Instruments · Marine chronometer
Marine chronometer by James Mccabe, Royal Exchange, London, c. 1830
- Maker / attribution
- James Mccabe (maker)
- Date
- c. 1830
- Historical period
- Precision & Scientific Horology (1750 – 1850)
- Country of origin
- England
- Place
- Royal Exchange, London
- Object type
- Marine chronometer
- Materials / technique
- brass, mahogany
- Stock no.
- SKU 378
- Credit line
- Dealer listing, Howard Walwyn (SKU 378)
- Catalogue title (original)
- JAMES MCCABE, N° 393, A fine early brass bound mahogany cased two-day marine chronometer. (English)
View the source record (dealer listing) ↗ (opens another website in a new tab)Suggest a correction
Record summary
Catalogued by Howard Walwyn Fine Antique Clocks (dealer), London (stock number SKU 378), this is a marine chronometer by James Mccabe, made in Royal Exchange, London, England, dated c. 1830. The Atlas places it in the Precision & Scientific Horology period (1750 – 1850) of its Instruments collection. Materials and techniques recorded by the source: brass, mahogany. 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
Dealer description — Howard Walwyn
A fine early brass bound mahogany cased marine chronometer of 2 day duration retailed by this celebrated maker to the British Admiralty. The 4 inch circular silvered dial with convex glass is signed James McCabe, Royal Exchange, London . It is also numbered 393 with subsidiary up and down and seconds dials and gold hands. The fine quality movement has an original spring detent chronometer escapement with maintaining power and all the associated mechanical refinements. These include a late Pennington type screw balance wheel, blued steel helical hairspring and jewelled holes for the escape wheel and balance. The movement with polished and spotted plates is contained within a gimballed brass surround. The fine mahogany veneered box has an observation lid, brass bound corners and raised carrying handles. Date : circa 1830 Dimensions : 6 ¼ in (15.75 cm) square * James McCabe , who is recorded in Brian Loomes’ Clockmakers of the World: 21st Century Edition as working and retailing in the Royal Exchange between 1811 and 1868, was a noted clock and marine chronometer maker. Provenance: An English private collection . HW6153
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.
Read next:FuseeDetent escapement
Related records
Clocks · c. 1840–50
Carriage clock by James Mccabe, Royal Exchange, London, c. 1840–50
Howard Walwyn Fine Antique Clocks (dealer), London
Instruments · 1731–1776
Azimuth compass sundial by James Ferguson, London, England, 1731–1776. Could also be used as a tablet sundial - string gnomon is missing (see note).
Science Museum Group, London
Instruments · 1738–1777
Azimuth sundial 4 3/8" diam, with folding gnomon fitted in mahogany case, made by B. Martin
Science Museum Group, London
Instruments · 1750–1800
Single sand glass in four pillared wooden mount. 17 minutes. Horne Type B. Second half of the 18th century
Science Museum Group, London
Instruments · 1751–1825
Sundial, by Troughton, in case. Invented and made by Troughton
Science Museum Group, London
Instruments · 1751–1850
Universal Sundial; by Dollond and large brass stand, engraved "Dollond London" 6-inch hours circle, divided to 2 min, 3 levelling screws
Science Museum Group, London
Instruments · 1760–1769
Armillary / astronomical instrument by John Bird, England, 1760–1769
Science Museum Group, London
Instruments · 1763–1829
Chronometer watch by Thomas Earnshaw No.498, with later barrel cover numbered 2829, balance cock and regulator. In 18 ct. gold case hallmarked 1807/8
Science Museum Group, London