L. Leroy & Cie. Keyless Pocket Chronometer
Record status
Individual type · partial
Period
circa 1913
This 18K gold keyless pocket chronometer, manufactured circa 1913, is signed by L. Leroy & Cie., Paris. The timepiece features a three-body massive "bassine" polished gold case with a hinged cuvette.
The white enamel dial displays Arabic numerals, an outer Arabic minute ring, and a recessed subsidiary seconds dial, complemented by gold spade hands. The 19-ligne movement is constructed in gilt brass and contains 20 jewels. It utilizes a brass-invar Guillaume balance adjusted by Quelos and a blued steel balance spring with a terminal curve. A key feature is the punch-mark of a viper's head, indicating it was set by the Observatory of Besançon.
The watch was awarded a Bulletin de Premiere classe at the 1913 Timing Contest organized by the Observatoire National de Besançon. It is signed on the dial, case, and movement, and includes copies of the original timing records.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Type
- Keyless pocket chronometer
- Maker
- L. Leroy & Cie.
- Material
- 18K Gold
- Condition
- Very good
- Case Style
- Bassine
- Observatory
- Observatoire National de Besançon
- Balance type
- Brass-invar Guillaume balance
- Movement size
- 19 ligne
- Serial number
- 2769 (movement), 9288 (case)
- Place recorded
- France
- Maker / attribution
- L. Leroy & Cie.
Design
- Visible features
- • Hinged gold cuvette present • White enamel dial with sunk subsidiary seconds • Gold spade-style hour and minute hands • Punch-mark in the form of a viper's head on the movement
- Case and Dial Construction
- The pocket chronometer is housed in a three-body, massive gold case of the "bassine" style, characterized by a polished finish. The design includes a hinged gold cuvette protecting the movement. The dial is rendered in white enamel and features black-painted Arabic numerals for the hours, paired with a distinct outer Arabic minute track. A sunk subsidiary seconds dial is positioned at the six o'clock mark. The watch is equipped with gold spade-style hands. The dial is signed by the manufacturer, L. Leroy & Cie.
- Signatures and Documentation
- The watch is consistently signed on the dial, case, and movement with the mark of L. Leroy & Cie. The serial numbers are recorded as 2769 for the movement and 9288 for the case. The lot is accompanied by physical documentation in the form of copies of the original records from the 1913 timing contest and the award bulletin, providing context for the chronometric certification of this specific instrument.
- Movement and Chronometric Performance
- The watch is driven by a 19-ligne gilt brass movement containing 20 jewels. Technical specifications include a brass-invar Guillaume balance adjusted by Quelos and a blued steel balance spring featuring a terminal curve. The movement is marked with a viper's head, identifying it as having been set and tested by the Observatory of Besançon. The piece achieved a Bulletin de Premiere classe designation at the 1913 Timing Contest held by the Observatoire National de Besançon. Performance records indicate a mean average daily rate of +/- 0,32, a compensation error at 20° of +/- 0,136, and a mean error in two positions of +/- 3,14.
Identification
- Serial number
- 2769 (movement), 9288 (case)
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: Timing data presented is derived from provided copies of records
- Research required: Exact individual watchmaker or assembler credited as 'Quelos' is an attribution of balance adjustment only