Skip to content
The Encyclopedia of Horology

Marine chronometer · Eight-day marine chronometer

John Poole Eight-Day Marine Chronometer No. 2975

Partially verified

According to the auction catalog, this eight-day marine chronometer by John Poole features an Earnshaw-type detent escapement mounted on a subframe with a blued steel helical spring, bi-metallic balance, cylindrical timing weights, and Poole's auxiliary compensation. The movement is fitted with maintaining power, spotted plates, and a chain fusee. The 4.25-inch silvered Roman dial includes subsidiary dials for seconds and state of wind, signed and numbered 2975. The brass bowl is suspended in gimbals with a counterweight and sprung dust cover within a three-tier rosewood case featuring brass-banded edges, campaign handles, and an ivory plaque.

John Poole eight-day marine chronometer No. 2975 in three-tier rosewood case with brass gimbals
John Poole eight-day marine chronometer No. 2975 in three-tier rosewood case with brass gimbals — Bonhams. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.bonhams.com
Category
Marine chronometer · Eight-day marine chronometer
Maker / attribution
John Poole
Reference
Not recorded
Catalogue / lot identifier
75
Source-reported date
third quarter of the 19th century
Country
United Kingdom
Source-reported serial
2975

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

Dial and Visual Presentation

The instrument is described in the auction catalog as having a 4.25-inch silvered dial with Roman numerals and two subsidiary dials indicating the state of wind and running seconds. Visible inspection confirms the Roman hour chapter ring, the state-of-wind subsidiary register positioned below XII, and the subsidiary seconds dial placed above VI.

The dial is recorded as signed and numbered, corresponding to the lot heading naming maker John Poole at 57 Fenchurch Street, London, and serial number 2975. The chronometer bowl is visibly supported by a brass gimbal mounting within a wood chronometer box.

Evidence for this section
  • “the signed and numbered 4.25 inch silvered Roman dial with subsidiary state of wind and seconds dials”
  • “John Poole, 57 Fenchurch Street, London, No 2975”
  • “Silvered dial with Roman hour numerals, subsidiary state-of-wind dial below XII, and subsidiary seconds dial above VI”
  • “Chronometer bowl mounted on brass gimbal ring with locking and gimbal hardware visible”

Case and Mounting Construction

The chronometer is housed within a three-tier rosewood case recorded with an overall height of 22 cm (8.5 inches). The exterior woodwork features brass-banded edges and strung borders, with recessed campaign-style handles mounted on the case sides and an ivory plaque inlaid on the cover.

Direct observation shows the three-tier box with brass corner banding, a recessed handle on the side, a keyhole at the front, and a white plaque on the upper lid. The brass bowl is held in gimbals and is cataloged as being numbered and fitted with a counterweight and a sprung dust cover.

Evidence for this section
  • “The three tier case with brass banded edges and strung borders, the cover set with a signed and numbered ivory panel, the sides with campaign handles”
  • “the gimbals supporting the numbered bowl with counter weight and sprung dust cover”
  • “Height 22cm (8.5in)”
  • “Open three-tier rosewood chronometer box displaying brass corner banding and strung inlay borders”
  • “Recessed brass flush campaign-style handle on the side of the wooden box and keyhole at the front”
  • “Small white rectangular plaque inlaid on the upper edge of the case lid”

Dating and Regulatory Notices

Bonhams describes the piece as dating to the 'third quarter of the 19th century'. No specific year of manufacture or workshop completion entry is recorded in the catalog entry.

The lot includes warning symbols and clauses related to ivory and endangered species controls. The catalog notes that the item contains ivory, cannot be imported into the United States or the European Union, and is subject to CITES export regulations outside the United Kingdom.

Evidence for this section
  • “third quarter of the 19th century”
  • “This lot contains or is made of ivory and cannot be imported into the USA or any country within the EU.”
  • “Subject to CITES regulations when exporting items outside of the UK, see clause 13.”

Open research questions

  • Do workshop ledgers or Admiralty records confirm the exact production date and delivery client for John Poole chronometer No. 2975?
  • Does the serial number 2975 appear consistently on the movement subframe, plates, and brass bowl interior as well as the dial and ivory plaque?
  • What specific mechanical configuration of John Poole's auxiliary compensation is implemented on the balance rim of this eight-day movement?

Source evidence

Recorded claims and source quotations for John Poole Eight-Day Marine Chronometer No. 2975
FieldSource-reported valueSource quotation
Maker Address57 Fenchurch Street, London“John Poole, 57 Fenchurch Street, London, No 2975”
Escapement and BalanceEarnshaw type detent escapement on subframe with Poole's auxiliary compensation“Earnshaw type detent escapement mounted on a subframe with blued steel helical spring and bi-metallic balance with cylindrical timing weights and Poole's auxiliary compensation”
Dial Diameter4.25 inches“signed and numbered 4.25 inch silvered Roman dial”
Case ConstructionThree-tier rosewood case with brass banding and campaign handles“The three tier case with brass banded edges and strung borders, the cover set with a signed and numbered ivory panel, the sides with campaign handles”
Case Height22 cm (8.5 in)“Height 22cm (8.5in)”
Gimbal and Bowl ConfigurationNumbered brass bowl supported on gimbals with counterweight and sprung dust cover“the gimbals supporting the numbered bowl with counter weight and sprung dust cover”
Case DimensionsHeight 22 cm (8.5 in)“Height 22cm (8.5in)”
Auction ResultSold for £8,125 including buyer's premium on 29 June 2017“Sold for £8,125 inc. premium”

Visible details

  • Open three-tier rosewood chronometer box displaying brass corner banding and strung inlay borders
  • Silvered dial with Roman hour numerals, subsidiary state-of-wind dial below XII, and subsidiary seconds dial above VI
  • Chronometer bowl mounted on brass gimbal ring with locking and gimbal hardware visible
  • Recessed brass flush campaign-style handle on the side of the wooden box and keyhole at the front
  • Small white rectangular plaque inlaid on the upper edge of the case lid

Research qualifications

  • Movement mechanics including the chain fusee, spotted plates, and auxiliary compensation escapement are enclosed within the brass bowl and not visible in the photograph
  • Case contains ivory, which is subject to CITES and regional trade regulations

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

Consulted source

Bonhams : A fine and rare third quarter of the 19th century rosewood eight day marine chronometer with auxiliary compensation John Poole, 57 Fenchurch Street, London, No 2975

Reviewed 2026-10-21 · Record 5fae43c193

Terms in this record

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

Other eight-day marine chronometer records