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The Encyclopedia of Horology

Tool · Galvanometer

Moving magnet galvanometer by Hunt and Roskell

Partially verified

This moving magnet galvanometer was manufactured by the firm Hunt and Roskell in Clerkenwell, London. Dated between 1843 and 1897, the instrument is housed in a sloped wooden casing, designed to display a time-related indicator to the public. The face of the instrument features an inscription stating: 'This needle is deflected precisely at each hour, Hunt & Roskell Ltd, jewellers and watchmakers'. It incorporates the text 'Greenwich Mean Time' on the dial, reflecting its role in the nineteenth-century system of telegraphic time distribution. The overall dimensions of the piece are 115 mm by 115 mm by 75 mm. The object was acquired from Christie, Manson and Woods Limited and is currently held in the Science Museum Group collection.

A moving magnet galvanometer by Hunt and Roskell in a sloped wooden housing, featuring a dial inscribed with instructions regarding the hourly needle deflection.
A moving magnet galvanometer by Hunt and Roskell in a sloped wooden housing, featuring a dial inscribed with instructions regarding the hourly needle deflection. — Science Museum Group. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
collection.sciencemuseumgroup.org.uk
Category
Tool · Galvanometer
Maker / attribution
Hunt and Roskell
Reference
Not recorded
Catalogue / lot identifier
1985-76
Source-reported date
1843-1897
Source-reported place
United Kingdom

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

Construction and Design

The instrument is presented in a wedge-shaped wooden case, providing an angled orientation for the circular dial face. This form factor suggests the object was intended to be positioned on a flat surface, such as a shop counter or behind a window pane, to ensure the dial was easily visible to passers-by.

A brass bezel surrounds the dial, which is protected by a glass covering. The dial face itself is inscribed with the text 'Greenwich Mean Time' and the manufacturer's name, 'Hunt & Roskell Ltd, jewellers and watchmakers', alongside operational instructions stating that the needle is deflected at every hour.

Evidence for this section
  • “overall: 115 mm x 115 mm x 75 mm”
  • “The face of the instrument reads: 'This needle is deflected precisely at each hour, Hunt & Roskell Ltd, jewellers and watchmakers'”

Functional Purpose

During the nineteenth century, the distribution of time in Britain relied heavily on telegraphy. Large horological establishments often employed galvanometers as a means of providing a public time service. By connecting these instruments to telegraphic time signals transmitted from Greenwich, watchmakers could offer accurate time to the public.

The galvanometer serves as a visual indicator, with its needle mechanism reacting to incoming electrical signals.

Evidence for this section
  • “The principle way time was distributed in Britain in the nineteenth century was by telegraph”
  • “some of the large clock and watchmakers displayed a galvanometer in their windows to provide a time service for passers-by.”
  • “These timepieces could be set accurately with a simple indicator worked by time signals telegraphed from Greenwich.”

Provenance and Documentation

The instrument is documented under the accession number 1985-76 within the Science Museum Group collection. Information regarding its provenance identifies that the object was purchased from the auction house Christie, Manson and Woods Limited.

The records classify the item as a moving magnet galvanometer, specifically linked to the location of Clerkenwell, London, where the makers operated. The identification of the maker and the specific temporal range of the object are supported by the provided museum documentation.

Evidence for this section
  • “Accession number: 1985-76”
  • “Purchased from Christie, Manson and Woods Limited”

Open research questions

  • What specific telegraphic circuit was used to drive the galvanometer at the Hunt and Roskell premises?
  • Are there extant internal records detailing the specific installation and maintenance of this device?

Source evidence

Recorded claims and source quotations for Moving magnet galvanometer by Hunt and Roskell
FieldSource-reported valueSource quotation
MakerHunt and Roskell“made by Hunt and Roskell Limited”
Accession Number1985-76“1985-76”
Date1843-1897“1843-1897”
Place of ManufactureClerkenwell, London, England“Clerkenwell, Islington, London, Greater London, England, United Kingdom”
Dimensions115 mm x 115 mm x 75 mm“overall: 115 mm x 115 mm x 75 mm”
Dial InscriptionThis needle is deflected precisely at each hour, Hunt & Roskell Ltd, jewellers and watchmakers“This needle is deflected precisely at each hour, Hunt & Roskell Ltd, jewellers and watchmakers”

Visible details

  • Sloped wooden housing for desk or window display
  • Circular brass bezel securing the dial cover
  • Single vertical indicator needle
  • Text on dial includes 'Greenwich Mean Time'

Research qualifications

  • Specific manufacture date within the 1843-1897 range is unverified
  • Exact internal mechanism components are not visible in the provided photos

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

Consulted source

Moving magnet galvanometer with dial inscribed "Greenwich Mean Time", 1843-1897

Reviewed 2026-10-26 · Record 8e17c661c5

Terms in this record

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

Other galvanometer records