The white sharks are the dread of sailors in all hot climates, for they constantly attend vessels in expectation of anything which may be thrown overboard. A shark will thus sometimes traverse the ocean in company with a ship for several hundred leagues. Woe to the poor mariner who may chance to fall overboard while this sea-monster is present.

Some species of sharks grow to an enormous size, often weighing from one to four thousand pounds each. The skin of the shark is rough, and is used for polishing wood, ivory, etc.; that of one species is manufactured into an article called shagreen: spectacle-cases are made of it. The white shark is the sailor's worst enemy: he has five rows of wedge-shaped teeth, which are notched like a saw: when the animal is at rest they are flat in his mouth, but when about to seize his prey they are erected by a set of muscles which join them to the jaw. His mouth is so situated under the head that he is obliged to turn himself on one side before he can grasp any thing with those enormous jaws.