Folks, The old projection used for ALL 15' Quadrangles used in the United States since the program began in the 19th century (with planetable and alidade methods), until the 1970's is the American Polyconic. Central Meridian was the the center meridian of each sheet, the ellipsoid was the Clarke 1866, and the Datum(s) were the various North American ones. I do not know if the New England Datum was ever used for 15' Quad mapping, it WAS used for coastal charts. There may have been a few sheets cast on the Bessel 1841 ellipsoid before 1870.
The projection was invented by Ferdinand Hassler, the first Superintendant of the Coast Survey. Prof. Cliff Mugnier LOUISIANA STATE UNIVERSITY --------------------------------------------- Cinda I forwarded your question on to our USGS customer service. You should hear from them sometime this week. Jack Forbes I am trying to track down the projection used for older (about 1964 or a bit older) USGS Topo quads, 1:62,500 15 minute series. Does anyone know? TIA Cinda Graubard GeoMax --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 4716
