- Museum number
SUBSIDIARY SECONDS POCKET-CHRONOMETER MOVEMENT WITH LEVER CHRONOMETER ESCAPEMENT.
Lever chronometer escapement; `Robin' type.
- Production date
Diameter: 43 millimetres (back-plate)
Diameter: 47.30 millimetres (dial)
Thickness: 11.50 millimetres
- Curator's comments
- Comment from Anthony G. Randall and Richard Good, Catalogue of Watches in the British Museum. Vol. VI (1990)
Maker Unknown, but English, c. 1865
Watch Movement with Robin Type Escapement
Signature: On the back plate 'Patent Union Chronometer 3060'.
Dial and hands: Flat enamel dial with sunk subsidiary seconds, secured to the front plate by three feet and pins. Some damage to enamel. On the back the marks 25 and B in the enamel. Gold minute and hour hands, blued steel seconds hand.
Ebauche marks H.F., 18, 2, 3060; also o under the balance cock foot on both plate and foot.
Front plate diam. 46.4 mm; back plate diam. 43.0 mm; frame h. 7.7 mm.
Frame: Half plate construction with three turned pillars, the back plate secured by recessed, blued steel screws. The movement held in its case by a peg in the edge of the front plate and a dog screw on the edge of the back plate. An unusual fourth, escape wheel bridge with the end turned back on itself. The top pivot of the pallets in an adjustable cock as in registration nos 1958,1201.1829, 1958,1201.1830 and 1958,1201.1828. The brass parts gilded.
Fusee: Keywind fusee with the usual stop-work and maintaining power, the maintaining ratchet wheel steel. Setting-up-work in a shallow recess in the front plate, the barrel arbor with an extended square on that end only.
Going train: The centre arbor hollow for the hand-set arbor carrying the cannon pinion. Conventional train and layout, the brass wheels burnished on both sides and not gilded, the steel pinions and arbors well finished and polished.
Jewelling: The pivots of the fourth and escapement arbors in pierced jewels, those of the escape wheel and balance staff pivots with endstones.
Escapement: Patent Union Chronometer escapement (see registration no. 1958,1201.1830).
Balance: Bimetallic two-armed balance with gold screws and quarter screws. Diam. 18.6 mm, h. 1.4 mm.
Balance spring: Blued steel spiral balance spring with an overcoil and terminal curve. A polished steel stud on the balance cock and a round brass collet on the balance staff. Regulation by a polished steel index on the balance cock.
Great wheel (fusee) 70 teeth
Centre pinion 10 leaves, wheel 64 teeth, 5 arms
Third pinion 8 leaves, wheel 60 teeth, 5 arms
Fourth pinion 8 leaves, wheel 63 teeth, 5 arms
Escape pinion 7 leaves, wheel 15 teeth, 3 arms
Beats per hour: 16,200
Cannon pinion 12 leaves, minute pinion 10 leaves.
Hour wheel 40 teeth, minute wheel 36 teeth.
Provenance: Ilbert Collection; Ilbert purchased this watch in the Caledonian Market in 1932.
- Not on display
Latest: 4 (2017) some verdigris
4 (Oct 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.1742 (Ilbert Collection)
Previous owner/ex-collection number: M39 (Ilbert Ledger)