United States. Geological Survey. U.S.G.S. Alternate title: Providence, Mass.-R. I. Polyconic projection. Relief shown by 20 feet contour interval and spot heights. Surveyed in 1885 and 1887. Surveyed in cooperation with the states of Massachusetts and Rhode Island. Triangulation, coast line and part of coast by U.S. Coast and Geodetic Survey. Verso: The topographic maps of the United States.