Breguet et Fils, Paris, c.1822 No.3157

2 day marine chronometer in mahogany box

For biographical details of the firm of Breguet of Paris, see pp.xxx

Box/Mounting

Two-tier, plain mahogany box measuring 175mm high, 222mm wide, and 190mm deep. The top of the box has an inset lid with side-pin hinges allowing it to open to about 120°. The lid is inlaid with a brass, diamond-shaped plaque, engraved: “3157”, and opens to a circular glazed panel retained with narrow brass bezel, screw-fixed from the underside. The front of the upper half has a push button brass catch for the lid with brass, circular escutcheon and brass spring inside the upper half to ‘jump’ the lid open when the button is pressed. In side the back of the upper half is inscribed in ink: “3157 / Novembre 1878” (?). The lock on the lower half is stamped on the upper edge: “328”, and has an oval, brass escutcheon on the front. The box has a full-width, ‘butt’-type, hinge and a brass strut on the right hand side, restraining the upper half to 90°opening. There is a raised step running around the inside of the junction on the lower half, mating with a rebate in the junction of the upper half and forming a dust seal when closed.

The box fittings are similar to the standard French type, with brass drop handles on the sides and lacquered brass gimbals with a narrow, straight-sided bezel retained with two side screws and having a brass sight ring and beveled flat glass over the dial. The centre body of the movement-housing doubles as the brass edge of the movement and has a barleycorn knurled beading running round the outside. Both bezel and bowl are fixed to it with a pair of screws. The thick, oval gimbal ring has a concave inner edge to the upper surface, and two flat brass arms can be swung in from the rear left and front right corners of the box to engage with blocks on the bowl, securing the gimbals. When these arms are in place and the lid is closed, cast brass pegs fixed up inside the upper half of the box prevent them from swinging open. When these arms are not in use they are swung out and stowed on little brass pillars on the edge of the box. The heavy brass bowl has an upstanding beading on the base, within which are the two winding holes. No direction-of-winding arrows now present. There are two small plain holes drilled into the edge of the beading, with no apparent function. The Breguet-type ratchet key is stowed in a standard, Breguet-type boxwood socket in the rear right of the box, and has a brass retaining fork fixed up inside the upper half which secures the key in place when the box is closed. In the right and left sides of the lower half of the box there are vertical holes going through to the base, intended for wood screws to fix the box to a wooden surface when in use on board ship. The underside of the box is plain, without baize covering.

Dial and hands

The 98.6 mm Ø, engraved and wax-filled, French-silvered matt-finish dial is fitted snugly in a rebate in the front of the brass edge, fixed with one screw at the top of the seconds dial, into the train bridge beneath. To free the dial from the brass edge, a pin hole in the brass edge allows a pin to be inserted, which enters a small ramped groove at the 6 o’clock’ position on the back of the dial, forcing it up and releasing it. The movement is attached to the brass edge with three steel screws from the inside. The subsidiary hours and minutes dial has roman hour numerals and arabic ten-minute figures with a large seconds dial below having arabic ten second figures and with straight batons at five-second intervals. The dial is signed across the centre: “Breguet et fils Hgers de la Marine / Royale / No.3157 ”. Above the upper dial is engraved: “F” and “DÉPÔT DE LA MARINE”. On the left of the upper dial is a stop-start control lever marked: “BALANCIER / Fixe / Libre”. The back of the dial is scratched: “3157 / F”. Blued steel demi-lune hands with a fine, blued steel pointer seconds hand with a counter-poised tail.

Movement

Breguet Grande Horloge Marine format double-barrel calibre movement with the train mounted under a bridge on the front of a central brass plate with twin going barrels mounted on a large double-cock on the rear of the plate. The general level of finish of the movement is high with most movement parts flat-polished.

The underside of the main plate is stamped: “3157” next to the foot of the fourth wheel blocking detent. and “13” near the barrel. The double going barrels have spring-clicks alongside the ratchet wheels on the cocks, and brass and steel Breguet-type stopwork mounted on the caps of both barrels. There is a four-wheel train with the two great wheels on the barrels, the greats both meshing with the second (‘centre’) wheel in a straight line, the second pinion being . The wheels are all brass with the fourth wheel run in a cock on its lower pivot. There is a meshing inspection hole by the 2nd/3rd pivot in the main plate and by the 3rd / 4th pivot in the bridge.

Escapement, balance, spring and jewelling

Breguet-type spring detent escapement with double-spring detent mounted, via a brass block with 2 screws, on a brass cock. The cock, which has been moved a couple of times (probably during manufacture. Plugged holes for screw and steadies), has “38” scratched on its foot, The escapement as a whole is mounted on the ‘Navette’-shaped escapement platform. The platform is scratched “R” and “L” by the two steel steady pins, on the underside (distance between pin centres: 51.0mm) and there are five unused holes in the navette baseplate adjacent to the escapewheel (possibly originally for escape-locking device, now superseded by fourth wheel detent lock). The detent has a screwed-on, gold passing spring running alongside the detent blade, and with a polished-steel locking ‘stone’. The impulse roller has a steeply raked, pale pink impulse jewel with cut out opposite for poising, and the discharge roller has a deep red stone inset. The balance staff has two nicks on its body, for holding the staff when removing the rollers. The platform of the escapement is fixed with three screws, one of which, when unscrewed, releases a spring detent into engagement with the fourth wheel preventing a ‘runaway’ should there still be power on the train. There is a stop-start control on the dial which connects a steel spring blade mounted on a brass column by the balance, the blade gently touching the rim of the balance to stop it, when actuated.

The undersprung, two-arm bimetal balance has very slightly tapered blued-steel arms and the rims have brass meantime nuts mounted on fixed threads at the end of the arms and at 90° on the rims. There are also additional small, white metal (probably platinum) meantime nuts mounted on the rims just to one side of the balance arms, and similar compensation screws adjacent to the meantime screws at 90° (holes present for a choice of six positions). The grey-finished steel helical balance spring has no terminals but is thinned towards the centre and is of the ‘barreling’ type, where only the middle coils breathe during running. The stud, which has the spring pinned to it, is clamped to an adjustable brass stud-block which has a central screw and three positioning screws to aid slight isochronal adjustments and to position the lower termination of the balance spring correctly. The upper jewelling of the balance pivot consists of a red hole in a brass setting with a facetted diamond endstone in a steel setting, all fixed on the balance cock in a steel ‘parachute’ shock-protection device. The other jewelling, which is mounted in brass settings (escape endstones in steel coquerette settings), extends to the balance and escape wheel with endstones and the escapement parts as mentioned, all stones a light pink, the lower balance hole having a red stripe through it. The centre third and fourth wheels have steel coquerette endplates on the ‘upper’ (lower when in use) pivots.

Alterations/condition

The push-button spring for the lid required re-tensioning to work correctly. The winding key required dismantling and cleaning / re-lubricating to enable it to work reliably. The brasswork of the box is rather roughly refinished in places and the lacquer is slightly breaking down in places, but is generally sound. The surface finish of the box is generally sound with some slight old knocks and marking. There is one crack running from front to back on the lid and one discoloured dent on the edge of the front right of the lid.

The movement is in generally sound condition with some light spotting to the brasswork but virtually no signs of wear from use, the pivots in fine polished condition and the pinions unmarked. A spot of heavy corrosion under the main train bridge, emanating from an original casting flaw, was cleaned out mechanically.

Barrels & MSS were thick with old hardened oil; cleaned with acetone. Spring No.1 was in ‘barrel 2’ and vice-versa, so put back in correct barrels (set-ups as found were 1 ¾ & 2 turns respectively).Note: braces in barrels have a longer tab which should be at the cap end, so as not to rub on the main plate when running. The escape cock has a stripped thread on the screw. Fitted as securely as possible without over-tightening. The movement was generally wiped clean and holes pegged perfunctorily, but the movement has not been fully cleaned.

The Breguet-type winding key is probably a later replacement. The balance stop arm is a later replacement and now acts on the outside of the balance whereas originally it would have acting inside, on a pin on the balance arm which is now missing.

Possibly chron has been rusty in the past and steel work refinished. Balance spring with pinned stud and detent are probably later replacements. Diamond endstone may also be a later replacement.

The brass retaining screws for the movement are later replacements and the bezel retaining screws are missing.

Dial letters…

Commentary, Provenance, etc
xxxxxxx


Main Plate: 97.4

Barrels:

Left (next to scape cock and all parts marked with one spot)

Inside barrel: 38.2 brace in barrel at 90° from hook

Arbor: 11.6 brass, with brass hook, not snailed.

Thickness: 0.20 – 0.23

Height: 21.7

Spring Signature: “Vincent”, “Vincent Aout 1820”, “No 3069” (?) and “No.1”, on outside of spring near end.

Set-up: 2 turns (total output 11 ¼ turns)

Right (next to balance cock and all parts marked with two spots)

Inside barrel: 38.5 brace in barrel at 90° from hook

Arbor: 11.6 brass, with brass hook, not snailed

Thickness: 0.20 – 0.24

Height: 21.7

Spring Signature: “Vincent Aout 1820” and “No.2”, on outside of spring near end

Set up: 2 turns (total output: 12 ½ turns)


TRAIN COUNT


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

Great (left): 120 / 44.0
Ratchet (left): 35 / 13.3 Brass
Stopwork driver (left): 10 / 14.6 Brass with steel finger
Stopwork driven (left): 8 / 12.1 Brass `with steel stop-piece
4 turns of barrel produced

Great (right): 120 / 44.0
Ratchet (left): 35 / 13.3 Brass
Stopwork driver (left): 10 / 14.7 Brass with steel finger
Stopwork driven (left): 8 / 12.1 Brass `with steel stop-piece
4 turns of barrel produced


Centre/2nd: 96 / 35.7 + 9 / appr. 4.0 4 curved crossings. flat grained finish
Pinion nicely finished

Third: 90 / 33.75 + 12 / 4.65 “

Fourth: 80 / 27.0 + 12 / 4.55 “

Escape: 18 / 19.8 + 12 / 4.25 “

Balance Frequency: 14,400 vbs/ hr (half seconds)

Hour: 48 / 16.5

Minute Wheel: 42 / 15.5

Minute Pinion: 12 / 4.8 (Brass)

Cannon: 14 / 5.8 (Polished steel, wheel blued)

Impulse pallet tip Ø: 6.9

Discharge pallet tip radius: 2.0

Balance Ø: 36.1 Balance Mass (incl. b/spring & stud): 5.2g

Balance spring Ø: 12.0 Material: Grey-finished steel

Turns: 10 (anti c/w down)