Accession No
3890
Brief Description
chronograph and chronometer, by T. and F. Mercer, English, c. 1930
Origin
Eywood Road; St. Albans; England
Maker
Thomas and F. Mercer
Class
navigation; mechanical horology
Earliest Date
1926
Latest Date
1950
Inscription Date
1923
Material
metal; wood; glass
Dimensions
box 1 length 280mm; breadth 157mm; height 200mm; box 2 length 280mm; breadth 210mm; height 170mm; chronograoh length 280mm; breadth 135mm; height 170mm; chronometer diameter 150mm; height 170mm
Special Collection
Provenance
Transferred from Department of Geography, University of Cambridge, Cambridge, England, 1992.
Inscription
‘T. & F. Mercer
CHRONOMETER MAKERS TO THE ADMIRALTY,
THE INDIAN, COLONIAL & U.S.A. GOVERNMENTS.
EYWOOD ROAD, ST.ALBANS,
ENGLAND’ (side of chronograph)
‘KEW RECORD 1925
KEW AIRCRAFT RECORD 1926
THOMAS MERCER
GROUP PRIZE NEUCHATEL, 1923.
MAKER TO THE ADMIRALTY
Eywood Rd. St. Albans.’ (dial of chronometer)
Description Notes
Chronograph and chronometer, by T. and F. Mercer, English, c. 1930.
Battery run, 2-speed chronograph, attached into fitted wooden box. Winder. Ink bottle. Chronometer and signal-key points. Box covered in khaki heavy duty material. Corners and edges protected by metal fixtures. Leather strap and buckle to fasten. Chronometer in separate similar box, padded with sponge. Winding key. Duster. Detchable lid, and detachable glass front to dial. 24 hour clock with metallic blue hands. Microphone point.
Condition fair (does not appear to work); incomplete (key to lock box missing)
References
Events
Description
Chronometers are very accurate clocks which were taken on board ship as a means to find longitude. A ‘Two Day’ chronometer is one that must be wound every two days.
The chronometer is set to show time at the port of departure, and during the voyage is compared with the ship’s local time as given by the sun. The earth rotates around its axis – 360° in longitude – every 24 hours, or 15° every hour. Thus a difference of four minutes between the time shown by the chronometer and local time by the sun is equal to a change of 1° of longitude.
04/08/2008
Created by: Dr Anita McConnell on 04/08/2008
FM:44584
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