- Museum number
Pivoted detent escapement; keyless.
Silver hunting case.
- Production date
- Curator's comments
- Comment from Anthony G. Randall and Richard Good, Catalogue of Watches in the British Museum. Vol. VI (1990)
Made by Charles Suchy & Fils, c. 1875
Signature: On the centre arbor bridge 'Ch. Suchy & fils.' On the underside of the tourbillon carriage ' Ernest Guinand au Locle ' (died 1879).
Case: Plain silver hunter case numbered 26403, the Swiss silver quality mark 0,900 and a bear with the letter L in separate cartouches, on the cover and both backs, L the mark for Le Locle. A large heavy pendant, also with a bear, and gold-covered winding button with central push-piece to operate the case lock spring. The front cover opened by a single fly spring, to reveal a glazed bezel protecting the dial and hands. Diam. 55.4 mm, overall h. 15.5 mm.
Dial and hands: Flat enamel canister dial with sunk subsidiary seconds snapped into a nickel ring, itself snapping onto the edge of the front plate, and with one positioning peg.
The matching minute and hour hands set with small faceted paste stones and, like the seconds hand, apparently made of red gold. The seconds hand shaped as an arrow.
Ebauche marks 26403.
Front plate diam. 44.5 mm; front plate th. 3.9 mm (reduced to 2.3 mm under dial); frame th. 8.8 mm; tourbillon h. across pivot shoulders 7.75 mm; tourbillon overall diam. 18.8 mm; h. of tourbillon frame 3.85 mm.
Frame: Similar to that by Pellaton (registration no. 1958,1201.882) and almost certainly from the same supplier. The material of the frame is nickel brass and the surface finish a series of ring patterns with snailing radiating from the centre. The movement fixed in its case by three dog screws in the edge of the front plate under the dial, and with a positioning peg.
Going barrel and keyless work: Similar to registration no. 1958,1201.882, except that the hand-set lever operating piece is polished steel.
Going train: Similar to registration no. 1958,1201.882, but the wheels made of red gold.
Jewelling: The pivots of the centre, third, tourbillon and escapement arbors in pierced jewels, those of the balance staff with endstones. The third and fourth arbor lower jewels, set in a separate bridge, with curved surfaces towards the pivot shoulders. The third arbor upper jewel set directly in the front plate, and not in a separate cock as registration no. 1958,1201.882. The centre jewel in the bridge in a screwed setting, the screws with polished steel cup washers.
Tourbillon: Makes one revolution per minute and carries the seconds hand on an extended lower pivot. The steel carriage built up on a polished steel plate with three pillars carrying the upper pierced framework. All the upper and lower surfaces of the carriage polished, and with polished bevelled edges. Separate cocks pinned and screwed to the steel plate carry the bearings for the escape and detent arbor pivots. The fourth pinion driven into a polished steel disc screwed and pinned to the underside of the steel plate. The lower balance bearing a pierced jewel setting screwed into the disc with the fourth pinion on the other side. The endstone rubbed into its setting on the end of the pinion. The balance upper pierced jewel rubbed into the material of the steel pierced framework, with the endstone in the boss with the upper carriage pivot on the other side. The index pivots and is held on a taper on the edge of this boss. The carriage is not properly poised although two steel poising screws are fitted opposite the escapement on the steel plate. Engraved on the bottom of the carriage is the signature 'Ernest Guinand au Locle'.
Escapement: Pivoted detent escapement with the first tooth after that which has just given impulse locking on. The thin red gold escape wheel lightly crossed out, and burnished on both sides. The steel impulse roller polished all over, and with a radial impulse pallet. The discharge roller and pallet made from a single piece of ruby. The pivoted detent with a spiral return spring, short counterpoising tail, later gold passing spring held by a screw in the edge of the detent boss and a half-round locking stone. Banking is provided for the steel boss round the locking stone against the head of a gold screw set in the steel tourbillon plate.
Balance: Bimetallic two-armed balance with gold screws, the arms of sage-leaf shape, and joining the rim halfway up the inside, no quarter screws for timing purposes. Diam. of rim 15.1 mm, h. 1.38 mm.
Balance spring: Blued steel spiral spring of 13½ turns with an overcoil and terminal curve, pinned to a polished steel stud screwed to a cross-member of the upper part of the carriage frame. A round polished steel collet on the balance staff. The tail of the index moving over a gold scale screwed to the upper carriage frame.
Amplitude limiting device: Similar to (registration no. 1958,1201.882).
Great wheel (barrel) 96 teeth
Centre pinion 12 leaves, wheel 96 teeth, 5 arms
Third pinion 12 leaves, wheel 90 teeth, 5 arms
Fourth pinion 12 leaves, wheel 70 teeth, fixed with two screws
Escape pinion 7 leaves, wheel 15 teeth, 4 arms
Beats per hour: 18,000
Cannon pinion 12 leaves, minute pinion 10 leaves
Hour wheel 40 teeth, minute wheel 36 teeth
The cannon pinion is integral with its arbor which passes through the hollow centre pinion and is fixed by a polished steel ring and a transverse pin.
Crown wheel 24 spur, 14 ratchet teeth
Castle wheel (sliding pinion 14 ratchet teeth, 28 bevel teeth) Intermediate winding wheel 38 spur, 32 bevel teeth Barrel ratchet wheel 47 teeth Intermediate hand-set wheels, each 18 teeth
Provenance: Ilbert Collection; purchased by Ilbert in 1933.
Apart from the keyless work which seems to have come from a different source, the ébauche appears to be identical to that used by Pellaton (registration no. 1958,1201.882). The fourth wheel to escape pinion gear ratio is also different, giving a different number of beats per hour of the balance, but with the same centre distance, and the same module, about 013, for the gearing. The centre distance is therefore the same for the escape wheel to balance, but the escapement proportions chosen by the two makers are not the same.
- Not on display
- Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.1835 (Ilbert Collection)
Previous owner/ex-collection number: N85 (Ilbert Ledger)