Instruments · Marine chronometer
Marine chronometer no. 1153 by Farquhar
- Maker / attribution
- Farquhar (maker)
- Date
- 19th century
- Historical period
- Precision & Scientific Horology (1750 – 1850)
- Country of origin
- Unrecorded in source
- Object type
- Marine chronometer
- Materials / technique
- mahogany; brass; steel; ivory (cites)
- Dimensions
- Overall: 135 x 140 x 135 mm
- Holding institution
- Royal Museums Greenwich
- Accession / object no.
- ZAA0051
- Credit line
- National Maritime Museum, Greenwich, London
- Catalogue title (original)
- 1153 (English)
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Record summary
Held and catalogued by Royal Museums Greenwich (object number ZAA0051), this is a marine chronometer by Farquhar, dated 19th century. The Atlas places it in the Precision & Scientific Horology period (1750 – 1850) of its Instruments collection. Materials and techniques recorded by the source: mahogany; brass; steel; ivory (cites). Recorded dimensions: Overall: 135 x 140 x 135 mm. The record is illustrated with 2 photographs.
Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.
Catalogue description
Catalogue description — Royal Museums Greenwich
This particular instrument began its life as chronometer No. 1153, made by the firm Parkinson & Frodsham. Part of the inside of the dial has been hammered, where the original signature by the makers would have been. It would seem that William Farquhar, of King Street, London, acquired the chronometer and gave it a re-fit, effectively presenting it as a new chronometer, in about 1860. This refit probably included a new escape wheel and rollers, the fitting of up-and-down work, a new cannon pinion, and a new bezel with sight-ring to give the instrument a more modern appearance. Prior to this, during its life as No. 1153 the chronometer belonged to Captain Edward Cottle, who left instructions with the chronometer-makers Bond & Son of Boston to loan it out on his behalf. John Richards, of the Brig Chatham, agreed to loan the instrument for five months, at the rate of five dollars per month. However, it was returned after three months at a total cost of $15. The leasing of chronometers to ships Captains was standard practice by Bond’s and other makers, but such instruments were usually the property of the company and it is unusual to see loans being made on behalf of third parties in this way. It is a small two-day marine chronometer, with a fusee and Harrison’s maintaining power, an Earnshaw-type spring detent escapement and a bimetal compensation balance.
Historical context
Precision & Scientific Horology (1750 – 1850)
Harrison solves longitude; Mudge invents the lever; Breguet's Paris workshop defines the modern watch.
The longitude problem was solved by the marine chronometer and lunar distance methods; dividing engines made precision scales possible, and observatories set time by transit instruments.
Read the period in the timelineMore instruments from this periodEarlier: Early Modern Horology
Atlas type guide
Marine chronometers
A marine chronometer is a precision timekeeper carried at sea to find longitude: the navigator compares local noon, observed with a sextant, with the time at a reference meridian kept by the chronometer. Each hour of difference corresponds to fifteen degrees of longitude. John Harrison proved the method in the 1760s; Pierre Le Roy, Ferdinand Berthoud, John Arnold and Thomas Earnshaw then developed the detent escapement and the compensation balance that made chronometers practical to manufacture.
By the nineteenth century London, Liverpool, Le Locle and Glashütte supplied navies and merchant fleets. A typical box chronometer has a spring-detent escapement, a fusee to equalise mainspring torque, a bimetallic compensation balance with a helical balance spring, and is mounted in gimbals inside a wooden box so that it stays level.
What to look for
- Gimbals and a three-tier wooden box with a glazed inner lid.
- A power-reserve ('up and down') indicator on the dial, usually showing 56 hours on two-day instruments.
- Spring-detent escapement and a cylindrical (helical) balance spring visible through the movement.
- Admiralty or navy marks (broad arrow), and rating certificates from observatories.
- The maker's number on the dial and movement; many makers' registers survive, allowing dating.
Dating clues
- Earnshaw-type spring-detent chronometers became standard after about 1800.
- Auxiliary compensation devices on the balance appear from the mid-nineteenth century.
- Quartz and radio time signals ended routine use of mechanical chronometers in the 1970s and 1980s.
General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.
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