Thesaurus Term/Concept: NOCTURNAL
| Identifier | 97399 |
|---|---|
| Class | MDA OBJECT TYPE |
| Status | Preferred |
| Index? | Yes |
| Scope Note | An astronomical instrument for telling the time at night. The date is set on the nocturnal then its pointers lined up with the Pole Star and the two primary stars in the Great Bear, thus allowing an approximate time to be read off. |