates.] 

 (New York : John Wiley & Sons, 1920. Price 45s. net.) 



All who are interested in the important subject of food inspection and 

 analysis will welcome the appearance of the fourth edition of this standard 

 work, which represents an advance on the previous editions in more than 



