Tripod signal with tin cone for reflecting sunlight.At signal West Base, west end of Great Fire Island Base Line.Constructed by survey crews under direction of Ferdinand Hassler.Sketch by Assistant John Farley - view looking to east
3/18/2019 3:06:40 PM
Date: 1837?
Credit: NOAA John Farley collection
Location: Fire Island, New York
Subject: Geodesy
Subject: Triangulation
Subject: Towers
Subject: Wooden