Air Photography Applied to Surveying

Abstract

NO one could be better qualified than Dr. Hart to write this book, on the use of air photographs in the making of maps. Unfortunately for the advocates of this new method of surveying, they have had not only to amplify and perfect the instruments, the cameras and aeroplanes as well as the ground instruments, but they have also had to persuade the future users of the maps and surveyors that the resultant maps in many cases will be better in quality, quicker and cheaper in execution, and more accurate than maps made by older methods. Now when we consider the reasons for this rather curious state of affairs, we must attribute the blame fairly between the conservatism of surveyors and the over-statement of the merits of these air survey methods by some of the original advocates. There is, moreover, one other reason, and that is that this new method was left to commercial companies to develop, while heretofore it had always been Governments which had supplied maps. It was therefore often difficult for a man to realize that the sheet he could buy for 2s. 6d. had cost thousands of pounds to survey, and that the advocate was not only trying to sell him something, but also to sell something really good.

Air Photography Applied to Surveying

By Dr. C. A. Hart. Pp. xx + 366 + 4 plates. (London, New York and Toronto: Longmans, Green and Co., Ltd., 1940.) 25s. net.