An extremely rare and excellently preserved navigation instrument dated 1762, this backstaff, or Davis Quadrant, is attributed to maker Benjamin King of Newport, Rhode Island. It is impact stencil signed with his name, with an exceptional array of degree scales on each arc, including a Gunters Scale on the verso, quite rare and desirable on such a navigation instrument.

Dimensions: 25 5/8 inches long x 15 1/4 inches high x 5/8 inch deep.