Three tier, brass, double-strung, ebony box, 190mms high, 190mms wide and 185mms deep, with an inlaid, brass, scalloped star escutcheon on the front , above is a circular ivory plaque, engraved: ‘↑ / 5685 / TWO DAYS’. The lid of the box is on butt hinges and has a brass, shield-shaped inlay in the lid, without engraving. The upper half is on a full-width hinge and has a narrow scratched moulding just above the junction with the lower half. On the front of the upper half is a rectangular bevelled ivory tablet engraved: ‘JAMES POOLE & Co. / 33, SPENCER St. CLERKENWELL, LONDON’ and the push-button for the lid has a brass, shield-shaped inlaid surround. The box has raised beading running along 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 standard, with brass flush handles to sides and lacquered brass gimbals. The interior fittings are of standard layout, with a strut to the upper half, stopping it open at ninety degrees. The original, rising-ratchet winding key has a typical, waisted handle and is engraved: ‘5685’. The bezel is of the open, silvered site-ring form, without knurling on the edge, and has a flat bevelled glass over the dial. The brass bowl has turned rings and sweeps out slightly at the top in the standard pattern. The bottom of the box has a coarse, dark green baize covering.

The silvered brass dial is fixed into the brass edge with three small, blued steel screws, a notch in the dial at XII locating it correctly and a notch in the brass edge at V providing lever access for removal. The movement is fixed into the brass edge with three brass screws, and the brass edge locates in the bowl with a pin in the edge of the dial at XII. The dial has roman hour numerals and the seconds dial has Arabic ten-second figures with straight batons at alternate five second intervals. The dial is signed across the centre: ‘ JAMES POOLE & Co. / MAKERS TO THE ADMIRALTY, / LONDON, No.5685’ The up and down dial, below XII, is marked in Arabic in eight hour intervals: ‘0…56’ and is marked ‘~UP~’ by 0, ‘WIND’ by 24, and ‘DOWN’ by 56. The chronometer has polished blued steel spade and poker hands with a fine pointer blued steel seconds hand with a counter poised tail and a blued steel up and down pointer.

Fine, standard type, two-day full plate fusee movement with four turned pillars, all fixed with polished and blued steel screws. The general level of finish of the brass-work is very high with all brass movement parts highly polished and machine-spotted all over. The fusee, which has Harrison’s maintaining power, has a bronze pipe and brass collar screwed to the potence plate around the winding square. The set up ratchet wheel and click are of blued steel. The chronometer has a four-wheel train plus a great wheel, with the third wheel run within the pillar plate with a third/fourth wheel bar.

The chronometer contains a typical Earnshaw spring detent escapement with a fine, highly polished foot detent, a screwed on, gold passing spring and light pink locking stone, and with a gilt-brass detent banking piece. The impulse roller has a radially set, red impulse jewel and the discharge roller has a similar stone inset. The two-arm bimetallic balance has Poole’s auxiliary. It has straight, narrow arms. Brass, mean-time nuts are mounted on fixed threads at the end of the arms and the bimetal rims extend to within a couple of degrees of short of extensions of the rim on the other side of the arms. Round brass compensation weights, with narrow bevelled top edges, are attached to the middle of the rims. The finely polished, blued steel helical balance spring has terminals on both ends, the upper terminal attached to a gilt-brass pointer stud. The jewelling extends to the balance (diamond upper endstone in a blued steel setting) and escape wheel, with endstones, the lower fourth hole and the escapement parts as mentioned.

The chronometer is in fine, original condition. The brass furniture and gimballing have been rather heavily polished and lacquered. The dial silvering is good and the movement is in excellent condition, though the spotting is now somewhat fainter than when first made, and there is a large fingerprint near the fusee pipe.

The chronometer was purchased by the Admiralty in 1883 and was in extensive R.N. service until at least 1930 after which the records do not survive.