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The Encyclopedia of Horology

Pocket watch · Chronograph pocket watch

L. Leroy & Cie. Keyless Dress Watch with Chronograph

Partially verified

This 18K gold keyless dress watch, manufactured by L. Leroy & Cie. circa 1915, features a chronograph with an instantaneous 60-minute register. The three-body case, identified as 'forme collier', is polished and has an engraved monogram on the back. The gold engine-turned dial displays dauphine Arabic numerals, a fifths-of-a-second track, subsidiary seconds at 6 o'clock, and a 60-minute register at 12 o'clock. It is equipped with blued-steel Breguet hands. The movement is a 19-ligne gilt brass caliber with 29 jewels, utilizing a straight-line lever escapement. A notable feature is the special balance, which is cut on each side at the mid-point of the rim to account for a self-compensating balance spring constructed from nickel and steel. The chronograph function is controlled via a button located in the winding crown.

View of the gold engine-turned dial and the 19-ligne gilt brass movement of the L. Leroy & Cie. pocket watch.
View of the gold engine-turned dial and the 19-ligne gilt brass movement of the L. Leroy & Cie. pocket watch. — Antiquorum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
catalog.antiquorum.swiss
Category
Pocket watch · Chronograph pocket watch
Maker / attribution
L. Leroy & Cie.
Reference
Not recorded
Catalogue / lot identifier
241
Source-reported date
circa 1915
Source-reported place
France
Source-reported serial
67394

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 Dial

The timepiece is housed in a three-body 18K gold 'forme collier' case featuring a polished finish. The case back is decorated with an engraved monogram. The watch is operated via a keyless winding mechanism, with a button integrated into the crown serving as the chronograph actuator.

The gold dial exhibits an engine-turned pattern and displays Arabic numerals in a dauphine style. Time and chronograph functions are tracked via an outer minutes and fifths-of-a-second track, while subsidiary dials provide seconds at the 6 o'clock position and a 60-minute register at the 12 o'clock position. The hour, minute, and chronograph indications are completed by blued-steel Breguet hands.

Evidence for this section
  • “Three body, "forme collier", polished, the back engraved with a monogram.”
  • “Gold engine-turned with dauphine Arabic numerals, outer minutes and fifths of a second track”
  • “Blued-steel ?Breguet? hands.”

Movement and Escapement

The watch is powered by a 19-ligne gilt brass movement containing 29 jewels. The escapement is a straight-line lever type, paired with a blued-steel Breguet balance spring. An index regulator is present to facilitate timing adjustments, and the chronograph mechanism remains visible in the movement layout.

A defining technical feature is the special balance, which is cut at the mid-point of each side of the rim. The auction documentation explains that this design compensates for a balance spring manufactured from nickel and steel, which exhibits near self-compensating properties, thereby reducing the required arc of expansion for the bimetallic arms.

Evidence for this section
  • “19"', gilt brass, 29 jewels, straight line lever escapement”
  • “bimetallic compensation balance cut in the middle of the rim”
  • “The special balance is cut on each side at the mid-point.”

Condition and Attribution

The auction description assigns a general grade of 'AA Very good' to the lot. However, individual components show varying degrees of preservation.

The piece is attributed to L. Leroy & Cie. of Paris, with the address 7 Boulevard de la Madeleine cited as part of the maker's identification.

Evidence for this section
  • “Grading System Grade: AA Very good”
  • “Overhaul recommended, at buyer's expense”
  • “Dial: 3-5-01 Good Poor”

Open research questions

  • Does the serial number 67394 correlate with specific internal production records of L. Leroy & Cie. from 1915?
  • Are there other known examples of this 'special balance' configuration in L. Leroy chronographs of this era?

Source evidence

Recorded claims and source quotations for L. Leroy & Cie. Keyless Dress Watch with Chronograph
FieldSource-reported valueSource quotation
MakerL. Leroy & Cie.“L. Leroy & Cie. A Paris”
Serial Number67394“No. 67394”
Case material18K gold“18K gold”
Case typeThree body, forme collier“Three body, "forme collier”
Jewel count29 jewels“29 jewels”
Diameter57 mm“Diam. 57 mm.”

Visible details

  • Engine-turned gold dial surface
  • Chronograph activation via crown button
  • Monogram engraved on case back
  • Visible gilt brass movement plates

Research qualifications

  • The auction house reports an overhaul is recommended.
  • The dial condition is described as poor in specific areas.
  • The balance spring composition is based on the source's interpretation of early materials.

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

Consulted source

'Special Balance' L. Leroy & Cie. A Paris, 7 Boulevard de la Madeleine, No. 67394. Made circa 1915. Very fine and rare, 18K gold, keyless dress watch with chronograph, instantaneous 60 minute register and special balance.

Reviewed 2026-10-26 · Record 6219c329e2

Terms in this record

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

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