This Unknown Region comprises an area of 2,500,000 square miles; an immense portion of the terrestrial surface to be shut out from the knowledge of Civilized Man. Its further exploration, if practicable, cannot but be rich in valuable results. Not only would it furnish the shortest route from the West to the East, from progressive Europe to conservative Asia, from the Atlantic to the Pacific, but it could not fail to add in a very important degree to our stores of scientific information. Sir Edward Sabine is surely right when he says, that it is the greatest geographical achievement which can be attempted, and that it will be the crowning enterprise of those Arctic researches in which England has hitherto had the pre-eminence. We may briefly indicate to the reader some of the advantages which might be expected from exploration in the Unknown Region. It would unquestionably advance the science of hydrography, and lead to a solution of some of the more difficult problems connected with the Equatorial and Polar ocean-currents, those great movements of the waters of which, as yet, we know so little. A series of pendulum observations, it is said, at and near the North Pole, would be of essential service to the science of geology. We are unable, at present, for want of sufficient data, to form a mathematical theory of the physical condition of the Earth, and to ascertain its exact configuration. No pendulum observations have been taken nearer than 600 or 620 miles to the North Pole. Again: what precious information respecting the strange and wonderful phenomena of magnetism and atmospheric electricity would certainly be acquired! How much we have yet to learn in reference to the Aurora, which can be learned only in high latitudes, and at or near the point which apparently represents a magnetic focus or centre! It has also been pointed out by Mr. Markham that the climate of Europe is largely affected by the atmospheric conditions of the Polar area, in which the development of extremely low temperatures necessarily leads to corresponding extreme changes of pressure, and other atmospheric disturbances, whose influence extends far into the Temperate Zone. For the satisfactory appreciation of these phenomena, says Mr. Markham, a precise knowledge is required of the distribution of land and water within the Polar Region; and any addition to our knowledge of its unknown area, accompanied by suitable observations of its meteorology, cannot fail to afford improved means of understanding the meteorology of our own country, and of the Earth generally.