Field chronometer, mark IV, no 1621. memorabilia. — view 1 of 1
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Instruments · Chronometer

Field chronometer, mark IV, no 1621. memorabilia.

DocumentedDocumented from the holding institution's catalogue record.
Maker / attribution
Taylor & Hobson Ltd. (maker) (maker)
Date
1621
Country of origin
Unrecorded in source
Object type
Chronometer
Holding institution
Science Museum Group, London
Accession / object no.
1993-2054

View the source record ↗

Record summary

Held and catalogued by Science Museum Group, London (object number 1993-2054), this is a chronometer by Taylor & Hobson Ltd. (maker), dated 1621. The Atlas places it in the Early Modern Horology period (1600 – 1750) of its Instruments collection. The record is illustrated with 1 photograph.

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

The source record does not include a narrative description. The structured fields above are reproduced from it.

Historical context

Early Modern Horology (1600 – 1750)

Huygens' pendulum and balance spring transform accuracy; English makers develop the anchor and deadbeat escapements.

Pocket sundials, Butterfield dials and sandglasses remained essential companions to imperfect clocks; navigators used sandglasses and the log line; observatories began to combine telescopes with pendulum clocks.

Read the period in the timelineMore instruments from this periodEarlier: Renaissance Horology

Atlas type guide

Chronographs and split-seconds watches

A chronograph is a watch with an additional seconds hand that can be started, stopped and returned to zero independently of the timekeeping. Louis Moinet built an early example in 1816 and Nicolas Rieussec a recording 'chronographe' in 1821; Adolphe Nicole's heart-shaped reset cam (patented 1862) made the modern return-to-zero possible. Split-seconds (rattrapante) chronographs add a second hand that can be stopped for intermediate times; flyback chronographs restart instantly.

Chronographs were essential tools for doctors (pulsometer scales), artillery (telemeter), engineers and sport. In wristwatches, Valjoux, Venus, Lemania and later the automatic chronographs of 1969 (Zenith El Primero, the Chronomatic Calibre 11 group and Seiko 6139) are milestones.

What to look for

  • Push-pieces on the case band or a single button in the crown (monopusher).
  • Subsidiary registers for minutes and hours; tachymeter, telemeter or pulsometer scales.
  • Column wheel versus cam control visible in the movement.
  • Calibre markings of specialist makers (Valjoux, Lemania, Venus, Landeron).

Dating clues

  • Pocket chronographs with heart cam reset: after 1862.
  • Wrist chronographs: from c. 1910; two-button designs from the 1930s.
  • Automatic chronographs: from 1969.

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:ChronographFlyback chronographChronograph

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