- Museum number
MOVEMENT AND DIAL OF A LEVER WATCH WITH MINUTE-REPEAT.
3/4-plate; fusee; Harrison's maintaining power; keyless winding.
Ratchet-tooth lever escapement; split bimetallic balance; helical balance spring.
Slide-operated minute-repeating mechanism sounding on two steel gongs.
White enamel dial, Roman hours I-XII, sunk subsidiary seconds.
Hunter case missing.
- Production date
Diameter: 44 millimetres (movement)
Thickness: 12 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by John Bennett
London and Switzerland, c. 1870.(1)
Movement of a fusee keyless ratchet tooth lever watch with minute repeating.
Signature: On the dial 'BENNETT 65 & 64 CHEAPSIDE LONDON 15737' and on the back plate 'Bennett 65 & 64,Cheapside, London No. 15737'.
Case: Missing, but was of hunter type with the pendant at III o'clock. The movement was located in the case by a stud and retained by two dog screws.
Dial & Hands: Flat dial with a sunk centre. The subsidiary seconds dial at IX o'clock is also sunk.(2) The dial has slight hairline cracks. On the back a number 'XII' is fired into the counter-enamel. Blued-steel spade-pattern hour and minute hands and blued-steel seconds hand.
Dial-plate: None intended, the dial has two feet retained by screws passing through the edge of the recessed front plate.
Dust-cap: None intended.
Ebauche Marks: Stamped 15737 on the front plate and scratched 87567 on the outside edge of the front plate.
Frame: 3/4 plate layout, the back plate supported by four turned pillars and retained by screws. The front plate with flanged edge and deeply recessed front face to accommodate the minute repeating and keyless work. The rim of the front plate providing the dial seating is engraved with sixty divisions to aid the checking and adjustment of the repeating work. There is a separate screwed-on brass bush for the rear fusee pivot and combined cock for the escape wheel and pallets. The balance cock is plain. There is a separate cock on the dial side of the front plate providing an extra bearing for the extended fourth wheel arbor which carries the seconds hand.
Fusee, Barrel and Mainspring:
Fusee: five-turn fusee with Harrison's maintaining power and with a steel maintaining ratchet wheel.
Barrel: flanged at the cap end. Internal diameter 14.0 mm, height 2.4 mm. The set-up work for the barrel is mounted on the back plate, the ratchet is provided with a spring.
Mainspring: height 2.2 mm, thickness 0.17 mm
Barrel Arbor: diameter 4.5 mm, not snailed.
Train: A good quality high-count train with all the wheels gilded, the centre, third and fourth wheels with six crossings.
Jewelling: Jewelled bearings for the third wheel onwards, including the extra bridge on the front plate for the extended fourth arbor. The escapement has ruby endstones throughout, except for a diamond in the balance cock. The repeating train is jewelled except for the hammer holes. All the jewels visible from the back of the movement and all the escapement jewels are in screwed settings. The other jewels rubbed in.
Escapement: An acute angle layout ratchet tooth lever escapement with short lever, double roller and D-shaped impulse pin. The enclosed pallet stones have convex impulse and locking faces. The gold dart is attached to the lever by two gold rivets. Unusually, the small roller is between the balance and the impulse roller. The polished brass escape wheel has three crossings.
An equal impulse escapement.
No. of teeth embraced 32.
Balance & Spring: A small heavy split bimetallic balance with gold compensation and quarter screws. Balance diameter 13.8 mm, thickness 1.37 mm. Free sprung blued-steel helical spring with six turns and terminal curves attached to a polished steel index screwed to the balance cock table and to a poised steel collet, split one side, on the balance staff.
Means of Regulation: Because the balance is free sprung the quarter screws are used for adjusting the rate.
Train Counts and Beat Rate:
Great wheel 75 (fusee)
Centre wheel 80 pinion 12
Third wheel 75 pinion 10
Fourth wheel 80 pinion 10
Escape wheel 15 pinion 8
Beat rate: 18,000
Motion work: cannon pinion 12
minute wheel 36, minute pinion 10
hour wheel 40
A new tooth let into the minute wheel.
Repeating work: Slide-operated minute repeat mechanism of conventional design in most respects. Six wheel train, powered by a fixed barrel screwed to the back plate, terminating with a weighted pinion. This last pinion runs in a moveable bearing which enables the speed of striking to be adjusted. The under dial work consists of the usual circular racks for the hours and quarters with a four-lobe minute snail mounted on the cannon pinion. The repeating system differs from the norm in the fact that the winding rack does not mesh directly with the pinion on the repeating barrel arbor but, because of the layout, winds through an intermediate wheel. Normal all-or-nothing work is fitted and there is a surprise piece on the minute snail. The hammers strike on two steel wire gongs attached to a common block screwed to the inside of the front plate.
Winding system: Rocking-bar keyless winding. When the button is turned in one direction a spring-stop in the winding wheel throws this wheel into mesh with the wheel on the fusee arbor. The spring-stop is then overcome and winding is effected. When the hand-set push piece is pressed in, the hand set wheel comes into engagement with the minute wheel and ratcheting again occurs at the winding wheel but without it being thrown into mesh with the fusee winding wheel. Instead of the usual bevel geared winding wheel here, this wheel has contrate teeth on its inside face so that it would have meshed with a straight cut pinion on the winding stem.
Movement: diameter 43.8 mm, height 12.0 mm, pillar height 3.1 mm.
Provenance: Formerly in the Ilbert Collection. Ilbert purchased this from Harris of Piccadilly 27/5/32.
(1) This watch was made in the period just preceding John Bennett's knighthood in 1872 and although the movement is signed with his name, it is nevertheless a superb example of the high quality Swiss work available at the time. Movements such as this were imported in a state ready for finishing, dialling and casing by the London trade. John Bennett was in trouble generally at this time with the English watch-making establishment for using Swiss suppliers in this way. It was, however, to become normal practice for even the best retailers to offer Swiss made complicated watches as a less expensive alternative to those made entirely in England. Cat. no. 305 (registration no.1958,1201.1465) is an example of an ebauche showing at what stage these watches with Swiss made complicated work came to the trade for finishing.
(2) The unusual position of the subsidiary seconds is caused by a movement intended for a conventional open face case, where the pendant is positioned at XII and the seconds at VI, having been fitted into a hunter case. The dial is designed to suit this configuration.
- Not on display
- Latest: 2 (1994)
- 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.0928 (Ilbert Collection)
Previous owner/ex-collection number: M31 (Ilbert Ledger)