Longines Observatory Calibre 26.99 deck chronometer
Record status
Individual type · partial
Period
circa 1913
Maker / issuer
LonginesThis large Swiss deck chronometer by Longines features caliber 26.99, an observatory-grade movement housed in a tiered base metal case fitted inside a wooden block.
The white enamel dial displays stylized Arabic numerals, an outer railway minute track, and subsidiary seconds at 6 o'clock with blued steel hands. Fitted with movement number 2971458, the watch competed in the 1920 Neuchâtel Observatory chronometer competition and the 1930 Geneva Observatory trials under regulator David Perret of St-Imier, according to auction documentation. The movement is reported to include a lever escapement, Guillaume compensation balance, and blued Breguet balance spring.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Type
- Deck chronometer
- Origin
- Schweiz
- Weight
- 241 g
- Calibre
- 26.99
- Regulator
- David Perret of St-Imier
- Dimensions
- 68 mm
- Place recorded
- Switzerland
- Movement Number
- 2971458
- Maker / attribution
- Longines
Design
- Visible features
- • White enamel dial with stylized Breguet-style Arabic numerals and blued hands • Small seconds subdial located at the 6 o'clock position • Fitted in a square-profile wooden block stamped with 2971458 on the lower right front • Fluted winding crown with an oval top bow protruding from the wooden case
- Construction and Dial
- The watch is housed in a tiered, base metal case with a glazed movement. It is fitted within a square-profile wooden block that is stamped with the number 2971458 on the lower right front. A fluted winding crown with an oval top bow protrudes from the wooden case. The watch features a white enamel dial with stylized Arabic numerals and blued hands. A subsidiary seconds subdial is located at the 6 o'clock position.
- Technical Specifications
- The movement is a bridge construction featuring a lever escapement, a Guillaume gold screw compensation balance, and a blued Breguet balance spring with two terminal curves by Phillips. The balance and mainspring barrel were enlarged to accommodate the movement's dimensions. Regarding historical performance, the chronometer achieved a score of A=13.70 points in the 1920 Neuchâtel trials with a mean daily rate deviation of 0.17 seconds.
- Object Identity and Provenance
- This Longines deck chronometer is identified by movement number 2971458 and is dated to approximately 1913. The movement, caliber 26.99, was reserved exclusively for use in observatory competitions by the manufacturer's regulation department. The movement has a recorded history of participation in institutional trials, specifically the 1920 Neuchâtel Observatory chronometer competition ('Chronomètres de Poche 1re Classe') and the 1930 Geneva Observatory competition. In both instances, the regulator was identified as David Perret of St-Imier.
Identification
- Reference
- Cal. 26.99
- Serial number
- 2971458
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: Rear case and movement interior are not visible in the provided image
- Research required: Extract documents mentioned in the description are not pictured