Brock, Arthur J. and Norman
Hagley Museum and Library
PO Box 3630
Wilmington, DE 19807-0630
25 slides : b&w; ; 35 mm. 43 photographic prints ; 8 x 10 in. or smaller. 12 items.
The Brock brothers, Arthur Jr. and Norman H., and Edward H. Cahill, their principal designer and co-inventor, were early innovators in aerial camera and mapping instrument development. Cahill has been credited with designing the first mapping camera ever carried on an airplane in the United States. The collaboration between the Brock brothers and Cahill resulted in the "Brock process," a pioneer method of photogrammetric mapping. The collection consists of graphic materials compiled by Harry Tubis, a one-time employee of Brock and Weymouth, Inc., during the research and writing of his article "The Brock brothers and the Brock process," which appeared in Photogrammetric Engineering and Remote Sensing, v. 52, no. 8, Aug. 1976. The materials, which are primarily slides and photographs, show instruments used by the Brock brothers in the invention of aerial cameras and mapping development such as roll-film and plate cameras, enlargers, stereometers, projectors, and tracing instruments. The collection also houses several maps made by the company, including a copy of the first topographic map made in the United States by photogrammetric methods, of Media, Pennsylvania (1922). Maps of the Hoover Dam Project (1930); the Sellers estate, Delaware (1927); the Green River area, South Carolina (1924); and the areas surrounding Gasny, France (1927) and Vecchiano, Italy (1927) are also part of the collection. In addition, there are aerial photographs of Media, Pennsylvania, and other unknown locations.