Nocturnal, 1974

Record summary

Held and catalogued by Royal Museums Greenwich (object number AST0144 AST0144 N31 D8810), this is a nocturnal, made in San Francisco, dated 1974. The Atlas places it in the Quartz Revolution period (1969 – 1990) of its Instruments collection. Materials and techniques recorded by the source: metal metal. Recorded dimensions: Overall: 7 x 146 x 95 mm. The record is illustrated with 1 photograph.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

The source record does not include a narrative description. The structured fields above are reproduced from it.

Atlas type guide

Nocturnals

A nocturnal tells the time at night from the rotation of the stars around the celestial pole. The user sights Polaris through the central hole and turns a long pointer to align with the 'guard' stars of the Little Bear or the 'pointers' of the Great Bear. A calendar scale set to the date converts that angle to the hour.

Nocturnals were used from the sixteenth to the eighteenth century by navigators and travellers. Many are made of boxwood or brass, with tactile teeth on the hour disc so that the time can be counted in the dark.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.