centre-seconds watch;
chronometer;
self-winding watch;
wrist-watch;
watch-case
- Museum number
- 1989,0407.12
- Description
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CHROME-PLATED CASED AUTOMATIC CENTRE-SECONDS WRIST-WATCH.
Movement with club-tooth lever escapement and automatic rotary winding.
Silvered dial with raised gilt Arabic hour numerals at 3, 6, 9, 12 and batons for the remainder.
Gold-plated hour and minute hands; blued-steel seconds hand.
Chrome-plated case with screw-on stainless steel back inscribed on inside with Rolex insignia.
- Production date
- 1947-1953
- Dimensions
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Diameter: 32.30 millimetres (case)
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Diameter: 25.90 millimetres (dial)
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Length: 37 millimetres
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Thickness: 13.70 millimetres
- $Inscriptions
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- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Rolex Watch Co.
Switzerland, c. 1937
Self winding wrist watch with club tooth lever escapement.
Signature: On the dial 'ROLEX OYSTER PERPETUAL OFFICIALLY CERTIFIED CHRONOMETER SWISS MADE' and the Rolex trade mark.
On the winding button 'ROLEX OYSTER' with between the Helvetia cross.
Case: Two piece stainless steel case with a screw back. Inside the back is the Rolex trade mark and 'ROLEX GENEVA SWISS PATENTED' and the number 5048. Because of the shape of this back the watch is familiarly known as the 'Bubbleback'. The case back is knurled and requires a special key to open it.
Dial & Hands: Raised gilt Arabic numerals at 12, 3, 6 and 9 and batons marking the other hours. A black minute circle with fifth seconds divisions. Gilt hour and minute hands, a blued steel centre seconds hand.
On the back of the dial are the numbers 103 and 834 with a star between the two numbers. The two dial feet are held by screws in the side of the front plate.
Movement:
Ebauche Marks: On the front plate under the dial is 'ROLEX PATENTED SIZE -N - A'
Frame: A nickel silver movement, a bridge for the barrel, another for the train. A bridge for the pallets and a cock for the balance.
On the self winding weight is 'ROLEX PERPETUAL CHRONOMETER SWISS MADE PATENTED'. On the self winding weight train cover is 'PATENTED' with on either side 3 stars and on one side 'TRIGGER SCREW' and on the other 'VIS TIRETTE' with between these two legends an arrow indicating the position of the bolt screw. On the back plate is the number N 2429 with, on the inside of the front plate, another number 81276. On the barrel and keyless bridge is '18 RUBIS SWISS MADE', on the train bridge is 'TIMED 6 POSITIONS ROLEX CHRONOMETER'.
Barrel and Mainspring: The going barrel I diameter 10.0 mm., height 1.60 mm.
Mainspring: height 1.40 mm, thickness 0.09 mm.
Barrel Arbor: diameter 2.8 mm, snailed.
Hooking: Three notches in the barrel wall restrain the slipping mainspring. There is a thick turn of spring to which the mainspring is riveted.
Train: All the brass wheels gilded, the centre wheel, third and fourth wheels with five crossings. The steel escape wheel with four.
Jewelling: Jewelled bearings from the third wheel onwards and at the centre in the train bridge, all the jewels pressed in, and where applicable bombé. Ruby endstones to the balance and to the escape wheel.
Escapement: A straight line layout, club tooth lever escapement with short lever, double roller and the impulse pin D shaped in section. 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 gold screws and two gold timing screws. Balance diameter 8.95 mm., thickness 0.7 mm. A self-compensating flat spiral spring with 16 turns and a terminal curve.
Means of Regulation: A micrometer index on the balance cock registers against a vernier divided scale with '+' and '-' engraved on the balance cock table.
Train Counts and Beat Rate:
Great wheel 70 (barrel)
Centre wheel 64 pinion 10
Third wheel 60 pinion 8, with mounted on the pinion the seconds driving wheel of 90 driving the idle pinion of 12. This has its backlash taken up by a drag spring.
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 positive stem set keyless work.
Self winding work: The weight is secured by a central fixing screw the head of which is locked by a screw which can be located in one of five holes in the weight. Another second screw hole in the screw head gives effectively ten positions for the locking screw so it can be inserted when the fixing screw is really tight without any need to over-tighten it. The weight is squared onto a pinion which works with a face click so that winding occurs in one direction only. A ratchet also prevents the first wheel in the self winding train from moving backwards. There are three wheels and pinions in the self winding train which end by winding a wheel that is loosely mounted on the bottom of the barrel arbor. This wheel too is connected through a ratchet and small ratchet wheel with the arbor so that manual winding can take place without affecting the self winding work. Another and similar click and small ratchet wheel is mounted upon the barrel ratchet wheel for yet again the barrel ratchet wheel is mounted loosely on the arbor, the small ratchet wheel being squared onto the arbor.
Dimensions:
Case: Diameter 32.0 mm., height 13.8 mm.(over the glass)
Movement: diameter 25.8 mm., height mm.
Provenance: Purchased in 1989 with the aid of funds from the Dingwall Bequest.
Notes:
See James L. Dowling and Jeffrey P. Hess 'The Best of Time ROLEX WRISTWATCHES'. PA - U.S.A. 1996.
This watch is very well finished and of high quality.
- Location
- Not on display
- Condition
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Latest: 4 (2017) mmnt not seen
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4 (Jul 1995)
- Acquisition date
- 1989
- Department
- Britain, Europe and Prehistory
- Registration number
- 1989,0407.12
