222 TRANSACTIONS OF SECTION E. 



The small detacliment under Col. Beazley was also responsible for (a) pro- 

 viding map compilation -with fixed points to tie down the air-photographs; 

 (6) providing batteries that required them with artillery _ boards ; (c) fixing 

 objects and targets in enemy territory and the sites of batteries. 



The latitude and longitude of Fao at the mouth of the Shatt-el-Arab had been 

 previously accurately determined bv the Survey of India. The longitudes of 

 Baghdad and Kermanshah were determined bv wireless from Fao, the latitude 

 of these places being known. On these co-ordinates the whole of the triangu- 

 lation carried out was hnsed. 



No geodetic triangulation was attempted : the destructive proclivities of the 

 Arab and the flat nature and unsettled state of the country put all scientific 

 survey out of the question. All that could be attained was a general map of 

 as large an area as possible on the ^-inch scale, larger scales Taeing used wherever 

 required by the military authorities. Triangulation was for the most part con- 

 fined to the more important rivers, the deserts and swamps elsewhere making 

 more than a few extensions impossible: strong escorts were required, and 

 transport on a liberal scale for water and rations had to be provided whenever 

 the rivers were left. 



The flat nature of the countrv made triangulation very diflicult, involving a 

 verv larffe number of short-sided triangles ; mounds were only occasionallv met 

 ■with. Mirage also greatly hampered the work ; in the hot weather distant 

 obiects frequently disappeared at 10 a.m. and did not reappear till about 

 4.30 P.M. Under the=6 circumstances it was impossible at times for the trian|gu- 

 lation to keep pace with rapidly moving columns, and recourse had to be made to 

 measuring distances by means of cyclometers fitted to bicycle wheels. As soon 

 as the triangulation was pushed up behind the moving columns the scattered 

 bits of survey based on (a) triangulation, (b) measuring wheels, were linked up 

 and adjusted, more complete surveys of the areas covered being subsequently 

 rarried out. _ _ • 



An interesting experiment was tried by map compilation at Baghdad, which 

 was quite successful, i.e. a 12-inch survey of the city based on air-photographs 

 tied down to fixed points. The map was completed in about a fortnight. To 

 have carried the same operation out bv ground survey would have taken several 

 weeks. When photographing from the air the neighbourhood of Samarrah in 

 connection with a large-scale survey required by the military authorities, the 

 outline in detail of a very large ancient city was revealed ; the traces of walls, 

 fnundatinns. public o-ardens. etc., which were not visible to anvone on the ground 

 showed up quite plainly on the photographs, and re^^ealed the fact that surveys 

 of areas for archEelogical research can in future be greatly assisted by air- 

 photography. 



A rapid means of topographical sketching from an aeroplane was evolved by 

 Col. Boazley to take the place of air-photogranhy over unmapped areas when 

 time does not permit the latter process. By this method a map of the a-round 

 over which operations are contemplated can be very rapidly prepared and issued 

 to the troons beforehand. Col. Eeazley's aeroplane was shot down and he 

 was captured by the T'urks, stopping the work. Further experiments are now 

 being carried out. The method is applicable to unsurveyed areas in arid 

 oountrio.s when it is not desirable to incur the expense of air-photographic 

 surveying. 



3. Thr Geographical Position and Site of Bnurncvwuth. 

 By C. B. Pawcett. 



Bournemouth is a new town and of a new type. As a town of any size it is 

 Darely forty years old. The O.S. map of 1811 showed the site as open heath land 

 crossed by an unfenced road from Christchurch to Poole. There was one house, 

 with a lodge, at Boscombe, and decoy ponds for wild fowl occupied the present 

 site of the lower Public Gardens. 



The town is built on a low wedge-shaped plateau between the Stour Valley and 

 Bournemouth Bay. This is formed of unconsolidated materials, mainly tertiary 

 sands and gravel. The Bay. is in the axial valley of the Hampshire Basin, and 

 the minor surface features are a result of this position and the physical history of 

 that region. The depression of the basin let in the sea to produce the cliffs, 



