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The Encyclopedia of Horology

Marine chronometer · Two-day marine chronometer

Thomas Mercer late 19th century 2.5 day marine chronometer

Partially verified

This late 19th-century marine chronometer is attributed to Thomas Mercer of London. Suspended in a gimballed brass bowl within a brass-bound teak box, the chronometer features a 2.5-day duration movement reported to incorporate a Poole auxiliary balance. The silvered dial carries black Roman hour numerals, outer minute indices, a subsidiary seconds dial, and a state-of-wind indicator below twelve o'clock. Engraved medal motifs commemorate exhibition awards from Paris 1867 and Philadelphia 1876. The dial is signed and numbered 5548, while the case is source-reported to bear a label for retailer H. Hughes & Son Ltd marked with number 1570.

Top-down oblique view of the Thomas Mercer marine chronometer in its gimballed brass bowl and wooden case.
Top-down oblique view of the Thomas Mercer marine chronometer in its gimballed brass bowl and wooden case. — Gorringe's. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
auction.gorringes.co.uk
Category
Marine chronometer · Two-day marine chronometer
Maker / attribution
Thomas Mercer
Reference
Not recorded
Catalogue / lot identifier
249
Source-reported date
late 19th century
Country
United Kingdom
Source-reported serial
5548

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Object Identity and Documentation

This marine chronometer is attributed to the maker Thomas Mercer of London and is dated to the late 19th century. The piece bears the serial number 5548. A secondary identity is provided by a retailer's plaque attached to the teak case, associated with H. Hughes & Son Ltd, which carries the number 1570.

The object is housed in a brass-mounted teak case measuring 7.25 inches in width, 7.25 inches in depth, and 8 inches in height. The case includes an original lock and a working key, though the key is not numbered.

Evidence for this section
  • “Thomas Mercer of London. A late 19th century 2.5 day marine chronometer”
  • “numbered 5548”
  • “label for H. Hughes & Son Ltd, number 1570”
  • “case width 7.25in. depth 7.25in. height 8in.”
  • “has original lock and working key”
  • “key looks original but is not numbered”

Dial and Mechanism Features

The instrument features a silvered dial engraved with illustrations of prize exhibition medals from Paris and Philadelphia. The dial carries the serial number 5548.

The internal mechanism is specified as a 2.5-day duration movement. The balance is fitted with a Poole auxiliary balance. According to the source, the movement was functional at the time of cataloging, though it has not been tested for timekeeping accuracy.

Evidence for this section
  • “silvered dial engraved with Philadelphia and Paris Prize Exhibition medals”
  • “numbered 5548”
  • “2.5 day marine chronometer”
  • “Poole auxiliary on the balance”
  • “movement is going but not tested for timekeeping”

Condition and Observations

The exterior teak case exhibits some fading, a crack running across the back of the lid, and a dent on the front edge. The H. Hughes & Son retailer plaque is described as chipped on its left side. The dial shows signs of slight oxidation.

Descriptions provided by the source do not constitute a formal condition report; the absence of a stated defect does not imply the item is free from wear, tear, or effects of aging.

Evidence for this section
  • “Outer case a little faded with a crack running across the back of the lid and a dent to the front edge”
  • “Hughes & Son plaque a little chipped to the left side”
  • “dial with very slight oxidisation”
  • “The absence of a condition statement does not imply that the lot is in perfect condition or completely free from wear and tear, imperfections or the effects of aging.”

Open research questions

  • Do Thomas Mercer factory production records verify serial number 5548 as late 19th century?
  • Does the inclusion of the Philadelphia (1876) and Paris (1867) medals suggest a minimum production date post-1876?
  • What is the significance of the retailer number 1570 associated with H. Hughes & Son Ltd?

Source evidence

Recorded claims and source quotations for Thomas Mercer late 19th century 2.5 day marine chronometer
FieldSource-reported valueSource quotation
MakerThomas Mercer of London“Thomas Mercer of London.”
Movement Duration2.5 day“2.5 day marine chronometer”
Movement Serial Number5548“numbered 5548”
Balance FeaturePoole auxiliary“Poole auxiliary on the balance”
Retailer LabelH. Hughes & Son Ltd, number 1570“label for H. Hughes & Son Ltd, number 1570”
Case Dimensions7.25in. width x 7.25in. depth x 8in. height“case width 7.25in. depth 7.25in. height 8in.”
Auction Result£2,000“Sold for £2,000”

Visible details

  • Silvered dial displays Roman numerals, subsidiary seconds dial, and an up/down state-of-wind indicator.
  • Engraved exhibition medal illustrations on dial note Paris 1867 and Philadelphia 1876.
  • Brass bowl mounted in brass gimbal ring inside a wooden box with brass fittings.
  • Key is visible in the front keyhole escutcheon of the wooden case.
  • Instruction plaque regarding transit cork is screwed inside the lid.

Research qualifications

  • Internal movement and balance mechanism are not visible in the photograph.
  • Poole auxiliary balance is source-reported.
  • Retailer plaque for H. Hughes & Son Ltd is not visible in the primary photograph.
  • Source reports movement is going but was not tested for timekeeping accuracy.

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Thomas Mercer of London. A late 19th century 2.5 day marine chronometer, case width 7.25in. depth 7.25in. height 8in. Sale LSEPT20 - Lot 249 - - Gorringe's

Reviewed 2026-10-25 · Record 3070658521

Terms in this record

Glossary explanations for terms named in this object’s record.

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