Shows bottom types, buoys, and lighthouses. Relief shown by hachures. Depths shown by soundings and shading. Differs from other ed. of 1848 in that it has "Price 15 cents" under U.S. Coast Survey seal and does not have text in upper center margin. Includes sailing directions, note, table of tides, magnetic variance, and 3 coastal views by O.A. Lawson. In upper left margin: Harbor map no. In lower left margin: Reducation of topography by M.L. McClery, assistant. Do. of hydrography by Jno. Robertson. In lower right margin: Views by O.A. Lawson. Printed by H. Benner.