The ice of this berg, although opaque and vascular, is true glacier ice, having the fracture, lustre, and other external characters of a nearly homogeneous growth. The iceberg is true ice, and is always dreaded by ships. Indeed, though modified by climate, and especially by the alternation of day and night, the polar glacier must be regarded as strictly atmospheric in its increments, and not essentially differing from the glacier of the Alps. The general appearance of a berg may be compared to frosted silver; but when its fractures are very extensive, the exposed faces have a very brilliant lustre. Nothing can be more exquisite than a fresh, cleanly fractured berg surface: it reminds one of the recent cleavage of sulphate of strontian--a resemblance more striking from the slightly lazulitic tinge of each.--_U. S. Grinnel Expedition in Search of Sir J. Franklin._ IMMENSITY OF POLAR ICE. The quantity of solid matter that is drifted out of the Polar Seas through one opening--Davis’s Straits--alone, and during a part of the year only, covers to the depth of seven feet an area of 300,000 square miles, and weighs not less than 18,000,000,000 tons. The quantity of water required to float and drive out this solid matter is probably many times greater than this. A quantity of water equal in weight to these two masses has to go in. The basin to receive these inflowing waters, _i. e._ the unexplored basin about the North Pole, includes an area of 1,500,000 square miles; and as the outflowing ice and water are at the surface, the return current must be submarine. These two currents, therefore, it may be perceived, keep in motion between the temperate and polar regions of the earth a volume of water, in comparison with which the mighty Mississippi in its greatest floods sinks down to a mere rill.--_Maury._ OPEN SEA AT THE POLE. The following fact is striking: In 1662-3, Mr. Oldenburg, Secretary to the Royal Society, was ordered to register a paper entitled “Several Inquiries concerning Greenland, answered by Mr. Gray, who had visited those parts.” The nineteenth query was, “How near any one hath been known to approach the Pole. _Answer._ I once met upon the coast of Greenland a Hollander, that swore he had been but half a degree from the Pole, showing me his journal, which was also attested by his mate; where _they had seen no ice or land, but all water_.” Boyle mentions a similar account, which he received from an old Greenland master, on April 5, 1765. RIVER-WATER ON THE OCEAN.