octant
Datecirca 1790
Inventory Number5301
ClassificationOctant
Subject
Maker
Spencer, Browning & Rust
1784 - 1840
Cultural Region
Place of Origin
Dimensions41 × 33.6 × 7.2 cm (16 1/8 × 13 1/4 × 2 13/16 in.)
Material
DescriptionThe octant has an ebony frame and limb with a brass index arm, fittings, and a brass stop for the index arm. It also has inlaid ivory plates in the crossbar and on the back of the frame. The tangent screw is positioned on the front of the index arm and the clamping screw is on the back. The octant has three shades (one missing). Index-glass adjustment is made by a screw. On the horizon glass it is made by a lever, worm gear and a milled clamping screw and on the back horizon glass by a lever, wing nut and a milled clamping screw. The sight vane has two pinholes and a swivelling shutter, whereas the back sight vane has one pinhole. A pencil or screwdriver is missing from the crossbar.
It has a 13.75" radius, 0-20 vernier (0 right), -2° to 99° scale.
It is missing its box.
It has a 13.75" radius, 0-20 vernier (0 right), -2° to 99° scale.
It is missing its box.
Signedon ivory scale: SBR
E. & G. W. Blunt
Date: 1825-1860
Accessories: Keystone box (1996-1-0172b).
Object number: 1996-1-0172a
Spencer, Browning, & Company
Date: 1843-1850
Accessories: box with key, adjustment tool, telescope, eye tube, eyepiece shade
Object number: 5248
