- Museum number
MOVEMENT, DIAL AND DUST-CAP OF A HALF-HUNTER CASED, ANTI-MAGNETIC, LEVER WATCH.
3/4-plate, hunter layout, going-barrel, old-English-rocking-bar keyless-work, ratchet-click-arbor slotted like a screw head [so that spring can be let down from the back while movement is in case], ratchet-tooth lever-escapement, gold lever, Earnshaw bimetallic balance [using two white metals], white metal balance-spring with over-coil, [thus escapement is anti-magnetic].
White enamel dial; hours I-XII, sunk subsidiary seconds dial.
Dust cap, skeletonized - not covering back-plate or balance-cock table.
Blued steel spade hands, with half-hunter hour hand, blued steel seconds hand.
- Production date
Diameter: 45.10 millimetres (dial)
Diameter: 41.80 millimetres (dust-cap)
Thickness: 9.10 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by S. Smith & Son
London, c. 1900
Movement of a ratchet tooth lever watch.
Signature: On the dial 'S SMITH & SON LONDON 87 A 93' and 'NON-MAGNETIZABLE'. On the dust-cap 'REG. 289239'. On the back plate 'S. Smith & Son WATCHMAKERS TO THE ADMIRALTY, 9, STRAND London' an anchor and 'No 87a93'. Also on the back plate ' "THE STRAND WATCH" ENGLISH MADE'
Case: Missing but was a half hunter.
Dial & Hands: A flat dial with a sunk subsidiary seconds dial. The dial has three feet, two of which are retained by side screws. The third foot which located in a plain hole without a screw to grip it, is now missing. The letter 'A' in black, is fired into the counter-enamel. Blued-steel spade-pattern hands, the hour with a double swell for half hunter presentation, blued-steel seconds hand.
Dial-plate: None intended.
Dust-cap: A rim cap with additionally a piece covering the open area around the balance cock. Stamped '604' on the inside. The cap is retained by two dog screws which also served to retain the movement in the case.
Ebauche Marks: 21604
Frame: 3/4 plate layout, the back plate supported by three turned pillars and secured by screws. Inscribed '21604. PAT 18766 22674'1 on the inside of the back plate and numbered '04' on the underside of the combined cock for the escape wheel and pallets. Also, the number '604' is punched on the underside of the plain balance cock foot.
Barrel and Mainspring:
Barrel: going barrel with Geneva stop-work, the wheel missing, internal diameter 17.3 mm, height 2.50 mm.
Mainspring: height 2.25 mm, thickness 0.22.
Barrel Arbor: diameter 5.2 mm, snailed.
Hooking: pressed in tongue.
The barrel ratchet can be disengaged by turning a screw provided for the purpose so that with the aid of the button the watch can be let down.
Train: All the wheels gilded, the centre, third and fourth wheels with five crossings.
Jewelling: Jewelled bearings for the rear centre wheel pivot and then for the third wheel onwards, all the jewels in screwed settings. All the escapement bearings with ruby endstones.
Escapement: A right-angle layout ratchet tooth lever escapement with short lever, single roller and D-shaped impulse pin. The enclosed pallet stones have convex impulse and locking faces. Adjustable banking pins. The pallet body and the lever are made from gold, hence the legend 'NON-MAGNETIZABLE' on the dial. Gilded escape wheel with three crossings.
An equal impulse escapement.
No. of teeth embraced 32.
Balance & Spring: A split bimetallic balance with brass compensation screws and brass quarter screws, diameter 15.4 mm, thickness 1.25 mm. The inside part of the balance is an alloy of steel which is only slightly magnetic and the outside of the rim is a non-magnetic steel. The ratio of the thicknesses of the outside to the inside is 1:4. Flat spiral palladium balance spring of 15 turns with terminal curve attached to a polished steel stud, screwed to the balance cock table.
Means of Regulation: An index on the balance cock registers against a divided scale 'F' and 'S' inscribed on the balance cock table.
Train Counts and Beat Rate:
Great wheel 76 (barrel)
Centre wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 70 pinion 8
Escape wheel 15 pinion 7
Beat rate: 18,000
Motion work: cannon pinion 16
minute wheel 32, minute pinion 8
hour wheel 48
Winding System: Keyless winding with side-set rocking bar hand set mechanism.
Movement: diameter 45.1 mm, height 9.4 mm, pillar height 2.9 mm
Provenance: Formerly in the Ilbert Collection. Ilbert purchased this from Malcolm Gardner 20/11/1936
(1) The patent referred to here, number 18,766 of 20th October 1892 reads as follows:-
Barrel ratchets for watches. The barrel ratchet A alone is placed below the centre-wheel E in a recess of the pillar plate, and is retained in place by three screws B, with or without a bridge D, so that on removal of the barrel the ratchet cannot be raised so as to damage the centre wheel."
- Not on display
Latest: 3 (2017)
- 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.1148 (Ilbert Collection)
Previous owner/ex-collection number: P114 (Ilbert Ledger)