Two-day marine chronometer by Morris Tobias
Record status
Individual type · partial
Period
circa 1830
According to the Science Museum Group, this two-day marine chronometer was made circa 1830 in London by Morris Tobias. The piece is signed 'Morris Tobias maker to the Admiralty, 31 Minories London 1456'.
The source records that it features a silvered dial with an up-and-down indicator and subsidiary seconds, along with a spring detent escapement, a two-armed balance, and a cylindrical balance spring with overcoil. The movement is mounted within brass gimbals inside a wooden transport 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
- Two-day marine chronometer
- Materials
- Brass, steel, gold, rosewood, and glass
- Escapement
- Spring detent escapement
- Place recorded
- United Kingdom
- Balance and spring
- Two armed balance, cylindrical spring with overcoil
- Overall dimensions
- 180 mm x 190 mm x 195 mm
- Maker / attribution
- Morris Tobias
- Maker's signature and number
- Morris Tobias maker to the Admiralty, 31 Minories London 1456
Design
- Visible features
- • Textured spotting or engine-turned patterning covers the visible brass movement plates. • A blued cylindrical balance spring with an overcoil is visible below the balance cock. • The chronometer movement sits in a heavy brass gimbal ring within a wooden box fitted with brass hardware.
- Movement and Escapement
- The movement is recorded to feature a spring detent escapement. Observations of the exposed movement plates reveal textured spotting or engine-turned patterning. The balance assembly consists of a two-armed balance and a cylindrical spring with an overcoil. The internal mechanisms listed by the source remain largely obscured or internal.
- Construction and Housing
- The chronometer is housed within a wooden transport box featuring brass hardware. The movement is mounted in brass gimbals. The materials are documented as brass, steel, gold, rosewood, and glass. A silvered dial with a subsidiary up-and-down indicator and seconds is noted in the source documentation, though it is not visible in the provided top-down photograph.
- Identity and Attribution
- This marine chronometer is attributed to Morris Tobias of London. The Science Museum Group dates the piece to circa 1830. The object record notes a signature reading 'Morris Tobias maker to the Admiralty, 31 Minories London 1456'. This text is not confirmed via the provided photographic evidence.
Identification
- Serial number
- 1456
- 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 silvered dial and subsidiary indications reported by the source are on the reverse side and not visible in this top-down movement photograph.
- Research required: The signature and serial number are reported by the source catalogue text and cannot be fully transcribed from the photograph alone.