Ca. Ø62mm, ca. 177g, 3-part silver case, hallmarks London 1782, case maker's mark ITP, signed and numbered John Arnold chronometer movement, on the plate completely signed, Invenit et Fecit No.38/76, spring detent escapement, helical hairspring, diamond endstone, very early OZ balance, signed and numbered original enamel dial (hairlines), blued steel hands, in working order and in very beautiful condition. The chronometer is in a 3-part mahogany box with matching keys. This Arnold Chronometer is a museum rarity and has never been offered at an auction before. The watch was privately owned to this day and was previously considered lost. It is not registered in the list of known Arnold chronometers. The last beautifully preserved and historically significant comparable Arnold Chronometer (20/63) was auctioned by Dr. Crott for 143.900€! John Arnold is regarded as the most important English chronometer maker and manufacturer of the first pocket chronometer. John Arnold made about 94 pocket chronometers 'of the Best Kind' at that time and 37 are still registered as existent (in addition to the present chronometer No.76). Of these 38 chronometers about three-quarters are affected by more or less major changes in their originality (e.g. no Arnold escapement or balance, no original dial, no original case, etc.). - Source: https://www.cortrie.de/go/mG2). This Arnold chronometer belongs to less than 10 chronometers 'of the Best Kind' by John Arnold which can be regarded as almost original and unchanged! In Hans Staeger '100 years precision watches from John Arnold to Arnold &. Frodsham 1763-1862' the Arnold Chronometer No.75 is presented on pages 153 and 154 with the note that it is probably the 1st Arnold Chronometer with an OZ balance. The number 76 can be considered as the second earliest known Arnold chronometer with this balance.