Accession No

0352

Brief Description

universal equinoctial dial, by Ring, German, 2/2 18th C

Origin

Berlin; Germany

Maker

Ring

Class

dials

Earliest Date

1750

Latest Date

1800

Inscription Date

Material

metal (brass, silver, steel); glass

Dimensions

length 111mm; breadth 100mm; height 39mm

Special Collection

Robert Whipple collection

Provenance

Purchased by Robert Stewart Whipple from Antique Art Galleries, Grafton Street, London, on 03/08/1927.

Inscription

‘Ring a Berlin’

Description Notes

Universal equinoctial dial, by Ring, German, 2/2 18th C.

Brass with worn silvering. Rectangular base on 4 levelling screws with shaped heads. Inset compass with fleur-de-lis for North and remaining cardinal points marked in German; 32-point rose (8-point rose (?), 32 points marked); magnetic variation marked at 13˚ 30´ W of N with scale divided 20˚ - 0 - 20˚, numbered by 10˚, subdivided to 1˚ (scale is 15˚-[0]-15˚, numbered by 5˚; 1-2-2000); knob to raise and lock compass needle (not working; 1-2-2000). Hinged hour circle segment divided on inner silvered rim 4 - 12, 1 - 8, numbered by 1, subdivided to 30 minutes. (Folding pin gnomon on diametrical bar; 1-2-2000). Silvered latitude arm divided [17˚] - 90˚, numbered by 10˚, subdivided to 30´. Plumb bob on shaped gallows. Reverse of compass box carries table of latitudes (see history file).

Condition: good/fair; complete.

[NOTE: On 15/04/2015 XRF analysis was conducted on this instrument. Results and analysis are given in the ‘Notes’ field.]

References

Events

Description
The universal equinoctial ring dial was designed by the English mathematician William Oughtred in the first half of the seventeenth century. It could be used at any latitude, so was a popular timekeeper for sailors and other travellers. It was really a much simplified version of the armillary sphere, only keeping the parts which were needed for telling the time.

The universal equinoctial ring dial consists of two rings and a bridging bar inside the inner ring. The outer ring represents a circle passing through the North and South celestial poles. The inner ring is called the ‘equinoctial’ ring because it represents the celestial equator. The bridging bar represents the axis of the world, just as the gnomon on an ordinary horizontal dial does. So the instrument is a very simple model of the heavens.

FM:45404