wrist-watch;
watch-case
- Museum number
- 1989,0406.4
- Description
-
SILVER CASED ENAMEL-DIALLED SUBSIDIARY SECONDS CLUB-TOOTH LEVER WRIST-WATCH WITH LUMINOUS HANDS AND FIGURES.
Movement with club-tooth lever escapement.
White enamel dial with luminous-painted Arabic hours 1-12 and subsidiary seconds 10-60.
Pierced steel luminous-painted hour and minute hands; blued-steel seconds hand.
Silver Borgel-type case with spring-loaded stem and screw-on bezel; movement and dial are attached to the bezel which can be unscrewed after pulling out the button; two silver lugs provide attachment for the wrist-strap.
- Production date
- 1918
- Dimensions
-
Diameter: 35.20 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 V (Unpublished manuscript)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
Switzerland, c. 1918
Wrist watch in a silver Borgel(1) case with a club tooth lever escapement.
Signature: None but on the movement Swiss made.
Case: Two part silver Borgel case with import marks for 1918. Two case marks AGR in cameo, and F.B with a key beneath. In a rectangle also numbered 707962 and 5 with a 3 beneath and scratched B & G 8199.
The movement fits into a threaded ring which is silver plated and is scratch numbered 707962. This ring screws into the case and also has the bezel snapped onto it. The bezel is knurled to facilitate assembly. Whilst the ring and movement is being screwed in the winding button must be kept pulled out and can only be engaged when with the stem in the movement once the ring is screwed right home. The push pin in the case band works with a second pin which is housed in the threaded ring.
Dial & Hands: An enamel dial with skeleton Arabic numerals filled with luminous compound. A sunk subsidiary seconds dial. Skeleton blued-steel baton hands also filled luminous. A blued-steel seconds hand.
Movement:
Ebauche Marks: None.
A nickel silver movement with a bridge for the barrel, one for the train and cocks for the escape wheel, pallets and balance.
Barrel and Mainspring: A recessed cover to the going barrel.
Barrel: internal diameter 11.1 mm, height 1.4 mm.
Mainspring: height 1.4 mm, thickness 0.145 mm.
Barrel Arbor: diameter 3.8 mm, snailed.
Hooking: Pressed in tongue.
Train: All the brass wheels gilded, the centre wheel, third and fourth wheels with six crossings. The steel escape wheel with four.
Jewelling: Jewelled bearings from the third wheel onwards, all the jewels rubbed in. Ruby endstones to the balance that in the cock smashed.
Escapement: A straight line layout club tooth lever escapement with short lever, double roller and D-shaped impulse pin. The exposed pallet stones have flat acting faces. A steel escape wheel with four crossings.
An equal impulse escapement.
No. of teeth embraced 3½.
Balance & Spring: a monometallic balance with brass screws. Balance diameter 10.8 mm, thickness 0.7 mm. A self compensating flat spiral spring with 10 turns.
Means of Regulation: An index on the balance cock registers against a divided scale with 'F S' and 'A R' engraved on the balance cock table.
Train Counts and Beat Rate:
Great wheel 80 (barrel)
Centre wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 60 pinion 8
Escape wheel 15 pinion 6
Beat rate: 18,000
Motion work: cannon pinion 10
minute wheel 30, minute pinion 8
hour wheel 32
Winding System: Conventional side set positive keyless work. The stem split with a male square on the portion in the movement and a female square in that part on the winding button.
Dimensions: Case diameter 35.2 mm., height 11.4 mm.
Movement: Diameter 28.7 mm., height 7.0 mm.
Provenance: Purchased in 1989 with the aid of funds from the Dingwall Bequest.
Note:
(1) The Borgel case was the invention of François Borgel and was patented first by him in England as No. 20,422 on the 28th October 1891 and then in Switzerland Cl. 64 No. 4145 on the 12th November 1891, when his address was given as Geneva. These patents were for the pocket watch versions.
- Location
- Not on display
- Acquisition date
- 1989
- Department
- Britain, Europe and Prehistory
- Registration number
- 1989,0406.4
