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The Encyclopedia of Horology

Pocket watch · Tourbillon chronometer pocket watch

Louis Richard Triple Detent Constant Force One Minute Tourbillon Chronometer Pocket Watch

Partially verified

This 18k yellow gold pocket watch chronometer by Louis Richard dates to circa 1860 and measures 56 mm in diameter. According to Phillips, the manual-wind movement bears number 12 and case number 11846 12, featuring a triple detent constant force escapement and a one-minute tourbillon carriage. The dial is white enamel with black Roman numerals, blued steel hands, and a subsidiary seconds subdial at 6 o'clock. The source reports that the tourbillon carriage incorporates rest, impulse, and disengagement detents, a helical hairspring, and an 'A–M' lever to lock the third wheel. Accompanied by a key, the watch was previously owned by astronomer Harlow Shapley.

Dial view of the Louis Richard 18k yellow gold tourbillon chronometer pocket watch with winding key
Dial view of the Louis Richard 18k yellow gold tourbillon chronometer pocket watch with winding key — Phillips. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.phillips.com
Category
Pocket watch · Tourbillon chronometer pocket watch
Maker / attribution
Louis Richard
Reference
Not recorded
Catalogue / lot identifier
108
Source-reported date
Circa 1860
Country
Switzerland
Source-reported serial
12

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 Identification

This timepiece is an 18k yellow gold open-face pocket watch, measuring 56 mm in diameter. The white enamel dial is signed 'Louis Richard Locle' below 12 o'clock and features radial Roman numerals with an outer minute track. The watch is equipped with blued steel Breguet-style hands and a subsidiary seconds subdial at 6 o'clock.

The case is documented with the number 11846 12. The watch is accompanied by a winding and setting key.

Evidence for this section
  • “材料 18k yellow gold”
  • “White enamel dial signed 'Louis Richard Locle' below 12 o'clock”
  • “錶殼號碼 11846 12”
  • “尺寸 56mm diameter”

Movement Construction

The manual-wind movement is numbered 12 and features engravings including 'Invenit et Fecit'. According to the source report, the movement contains a one-minute tourbillon carriage and a three-arm bimetallic compensation balance with gold timing screws. The balance is free-sprung and fitted with a helical hairspring.

The source describes the movement as featuring frosted gilt plates, fourteen large ruby jewels, and a matte steel bridge secured with polished steel screws. A pivoted constant force spiral is also noted.

Evidence for this section
  • “機芯編號 12”
  • “movement further engraved "Invenit et Fecit"”
  • “The movement features a three-arm bimetallic compensation balance with gold timing screws, free-sprung and fitted with a helical hairspring.”
  • “The matte steel bridge, fourteen large ruby jewels, frosted gilt plates, and polished steel screws attest to the watch’s technical and aesthetic refinement.”

Technical Mechanisms

The tourbillon carriage is described as incorporating patented detents for rest, impulse, and disengagement. Maintenance features include a latch secured by a slide lever positioned between 5 and 6 o'clock.

Additionally, the movement includes a lever marked 'A–M' (Arret-Marche), which allows the third wheel to be locked. This mechanism enables the removal of the tourbillon for adjustment without requiring the release of mainspring tension.

Evidence for this section
  • “The tourbillon carriage—partially polished and partially matte—incorporates Richard’s patented three detents for rest, impulse, and disengagement.”
  • “the tourbillon frame is secured by a latch linked to a slide lever positioned between 5 and 6 o’clock”
  • “An additional lever, marked A–M (Arret-Marche stop and go in French), allows the tooth of the third wheel to be locked, permitting removal of the tourbillon”

Open research questions

  • Are there visual records or public exhibitions confirming the existence of the fourteen ruby jewels and matte steel bridge structure?
  • Does any additional documentation outside of the auction listing provide further evidence for the 'Circa 1860' date estimation?
  • Are there high-resolution images available that confirm the 'A-M' marking on the movement?

Source evidence

Recorded claims and source quotations for Louis Richard Triple Detent Constant Force One Minute Tourbillon Chronometer Pocket Watch
FieldSource-reported valueSource quotation
Movement Number12“機芯編號 12”
Case Number11846 12“錶殼號碼 11846 12”
Case Material18k yellow gold“材料 18k yellow gold”
Diameter56mm“尺寸 56mm diameter”
SignaturesDial and movement signed; movement further engraved 'Invenit et Fecit'“簽名 Dial and movement signed. movement further engraved "Invenit et Fecit"”
Model NameTriple Detent Constant Force One Minute Tourbillon Chronometer“型號名稱 "Triple Detent Constant Force One Minute Tourbillon Chronometer"”
ProvenanceFormer property of Harlow Shapley“Last offered in 1990, the watch was the property of Harlow Shapley”
ScarcityReported as the only known example“This watch is believed to be the only known example combining Richard’s constant force escapement with a tourbillon regulator.”

Visible details

  • White enamel dial signed 'Louis Richard Locle' below 12 o'clock
  • Radial Roman numerals, outer minute markings, and subsidiary seconds dial at 6 o'clock
  • Blued steel Breguet-style hands
  • Polished yellow gold open-face pocket watch case with rounded pendant and bow
  • Accompanying gold-tone winding/setting key pictured alongside the watch

Research qualifications

  • Movement details, including the tourbillon, triple detents, helical hairspring, and stop lever, are source-reported and not visible from the dial-side photograph
  • Case number and movement engravings are internal and not visible in the image

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

Consulted source

Louis Richard The Geneva Watch Auction: XXIII

Reviewed 2026-10-22 · Record 043776303c

Terms in this record

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