Skip to content
Marine chronometer by Parkinson & Frodsham, c. 1821–1822 — view 1 of 2
View 1 of 2 · Image: Howard Walwyn · original image source (opens another website in a new tab)

Instruments · Marine chronometer

Marine chronometer by Parkinson & Frodsham, c. 1821–1822

DocumentedDocumented from a dealer's listing; attribution and date as stated by the dealer.
Maker / attribution
Parkinson & Frodsham (maker)
Date
c. 1821–1822
Country of origin
Unrecorded in source
Object type
Marine chronometer
Dimensions
Height 16 cm
Stock no.
Product 4910
Credit line
Dealer listing, Howard Walwyn (product 4910)
Catalogue title (original)
PARKINSON & FRODSHAM. An early one-day marine chronometer of rare small size. (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 Product 4910), this is a marine chronometer by Parkinson & Frodsham, dated c. 1821–1822. The Atlas places it in the Precision & Scientific Horology period (1750 – 1850) of its Instruments collection. Recorded dimensions: Height 16 cm. 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

An exceptional early one-day marine chronometer by this famous partnership of rare small size and very early date. The small early style mahogany veneered box has raised Georgian loop carrying handles to the side and a plain hinged lifting lid above the glazed inner section. The 3-inch silvered brass dial has an engine turned brass bezel with a convex glass. The maker’s name, address and number are beautifully engraved below the XII and it has Roman chapters and Arabic five minute markers, original blued steel hands and a subsidiary seconds above VI. The signed chain fusee movement has cylindrical ring-turned pillars and bi-metallic compensated balance with diamond endpiece, blued steel hairspring, Earnshaw spring detent escapement and an internal springed dust cover. The chronometer retains its charming original tipsey winding key numbered 768 . Height : 6 ¼ in (16 cm) Width : 6 in (15.25 cm) Depth : 6 in (15.25 cm) HW6708

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:Detent escapement

Related records