Despite the storm without, a calm mathematical process is going on within the mind of that ardent observer. The Professor knew he was standing at a height of twenty-four feet nine inches above the flotation mark of the ship: and allowing five feet six inches as the height of his eye, he found the elevation he had obtained to be altogether thirty feet three inches. He now waited till the vessel subsided fairly for a few minutes into the trough of the sea in an even and upright position, while the nearest approaching wave had its maximum altitude. Here he found also, that at least one-half part of the wave intercepted by a considerable elevation his view of the horizon. He declared that he frequently observed long ranges extending one hundred yards on one or both sides of the ship--the sea then coming right aft--which rose so high above the visible horizon, as to form an angle estimated at two to three degrees when the distance of the wave's crest, was about a hundred yards off. This distance would add about thirteen feet to the level of the eye. This immense elevation occurred about every sixth wave. Now and then, when the course of a gigantic wave was impertinently interfered with by another liquid giant, and they thundered together, their breaking crests would shoot upward at least ten or fifteen feet higher--about half the height of the monument--and then pour down a mighty flood upon the poor Professor in revenge for his attempt to measure their majesties. No quantity of salt water, however, could wash him from his post, till he had satisfactorily proved, by accurate observation, that the average wave which passed the vessel was fully equal to the height of his eye--or thirty feet three inches--and that the mean highest waves, not including the fighting or broken waves, were about forty-three feet above the level of the hollow occupied at the moment by the ship. Satisfied at length of the truth of his observations, the Professor, half-pickled by the salt water, and looking, it must be confessed, very cold and miserable, descended to the cabin. Throughout dinner-time a conversation was kept up between the Professor and the captain--the latter appearing to be about the only individual on board who took any interest whatever in these scientific proceedings. The ladies, one and all, vowed that the Professor was a monster, only doing "all this stuff" in mockery of their sufferings. Toward night the wind increased to a hurricane; the ship trembled like a frightened child before the terrible combat of the elements. Night, with her pall, closed in the scene: it was a wild and solemn time. Toward morning the wind abated. For thirty hours a violent northwest gale had swept over the heaving bosom of the broad Atlantic.