Thesaurus Term/Concept: OCTANT
| Identifier | 143020 | 
|---|---|
| Class | MDA OBJECT TYPE | 
| Status | Preferred | 
| Index? | Yes | 
| Scope Note | An astonomical instrument, and navigational aid, in the form of one eighth of a circle and used to measure the angular altitude of heavenly bodies. Invented in 1731 and used into the 19th Century, it was superceded by the sextant. |