covering of the wires, notwithstanding their great conductivity, too hot to be touched. We heard immediately a smothered sound of extraordinary character, which was, in truth, no other than a scream deadened partly by the water, partly by the thick metal sheet interposed between us and the element. The steering screw was set in rapid motion, and at first revolving with some difficulty, afterwards moving faster and more regularly, presently released us. Its rotation was stopped, and we resumed our course. The serpent had relaxed his folds, stunned by the shock, but had not disentangled himself from the screw, till its blades, no longer checked by the tremendous force of his original grasp, striking him a series of terrific blows, had broken the vertebrae and paralysed if not killed the monstrous enemy.
At each side of the larger chambers and of the engine-room were fixed small thick circular windows, through which we could see from time to time the more remarkable objects in the water. We passed along one curious submarine bank, built somewhat like our coral rocks, not by insects, however, but by shellfish, which, fixing themselves as soon as hatched on the shells below or around them, extended slowly upward and sideways. As each of these creatures perished, the shell, about half the size of an oyster, was filled with the same sort of material as that of which its hexagonic walls were originally formed, drawn in by the surrounding and still living neighbours; and thus, in the course of centuries, were constructed solid reefs of enormous extent. One of these had run right across the gulf, forming a complete bridge, ceasing, however, within
