U.S. Coast Survey Report for 1866 Sketch Showing The Primary Triangulation Between Fire Island & Kent Island Base Lines Sections II & III From 1833 to 1851

An interesting U.S. Coast Survey chart showing the progress of the survey along the Eastern Seaboard. This chart shows triangulation data utilizing the primary points, island, and landmarks. The chart shows the coast from the western portion of Long Island Sound and Long Island to Delaware Bay and includes the upper reaches of the Chesapeake Bay, Alexandria, and Washington D.C. IMPORTANT NOTE: All of our United States Coast Survey (USCS), United States Coast & Geodetic Survey (USC&GS), and similar maps and charts have been professionally unfolded and flattened using humidity baths, semi-permeable membrane, and drying blotter techniques. Most others you typically see on eBay have not been, and worse, are quickly and crudely unfolded for the low-quality photos you see. Unfolding these maps in that way is damaging and weakens them. Please be aware.