- Museum number
POCKET-CHRONOMETER MOVEMENT WITH ARNOLD'S SPRING DETENT ESCAPEMENT AND DIAL WITH SUBSIDIARY SECONDS.
Chronometer watch movement and dial.
Full-plate; fusee; Harrison's maintaining power.
Arnold spring detent escapement; Arnold OZ balance; gold helical balance spring.
White enamel dial not original (A & D 1816).
Gold hour hand, blued-steel seconds hand, replacement minute hand.
- Production date
Diameter: 39.70 millimetres (back-plate)
Diameter: 43.10 millimetres (dial)
Thickness: 19.30 millimetres
- Curator's comments
- Comment from Anthony G. Randall and Richard Good, Catalogue of Watches in the British Museum. Vol. VI (1990)
Made by John Arnold and Son, 1787-1799
Signature: 'John Arnold & Son London Invt et Fect No. 298/599'.
Dial and hands: The enamel dial which is chipped is not original but was possibly made specially, the back is marked 'A & D ' - so possibly by Arnold & Dent. Under the dial is scratched 'F.B.y. 1816'. There is no dial plate, but the front plate is turned to resemble a normal dial plate at the edge. The dial is secured by three feet and pins to the front plate.
Gold hour and steel seconds hands. Minute hand a replacement.
Compare the movement with registration no. 1958,1201.1576.
Front plate diam. 43.0 mm; back plate diam. 40.0 mm; frame h. 10.0 mm.
Frame: Similar to 1958,1201.1576, but the case catch and spring and the hinge are still in place.
Barrel: Flanged at top, arbor squared both ends.
Fusee: Similar to 1958,1201.1576.
Going train: Similar to 1958,1201.1576.
Jewelling: The pivots of the fourth wheel and the escapement in pierced jewels. The escapement with endstones, a diamond in blued steel setting on the balance cock. The impulse and discharge rollers and the detent, jewelled.
Escapement: Arnold spring detent, see 1958,1201.1576. The top of the detent foot not polished, the passing spring of steel held with two rivets.
Balance: 'oz' balance made up as in 1958,1201.1576, but on a brass three-armed wheel having one small platinum poising screw set in the rim. Diam. 236 mm, h. 27 mm.
Balance spring: Gold helical spring of 4½ wide turns with terminal curves at each end, the upper one pinned to a blued steel stud screwed to the balance cock. Stud and collet both of steel with square holes.
Balance cock: Compare with 1958,1201.1576.
Going-train counts: As 1958,1201.1576.
Cannon pinion 10 leaves (not waisted and not retained by a pin), minute pinion 12 leaves
Minute wheel 40 teeth gilded brass, hour wheel 36 teeth gilded brass
Provenance: Ilbert Collection.
- Not on display
Latest: 3 (2017)
3 (Sep 1995)
- 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.1577 (Ilbert Collection)
Previous owner/ex-collection number: M42 (Ilbert Ledger)