Accession No
0346
Brief Description
universal equinoctial ring dial, by Andreas Conradi, German, 1738
Origin
Germany; Ulm
Maker
Conradi, Andreas
Class
dials
Earliest Date
1738
Latest Date
1738
Inscription Date
1738
Material
metal (brass)
Dimensions
length 148mm; diameter 117mm; thickness 22mm
Special Collection
Robert Whipple collection
Provenance
Purchased by Robert Stewart Whipple from Antique Art Galleries, London, on 03/08/1927.
Inscription
‘ANDREAS : CONRADI : ULM : FECIT : 1738’ (declination ring)
Description Notes
Universal equinoctial ring dial, by Andreas Conradi, German, 1738.
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 7 1/2 minutes. Declination ring with sliding (?) gnomon band with six pinholes; zodiac scale marked ‘Eccliptica’, divided to sign, subdivided to 10˚; in the opposing sector a scale of ‘Sonnen Untergang sonen aufgang’ followed by a table of time (see history file).
Reverse of meridian ring carries date scale divided to named month. Zodiac scale numbered by 10˚ and subdivided to 1˚ (1st Aries = 20 March) (on reverse of equinoctial ring; 17-1-2000). (Also on reverse of equinoctial ring a scale of days per month, numbered to approx. 10, divided to 1; 17-1-2000). Reverse of declination ring carries degree scale divided 0 - 360˚, numbered by 10˚, subdivided to 1˚. Meridian ring carries list of towns and latitudes on both sides.
Condition: good.
catalogue card - dials (universal equinoctial ring dials).
[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:40007
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