When Jules Verne wrote Twenty Thousand Leagues under the Sea, in 1873, his Nautilus was deemed by the reader untaught in naval constructive history a wild creation of the author's fancy, like his passenger-car shot to the moon from an enormous cannon. To-day there is not a naval commander who would not look grave and consider an immediate withdrawal of his ship when told an enemy's submarine was cruising in his neighbourhood.

In the face of open danger, visible to eye and ear, no officer of the navy blenches. The submarine is out of sight. It may be within a hundred yards of the ship when the report is brought. A man who will stand up against a wild beast or a band of savages without a tremor will turn white and shriek with terror if, when he is in the water, the cry of "Shark!" is raised. The shark betrays its presence by its black dorsal fin above the surface of the sea. When the fin disappears the danger increases, becomes terrible; the fear of the swimmer in the vicinity of that black, unseen peril overmasters him.

The submarine sinks, like the shark, to attack. Its gleaming back, surmounted by the small, round conning tower, disappears amid a swirl of foam. A single staff at the stern betrays its presence for a moment; then that, too, glides beneath the surface. Not a man on the battle-ship but shudders at the thought of that hidden monster under the waves, driven by the skill and hatred of the human brain.

Only tried and absolutely reliable men are chosen for the crew of the submarine. They must be ready to endure extreme discomfort and hardship and must hold their lives in their hands. A well-aimed shot from a war-ship, or a defect in the delicate machinery of the boat, and all is over. A submarine never is wrecked; it sinks, with all on board; it is obliterated.

The Japanese have been among the first to realise the terrible effectiveness of this formidable engine of war. No one outside a handful of men near the Mikado's throne knows how many submarine torpedo-boats are included in the Japanese navy, nor where they are stationed. Japanese naval officers and men form an ideal body from which the crews of these boats are to be chosen. In conflict with the enemy, whether on land or at sea, they reckon their lives as nothing. They seek eagerly for a glorious death at the hands of the foe, and when that is denied them and defeat is inevitable they prefer to die by their own weapons, or by leaping into the sea, rather than prolong what would be to them a life of disgrace.

Oto Owari was appointed, on the 11th of April in this eventful year, to the command of the submarine Octopus, then docked, under a concealing roof, at Sasebo. Three nights later he went on board with a picked crew at midnight, and the Octopus, first gliding out of the dock, and gathering speed until she reached open water, suddenly stopped her engines and began to sink, inch by inch. In one minute a dark spot on the sea, and a patch of foam, indicated the top of her conning tower; and a moment later she was out of sight. In the act of sinking, her prow was toward the west.

Early on the morning of April 13th, the Japanese fleet made a demonstration in the direction of Port Arthur. Always ready to accept a challenge while there was a shot in the locker, the Russians steamed out to meet them. There was but a brief exchange of battle courtesies. The Port Arthur ships were far out-numbered and out-metalled, and Admiral Makaroff, on the Petropavlovsk, signalled for his squadron to retire.

The Petropavlovsk was a first-class battle-ship of about 11,000 tons, with heavy armament of twelve-inch guns and secondary batteries. She had on board the admiral, the regular crew of 650 men, the Grand Duke Cyril, and, as a special guest, the famous painter Verestchagin. Makaroff, with several officers of high rank, having satisfied themselves that the ship was in no immediate danger, proceeding as she now was under good headway, toward her home port, with the Japanese fleet hull down in the offing, went below to breakfast. The Grand Duke and the great artist remained on the bridge with the commander of the flagship and its lieutenant. They scanned through their glasses the far-off pursuers, and the frowning forts on Golden Hill, and congratulated each other on the escape of the Russian squadron from the danger of annihilation by an immensely superior force. Not a man of them guessed the near presence of a peril, unseen beneath those waves, dimpling in the morning sunlight, more terrible than the whole array of Japanese battle-ships on the horizon. Verestchagin, then the greatest living painter of death on the battle-field, knew not that Death was at that moment gliding toward him; that he was taking his last look at the drifting clouds, the rippling sea, the blue hills of Manchuria. The Petropavlovsk sped onward, but faster, beneath the waves, sped the Octopus, guided by the fierce eyes, the strong hand, the glowing heart and brain of the small brown man erstwhile cabin steward of the Osprey.

Suddenly the great battle-ship quivered from stem to stern, as if she had struck upon a rock. The sea rose on the starboard side in a tremendous wave, and a roar like a broadside of a frigate filled the air, followed by a rattling, crashing discharge from the magazines. A huge gap appeared in the hull of the ship. A cataract of water poured in, and slowly turning upon her side, with one great, hissing gasp the Petropavlovsk sank.

The other ships of the squadron hastened to the spot, and almost before the fighting-tops of the battle-ship disappeared their boats were foaming across the water to pick up the survivors from the ill-fated vessel. The Grand Duke was saved, as were the lieutenant, two other officers, and about fifty sailors. Every other man went to the bottom. Never again would the guns of Russia boom out their noisy salute to the gallant admiral; and Verestchagin had made his last great study of Death.