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The Encyclopedia of Horology

Pocket watch · Jump hour calendar pocket watch

Blondeau à Paris Gold Jump Hour Calendar Watch, No. 1098

Partially verified

This gold open-face jump hour calendar pocket watch by Blondeau à Paris is dated by Sotheby's to circa 1820. Measuring 52 mm in diameter, the watch features an engine-turned gold case with a matching band, pendant, and bow. The silver guilloché dial displays jump hours in an aperture at 12 o'clock, complemented by an eccentric minute track with a blued steel hand. Three subsidiary dials provide running seconds, date of the month, and days of the week in French. According to the auction catalogue, the gilded movement features a cylinder escapement, plain gold three-arm balance, and standing barrel.

Dial view of the Blondeau à Paris gold jump hour calendar pocket watch showing silver guilloché dial and calendar registers
Dial view of the Blondeau à Paris gold jump hour calendar pocket watch showing silver guilloché dial and calendar registers — Sotheby's. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.sothebys.com
Category
Pocket watch · Jump hour calendar pocket watch
Maker / attribution
Blondeau à Paris
Reference
Not recorded
Catalogue / lot identifier
165
Source-reported date
Circa 1820
Country
France
Source-reported serial
1098

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

Dial Configuration and Visual Indicators

The watch presents a multi-register silver guilloché dial executing jump hour and calendar indications. Direct observation shows an engine-turned ground framed by smooth tracks, with an aperture positioned below 12 o'clock displaying jumping Arabic numeral 10. An eccentric central blued steel minute hand indicates against an Arabic numeral minute track calibrated to 60, while three recessed subsidiary dials indicate continuous seconds at the top, date of the month at the lower left, and French days of the week at the lower right.

The auction catalog similarly documents the dial as featuring 'silver guilloché with contrasting engine-turned finishes, aperture for jump hours, eccentric silvered minute ring, three subsidiary dials for seconds, day and date, blued steel hands'.

Evidence for this section
  • “Silver guilloché dial with finely textured engine-turned ground and smooth chapter rings.”
  • “Aperture positioned directly below 12 o'clock displaying jumping Arabic numeral 10.”
  • “Eccentric central blued steel minute hand indicating against an Arabic numeral minute track calibrated to 60.”
  • “Three recessed subsidiary dials indicating continuous seconds at the top, date of the month at the lower left, and French days of the week at the lower right.”
  • “silver guilloché with contrasting engine-turned finishes, aperture for jump hours, eccentric silvered minute ring, three subsidiary dials for seconds, day and date, blued steel hands”

Case Construction and Inscriptions

Constructed in gold with a catalog-stated diameter of 52 mm, the open-face case displays an engine-turned reeded or patterned bezel, a spherical pendant, and an oval bow. The auction text details the case as having an 'engine-turned back and band, gold pendant and bow', enclosing a polished gold cuvette.

According to the source, the cuvette is 'signed and numbered Blondeau, H ger B té du Roi, Rue de la Paix no. 19, à Paris, No. 1098'. The catalog further notes an 'indistinct maker's mark' and reports that the inside case back and cuvette are 'further numbered 16346'.

Evidence for this section
  • “Gold case with an engine-turned reeded or patterned bezel and a spherical pendant with an oval bow.”
  • “diameter 52mm”
  • “engine-turned back and band, gold pendant and bow”
  • “polished gold cuvette signed and numbered Blondeau, H ger B té du Roi, Rue de la Paix no. 19, à Paris, No. 1098, inside case back and cuvette further numbered 16346, indistinct maker's mark”

Movement Details and Source Boundaries

The movement is not visible in the provided dial photograph and is recorded solely via the catalog description. The auction entry notes: 'Movement: gilded, cylinder escapement, plain gold three-arm balance, standing barrel'. The piece is cataloged by the auction house under the heading 'A GOLD JUMP HOUR CALENDAR WATCH CIRCA 1820, NO. 1098' and listed as 'Property from the Masterworks of Time Collection'.

Because internal components, case back markings, and cuvette inscriptions are not depicted in the image, these details cannot be verified independently of the seller's documentation.

Evidence for this section
  • “Movement: gilded, cylinder escapement, plain gold three-arm balance, standing barrel”
  • “A GOLD JUMP HOUR CALENDAR WATCH CIRCA 1820, NO. 1098”
  • “Property from the Masterworks of Time Collection”

Open research questions

  • What specific hallmark or sponsor punch corresponds to the 'indistinct maker's mark' reported in the case back?
  • Does the jump hour mechanism operate instantaneously via a snail and lever or through a continuous or semi-instantaneous star wheel arrangement?
  • Does the secondary number 16346 represent a case maker's serial number or an inventory reference distinct from Blondeau's movement number 1098?

Source evidence

Recorded claims and source quotations for Blondeau à Paris Gold Jump Hour Calendar Watch, No. 1098
FieldSource-reported valueSource quotation
EscapementCylinder escapement“cylinder escapement”
BalancePlain gold three-arm balance“plain gold three-arm balance”
Case diameter52 mm“diameter 52mm”
Cuvette inscriptionBlondeau, H ger B té du Roi, Rue de la Paix no. 19, à Paris, No. 1098“signed and numbered Blondeau, H ger B té du Roi, Rue de la Paix no. 19, à Paris, No. 1098”
Secondary case number16346“inside case back and cuvette further numbered 16346”
Case maker's markIndistinct maker's mark reported“indistinct maker's mark”
Provenance noteMasterworks of Time Collection“Property from the Masterworks of Time Collection”

Visible details

  • Silver guilloché dial with finely textured engine-turned ground and smooth chapter rings.
  • Aperture positioned directly below 12 o'clock displaying jumping Arabic numeral 10.
  • Eccentric central blued steel minute hand indicating against an Arabic numeral minute track calibrated to 60.
  • Three recessed subsidiary dials indicating continuous seconds at the top, date of the month at the lower left, and French days of the week at the lower right.
  • Gold case with an engine-turned reeded or patterned bezel and a spherical pendant with an oval bow.

Research qualifications

  • Movement details, cuvette signature, and internal numbering are reported in the auction description and cannot be verified from the single dial-side photograph.

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

Consulted source

Blondeau à Paris | A Gold Jump Hour Calendar Watch Circa 1820, No.

Reviewed 2026-10-21 · Record 9f9cc99b5d

Terms in this record

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