Arnold No. 559: A Regency eight-day marine chronometer movement, the silvered dial signed J R Arnold 84. Strand London 559, with subsidiary seconds and up-and-down indication (1-7), blued steel hands, the movement top-plate finely engraved JNo. R. Arnold Invenit et fecit London No. 559, the Arnold escapement with 'Z' bimetallic balance, undersprung blued steel helical balance spring, Arnold stud second type format, original numbered bowl, now in a rosewood case on bun feet and with stepped chamfered top