Deck watch no. 10229 by Hamilton Watch Co

Catalogue description — Royal Museums Greenwich

A mahogany deck box fitted with a wide, nickel-plated piano hinge and a simple pressed, nickel-plated sliding button catch; the top is glazed with a circular 'porthole' in an inset upper surface. Mounted on this inset surface is a black plastic label, printed in white 'IMPORTANT / THIS HAMILTON CHRONOMETER WATCH (MODEL 22) is / protected with a safety setting device. To Set The Watch press the / shielded locking pin (to the left of pendant) in as far as it will go, pull / out stem, release locking pin, and set watch in regular manner. Then / push stem back into winding position.' There is a raised beading round the inside of the junction of the lower half, mating with a rebate in the upper half to form a dust seal when the box is closed. The box is lined with padded green baize in the lid and lower half, shaped to the form of the watch. The bottom of the box is covered with green baize. The frosted nickel, open-face case has the winding/setting crown inset into a solid pendant, with the safety release button to the left in the edge of the case. The convex glass is held in a screw-down, knurled, nickel bezel. The nickel, screw-down back is machine engraved on the back 'H.S.^2 / 10229', and has painted-on the earlier inventory and accession numbers 'Ch286 / A 77-1'. The inside of the back is stamped with the case manufacturer's mark 'KEYSTONE', and 'CO' in a shield, 'BASE METAL' and '670314'. Inside the back there is a snap-on inner dome, similarly painted with the inventory and accession numbers. The dial is matt-white and 60 mm Æ, retained with dial feet secured and side screws in the movement's main plate. The dial is signed 'HAMILTON / LANCASTER PA., U.S.A.' across the middle. The dial has all markings engraved and black enamelled including large vertical Arabic numerals. The seconds dial has Arabic ten-second figures. Black, spade and poker-hands have a counter-balanced black seconds hand. An up and down dial above the centre, is marked in eight hour intervals from '8 [to] 48'. It is marked 'UP' by eight and 'DOWN' by 48. The going barrel, barred movement is of bright, damascened, nickel, and is signed with black enamel-filled engraving on the barrel bridge 'HAMILTON WATCH CO., / MODEL 22 - 21 JEWELS / ADJ. TO TEMP. & 6 POS. / MADE IN U.S.A. / U.S. NAVY-BU. SHIPS-1942'. It is also marked on the main plate, by the balance cock foot '2F 10229'. Pulling out the winding crown actuates the hand setting, but only after a push piece is depressed in the side of the case. This is a safety feature to prevent accidental resetting of the hands. A polished steel index, mounted on the balance cock, acts on a snail cam for fine rating adjustment. The cam has a scale under it, engraved with 'F' and 'S' for fast and slow. There is a four-wheel train with a going barrel. The mainspring has no signature. There is a double roller, jewelled and club tooth lever escapement. The impulse roller has a clear jewelled impulse pin and pallets with clear stones. The pallets bank against brass banking pins. The uncut, ovalising balance is mounted with 14 brass screws around the rim, and four nickel compensation weights mounted on threads. Although the Model 22's balance is of the ovalising type, it is not of the bimetallic sort as fitted to the model 21. It is of a simpler design employing a single nickel alloy. During production of the alloy, the material is rolled, creating a 'grain', which with temperature change has a tendency to expand and contact more in one direction than the other. The balance is therefore cut from the material with the grain carefully orientated to ensure maximum ovalising effect with temperature change. The flat spiral, 'Hamilton Elinvar Extra' balance spring, with over coil, has an index mounted on the upper surface of the balance cock. The train is jewelled to the centre (21 jewels in total) with red stones in brass press-in settings, the balance and escape wheel has end stones in nickel settings. The instrument is in virtually mint, as new condition.