United States. Geological Survey. U.S.G.S. Alternate title: Bowers, Del. - N.J. Relief shown by 10 feet contour interval and spot heights. Polyconic projection."Culture and drainage in part compiled from aerial photographs taken by Air Corps, U.S. Army. Control by U.S. Geological Survey and U.S. Coast and Geodetic Survey. Surveyed in 1926 and 1933-1934." Verso: Description of the topographic map of the United States.