This marine chronometer has a fusee movement with an Arnold-type spring detent escapement. This instrument was almost certainly originally made by John Arnold and would have been mounted in an octagonal mahogany box similar to that of Arnold No. 23 (ZAA0012). It is uncertain when it was fitted into the current box. Thomas Prest, who signed the inside of the fusee, was Arnold’s principal finisher and foreman at the Well Hall manufactory. The chronometer was perhaps a special order from Arnold, for resale by Hind the watch jeweller (or just possibly by John Hinde the instrument maker), and would explain the absence of Arnold’s name on the dial and also on the movement, where it would normally have been engraved. The ‘1793’ on the dial is thus certainly a date. The identities of Watson and Phillips, who probably repaired the movement in 1893, are unknown. Watson may have been William Watson, who is known to have been working in High Holborn in the first part of the twentieth century.