As the invasion of the sea grew more and more serious, this flight by airship became a common spectacle over all the lower-lying parts of Europe, and in the British Isles. But, in the midst of it, the heavens opened their flood-gates, as they had done in the New World, and then the aeros, flooded with rain, and hurled about by contending blasts of wind, drooped, fluttered, and fell by hundreds into the fast mounting waves. The nebula was upon them! In the meantime those who had provided arks of one kind or another, tried desperately to get them safely afloat. All the vessels that succeeded in leaving their wharves were packed with fugitives. Boats of every sort were pressed into use, and the few that survived were soon floating over the sites of the drowned homes of their occupants. Before it was too late Yves de Beauxchamps and his friends launched their submarine, and plunged into the bosom of the flood. CHAPTER XIII STRANGE FREAKS OF THE NEBULA We return to follow the fortunes of Cosmo Versál's Ark. After he had so providentially picked up the crazed billionaire, Amos Blank, and his three companions, Cosmo ordered Captain Arms to bear away southeastward, bidding farewell to the drowned shores of America, and sailing directly over the lower part of Manhattan, and western Long Island. The navigation was not easy, and if the Ark had not been a marvelously buoyant vessel it would not long have survived. At the beginning the heavy and continuous rain kept down the waves, and the surface of the sea was comparatively smooth, but after a while a curious phenomenon began to be noticed; immense billows would suddenly appear, rushing upon the Ark now from one direction and now from another, canting it over at a dangerous angle, and washing almost to the top of the huge ellipsoid of the dome. At such times it was difficult for anybody to maintain a footing, and there was great terror among the passengers. But Cosmo, and stout Captain Arms, remained at their post, relieving one another at frequent intervals, and never entrusting the sole charge of the vessel to any of their lieutenants. Cosmo Versál himself was puzzled to account for the origin of the mighty billows, for it seemed impossible that they could be raised by the wind notwithstanding the fact that it blew at times with hurricane force. But at last the explanation came of itself. Both Cosmo and the captain happened to be on the bridge together when they saw ahead something that looked like an enormous column as black as ink, standing upright on the surface of the water. A glance showed that it was in swift motion, and, more than that, was approaching in a direct line toward the Ark. In less than two minutes it was upon them.