Brass and Wood Circumferentor, American, late 18th century, the 7 1/2-in. dia. maple circle with brass ring around the circumference calibrated 0-45 in eight segments, brass sighting vane with central thumb screw pivot, inset blued steel needle under glass with brass keeper, thumbscrew for keeper function and socket for tripod attachment on the underside all in an associated coopered box, dia. 9 in.
vertical sighting vanes now gone, brass in old surface, appears to retain the original glazing,