Octant

Catalogue number:
PH*314492

Inscriptions:
"E. & G. W. BLUNT, New York"

Dimensions:
radius 11 inches

Discussion:
This octant has an ebony frame, reinforced brass index arm, and telescopic sight. The ivory scale is graduated every 20 minutes from -2^o to +111^o and read by vernier and tangent screw to single minutes of arc. This instrument was presumably made after 1857 when the Blunts began offering nautical instruments "of American manufacture," and before 1866 when the firm became Blunt & Nichols.

A brass nameplate reads: "George Davidson. Philadelphia, P^a." George Davidson (1825-1911) was a surveyor, geodesist and astronomer affiliated with the U.S. Coast Survey.

Ref: Deborah J. Warner, "American Octants and Sextants: The Early Years," Rittenhouse 3 (1989): 86-112, on 91-92.

"George Davidson," American National Biography, vol. 6, pp. 143-144.

Further Information:

Blunt (New York)
Octant