United States. Geological Survey. U.S.G.S. Alternate title: Lambertville. In upper margin: Topography. Relief shown by 20 feet contour intervals. Triangulation by U.S. Coast and Geodetic Survey. Topography by the Geological Survey of New Jersey. Surveyed in 1887-88. Verso: legend and explanatory notes, "The topographic map of the United States".