James Hornby Pocket Chronometer
Record status
Individual type · partial
Period
Circa 1859-1860
This 18k yellow gold pocket chronometer, created by James Hornby circa 1859-1860, is a half hunting-case, key-winding instrument measuring 49.8 mm. The case features engine-turned (guilloché) decoration on both the cover and the case-back.
It utilizes an 18-ligne, 3/4 plate, gilded brass movement with a fusee and chain mechanism. A defining feature is the "improved" Guye spring detent escapement, which is stamped "Guye's Patent / Escapement" on the movement. The caliber includes gold screwed-chatons, a cut bimetallic compensated balance with gold poising screws, a free-sprung cylindrical hairspring with terminal curves, and a diamond end-stone. The white enamel dial displays radial Roman numerals and yellow gold double "Spade" hands, with a subsidiary seconds dial positioned at 6 o'clock.
Signatures are present on the dial, case, and movement. The case is marked "H F" and bears a Chester letter-date for 1859-1860.
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
- Half hunting-case key-winding pocket chronometer
- Maker
- James Hornby
- Diameter
- 49.8 mm
- Hallmarks
- Chester 1859-1860
- Case number
- 14.0
- Case material
- 18k yellow gold
- Place recorded
- England
- Escapement type
- Improved Guye detent
- Movement number
- 39113
- Movement caliber
- 18-ligne 3/4 plate
- Maker / attribution
- James Hornby
Design
- Case and Dial
- The watch is housed in an 18k yellow gold half hunting-case measuring 49.8 mm in diameter. The exterior surfaces of the cover and the case-back are finished with a guilloché or engine-turned pattern. The case bears the mark "H F" and includes a Chester letter-date corresponding to the production year of 1859-1860. The dial is constructed of white enamel and features black radial Roman numerals for the hours. It includes a subsidiary seconds register located at the 6 o'clock position. The time is indicated by yellow gold hands in a double "Spade" style. The auction description notes the presence of a hairline on the enamel dial.
- Visible features
- • Engine-turned guilloché finish on the case exterior • Radial Roman numerals on white enamel dial • Subsidiary seconds dial at the 6 o'clock position • Yellow gold double 'Spade' hands
- Movement and Escapement
- The timepiece is powered by an 18-ligne, 3/4 plate, gilded brass movement utilizing a traditional fusee and chain mechanism. The movement is fitted with gold screwed-chatons. The regulation system incorporates a cut bimetallic compensated balance with gold poising screws and a free-sprung cylindrical hairspring featuring terminal curves. A diamond end-stone is present within the train. The watch employs an "improved" Guye spring detent escapement, which is a specific mechanical feature of this chronometer. The movement is explicitly stamped with the text "Guye's Patent / Escapment," identifying the technical basis of the escapement design.
- Signatures and Attribution
- The horological object is attributed to the maker James Hornby and dated to the period circa 1859-1860 based on the Chester assay markings found on the case. Signatures verifying the authenticity and identity of the piece are documented by the source as appearing on the dial, the case, and the movement. The case number is recorded as 14.0 and the movement number as 39113.
Identification
- Serial number
- 39113
- 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: The auction description reports a hairline on the enamel dial.
- Research required: The auction description recommends an overhaul at the buyer's expense.