This caricature illustrates a cannon ball on its path of destruction through the unwitting crew of a Royal Naval warship as they relax off-watch on deck, playing cards and about to share two bowls of hot punch. Although guns are included in the background (which merchant ships also carried) it is the men's dress which indicates the intended naval context. It is also not unusual that a black sailor is shown, since by the end of the 18th century they were common enough in the Navy to make their inclusion in pictures a symbol of how various the origin of crews could be: other ethnicities were present but far less identifiably in terms of clear images. Here the subject harks back to the Anglo-French wars of 1793-1815, despite being printed slightly later. Other characteristic details are the use of a sea chest as a seat, a pewter mug, and the fact that one seaman is holding a square green-glass 'case' bottle - typically for spirits. This is one of a series of five 'Arithmetic' prints published by Heath, who was a well-known publisher: he appears to have taken them over from William Cole of Newgate Street, London, whose erased but still legible inscription and the date July 1827 appear on Plate 3, 'Multiplication' in the British Museum. This has the full set but only the present example uses a nautical subject. [PvdM 5/12]