Early Bronze and Ivory Sextant in Mahogany Box
Early bronze and ivory French hand-held Sextant encased in its original mahogany box with dove tailed joinery and green felt lining, circa early 19th century. It is marked "Le petite Harre" below the ivory composite arc and has a polished wood handle. A sextant is an optical instrument used in navigation invented in 1730. It measures the angle of celestial bodies above the horizon from the observer's position. The sextant is so named because the early instrument had a calibrated arc that is one-sixth of a circle -- a graduated 60° arc. Knowing the angular elevation of a known star, and the exact time, one can calculate the Latitude position of the observer.
Early marine sextants were hand held and had a fixed telescope leveled on the horizon. A radial arm is moved against an arc scaled in degrees. Adjust the radial arm until a known star's image reflects from the index mirror and then off the horizon mirror until down the telescope until it lines up with the horizon. The radial arm's position on the scale gives the star's elevation.
This sextant measures approximately 9ý long and is in very good condition. The box is 11ý wide x 9.75ý deep x 5ý high and has normal wear appropriate for its age.
|Materials:||bronze and mahogany|| |
|Item #:||36|| |
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