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The Encyclopedia of Horology

Pocket watch · Astronomical pocket watch

Paul Ditisheim Astronomical Precision Pocket Watch No. 13784

Partially verified

This astronomical precision pocket watch by Paul Ditisheim features a 61mm 18ct yellow gold Empire case with a reeded band. The white enamel multi-piece dial displays Arabic numerals, perpetual calendar indications with a four-year leap-year cycle, sunrise and sunset indications, subsidiary seconds, moon phases, and an equation of time sector calculated for the Paris Meridian. The source reports that the watch is powered by a 21''' frosted gilded three-quarter plate movement featuring 21 jewels, a straight-line lever escapement, bi-metallic compensation balance, and palladium hairspring with Philips terminal curve. Movement and cuvette engravings record a first-class rating from the Neuchâtel Observatory.

Dial view of Paul Ditisheim astronomical pocket watch No. 13784 showing perpetual calendar, equation of time, and astronomical indications
Dial view of Paul Ditisheim astronomical pocket watch No. 13784 showing perpetual calendar, equation of time, and astronomical indications — Sotheby's. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.sothebys.com
Category
Pocket watch · Astronomical pocket watch
Maker / attribution
Paul Ditisheim
Reference
Not recorded
Catalogue / lot identifier
116
Source-reported date
Circa 1899
Country
Switzerland
Source-reported serial
13784

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 Construction and Exterior Markings

The watch is housed in an 18ct yellow gold Empire case measuring 61 mm in diameter, featuring a deeply reeded band flanked by olivette adjustment pushers. The openface case incorporates a pendant winding crown and bow at the top, consistent with visible observations.

According to auction cataloguing, the exterior case back displays sunburst engine-turning radiating from an oval cartouche bearing a 'J.F.' monogram. The interior case components carry multiple official stamps, including the Swiss Helvetia head assay mark, Crown assay, and French owl import marks on the bow, pendant, and interior rim, alongside Paul Ditisheim's 'PD' maker's punch mark and serial number 13784.

Evidence for this section
  • “18ct yellow gold Empire case, deeply reeded band”
  • “gold case back with sunburst engine-turning emanating from small J.F. monogram within oval cartouche”
  • “inside case back with Swiss Helvetia head assay mark, Crown assay, French owl import mark, inside back and cuvette interior both numbered 13784 and with PD punch mark”

Dial Display and Astronomical Indications

The white enamel dial is reported by the source as a 9-piece construction, displaying Arabic numerals and four distinct subsidiary registers at 12, 3, 6, and 9 o'clock. Blued steel Breguet hands indicate standard time, accompanied by a slender gold sun-tipped hand pointing to an equation of time sector calibrated along the upper minute track.

The dial displays extensive astronomical and calendar information calculated specifically for the Paris meridian. The 12 o'clock register tracks months across a four-year leap-year cycle, while the registers at 9 and 3 o'clock display day and date alongside sunrise ('lever') and sunset ('coucher') times. A combined subsidiary seconds dial and moon-phase aperture sits at 6 o'clock, bordered by the signatures 'PAUL DITISHEIM LA CHAUX DE FONDS' and perimeter inscriptions 'TEMPS MOYEN À MIDI VRAI' and 'MÉRIDIEN DE PARIS'.

Evidence for this section
  • “white enamel 9-piece dial, Arabic numerals, minute ring with adjacent sector for equation of time indication centred at 12 o’clock”
  • “two further subsidiaries at 9 and 3 o’clock calibrated in French respectively for times of sunrise ( lever ) sunset ( coucher ) in hours and minutes with inner discs for day and date”
  • “Temps Moyen à Midi Vrai, Méridien de Paris”

Reported Movement and Rating Credentials

The internal mechanism is not visible in the primary dial photograph; details are provided solely by the cataloguer's technical report. It is recorded as a 21''' frosted gilded three-quarter plate movement operating with a straight-line lever escapement and 21 jewels. The regulation assembly reportedly consists of a bi-metallic compensation balance with gold and platinum screws, an index regulator, and a palladium hairspring formed with a Philips terminal curve.

The watch incorporates chronometric observatory credentials recorded on both the mechanism and cuvette. The movement back plate is engraved 'Bulletin de 1ère Classe de l’Observatoire, no. 13784', while the gold cuvette details its origin and accolades, citing 'Bulletin de 1ère Classe de l’Observatoire de Neuchâtel, Fabrique par Paul Ditisheim à La Chaux de Fonds, Grand Prix Exposition Universelle Paris 1900'. Accompaniments documented by the source include a copy of the Neuchâtel Observatory Chronometer Certificate and a fitted presentation box marked for Parisian retailer Idrac-Leroy.

Evidence for this section
  • “21’’’ frosted gilded three-quarter plate movement, straight line lever escapement, 21 jewels, bi-metallic compensation balance with gold and platinum screws, palladium hairspring with Philips terminal curve”
  • “back plate engraved Bulletin de 1ère Classe de l’Observatoire, no. 13784”
  • “gold cuvette engraved No. 13784 Bulletin de 1ère Classe de l’Observatoire de Neuchâtel, Fabrique par Paul Ditisheim à La Chaux de Fonds, Grand Prix Exposition Universelle Paris 1900”

Open research questions

  • Does physical deconstruction confirm the dial's reported 9-piece enamel assembly, or does it utilize fewer joined sections?
  • Does the Neuchâtel Observatory archival registry corroborate the exact testing dates and recorded rate deviations cited in the accompanying certificate copy for movement no. 13784?
  • What relationship existed between Paul Ditisheim and the Paris retailer Idrac-Leroy regarding the commissioning and initial delivery of the watch around 1899–1900?

Source evidence

Recorded claims and source quotations for Paul Ditisheim Astronomical Precision Pocket Watch No. 13784
FieldSource-reported valueSource quotation
Case material18ct yellow gold“18ct yellow gold Empire case, deeply reeded band”
Case diameter61mm“diameter 61mm”
Jewel count21 jewels“21 jewels”
Movement specification21''' frosted gilded three-quarter plate“21’’’ frosted gilded three-quarter plate movement”
Hairspring specificationPalladium hairspring with Philips terminal curve“palladium hairspring with Philips terminal curve”
Escapement typeStraight line lever escapement“straight line lever escapement”
Balance assemblyBi-metallic compensation balance with gold and platinum screws“bi-metallic compensation balance with gold and platinum screws”
Retailer marking on boxIdrac-Leroy, Horloger, 22 Rue du Bouloi, Paris“purple silk lining to lid with gilt lettering ‘Idrac-Leroy, Horloger, 22 Rue du Bouloi, Paris”

Visible details

  • Openface pocket watch with white enamel dial and subsidiary dials at 12, 3, 6, and 9 o'clock
  • Blued steel Breguet hands paired with a slender gold sun-tipped equation hand pointing near 12 o'clock
  • Outer perimeter inscribed 'TEMPS MOYEN À MIDI VRAI' and 'MÉRIDIEN DE PARIS' with 'PAUL DITISHEIM LA CHAUX DE FONDS' at 6 o'clock
  • Yellow gold case with top winding crown, bow, and lateral olivette pushers along the reeded band

Research qualifications

  • Case back engine-turning, interior cuvette, movement layout, and fitted box are documented in auction text but not visible in the primary dial image
  • The 9-piece construction of the enamel dial cannot be independently verified from the front image alone

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

Consulted source

Paul Ditisheim | A highly important astronomical chronometer rated

Reviewed 2026-10-21 · Record e6229ffb5d

Terms in this record

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

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