Four-Vane Surveyor's Compass

Four-Vane Surveyor's Compass, early 19th century with mid 19th alterations, constructed from a mahogany-bodied surveyor's compass with printed dial signed James Gale, Salem and engraved by Callender, now with silvered brass without cardinal points but outer circle of four 90degree quadrants, blued steel needle marked N and S, brass outer circle divided 0--170-0-170 and 10-360 joined by six spokes to central hub, twin fixed vanes and twin rotating vanes with verniers, three bubble levels and staff mount, lg. 14 1/2 in, (one level broken), in fitted wood case with accessories shelf.