- Museum number
- 1958,1201.1242
- Description
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Stop watch
Fusee, Harrison's maintaining power; stop lever.
Rack lever escapement.
Cream enamel dial, Roman hours, subsidiary seconds.
Gold hour and minute hands, replacement blued-steel seconds.
Silver case; London H.M. 1924. Maker's mark R.G.M.
- Production date
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1805-1815
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1924 (case)
- Dimensions
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Diameter: 56.60 millimetres (case)
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Diameter: 48 millimetres (dial)
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Thickness: 31.40 millimetres
- $Inscriptions
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- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Maker anonymous (with spurious signatures of Arnold and Frodsham).(1)
London, c. 1810
Silver cased rack-lever stop watch.
Signature: On the dial 'FRODSHAM GRACECHURCH STREET LONDON'(2) and 'John Arnold Strand No 1794' on the movement.
Case: Silver consular case, hallmarked London 1924 and with the casemaker's mark RGM in a rectangular cameo.(3) The pendant is punched with the maker's mark CH in cameo, a lion passant and the date letter V.(4) Although made in 1924, the case is in an early 19th century style and bears the watch movement number in both backs.
Dial and Hands: Later flat dial with a subsidiary seconds dial with each 10th second numbered and a star to mark the five second intervals. A letter 'F' fired into the counter-enamel. The gold spade-pattern hour and minute hands do not match the dial. The blued-steel seconds hand is not original.
Dial-Plate: Scratched '281068 GWG' ? and also 'Strelle'.(5)
Dust-Cap: missing
Movement:
Ebauche Marks: None
Frame: A full plate layout with four turned pillars. A typical Liverpool balance cock engraved with foliate scrolls and with the regulator mounted on it.
Fusee, Barrel and Mainspring:
Fusee: six-turn fusee with Harrison's maintaining power, the maintaining ratchet wheel of brass.
Barrel: flanged, internal diameter 18.0 mm, height 5.0 mm.
Mainspring: height 4.7 mm, thickness 0.20 mm.
Barrel arbor: diameter 5.5 mm, not snailed.
Hooking: square.
Train: Train gilded throughout, the centre wheel solid, the third and fourth wheels with five crossings.
Jewelling: Jewelled bearings from the fourth pinion onwards with endsones for the escape wheel and balance, with a diamond in the balance cock and a ruby in a wedge in the potence.
Escapement: An acute-angle layout rack lever escapement with two-way slides. The enclosed pallet stones have flat acting faces. The brass escape wheel has three crossings.
An equal impulse escapement.
No of teeth embraced 32.
Balance and Spring: An oversprung, flat-rimmed, polished steel, three-arm balance, diameter 20.3 mm, thickness 0.5 mm. A blued-steel flat spiral spring with 7 3/4 turns. The brass stud screwed to the back plate is either a replacement or has been refinished.
Means of regulation: A polished steel index, mounted on the balance cock, registering against a divided scale engraved at the balance cock junction with 'S' and 'F' at the ends.
Thermal compensation: A bimetallic compensation curb mounted on the index, made in two parts held together by two screws.(6)
Train Counts and Beat Rate:
Great wheel 60 (fusee)
Centre wheel 64 pinion 12
Third wheel 60 pinion 8
Fourth wheel 56 pinion 8
Escape wheel 15 pinion 7
Beat rate 14,400
Motion work: cannon pinion 12, minute wheel 48
minute pinion 14, hour wheel 42
Stop Mechanism: The stop pin which originally acted on with the pallet frame has been cut off.
Winding Mechanism: Key wound
Dimensions:
Case: diameter 56.7 mm, height (over glass) 21.0 mm.
Movement: diameter 47.3 mm, height 17.3 mm, pillar height 5.1 mm.
Provenance: Formerly in the Ilbert collection, purchased by Ilbert from Ash in 1932.
Notes:
(1) This Liverpool movement has nothing to do with either Arnold or Frodsham.
(2) The name of Frodsham is associated with Gracechurch Street from 1825-1901.
(3) Possibly the mark of Richard George Merrick of 53 Lever Street Goswell Road, London, see Priestley, p.169.
(4) The date letter for Birmingham 1920. The pendant maker's mark is possibly that of Charles Harrold & Co. of Handsworth, Birmingham, see Priestley, p.160.
(5) The only recorded Strelle is Anton Strelle of Vienna, 1841-1861, see F. H. Van Weijdom Claterbos, 'Lijst Van Weense Uurwerkmakers', 1973, p.96.
(6) The quality and manner of construction of the balance spring stud and the bimetallic compensation curb suggest that they are both later modifications, perhaps dating from the same time as the dial and case.
- Location
- Not on display
- Condition
- Latest: 2 (2017)
- Acquisition date
- 1958
- Department
- Britain, Europe and Prehistory
- Registration number
- 1958,1201.1242
- Additional IDs
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Previous owner/ex-collection number: CAI.1242 (Ilbert Collection)
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Previous owner/ex-collection number: M122 (Ilbert Ledger)
