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The Encyclopedia of Horology

Pocket watch · Torpedo boat chronometer

Longines US Navy Torpedo Boat Chronometer

Partially verified

Catalogued as a first-series US Navy torpedo boat chronometer produced circa 1906 by Longines in Switzerland, this large 68 mm open-face silver pocket watch features a silvered dial with bold black Arabic numerals, spade-style hands, a running small seconds subdial at 6 o'clock, and an Up/Down 50-hour power reserve indicator positioned below 12 o'clock. The source documents the piece as being powered by calibre 24.99 with movement number 1927947, regulated by Arnold Vuille-Roulet. The case incorporates a gold crown and hinge, with case-back military engraving reading 'US Navy 1927947'.

Dial view of Longines US Navy torpedo boat chronometer pocket watch
Dial view of Longines US Navy torpedo boat chronometer pocket watch — Auktionen Dr. Crott. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.invaluable.com
Category
Pocket watch · Torpedo boat chronometer
Maker / attribution
Longines
Reference
Cal. 24.99
Catalogue / lot identifier
146
Source-reported date
circa 1906
Country
Switzerland
Source-reported serial
1927947

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

Object Identity and Documentation

This timepiece is catalogued as a first-series US Navy torpedo boat chronometer produced by Longines. It is accompanied by copies of the Bulletin 2me Classe de l'Observatoire Astronomique de Neuchatel, 1908, and the Bulletin 1ère Classe de l'Observatoire Astronomique de Neuchatel, 1916. The watch is identified by the movement and case serial number 1927947, with production estimated at circa 1906.

The object bears a specific military engraving on the case-back reading 'US Navy 1927947'. While these details are provided by the cataloguer, they remain subject to independent verification as the movement and case-back are not visible in the provided photograph.

Evidence for this section
  • “A rare, fine US Navy torpedo boat chronometer from the 1st series”
  • “with copies of the Bulletin 2me Classe de l'Observatoire Astronomique de Neuchatel, 1908 and of the Bulletin 1ère Classe de l'Observatoire Astronomique de Neuchatel, 1916”
  • “military engraving "US Navy 1927947"”

Construction and Dial Features

The watch features a large 68 mm open-face silver case, described as tiered with a gold crown and hinge. The silvered dial is marked with black Arabic numerals and includes an outer railway minute track. The watch is signed 'LONGINES' and inscribed along the lower rim with the manufacturer details.

Functional components include a small seconds subdial at 6 o'clock and a 50-hour power reserve indicator positioned below the 12 o'clock numeral. The auction condition report notes micro-scratches on both the case and the dial.

Evidence for this section
  • “Dimensions 68 mm”
  • “Case: Silver, military engraving "US Navy 1927947", tiered, gold crown and hinge.”
  • “Up/Down 50-hour power reserve subdial indicator positioned below the 12 o'clock numeral.”
  • “Case: very good, micro scratches, slightly rubbed. Dial: very good, micro scratches.”

Mechanism Specifications

The movement is identified as Calibre 24.99, a bridge movement featuring a lever escapement, a Guillaume gold screw compensation balance, and a blued balance spring according to Phillips. Regulation of the movement was performed by Arnold Vuille-Roulet.

The auction condition report classifies the movement condition as 'good, to be restored'.

Evidence for this section
  • “Movm.: Bridge movement, lever escapement, Guillaume gold screw compensation balance, blued balance spring according to Phillips.”
  • “regulated by Arnold Vuille-Roulet”
  • “Movm.: good, to be restored.”

Open research questions

  • Do internal movement photographs confirm the presence of the specified Guillaume balance and Phillips-adjusted spring?
  • Can US Navy records corroborate the specific provenance or issuance of serial number 1927947?
  • Is there physical evidence of the military engraving on the case-back distinct from the cataloguer's description?

Source evidence

Recorded claims and source quotations for Longines US Navy Torpedo Boat Chronometer
FieldSource-reported valueSource quotation
Lot NumberLot 146“Lot 146 : Longines - US Navy”
Movement Number1927947“Movm. No. 1927947”
Calibre24.99“Cal. 24.99”
Case Number1927947“Case No. 1927947”
Dimensions68 mm“Dimensions 68 mm”
OriginSwitzerland“Origin Schweiz”
Military EngravingUS Navy 1927947“military engraving "US Navy 1927947"”
RegulatorArnold Vuille-Roulet“regulated by Arnold Vuille-Roulet”
Weight250 g“Weight 250 g”

Visible details

  • Open-face silver case with a prominent bow and a contrasting gold-toned crown.
  • Silvered dial with black painted Arabic numerals and an outer railway minute track.
  • Up/Down 50-hour power reserve subdial indicator positioned below the 12 o'clock numeral.
  • Small seconds subsidiary register positioned at 6 o'clock.
  • Signed 'LONGINES' in the dial center and inscribed along the lower rim 'FABRIQUE DES LONGINES FRANCILLON & CE ST IMIER (SUISSE)'.

Research qualifications

  • The movement and the case-back military engraving described by the auctioneer are not visible in the supplied single-view photograph.
  • The auction condition report lists the movement condition as 'good, to be restored'.

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

Consulted source

At Auction: Longines - US Navy

Reviewed 2026-10-25 · Record 43794ad4db

Terms in this record

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