The vast islands of floating ice which abound in the high southern latitudes, are a proof that they are visited by a much severer degree of cold than equal latitudes toward the north pole. Captain Cook, in his second voyage, fell in with one of these islands in latitude fifty degrees, forty minutes, south. It was about fifty feet high, and half a mile in circuit, being flat on the top, while its sides, against which the sea broke exceedingly high, rose in a perpendicular direction. In the afternoon of the same day, the tenth of December, 1773, he fell in with another large cubical mass of ice, about two thousand feet in length, four hundred feet in breadth, and in hight two hundred feet. Mr. Foster, the naturalist of the voyage, remarks that, according to the experiments of Boyle and Marian, the volume of ice is to that of sea-water as ten to nine: consequently, by the known rules of hydrostatics, the volume of ice which rises above the surface of the water, is to that which sinks below it as one to nine. Supposing, therefore, this mass of ice to have been of a regular figure, its depth under water must have been eighteen hundred feet, and its whole hight, twenty hundred feet: estimating its length, as above, at twenty hundred feet, and its breadth at four hundred feet, the entire mass must have contained sixteen hundred millions of cubic feet of ice. Two days after, several other ice-islands were seen, some of them nearly two miles in circuit, and six hundred feet high; and yet such was the force of the waves, that the sea broke quite over them. They exhibited for a few moments a view very pleasing to the eye; but a sense of danger soon filled the mind with horror; for had the ship struck against the weather-side of one of these islands, when the sea ran high, she must in an instant have been dashed to pieces. The route to the southward was afterward impeded by an immense field of low ice, the termination of which could not be seen, either to the east, west or south. In different parts of this field were islands, or hills of ice, like those which had before been found floating in the sea.