One must accept _cum grano salis_ the stories told by writers regarding the time that divers were able to continue under water. Beckmann said that the divers of Astrakhan employed in the fishery there could remain for seven minutes under water. The divers in Holland seem to have been very expert, for an observer, during the time they were under water, was obliged to breathe at least ten times. “Those who collect pearl-shells in the East Indies can remain under water a quarter of an hour, though some are of opinion that it is possible to continue longer; and Mersenne mentions a diver, named John Barrinus, who could dive under water for six hours.” Beckmann evidently found it a little difficult to swallow this, so he adds, “How far this may be true I shall leave others to judge.” An account of a Sicilian diver, Nicolo Pesce, given by Kircher, is yet more marvellous than any of those just cited. So great was his skill that he carried letters for the king from Sicily to Calabria. The story goes that the king offered him a gold cup if he would explore the terrible Gulf of Charybdis. He remained for three-quarters of an hour amidst the foaming abyss and on his return described all the horrors of the place to the astonished monarch, who requested him to dive once more to further examine the gulf. For some time he hesitated, but upon the promise of a still larger cup and a purse of gold he was tempted to plunge again, with the melancholy result that he never came to the surface again. A history of the art and practice of diving, although it would present many points of interest, is foreign to our subject, and attention must be confined to the question of submarine warfare. Some writers on this subject, whilst making such statements as “The confinement of gunpowder in watertight cases and its submarine explosion for the destruction of floating and other bodies is almost as old as villainous saltpetre itself,” or “The ancients understood the manufacture of subaqueous explosives or at least combustibles,” do not trouble to give any particular instances. A French writer is reported to have collected accounts of the use of such devices against ships below the water-line, but a diligent search has failed to reveal the name of the author. “The fact that some under-water explosive compound,” said Admiral Cyprian Bridge, in an article he contributed to _Fraser’s Magazine_ many years ago, “had been known in ancient times was not lost sight of in the stirring intellectual revolution of the Renaissance, which, amongst other legacies, bequeathed to mankind the outlines of the modern art of war. It is not surprising, therefore, that we should meet with the use of such an agent in the wars of the sixteenth century. The most celebrated instance of its employment was by the Italian Giannibelli (_sic_) at Antioch during the siege of the city by the Prince of Parma.”