Marine chronometer no. 1483 by Friedrich Moritz Krille

Catalogue description — Royal Museums Greenwich

Krille, Altona, c.1850 No.1483 2 day marine chronometer in mahogany box Krille…….. Box/Mounting Three-tier, brass-bound, mahogany box measuring 165mm high, 168mm wide, and 153mm deep, The lid of the box has special hinges allowing it to open to 90° only, the hinges stamped: “P.MOORE / REGISTERED / TPTy 27184”. The lid opens to a glazed panel retained with narrow half-round wooden beading. The front of the upper half has a push button brass catch with brass, ‘scalloped star’ inlaid escutcheon, and. an ivory tablet inset, engraved: “KRILLE / 1483”. The lock on the lower half is of continental (German?) origin, and has a brass, ‘scalloped lozenge’ escutcheon. The box has an ebony beading running along the centre of the junction on the lower half, mating with a groove in the junction of the upper half and forming a dust seal when closed. The box fittings are standard, with brass drop handles on the sides, brass ‘scalloped star’ washers to the gimbal screws on the sides and lacquered brass gimbals with a narrow, shaped, screw-down bezel (4 full turns) with a beveled convex glass over the dial. The thick gimbal ring has a half-round upper surface, and the heavy brass bowl has a swiveling brass dust shutter over the winding hole on the base. The upper half has a brass strut allowing it to open to 90° only. The interior fittings are otherwise of standard layout. The underside of the box has a green baize covering. Dial and hands The 88 mm Ø, engraved and wax-filled, French-silvered matt-finish dial is attached to the brass edge on the front with two screws. The movement is attached to the brass edge with three brass screws. The dial has roman hour numerals with a large seconds dial at XII o’clock having Arabic ten-second figures with straight batons at alternate five-second intervals and with the top of the minute marked as “0”. The dial is signed across the centre: “Krille Altona / 1483”. The sector up and down dial, above VI, is marked in Arabic in seven-hour intervals:”0 – 56”. The back of the dial is stamped: “1483” and the inside of the brass edge is signed “1483”, but corrected from “1482”. Gold spade and poker-hands with a fine, blued steel pointer seconds hand with a counter-poised tail and a gold up and down pointer. Movement Full-plate fusee movement with four straight-sided, tapered pillars, the potence plate fixed with polished blued steel screws. The general level of finish of the movement is very high with all movement parts flat-polished and with fine hand-curling. The underside of the pillar plate is stamped: “1483” and “13” near the barrel. The underside of the potence plate is also stamped “13” adjacent to the barrel and there are four small dots marked on the column of the potence. The reverse fusee has Harrison’s maintaining power, with a wire type return spring screwed from above. Continental-style stopwork mounted on the underside of the pillar plate. The stop-wheel, which runs on the underside of the pillar plate, attached with a shoulder screw threaded into it from the other side of the plate (the shoulder running in the plate), is advanced by a finger on the fusee arbor. The mainspring has a square hooking in the barrel and is signed on the inside “Geo Cotton & Sons Jan 1923”. There is a four-wheel train and a great wheel, the wheels brass with the fourth wheel run in a cock on its lower pivot. Escapement, balance, spring and jewelling Earnshaw-type spring detent escapement with dovetail-foot detent mounted on a gilt brass block on the potence plate. The detent has a screwed-on, gold passing spring running alogside the detent blade, and with a pale pink jewelled locking stone. The impulse roller has a radially set, red impulse jewel and the discharge roller has a similar stone inset. The undersprung, two-arm bimetal balance has straight, narrow blued steel arms and the rims have four brass compensation screws on each side and brass meantime nuts mounted on fixed threads at the end of the arms and at 90° on the rims. There are also additional small, brass meantime nuts mounted on the rims just to one side of the balance arms. The polished, blued steel helical balance spring has terminals on both ends, the upper terminal with a stud fixed on the balance cock with a side screw for fine isochronal adjustments. The jewelling, which is mounted in brass settings (upper balance diamond endstone is in a blued steel setting), extends to the balance and escape wheel with endstones, the lower fourth hole with a rubbed in jewel hole in the cock and the escapement parts as mentioned. Alterations/condition The push-button for the lid is missing. The winding key is missing. The surface of the box is sound with a few general slight knocks and marks and the brasswork of the box is tarnished and grimy in places and the lacquer is partially missing, but is generally sound. The movement is in generally sound condition with some light spotting to the brasswork. 9 teeth on set up, as found. 1 weak link in fusee chain (tightened up). Upper barrel arbor bearing (runs in cap) quite worn. The oil was very gummy, and the upper fourth pivot, which has been bushed in white metal (probably nickel) was particularly stuck. The movement has only been very lightly cleaned during inspection. Commentary, Provenance, etc This chronometer is a typical example of Krille’s work. The box would have been imported in an almost complete state from London and had the lock and gimbals fitted in Germany. The movement and bowl are also typical and would all have been made in Germany. Potence Plate: 73.4 Pillar Plate Ø: 73.4 Plate distance: 17.4 Inside barrel Ø: 31.5 Arbor Ø: 9.9 brass, not snailed. Thickness: 0.32 – 0.35 Height: 13.2 Spring Signature: “Geo. Cotton & Sons Jan 1923”. TRAIN COUNT Wheel / Pinion (+ext dia) Comment: Crossings? Marks?Jewelled? Fusee/Great: 84 / 30.6 No.of Turns: 8 Ratchet: 35 / 13.3 Brass Maintaining Power: 116 / 28.2 Brass Centre/2nd: 90 / 24.2 + 12 / 4.6 5 tapered crossings Third: 80 / 22.