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Intrument makers on the Thames |
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| © National Maritime Museum, London |
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| Repro ID: D6404 |
| Description: The octant was developed in the early 1730s by John Hadley. The instrument enabled the observer to make more accurate measurements than had previously been possible with the backstaff. By using a reflected image the observer was able to measure two points simultaneously. The frame of this early example is made from mahogany and has a boxwood scale. Brass fittings hold the optics in position. There is no telescope and observations were made through a simple pin-hole sight. A small ivory plate in the middle of the instrument indicates that it was made by George Adams in 1753, at this time he worked from premises in Fleet Street at the corner of Racquet Court. |
| Creator: George Adams |
| Date: 1753 |
| Credit line: National Maritime Museum, London | |
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