Thomas Earnshaw No. 365/2536 One-Day Marine Chronometer
Record status
Individual type · partial
Period
circa 1805
This one-day marine chronometer by Thomas Earnshaw features a 3-inch silvered dial with Roman numerals, subsidiary seconds, plain blued steel hands, and signatures reading 'Thos.
Earnshaw, INVT ET FECIT, No 365, ONE DAY'. The four-pillar movement is signed 'Thos. Earnshaw, Invt et fecit, No 365, London 2536' and incorporates an Earnshaw-type spring detent escapement, a bimetallic Z-balance with brass weights, and a helical spring. Housed in a brass bowl with a skirt counterweight, it is presented in an associated mahogany box.
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
- One-day marine chronometer
- Box Dimensions
- 5 inches (12 cm) square
- Dial Signature
- Thos. Earnshaw, INVT ET FECIT, No 365, ONE DAY
- Place recorded
- United Kingdom
- Movement Signature
- Thos. Earnshaw, Invt et fecit, No 365, London 2536
- Maker / attribution
- Thomas Earnshaw
- Escapement and Balance
- Earnshaw type spring detent escapement with bimetallic Z balance
Design
- Visible features
- • Silvered dial with black Roman hour numerals and an outer minute track • Large subsidiary seconds dial positioned above the 6 o'clock mark • Open wooden box displaying an aged paper label attached inside the upper lid • Brass chronometer bowl seated within the wooden case opening
- Movement Construction
- The four-pillar movement bears the signature 'Thos. Earnshaw, Invt et fecit, No 365, London 2536'. The mechanism utilizes an Earnshaw-type spring detent escapement, a bimetallic Z-balance with brass compensation weights, and a blued steel helical spring.
- Case and Associated Components
- The device is presented in a later associated mahogany box measuring 5 inches (12cm) square. The box features an aged paper label inside the upper lid and a re-engraved ivory plaque reading 'Earnshaw 365 Deckwatch'. The original gimbal and brass locking arms are noted as lacking.
- Dial and Exterior Observations
- The chronometer features a 3-inch silvered dial with black Roman numerals and an outer minute track. A subsidiary seconds dial is positioned above the 6 o'clock mark, accompanied by plain blued steel hands. The dial is signed 'Thos. Earnshaw, INVT ET FECIT, No 365, ONE DAY'. The movement is contained within a brass bowl featuring a skirt counterweight.
Identification
- Serial number
- 365/2536
- 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: Source notes that the gimbal and brass locking arms are lacking
- Research required: Housed in a later associated mahogany box with a re-engraved plaque