Accession No

0665

Brief Description

universal equinoctial ring dial, by Richard Glynne, English, first quarter 18th Century

Origin

England; London

Maker

Glynne, Richard

Class

dials

Earliest Date

1707

Latest Date

1730

Inscription Date

Material

metal (brass)

Dimensions

156mm diam.

Special Collection

Robert Whipple collection

Provenance

Purchased by Robert Stewart Whipple from Antique Art Galleries, Grafton Street, London, England on 12/02/1931.

Inscription

‘R. Glynne Fecit’

Description Notes

Universal equinoctial ring dial, by Richard Glynne, English, first quarter 18th century.

Meridian ring calibrated for all latitudes, divided in opposite quadrants 0 - [90˚], numbered by 10˚, subdivided to 30´. Suspension shackle with brass suspension ring. Equinoctial ring divided I - XII, I - XII, numbered by I, subdivided to 5 minutes; similarly divided on the inner face. Pierced bridge with date scale divided to named month, subdivided to 10 days; reverse carries zodiac scale divided to 5˚ (1st Aries = 21 March) and declination scale divided 23˚ 30´ - Æ - 23˚ 30´, numbered by 10˚, subdivided to 30´ (1st Aries = 10 March); pinhole gnomon.
Reverse of meridian ring marked with altitude quadrant, divided 0 - 90˚, numbered by 10˚, subdivided to 30´ [note corrections on the calibrated 50, 60, 70 to 60, 70, 80].

Good condition

[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.

01/02/2001
Created by: Dr Hester Higton on 01/02/2001

FM:39512