- Museum number
MOVEMENT AND DIAL OF A LEVER WATCH WITH TOURBILLON AND DATE-INDICATOR.
Fusee; Harrison's maintaining power.
Lever escapement; tourbillon.
White enamel dial with subsidiaries for date and seconds.
Blued steel spade hour hand; others missing.
- Production date
Diameter: 46.90 millimetres (dial)
Thickness: 15 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Jules Calame Robert.
La Chaux-de-Fonds, c. 1880
Movement of a watch with tourbillon lever escapement
Signature: On the barrel and fusee bridge 'Js Calame Robert CHAUX=DE=FONDS' and 'TOURBILLON' on the balance cock.
Case: Missing. The movement was fixed in its case by a peg and two dog screws in the edge of the front plate.
Dial and Hands: A flat dial with sunk subsidiary seconds dial and sunk day of the month dial.The dial is retained by two small screws passing through the dial near its edge and into the front plate. Two feet formerly on the dial have been cut off flush but there are no holes in the movement which would have accommodated them. The inscription '94575 R' in black is fired into the counter-enamel. Blued-steel spade pattern hour hand, the minute, seconds and calendar hands all missing.
Dial-Plate: None intended.
Dust-Cover: None intended.
Ebauche Marks: Stamped on the front plate under the dial 'J. CALAME ROBERT CHAUX-DE FONDS' and '94575'.
Frame: The front plate is recessed for the barrel, great wheel, centre wheel and the tourbillon. On the rear of the front plate there is a single bridge for the barrel, fusee and centre wheel. There are also separate cocks for the maintaining ratchet and for the third wheel. The balance cock is engraved with foliate scrolls and inscribed 'TOURBILLON' on a label. A large bridge on the front plate under the dial carries the bearings for the third wheel and tourbillon carriage. A chain guard is provided between the barrel and the tourbillon to protect the latter in the event of the chain breaking.
Fusee, Barrel and Mainspring:
Fusee: five-turn reversed fusee with Harrison's maintaining power with a steel maintaining ratchet wheel. The fusee arbor has a boss on which the great wheel pivots, with a plate held by three screws in a recess on the outside of the great wheel to hold the assembly together.
Barrel: flanged at the closed end and recessed into the front plate. Five-turn Geneva stop-work fitted in a shallow recess on the front plate and operated by the fusee arbor. Setting-up-work similarly fitted, the barrel arbor with an extended square on that end only, the ratchet with two teeth as in later marine chronometer practice. Barrel internal diameter 16.8 mm, height 4.3 mm.
Mainspring: height 4.10 mm, thickness 0.16 mm. Scratched '16 Lignes' on the outside of the outer end. A loose bride is fitted near the outer hooking.
Barrel Arbor: diameter 6.0 mm, snailed.
Train: Arranged in the usual way for a one-minute tourbillon. The centre wheel below the great wheel, the third wheel on the dial side of the front plate engaging with the fourth pinion on the tourbillon axis. The escape pinion pivoted on the edge of the carriage and meshing with the fixed fourth wheel screwed to the back plate concentric with and below the tourbillon carriage. The well-made train with brass wheels is gilded, the steel pinions and arbors nicely finished and polished. The centre arbor hollow for the squared hand-set arbor which carries the cannon pinion.
Jewelling: Jewelled bearings for the pivots of the third, tourbillon and escapement arbors, those of the escapement with endstones. The jewels for the rear third wheel, the tourbillon carriage and the jewels in the carriage cock are all in screwed settings, the others rubbed in. The train jewels bombé.
Tourbillon: Making one revolution per minute and carrying the seconds hand on an extended front pivot. The carriage is built up on a steel plate with three pillars carrying the upper pierced framework. Most unusually the pillars are only 0.5 mm in diameter with a broad base and a cantilevered arm at the top threaded for fixing purposes. A separate bridge encircling the balance staff carries the rear escapement bearings and is supported by three short integral pillars. A separate polished steel disc carrying the fourth pinion and the balance lower endstone in a brass setting is attached by three screws only to the bottom of the carriage. All the visible steel surfaces are highly polished with polished bevelled edges. The carriage is not properly poised and has a pronounced heavy spot opposite the escapement.
Escapement: A right-angle layout club-tooth lever escapement with a short lever, single roller and oval impulse jewel. The lever with a short tail banking between two polished steel banking pins. The exposed pallet stones have convex acting faces. The very lightweight steel escape wheel, with four crossings, is polished on both sides, with the impulse faces chamfered both sides. The single roller, with an oval impulse jewel, providing safety action with a v-shape filed in the material of the fork above and behind the notch.
An equal impulse escapement.
No of teeth embraced 32.
Balance and Spring: A split bimetallic balance, the arm of 'sage-leaf' pattern, with brass compensation screws but no quarter screws. The balance sunk out on both sides, leaving the arm midway between the top and bottom of the rim. Balance diameter 16.8 mm, thickness 1.2 mm. Blued-steel spiral spring of 162 turns with a terminal curve having a reversed curve, pinned to a round brass collet on the balance staff and polished steel stud on the tourbillon carriage.
Means of Regulation: An index is provided, concentric with the central boss of the upper part of the tourbillon carriage frame. There are no marks for it to register against.
Day of the month indication: A brass wheel mounted on the hour wheel pipe drives an intermediate date wheel with double the number of teeth. This intermediate wheel, which turns on a steel stud, carries a pin to index a star wheel every twenty-four hours. The day of the month hand is carried on the extended arbor of this star wheel.
Train counts and beat rate:
Great wheel 70 (fusee)
Centre wheel 80 pinion 12
Third wheel 90 pinion 10
Fourth wheel 72 pinion 12
Escape wheel 15 pinion 8
Beats per hour: 16,200
Motion work: Cannon pinion 12
minute wheel 36, minute pinion 10
hour wheel 40
Day of Month indicator: Calendar wheel 21
intermediate calendar wheel 42, star wheel 31
Movement: diameter 47.0 mm, height 9.9 mm, frame height 9.9 mm.
Provenance: Formerly in the Ilbert Collection. Purchased by Ilbert from Malcolm Gardner in 1936.
In Ilbert's inventory notebook, with the entry for this watch, is a letter from Paul Ditisheim to Major Paul Chamberlain:
32, Rue du Ranelagh (XVIE)
PARIS LE Aug 8th 1936
My letter was just dispatched when I received your good news of July 28th.
I can give you full information, over Jules Calame Robert, who has been acting as watch manufacturer, later on with his two sons at La Chaux de Fonds, for over 50 years. One of the junior members was active in political and corporative associations (Jules Calame Colix) and for a number of years President of the Society des fabricants d'Horlogerie de la Chaux de Fonds. This manufacture was in the old system of buying the rough work Fontaine Melon and others in the period 1850-1900. As regards the tourbillon picked up by M. Ilbert. The tourbillon work is whether by Albert Pellaton Le Locle or by Auguste Grether Ponts de Martel, specialists acting during the later part of the above mentioned period.
The firms seat was 4 Rue de Parc and later on the sons built a small factory close by (no. 2). My brother Henry bought both buildings direct from them when they retired as well to do people to Corcelles near Neuchâtel.
We are very pleased you keep very busy with guests and Horology in your summer resort. Many thanks for your sending the papers I am looking forward for the September Horology number which we now receive regularly at the Laboratory. We are going to spend a fortnight at Lepoy a little village of Loiret (90 miles away). We all three are joining in kindest regards to Mrs Chamberlain and to you.
Reinhard Meis, in Das Tourbillon, 1986, pp.122 and 123, illustrates three similar movements but all anonymous with two being given a Le Locle origin. In all three, however, the tourbillon has a detent rather than a lever escapement.
- 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.1138 (Ilbert Collection)
Previous owner/ex-collection number: P77 (Ilbert Ledger)