Accession No
2800
Brief Description
astronomical regulator, 8-day longcase clock, by William Hardy, English, 1824 (c)
Origin
England; London
Maker
Hardy, William
Class
astronomy; mechanical horology
Earliest Date
1824
Latest Date
1824
Inscription Date
Material
metal (brass, silver, mercury); glass; wood (mahogany); string
Dimensions
overall height 1840mm; dial plate diameter 303mm
Special Collection
Provenance
Transferred from Institute of Astronomy, University of Cambridge, Cambridge, England, 10/12/1980. Transported from National Maritime Museum, where it had been on loan 1967-1981.
Inscription
‘Willm. Hardy, Invt. et Fecit, London’ (dial plate)
Description Notes
Astronomical regulator, 8-day longcase clock, by W. Hardy, English, c. 1824.
Longcase regulator clock, 8-day. Mercury compensated pendulum with graduated rating unit above, silvered amplitude scale. Brass weight, cord line, 4-wheel train. Hardy’s constant-force escapement. Round silvered dial plate with 3 dials - minutes and subsidiary hours and seconds. Inner wooden cover for movement. Round-headed hood. Mahogany case with part-glazed trunk door.
Condition good; complete
References
Events
Description
An astronomical regulator is a fixed and highly accurate pendulum clock. A regulator dial has a large central minute hand, with the hours and seconds shown on smaller subsidiary dials within the centre of the face.
This astronomical regulator was made in the early 19th century for use in an observatory. It would have been used for (among other things) the timing of the transit of heavenly bodies as they passed over the meridian. In order to keep very accurate time, regulators such as this one include a mercury jar on the pendulum for compensating for temperature change, ensuring that the pendulum beats at the same rate even when it expands or contracts due to warming or cooling.
12/05/2014
Created by: Joshua Nall on 12/05/2014
FM:39925
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