Geographical Reconnaissance by Aeroplane Photography, with Special Reference to the Work Done on the Palestine Front: Discussion Author(s): Geoffrey Salmond, Coote Hedley, H. S. L. Winterbotham, A. R. Hinks and E. M. Jack Source: The Geographical Journal, Vol. 55, No. 5 (May, 1920), pp. 370-376 Published by: geographicalj Stable URL: http://www.jstor.org/stable/1780447 Accessed: 25-06-2016 21:41 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. The Royal Geographical Society (with the Institute of British Geographers), Wiley are collaborating with JSTOR to digitize, preserve and extend access to The Geographical Journal This content downloaded from 137.99.31.134 on Sat, 25 Jun 2016 21:41:03 UTC All use subject to http://about.jstor.org/terms 370 GEOGRAPHICAL RECONNAISSANCE BY the great utility of maps which are sufficiently complete in local features to enable one to identify one's position by reference to the map detail. Most of the pre-war reconnaissance maps which I have used in the East, and which would be probably regarded as good of their type, involved the need of constantly stopping to take bearings on some distant known points in order to ascertain one's position, and this is a tiresome proceeding. Some experiences in the field almost persuade one to put forward the thesis that in a reconnaissance map wealth of local detail and accuracy of relative position, by which the traveller knows exactly where he is and what features he is likely to meet, are to be preferred to a map which is poor in local detail even though the latitudes and longitudes are abso- lutely correct for those points which are shown. There is much to be said for this point of view, though it is perhaps scientifically unsound. It is the full and detailed picture of the ground which can be so quickly and easily secured by aeroplane photography; and if methods are forthcoming of utilizing this picture to make a good small-scale map by an easy, rapid, and reliable method, then air photography will have an important future. If, however, the methods are slow and cumbrous they will only be useful in special emergencies. The work already carried out in Palestine does seem to show that air photography possesses great advantages for reconnaissance work. The actual photography and mapping of 2000 square miles of country must be regarded as a real solid achievement rather than as an experi- ment. The methods may be criticized on theoretical grounds, but the results are the best answer to such criticism. Work on the same general lines has been successfully carried out in Egypt and Mesopotamia, which also shows that a practicable system has been attained from which much may be expected. Aerial photography must not, however, be applied to purposes for which it is unsuited; it can have no bearing on the geodetic side of survey work, and it is more suited for maps on a medium scale than for very large-scale maps or very small-scale maps. The methods described have been elaborated by the close co-operation of surveyors with members of the Air Force, and it seems probable that further progress will only be made by the collaboration of the producers and users of air photographs. It is this belief which has prompted the author to contribute this paper. Before the paper the PRESIDENT said' The lecturer this evening, Captain Hamshaw Thomas, was, before the war, more closely connected with the earth than with the air: a lecturer in Botany, and Fellow of Downing College, Cambridge. When the war broke out he joined the Air Force and has done some interesting reconnaissance work in Palestine. He will this evening give us the results of his experiences as to air photography. He will give us a different point of view from that which we heard last session-an account of air photography on the Western Front, which required very much more minute detail, This content downloaded from 137.99.31.134 on Sat, 25 Jun 2016 21:41:03 UTC All use subject to http://about.jstor.org/terms AEROPLANE PHOTOGRAPHY: DISCUSSION 37I whereas Captain Thomas's reconnaissance work was of a more general kind. I have very much pleasure in introducing him to you and asking him to read his paper. Captain Hamshaw Thomas then read the paper printed above, and a discussion followed. Major-General Sir GEOFFREY SAI.MOND: I have been listening to a very interesting lecture. Captain Thomas was my photographic officer in the Middle East for a considerable period, and really the success of General Allenby's force was, to a very great degree, attributable to the work Captain Thomas did. I would like, as we have been talking about aerial photography, to just state a few details of how aerial photography first came into being. Aerial photography, although it seems a strange thing, is very closely linked in its origin with artillery work and wireless, because it was the necessity of squared maps and great detail for efficient artillery co-operation in the early days of the war in I9I4, which made us go in for extreme accuracy and attempting to produce results from the air which otherwise we never should have attempted. Originally there was no method properly brought up to perfection of directing artillery fire with wireless, and the late Colonel D. S. Lewis, Royal Engineers, when we were on the Aisne, was the first officer who took this matter up, and taking the 80,000 map with which we were supplied in France, he squared that map in pencil and then made another map similarly squared, and gave it to a battery commander. This done he went out with his wireless machine and produced at once the most extraordinarily good results. The necessity of squared maps now became at once apparent, and when we moved up to Flanders squared maps were one of the first things with which we were supplied, and this was only brought about by the extraordinarily efficient and rapid manner in which the Map Department of the General Staff of G.H.Q. under Major Jack tackled the job. I always think we were indebted very much to his work in producing these squared maps, which became universal on the whole British front. About the same time that they were produced we tried to advance in aerial photography. The French, about October I914, were getting forward, and sent our General Staff some results which at once made us feel we had something to learn, and we set about it, and in a very short time, thanks to the help of Sir Frederick Sykes and Sir Hugh Trenchard, we had a photographic section going with both wings in France, subsequently developing into a photographic section with each army, and then more than that later on. Directly our photographic work began to progress the tremendous advantage of having the squared system of mapping became apparent, because our trenches were accurately photographed and the results pleased everybody. The next thing that happened was, that our results were becoming so good that the photographic section of the photographic staff at R.A.F. headquarters approached the Survey Department G.H.Q. in order to further co-ordinate our work, and once that was done, from that day forward we never looked back. It is this very close co-operation between aerial photography and the survey department which, I believe, is one of the chief lessons to be learned as the result of the war as far as aerial photography is concerned. In Palestine we always used to put our headquarters as close to the Survey Headquarters as possible, in order that this very close liaison should be kept going. The task in Egypt was, as Captain Thomas has said, very different from that in France. In France we could take our aerial photographs and base them on an accurate map. In Egypt that was impossible, and in October 1915, when I went out to This content downloaded from 137.99.31.134 on Sat, 25 Jun 2016 21:41:03 UTC All use subject to http://about.jstor.org/terms 372 GEOGRAPHICAL RECONNAISSANCE BY Egypt, I found that whereas a certain amount of information trickled out to what we called the " side shows," about the development of aerial photography, yet no real policy had been adopted. For instance, in Salonika they had squared maps which were on a French basis-because the French were there first, or about the same time, and the British adopted their method. In Gallipoli we adopted a method of squared maps which was suggested by the navy. In Egypt no method had actually been adopted, and the result was, artillery pilots who went out to the Middle East found they had to learn a different system of signalling in every theatre, and it was owing to the disadvantages of having to learn these different things that it was decided to introduce a uniform system which was immediately applied into Mesopotamia, Egypt, Salonika and India, and that system was the same as we had in France. I should like to mention the work Captain Thomas has referred to of Mr.