1407

English ebony octant, 1800s.

Currency:USD Category:Artifacts / Non-wreck Artifacts Start Price:325.00 USD Estimated At:400.00 - 600.00 USD
English ebony octant, 1800s.
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This item SOLD at 2023 May 04 @ 19:59UTC-4 : AST/EDT
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English ebony octant, 1800s. 1046 grams, roughly 13" x 10-1/2" x 3". This navigational device, made by Spencer & Co. of London (a well-established manufacturer between 1788 and 1840) was used to measure astronomical angles and therefore was most useful to sailors who needed to know latitudes. After the astrolabe came the quadrant, which by definition measured a quarter circle, but that device was cumbersome and came to be replaced with the octant (or reflecting quadrant), which utilized mirrors to get quarter-circle measurement from a device that was, in effect, only one-eighth of a circle. Technical specifications aside, this piece consists of an ebony frame with ivory inlay for gradations (in 5 degree increments from 105 to the left to 0 to the right) and with brass index arm and pinhole sight and mounts for the three mirrors (all intact). On the backside are three legs, for laying the instrument carefully on a horizontal surface when not in use. Everything seems to be in working order and intact, a lovely specimen for display. With photo-certificate.