- Museum number
CENTRE-SECONDS WRIST-WATCH WITH DATE INDICATOR AND AUTOMATIC WINDING MECHANISM.
Movement with club-tooth lever escapement.
Silver-coloured metal dial; applied gilt battons at the hours.
Gilt-metal hour, minute and centre-seconds hands.
Gold case with integral back and snap-on bezel.
Gold-plated and stainless steel expanding bracelet.
- Production date
- 1968 (case)
Diameter: 33 millimetres (case)
Diameter: 28.90 millimetres (dial)
Thickness: 10.30 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Jaeger Le Coultre
Switzerland, c. 1968
Self winding wrist watch with date and a club tooth lever escapement.
Signature: On the dial 'JAEGER-LE-COULTRE'. On the self winding weight 'FAB SUISSE SWISS JAEGER-LE-COULTRE'. On the movement 1913048.
Case: Two piece 9 ct. gold case hallmarked in the back Birmingham 1968 and 'BRITISH MADE B & S' and the number 423495.
Dial & Hands: A silvered dial with applied gold batons and a date aperture at 3 o'clock. The Jaeger Le Coultre trade mark also in an applied piece above the name which is printed in black. Skeletonised gilt Dauphine hands filled luminous. A gilt centre seconds hand.
Ebauche Marks: Z 883
Frame: A nickel plated brass movement. A bridge for the self winding work, one for the barrel, another for the train. Cocks for the pallets and the balance.
Barrel and Mainspring: A recessed cover to the going barrel marked to show which way up the shunting click goes.
Barrel: internal diameter 10.5 mm., height 1.2 mm.
Mainspring: height 1.2 mm., thickness 0.11 mm.
Barrel Arbor: diameter 3.1 mm., snailed.
Hooking: A slipping mainspring.
Train: All the brass wheels gilded, the centre, third and fourth wheels with five crossings. The steel escape wheel with four.
Jewelling: Jewelled bearings from the centre wheel onwards, all the jewels pressed in. Ruby endstones to the balance jewels. The self winding pivots are jewelled where they can be seen at the back of the movement.
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.
A mixed escapement.
No. of teeth embraced 3½.
Balance & Spring: a three arm monometallic balance with brass screws. Balance diameter 10.8 mm., thickness 0.5 mm. A 'self compensating' flat spiral spring with ? turns. It is clamped at the stud end and must be unclamped before the balance can be removed from its cock.
Means of Regulation: An index on the balance cock but not registering against a divided scale, there is a beat setting device.
Train Counts and Beat Rate:
Great wheel 80 (barrel)
Centre wheel 72 pinion 12
Third wheel 75 pinion 9
Fourth wheel 80 pinion 10
Escape wheel 15 pinion 8
Beat rate 18,000
Motion work: cannon pinion 15
minute wheel 45, minute pinion 12
hour wheel 48 (the hour wheel has a wheel of 22 mounted on it, this drives the calendar wheel of 44)
Winding System: There is a geared reduction between the weight and the barrel ratchet wheel. Rocking pinions enable winding in both directions. The barrel arbor has double ratcheting, one set works as the watch is being wound manually thus preventing the rotation of the self winding train and the other springless clicks work as the self winding is going on. The clicks are made springless so as to avoid frictional wastage occurring.
Keyless work: Conventional positive set keyless work
Dimensions: Case diameter 32.7 mm., height 10.0 mm.(over the glass)
Movement diameter 26.0 mm., height 8.0 mm.
Provenance: Purchased in 1987 with the aid of funds from the Dingwall Bequest.
- Not on display
- Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number