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The Encyclopedia of Horology

Pocket watch · Military chronograph pocket watch

Vacheron & Constantin Military Chronograph Corps of Engineers U.S.A.

Partially verified

This military chronograph pocket watch by Vacheron & Constantin is catalogued to circa 1918 and features a 52 mm four-body silver case bearing number 240379. According to the auction catalogue, the back is engraved 'Corps of Engineers U.S.A., N. 2337'. The signed white enamel dial displays outlined Arabic numerals, skeletonized hands, an outer track divided to 1/5th of a second, and a sunken subsidiary seconds register at 6 o'clock. The movement is reported as keyless winding, numbered 383320, with 20 jewels, a column-wheel chronograph under Paul Nardin patent 54714, a lever escapement, a blued Breguet hairspring, a cut compensated bimetallic balance with screws, and a micrometer regulator.

Dial view of the Vacheron & Constantin Corps of Engineers military chronograph pocket watch
Dial view of the Vacheron & Constantin Corps of Engineers military chronograph pocket watch — Aste Bolaffi SpA. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.the-saleroom.com
Category
Pocket watch · Military chronograph pocket watch
Maker / attribution
Vacheron & Constantin
Reference
Not recorded
Catalogue / lot identifier
90
Source-reported date
circa 1918
Country
Switzerland
Source-reported serial
240379

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 Markings

The watch is housed in a 52 mm four-body silver case bearing the number 240379. The case back is engraved with the inscription 'Corps of Engineers U.S.A., N. 2337'.

The movement is accessed via a keyless-winding system. A round chronograph pusher is positioned on the case band near 11 o'clock, adjacent to the bow.

Evidence for this section
  • “Case: signed, n. 240379, four-body in silver”
  • “back engraved with the inscription "Corps of Engineers U.S.A., N. 2337””
  • “Round chronograph pusher positioned on the case band near 11 o'clock adjacent to the bow”

Dial Specifications

The signed white enamel dial features Arabic numerals and skeletonized hands. Timing functions include a minute track divided into 1/5th of a second increments.

A sunken subsidiary seconds dial is located at the 6 o'clock position.

Evidence for this section
  • “Dial: signed, white enamel, Arabic numerals, minute track with 1/5th of second divisions, sunk subsidiary seconds dial, skeletonized hands.”

Movement Details

The signed, keyless-winding movement, numbered 383320, contains 20 jewels. It utilizes a column-wheel chronograph mechanism based on the Paul Nardin patent 54714.

Technical components include a lever escapement, a blued Breguet hairspring, a cut compensated bimetallic balance with screws, and a micrometer regulator.

Evidence for this section
  • “Movement: signed, key-Less winding, n. 383320, 20 jewels”
  • “column-wheel switching (patent by Paul Nardin 54714)”
  • “lever escapement, blued Breguet hairspring, cut compensated bimetallic balance with screws, micrometer regulator.”

Open research questions

  • What is the historical significance or production scope of Vacheron & Constantin chronographs engraved with 'Corps of Engineers U.S.A.'?
  • Does internal archive data exist to verify the assembly date of movement 383320?

Source evidence

Recorded claims and source quotations for Vacheron & Constantin Military Chronograph Corps of Engineers U.S.A.
FieldSource-reported valueSource quotation
Case Number240379“Case: signed, n. 240379, four-body in silver”
Case EngravingCorps of Engineers U.S.A., N. 2337“back engraved with the inscription "Corps of Engineers U.S.A., N. 2337”.”
Movement Number383320“Movement: signed, key-Less winding, n. 383320, 20 jewels”
PatentPaul Nardin patent 54714“column-wheel switching (patent by Paul Nardin 54714)”
Diameter52 mm“Diameter Ø: 52 mm”
Reported Conditionto be serviced“Note: to be serviced.”
Condition NoteTo be serviced“Note: to be serviced.”

Visible details

  • White enamel dial with openwork Arabic numerals and sunken subsidiary seconds dial at 6 o'clock
  • Silver case exhibiting natural surface patination and tarnishing
  • Round chronograph pusher positioned on the case band near 11 o'clock adjacent to the bow

Research qualifications

  • Case back engraving and internal movement are catalogued but not visible in the provided image
  • Auction catalogue notes the watch is to be serviced

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

Consulted source

VACHERON & CONSTANTIN CRONOGRAFO MILITARE CORPS OF ENGINEERS U.S.A, 1918 CIRCA Cassa: firmata, n.

Reviewed 2026-10-22 · Record 505cef3608

Terms in this record

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