The reports of the Shannon and of the Helvetia had rather exaggerated its size, and I estimated its length at only two hundred and fifty feet. As to its dimensions, I could only conjecture them to be admirably proportioned. While I watched this phenomenon, two jets of steam and water were ejected from its vents, and rose to the height of 120 feet; thus I ascertained its way of breathing. I concluded definitely that it belonged to the vertebrate branch, class mammalia. The crew waited impatiently for their chief’s orders. The latter, after having observed the animal attentively, called the engineer. The engineer ran to him. “Sir,” said the commander, “you have steam up?” “Yes, sir,” answered the engineer. “Well, make up your fires and put on all steam.” Three hurrahs greeted this order. The time for the struggle had arrived. Some moments after, the two funnels of the frigate vomited torrents of black smoke, and the bridge quaked under the trembling of the boilers. The Abraham Lincoln, propelled by her wonderful screw, went straight at the animal. The latter allowed it to come within half a cable’s length; then, as if disdaining to dive, it took a little turn, and stopped a short distance off. This pursuit lasted nearly three-quarters of an hour, without the frigate gaining two yards on the cetacean. It was quite evident that at that rate we should never come up with it.