Port & River — 1770
Octant, Hadley's octant
This octant, based on John Hadley's design was manufactured by Thomas Ripley of Wapping. Octants or reflecting quadrants were navigational aids that measured the altitude of the sun above the horizon at sea. Hadley produced the first version of his octant in 1730. An inscription on this octant notes it was presented to Alexander Mclaren on 17 September 1770. The octant has a mahogany frame inset with an ivory 5-0-95 degree scale. It also has a brass index arm with clamping screw and vernier and ivory maker's plaque. The octant is stored in a green-stained oak case with a maker's label applied to the interior. The fore sight and index mirror have been replaced and the back sight mirror is now missing.
- Category:
- Port & River
- Object ID:
- 86.111/1
- Object name:
- octant, Hadley's octant
- Object type:
- Artist/Maker:
- Ripley, Thomas
- Related people:
- Related events:
- Related places:
364 Hermitage Bridge Road, Wapping [Tower Hamlets], Tower Hamlets
- Production date:
- 1770
- Material:
wood, ivory, brass, metal
- Measurements/duration:
- H 430 mm, W 380 mm, D 80 mm (overall)
- Part of:
- —
- On display:
- London Museum Docklands: Trade Expansion Gallery
- Record quality:
- 100%
- Part of this object:
- —
- Owner Status & Credit:
Permanent collection
- Copyright holder:
digital image © London Museum
- Image credit:
- —
- Creative commons usage:
- —
- License this image:
To license this image for commercial use, please contact the London Museum Picture Library.