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The Encyclopedia of Horology

Pocket watch · Open-face pocket chronometer

L. Leroy & Cie open-face chronometer pocket watch with Guillaume balance

Partially verified

This open-face pocket watch by L. Leroy & Cie is dated by the auction house to circa 1913. Catalogued in an 18K yellow gold round-shaped case measuring 51 mm in diameter, the watch is powered by a 19-ligne gilded brass keyless-winding movement. According to the auction notes, the caliber features a going barrel, straight-line lever escapement, and a bimetallic Guillaume balance with a blued steel hairspring. The dial features Roman numerals, an outer five-minute track, and a subsidiary seconds dial at 6 o'clock. The lot was catalogued alongside an Extract from the Archives.

Front view of the L. Leroy & Cie open-face chronometer pocket watch
Front view of the L. Leroy & Cie open-face chronometer pocket watch — Antiquorum Genève SA. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.invaluable.com
Category
Pocket watch · Open-face pocket chronometer
Maker / attribution
L. Leroy & Cie
Reference
Not recorded
Catalogue / lot identifier
160
Source-reported date
circa 1913
Source-reported place
Not established

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

Case and External Construction

The pocket watch is catalogued as an open-face, keyless-winding timepiece measuring 51 mm in diameter, cased in round-shaped 18K yellow gold.

Visual observation shows a round polished yellow gold case with a fluted winding crown, an oval bow, and a small pin/pusher situated on the case band near the 11 o'clock position.

Evidence for this section
  • “18K yellow gold, open-face, keyless-winding, round-shaped, pocket watch”
  • “Dimensions 51 mm.”
  • “Round polished yellow gold case with a fluted winding crown, suspended oval bow, and a small pin/pusher on the case band near 11 o'clock.”

Dial Display

The dial is white with black Roman numerals and an outer track showing Arabic numerals at five-minute intervals. Time is indicated by Breguet-style open-tipped hour and slender minute hands finished in yellow.

A sunken subsidiary seconds register is positioned at 6 o'clock, corresponding to the catalogued description of subsidiary seconds at 6.

Evidence for this section
  • “White dial with black Roman numerals and an outer track with Arabic numerals at five-minute intervals.”
  • “Breguet-style open-tipped hour hand and slender minute hand in a yellow finish.”
  • “Sunken subsidiary seconds register positioned at the 6 o'clock position.”
  • “subsidiary seconds at 6”

Reported Movement and Archival Provenance

The movement is not visible in the provided lot photo and relies upon cataloguer descriptions. It is recorded as a 19-ligne gilded brass caliber with a going barrel, straight-line lever escapement, Guillaume balance, and a blued steel hairspring with terminal curve. The catalog states that the dial, case, and movement are signed.

According to an Extract from the Archives dated November 22, 2018, the watch was sold on December 8, 1913, to Monsieur Hainchelin for the amount of 600 francs.

Evidence for this section
  • “Caliber: 19''' gilded brass, with going barrel, straight-line lever escapement, Guillaume balance and blued steel hairspring with terminal curve”
  • “Signed: dial, case and movement”
  • “The Extract from the Archives, dated November 22, 2018, mentioned that this watch was sold on December 8, 1913, to Monsieur Hainchelin, for the amount of 600 francs.”

Open research questions

  • What movement and case serial numbers are recorded in the November 22, 2018 Extract from the Archives?
  • Does the case band pin at 11 o'clock control hand-setting via a pin-set mechanism, or is setting accomplished via the crown stem?
  • What specific text and hallmark stamps appear on the movement bridge and inner case back covers?

Source evidence

Recorded claims and source quotations for L. Leroy & Cie open-face chronometer pocket watch with Guillaume balance
FieldSource-reported valueSource quotation
Case Material and Configuration18K yellow gold, open-face, round-shaped“18K yellow gold, open-face, keyless-winding, round-shaped, pocket watch”
Caliber19''' gilded brass with Guillaume balance“Caliber: 19''' gilded brass, with going barrel, straight-line lever escapement, Guillaume balance and blued steel hairspring with terminal curve”
Dimensions51 mm“Dimensions 51 mm.”
SignaturesDial, case, and movement“Signed: dial, case and movement”
AccompanimentExtract from the Archives“Accesories: Extract from the Archives”
Original Sale Date and BuyerSold December 8, 1913, to Monsieur Hainchelin for 600 francs“this watch was sold on December 8, 1913, to Monsieur Hainchelin, for the amount of 600 francs.”
Archive Extract DateNovember 22, 2018“The Extract from the Archives, dated November 22, 2018”
SignaturesSigned on dial, case, and movement“Signed: dial, case and movement”

Visible details

  • White dial with black Roman numerals and an outer track with Arabic numerals at five-minute intervals.
  • Sunken subsidiary seconds register positioned at the 6 o'clock position.
  • Round polished yellow gold case with a fluted winding crown, suspended oval bow, and a small pin/pusher on the case band near 11 o'clock.
  • Breguet-style open-tipped hour hand and slender minute hand in a yellow finish.

Research qualifications

  • Movement and interior case details are not visible in the provided photograph and rely solely on auction catalog descriptions.
  • Movement and case serial numbers are not specified in the auction record.

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

Consulted source

Sold at Auction: L. Leroy & Cie , L. LEROY & CIE CHRONOMETER WITH GUILLAUME BALANCE

Reviewed 2026-10-21 · Record 767f8f4158

Terms in this record

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

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