Page:A voyage round the world, in His Britannic Majesty's sloop, Resolution, commanded by Capt. James Cook, during the years 1772, 3, 4, and 5 (IA b30413849 0001).pdf/124

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volume of ice is to that of sea-water, nearly 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 the piece which we now saw to be entirely of a regular figure, its depth under water must have been one thousand eight hundred feet, and its whole height two thousand feet, allowing its length as abovementioned two thousand feet, and its breadth four hundred feet, the whole mass must have contained one thousand six hundred millions cubic feet of ice.

These prodigious pieces of ice, in all probability, drift but very slowly and imperceptibly, since the greatest part of them being under water, the power of winds and waves can have but little effect; currents perhaps are the principal agents which give them motion, though I much question, whether their velocity is ever considerable enough to carry them two miles in four-and-twenty hours. At the time we met with this first ice, all our conjectures about its formation could not amount to more than bare probabilities, and had not sufficient experience to support them: but after we have made the tour of the globe, without finding the Southern Continent, the existence of which has been so universally believed in Europe; it seems in the highest degree reasonable to suppose this floating ice to