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The Encyclopedia of Horology

Clock · Mystery clock

Cartier Modèle A Mystery Clock

Partially verified

This Cartier Modèle A mystery clock dates to circa 1929, designed with a transparent rock crystal case resting upon a black onyx rectangular base with gold accents. The transparent dial reveals diamond-set platinum hands that appear to float, operated through concealed rotating crystal discs driven from the base. The dial features a mother-of-pearl chapter ring inset with diamond-paved Roman numerals and is framed by decorative mother-of-pearl border panels. The source reports the clock is powered by a manual key-wind European Watch & Clock Co Inc. 15-jewel, 8-day movement with a Swiss lever escapement and bimetallic balance, with winding and setting controls located underneath the base.

Front view of the Cartier Modèle A rock crystal, mother-of-pearl, and onyx mystery clock
Front view of the Cartier Modèle A rock crystal, mother-of-pearl, and onyx mystery clock — Phillips. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.phillips.com
Category
Clock · Mystery clock
Maker / attribution
Cartier
Reference
Not recorded
Catalogue / lot identifier
910
Source-reported date
Circa 1929
Country
France
Source-reported serial
2818

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

Visual Composition and Materials

The clock is configured with an upright, rectangular transparent rock crystal body characterized by canted corners and a stepped top moulding. Its transparent centre displays openwork diamond-set hands suspended inside an optical aperture, framed by an internal structure trimmed with mother-of-pearl strips, diamond studs, and scrollwork accents. The dial features a circular mother-of-pearl chapter ring mounted with diamond-paved Roman numerals and marked 'FRANCE' near its base.

The upper crystal structure is mounted atop a rectangular black onyx plinth base bordered by beaded gold trim and raised on small gold feet. According to auction documentation, the overall dimensions measure 13.5 cm in height, 8.5 cm in width, and 5 cm in length, executed in rock crystal, mother-of-pearl, yellow gold, and onyx.

Evidence for this section
  • “Rectangular transparent rock crystal body with canted corners and stepped top moulding”
  • “Circular mother-of-pearl chapter ring set with diamond-paved Roman numerals and 'FRANCE' marked near the base”
  • “Dimensions 13.5cm in height x 8.5cm width X 5cm length”

Reported Movement and Mystery Axle Mechanism

While internal mechanical components are concealed from view inside the plinth, the cataloguing states the clock is powered by a manual key-wind European Watch & Clock Co Inc. 15-jewel, 8-day movement fitted with a Swiss lever escapement and a bimetallic balance. Hand-setting and winding apertures are located underneath the base.

The illusion of free-floating hands relies on separate rotating transparent crystal discs. As described in the source, each disc is bordered by a toothed edge driven by axles and concealed driving pinions housed in the columns of the frame, rotating the hour and minute discs independently at different speeds.

Evidence for this section
  • “Powered by a European Watch & Clock Co Inc. 8-day movement with Swiss lever escapement, bimetallic balance, the hand-key-setting and winding mechanism is set underneath the base.”
  • “These discs are each surrounded by a tooth-edged boarder and driven by screws fixed at the ends of the axles, working at the levels of 3 and 9 o’clock, the driving pinions of the hands are hidden in each column of the frame.”

Markings and Source Documentation

The base bears engraved signatures reading 'Cartier Paris Londres New-York Made in France' alongside serial number 2818 and a hand-stamped number 0970. The inner yellow gold base is signed 'European Watch & Clock Co. Inc France', the concealed movement carries European Watch & Clock Co Inc. branding, and an additional stamped number 1104 is recorded. The base is also reported to bear French eagle beak hallmarks and a diamond-shaped 'MC' maker's mark.

Dating to circa 1929 is supported by the auctioneer's reference to archive documentation in 'The Cartier Collection: Timepiece', which records an original matching 1929 design drawing. The clock is noted to include an original presentation box and a numbered winding key matching the clock's stamped number, though neither accessory is depicted in the primary photograph.

Evidence for this section
  • “Base signed Cartier Paris Londres New-York Made in France, further numbers 2818 and hand stamped 0970, inner yellow gold base signed European Watch & Clock Co. Inc France.”
  • “two vivid and crisp hallmarks can be found: an eagle beak for its French origin and a diamond shaped MC hallmark”
  • “Crafted in rock crystal, gold, mother-of-pearl, and diamonds, it states that it is from 1929 in the Cartier Archives.”

Open research questions

  • What specific individual or workshop does the diamond-shaped 'MC' hallmark denote (e.g., Maurice Coüet or an associated Cartier workshop)?
  • How does the stamping '1104' correlate sequentially or administratively with case number '2818' and workshop stamp '0970' in Cartier's production ledgers?
  • Does the gear train employ the dual-axle system introduced in 1912 or the later single central axle variation referenced in the catalogue essay?

Source evidence

Recorded claims and source quotations for Cartier Modèle A Mystery Clock
FieldSource-reported valueSource quotation
Case Number2818, stamped 0970, 1104“Case No 2818, stamped 0970, 1104”
MaterialRock crystal, mother-of-pearl, yellow gold and onyx“Material Rock crystal, mother-of-pearl, yellow gold and onyx”
CalibreManual key-wind, European Watch & Clock Co Inc, 15 jewels“Calibre Manual key-wind, European Watch & Clock Co Inc, 15 jewels”
Dimensions13.5cm in height x 8.5cm width X 5cm length“Dimensions 13.5cm in height x 8.5cm width X 5cm length”
SignaturesBase signed Cartier Paris Londres New-York Made in France“Base signed Cartier Paris Londres New-York Made in France, further numbers 2818 and hand stamped 0970, inner yellow gold base signed European Watch & Clock Co. Inc France. Movement signed European Watch & Clock Co Inc.”
Maker's HallmarkEagle beak mark and diamond-shaped 'MC' mark“two vivid and crisp hallmarks can be found: an eagle beak for its French origin and a diamond shaped MC hallmark”
Accompanying AccessoriesOriginal fitted presentation box and numbered key“retains its original fitted presentation box and original numbered key, with the Cartier hand stamped number corresponding to the one on the clock”

Visible details

  • Rectangular transparent rock crystal body with canted corners and stepped top moulding
  • Circular mother-of-pearl chapter ring set with diamond-paved Roman numerals and 'FRANCE' marked near the base
  • Openwork diamond-set hands suspended in the transparent aperture
  • Rectangular black onyx plinth base bordered by beaded gold trim and gold feet
  • Internal framing accented by mother-of-pearl strips set with diamond studs and scrollwork motifs

Research qualifications

  • The internal mechanical movement, underside markings, and winding controls are concealed inside the base and not visible in the photograph.
  • The original presentation box and numbered winding key mentioned in the source are not depicted.

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

Consulted source

Cartier The Hong Kong Watch Auction: XIX

Reviewed 2026-10-21 · Record 651cb7f4ce

Terms in this record

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

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