16
Serious discrepancies and deficiencies having been found in the maps produced by the parties, the Tribunal (Award, p. 70), after the case had been submitted, exercising the authority conferred upon it by Article XIII of the Treaty of 1930, ordered the photographing and mapping of the contested territory. The topographic relief in this area ranged from sea level to over 7,000 feet. The aerial method of surveying was chosen as the quickest way of supplying the needed information; and its comparatively low cost was another important factor. The United States Army Air Corps photographed the project, using a four lens camera, which is somewhat similar to the newer five lens camera, with the exception that the trailing wing photograph is omitted. In all, 1,300 photographs, covering 6,500 square kilometers, were made at an elevation of 13,000 feet above sea level, giving an approximate sea level photographic scale of 1: 24,000. The photography was completed in 31 days, although the flying was handicapped to a considerable degree by the rainy season. The photographs were studied stereoscopically and matched in strip mosaics. Line maps, showing the culture and drainage data traced from the strip mosaics, were assembled on a scale of 1:100,000. Existing maps supplemented by additional ground control were used as the base for map compilation. The maps and photographs were used by the Tribunal in the study of topographical and culture conditions in critical areas, and also to mark out and describe the line of award. The ground control work was started in August, 1932. The maps and photographs were delivered to the Tribunal in December. The maps were annexed to and made a part of the award.
