- Museum number
MOVEMENT OF AN EIGHT-DAY WATCH.
Unusual construction; very large barrel, recessed into back-plate.
Club-tooth lever escapement.
- Production date
Diameter: 43.10 millimetres (front-plate)
Thickness: 15.50 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
La Chaux de Fonds, Switzerland, c 1930.
8 Day watch with club tooth lever escapement.
Signature: 'Octo + Mon Magnetic +' on the barrel cover. On the barrel retaining plate 'M PATENT SWISS 192455'. On the inside of the front plate 455 59 4 1
Dial and Hands: Missing.
Ebauche Marks: 492456, Under the back plate 31 7 59.
Frame: A large barrel covers nearly all of the back plate. The balance is located and supported by a circular bridge that fits into a recess in the back plate and is located by screws.
Barrel and Mainspring: Going barrel I. diameter 33.2 mm., height 4.0 mm.
Slipping Mainspring height 4.0 mm., thickness 0.29 mm.
Arbor: diameter 5.4 mm., not snailed.
Hooking: 6 notches in the barrel wall provide temporary restraints for the slipping mainspring.
Train: Brass wheels, not gilded and with five crossings except for the escape wheel which has four.
Jewelled: At the balance only, with ruby endstones. The jewels rubbed in.
Escapement: Club tooth lever, straight line layout, short lever, double roller, impulse pin elliptical in section. Pallet stones exposed, flat acting faces. Escape wheel brass. Pallet staff screwed in.
An equidistant locking escapement.
Number of teeth embraced 3½.
Balance: Monometallic balance, diameter 13.3 mm., height 0.90 mm. "Self compensating" flat spiral spring with 11½ turns.
Means of Regulation: Index registering against a divided scale on the balance bridge with engraved 'S F' and 'R A'
Train Counts and Beat Rate:
Great wheel mounted on the barrel arbor; 36 teeth, some broken, all damaged.
Intermediate wheel 64 pinion 13 (2 leaves broken)
Centre wheel 64 pinion 12
Third wheel 60 pinion 8
Fourth wheel 60 pinion 8
Escape wheel 15 pinion 6
Beat rate: 18,000
Motion work: cannon pinion 15
The minute wheel, minute pinion and the hour wheel are all missing but would have been the same as registration no. 1984,0702.5) i.e. minute wheel 30, minute pinion 8, hour wheel 48.
Keyless Work: Normal positive set keyless work.
Dimensions: Movement diameter 43.2 mm., height 14.6 mm.
Provenance: Formerly in the Ilbert collection
For a similar example see registration no. 1984,0702.5. Two types of these watches were made by Ernest Tolck see page 243 of the Horological Trades Directory of 1928.
- Not on display
Latest: 4 (2017)
4 (Dec 1994) Dirty.
- Acquisition date
- Acquisition notes
- Following the successful acquisition of the celebrated Ilbert collection of clocks (1958,1006 collection), prints and other related materials made possible by the generous donation of funds by Gilbert Edgar CBE Ilbert's watches were then acquired using funds provided by Gilbert Edgar, public donations and government funds.
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.3137 (Ilbert Collection)