Accession No

0625

Brief Description

vertical plate altitude dial, almucantar or Hevelius type, c. 1800

Origin

Maker

Class

dials

Earliest Date

1800

Latest Date

1800

Inscription Date

Material

metal (brass)

Dimensions

length 62 mm; breadth 46 mm

Special Collection

Robert Whipple collection

Provenance

Purchased by Robert Stewart Whipple from Antique Art Galleries, Grafton Street, London, on 16/10/1930.

Inscription

Description Notes

Altitude dial, almucantar or Hevelius type.
Shaped brass plate (lacks suspension ring).
One face: index arm turns over calendar scale; stamped calibrations by (initialled) month, divided to 10 days.
Other face: gnomon hinged from index arm so as to turn over an uncalibrated eclination scale (vernal equinox at March 15th). When suspendedthe plate is turned parallel to the sun’s rays and the gnomon casts a shadow onto the shaped hour line with stamped digits for hours before and after noon, 4 - 12, 1 - 8, numbered by 1, subdivided to 30 minutes.

Condition: fair (gnomon stuck; 31-1-2000); incomplete (suspension ring missing).

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

References

Events