universal ring sundial
Date: 1635-1653
Inventory Number: 7900
Classification: Sundial
Subject:
Maker: Elias Allen (circa 1588 - 1653)
Cultural Region:
Place of Origin:
Dimensions:
open: 11.3 x 9 x 7.8 cm (4 7/16 x 3 9/16 x 3 1/16 in.)
closed: 11.3 x 9 x 0.6 cm (4 7/16 x 3 9/16 x 1/4 in.)
Material:
Description:
This universal ring dial is made of brass. The suspension ring is attached to a cursor that slides in a track. The meridian ring is divided 0°-84°, by 1° intervals. The equatorial ring has hours III-XII-IX, with divisions every 1/4 hour on the inside edge. The declination scale on the bridge is marked in initials of the months and divided into 5-day intervals. The reverse side is plain.
There is a gazetteer of 27 cities engraved on the instrument. Eight English towns are on one face of the meridian ring and ten European towns are on the reverse. Nine more English towns are engraved on the underside of the equatorial ring. Latitudes are given in degrees and minutes.
There are signs of repair on the suspension bracket and the meridian ring.
There is a gazetteer of 27 cities engraved on the instrument. Eight English towns are on one face of the meridian ring and ten European towns are on the reverse. Nine more English towns are engraved on the underside of the equatorial ring. Latitudes are given in degrees and minutes.
There are signs of repair on the suspension bracket and the meridian ring.
In Collection(s)
Signedon equatorial ring: Elias Allen fecit
FunctionThe universal ring dial is a form of universal equatorial dial that has the advantage of being self-orienting. No magnetic compass is needed.
Historical AttributesThis is a very early example of a universal ring dial, and it is made by the instrument maker for William Oughtred, the mathematician who invented this form of sundial.
Curatorial RemarksXRF analysis of the metals was done by Katherine Eremin and Sara Schechner in August 2007.