Motel, Paris c.1820 No.59

2 day marine chronometer in mahogany box

Motel……..


Description

Box/Mounting

Plain, two-tier mahogany box, 135mms high, 165mms wide and 165mms deep, with a sliding dovetailed lid inset into the top.The lid slides off forward to reveal a porthole, glazed in a brass bezel, enabling the dial to be viewed. The top of the lid has a brass, diamond inlay in the centre, engraved: “N.39” and “M” and is scratched: “79” on the underside. The box has an inlaid brass diamond escutcheon on front, and diamond-shaped brass inserts in the sides supporting the gimbal bearings inside. The box has a half-round beading as a dust seal at the joint, a full-length, butt-type hinge which is stamped: “24”, and a two-pronged, double throw lock. The bottom of the box projects beyond the sides forming a half-round beading to the base.

Standard, lacquered brass gimbals, stamped on the back part of the gimbal ring: “24”, with a later, English, rising-ratchet winding key, stamped: “1533” mounted in a shelf on the rear right. The gimbals have a deep bevel on the upper inside edge and have Motel’s own locking arrangement in which a cradle rises up under the owl to secure the whole assembly. A quarter turn clockwise of the locking knob in the front right of the box causes the knob and its arbor to move down. The lower end of the arbor pushes down a ‘see-saw’, the other end of which terminates in a circular cup, and this rises up and embraces a cone on the rounded base of the bowl, centering and securing it. A spring reverses the action of the see-saw when the locking is turned back. The arrangement for housing the movement also includes a number of special features associated with Henri Motel, including a stop/start device, a front-winding arrangement and Motel’s ‘secret locking’ to prevent casual access to the movement.

The movement is screwed into a separate straight-sided brass drum of 96.8mm, which sits snugly in the bowl, the inside of the bowl being lined with green velvet (the side lining now missing). A projecting screwhead, on the upper-rear of the movement drum, locates in a notch on the top edge of the bowl, at XII o’clock position, to ensure the movement is correctly disposed in the bowl.

This secondary drum has a flanged bezel with a slightly domed glass, fixed over movement with three side screws. At the ‘6 o’clock’ position on the bezel there is a steel square, actuated with the winding key, for stop/start function. Engraved next to this control is “A” (Arrêt) and an anti-clockwise arrow, for stopping the balance, and a clockwise arrow and “M” (Marche) for starting it running again. On the underside of the bezel this control has a fork which embraces a short lever on the movement between the dial and the pillar plate. Between ‘2 & 3 o’clock’ on the bezel is a sliding shutter, covering the square for front winding of the chronometer. Inside the movement drum is the gearing for this, which consists of a brass spur wheel mounted on an arbor with the winding square, the arbor angled at approximately 10 and run in a potence inside the drum and a hole in the upper edge. When the movement is in place, this wheel meshes with a bevel wheel mounted on the fusee arbor.

With the bezel off, the brass edge which retains the dial is exposed. This is engraved around the side: “N59 HRE MOTEL HGER DE LA MARINE RLE”. In its fitting to the drum, the movement employs Motel’s secret locking, based on the designs of Louis Berthoud. When being fitted, the movement, held by the brass edge, is lowered into the drum about 10° anti-clockwise from its proper position, and then rotated clockwise to the position where the winding wheels mesh correctly. Here, rotation is stopped by a projection of the potence plate meeting a steel stop pin inside the drum. At the same time a spring-loaded brass bolt drops into a notch in the edge of the drum, preventing the movement from being rotated back the other way. Once locked in this way, the only way to get the movement out of the drum is to release the brass bolt by pushing a tiny pin into a hole in the side of the brass edge, next to the bolt, whilst turning the movement anti-clockwise. There is an arrangement for disabling the secret locking device; a pin can be inserted through the pillar plate which, if aligned with one in the brass bolt, secures it back in the unlocked position.

The underside of the box is plain, without covering.

Dial & Hands

The 79.0mm matt-silvered brass dial has roman hour numerals and a seconds dial in the lower half marked with Arabic ten-seconds intervals. The dial is signed: “H ri Motel / H ger de la Marine R le“ in the upper half and: “N59” in the seconds dial. Two pins attach the dial to the movement, the edge of the dial fitting in the brass edge which is scrwede to the pillar plate. The rear of the dial is stamped: “59” and is scratched: “1556”. The whole of the area across the middle of the dial has been ‘knocked out’ from behind, apparently to enable the signature to be re-engraved in the current position. The hands are all finely polished blued steel, the hour and minute of demi-lune type and the seconds a straight pointer with counter poise.

Movement
Louis Berthoud type, one-day full plate fusee movement with four highly polished steel pillars, the pillars having a tapering foot and cross-drilled ‘capstan’ screws with blued steel washers, all dot marked for correct location. The movement is highly finished throughout, the plates, all brass movement parts and the wheels all having a fine, neat curled decoration all over. The upper plate is engraved on top: “Construite par / Hri Motel / N.59” and the pillar plate is stamped: “59” on the underside. The mainspring set-up is on the pillar plate under the dial. The mainspring was braced in the barrel about 100 round from the hook (brace now missing) and is an unsigned, 20th century replacement. . The fusee has Harrison’s maintaining power. Conventional four-wheel train plus great wheel, the great, the third and the fourth lower pivots all run on cocks on the dial side, the third with a removable brass pivot hole and a steel endpiece. The centre wheel front pivot is run in a large, circular removable brass bearing. The upper barrel arbor pivot is run in a cock on the upper plate, the fusee pivot runs in a removable bearing, the centre and third pivots are all run in removable brass holes with steel endpieces, and the fourth has a jewelled hole and endstone, the latter set in a polished steel coquerette. . The hour wheel is mounted on a bridge over the cannon pinion, the minute wheel is run under a cock, the secret bolt is mounted in a groove in the pillar plate and has a fine steel return spring, and the blued steel stop/start lever has a steel two-position jump-piece acting on it. All this under-dial work is beautifully and crisply finished.

Escapement, Balance & Spring and Jewelling

Typical Louis Berthoud-type pivoted-detent escapement mounted on a pointed oval ‘navette’ type platform, fixed between the plates on the pillar plate, and with the detent and escape wheel run on the platform, under cocks, the balance staff pivoted on this lower plate but with the balance run above the upper plate, under a bridge. The stop/start lever is mounted between the plates alongside the platform and the lever interacts with a pin on the balance when in use. The lever terminates in a steel pivoting nose which will allow the balance to pass by in one direction but will stop it near the extent of its swing, on its return. There is however a tendency for the balance to be stopped rather suddenly by this device, and the lever has the additional feature of being loosely mounted on the staff and connected to it through a strong buffer spring to reduce shocks to the balance when stopping it. Moving the lever back then releases the balance which will immediately resume its running amplitude.

The detent is mounted under a cock on the platform, the foot of the cock being located on two steel steady pins standing up off the platform. The rear of these two steady pins is mounted eccentrically on a steel screw head, and turning the screw head swings the foot sideways slightly, adjusting the position of the upper pivot of the detent and thus slightly altering the depthing of the detent. The detent has a red locking jewel and there is a small brass cock mounted alongside on the platform, with a rubbed-in pink jewelled plate for the steel detent tail to bank against. The detent has a steel return spring acting on a gold pin on the detent staff and the steel passing spring banks on a gold pin on the detent. The escape wheel teeth have spread tips with a hole drilled near the tip, like those of Louis Berthoud’s escape wheels, possibly for oil retention (though the teeth should not need lubrication). The impulse roller has a polished steel, radial impulse pallet and the discharge roller is also in polished steel.

The typical, Motel-type bimetallic balance has four very slightly tapered steel arms, the four bimetal rims each having a brass segmental weight with 2 large platinum screws and one central gold screw, and a small gold, fine-poising screw in the end of each weight. A steel pin projecting down from the outer end of one of the arms interacts with the stop/start lever as described above. The blued steel conical balance spring has no terminal curves but the upper terminal has a concentric clamp on the stud, with a three-screw adjustable foot for fine isochronal adjustments. The jewelling, all pink stones (except the diamond (?) upper balance endstone, which is in a gold cap setting), extends to the balance, escape wheel and upper fourth, with endstones, jewelled holes to the lower fourth, and the escapement parts as mentioned.

Alterations / Condition

The green velvet around the inside of the drum is now missing, only the base retaining its covering. The glass is missing from the circular panel under the lid.The brass work of the box, bowl and drum is in sound condition; the lacquering is becoming streaky and the colour of the brass is now gold to brown in some places.

One of the four steel screws retaining the brass edge to the pillar plate has broken off and has only one thread, but just holds. Another of these screws `is missing and is replaced with a smaller screw. The two small screws holding one of the dial feet to the dial have stripped their threads, but will just hold. The dial silvering is somewhat tarnished round the edge of the dial but is otherwise sound, if a little patchy in places.

The movement appears to be substantially original and in very fine condition. The endstone on the lower escape wheelo piv ot has probably been replaced, the stone now held in with shellac. The base of the fusee has been fragile where the chain groove runs to the base and leaves the metal exceedingly thin, and this has been very neatly repaired by inserting a sliver of brass and running in lead solder (probably a repair from the time of manufacture).

Provenance, Acquisition & Notes

Why front winding and not wind through dial. (as with LB and later L.C.B; dust protection). Parts of winding wheel in drum seem to have been screwed in before bottom was soldered on and are almost impossible to unscrew.

It is interesting to note that in the majority of French chronometers made before the middle of the 19th century the bezels are screwed securely closed, preventing easy access to the hands. Even were access gained, the hands themselves are so fragile, that setting by anyone but trained specialists might easily damage them. The inference is that such chronometers, once set and running, were never reset, but simply had the error, however large, allowed for.


The chronometer was offered to Sir James Caird on 3 January 1939 by the antique watch and clock dealers Clowes and Jauncey. After asking the advice of R.T.Gould, who then inspected the chronometer at the dealers on 12 January, the museum’s Director, Sir Geoffrey Callender accepted `the offer and the chronometer was purchased for the museum by Caird for £28 on 20 January.

This is a very fine and representative example of the first form of Berthoud-influenced chronometer made by Motel.


Upper Plate: 73.8

Pillar Plate Ø: 75.2

Plate distance: 15.1

Inside barrel Ø: 30.6

Arbor Ø: 10.2 brass, not snailed.

Thickness: 0.25 not tapered

Height: 10.0

6 ½ full turns total output from barrel

Set up (31 teeth as found) 20

Wheel / Pinion (+ext dia) Comment: Crossings? Marks?Jewelled?

Fusee/Great: 108 / 31.5 No.of Turns: 8. Chain 54.5mm long, 215 links

Ratchet: 54 / 14.4 Steel 2 clicks, near simultaneous

Maintaining Power: 120 / 28.2 Steel

Centre/2nd: 128 / 30.3 + 26 / 8.0 4 sl. tapered crossings. Fixed with 2 b.s screws

Third: 120 / 28.4 + 16 / 4.1 “ Riveted

Fourth: 140 / 27.0 + 16 / 4.0 “ Fixed with 2 b.s.screws

Escape: 15 / app.16 + 14 / 3.0 4 curved crossings Fixed with 2 steel screws

Balance Frequency: 18,000 vbs/ hr (5 beats in 2 seconds)

Hour: 64 / 15.0

Minute Wheel: 54 / 13.9

Minute Pinion: 16 / 4.0 (Highly polished steel, runs on pivots)

Cannon: 18 / 5.2 “

Set up ratchet: 32 / 14.8 Steel. 1 dot on upper side for square orientation

Winding bevel wheel in drum: 50 / 17.8 (Brass, round bottom teeth)

Winding bevel wheel on fusee: 50 / 18.4 (Steel, round bottom teeth)

Impulse pallet tip Ø: 5.5

Discharge pallet tip radius: 1.4

Balance Ø: 26.8 Balance Mass (incl. b/spring & stud): 3.7g

Balance spring Ø: (conical) from 8mm at the top, to 5.5mm Material: Blued steel

Turns: 12 ½ (a.c/w down)