479. Thickness of a winter's ice.—On the first of April De Haven measured the ice, and found it seven feet two inches thick. It was formed probably mostly of rain and river water, which, like our own littoral waters (§ 426), protect the Salter and
Ocean, and that, too, not far from the entrance into it of some of the channels which connect it with Baffin's Bay on the polar side of 75°. The Fox was attempting to pass from Melville Bay over to Lancaster Sound.in August, 1857, When, on the th day of that month she fell in with ice, in which she was finally frozen up, and remained so for 242 days, during which time she was drifted to the southward 1194 miles, which gives an average rate of five miles a day. "This drift, the drift of the Resolute, of the Advance, and Rescue, each upwards of a thousand miles—appears to indicate that a similar drift takes place every year. They show the existence of a polynia, and indicate that the open sea is to be sought for at no greater distance from Kennedy's Channel on the one hand, and Maury's on the other. This conclusion is reached by a process of reasoning of this sort: "When each one of these vessels was released from her cold fetters, there was doubtless behind her, and between her place of release and her place of original imprisonment, an uninterrupted reach of a thousand miles covered with ice; which ice, during the fall, the winter, and early spring, drifted out of the Arctic Ocean. Now we have the choice of two suppositions, and of only two, in explanation of this phenomenon, and they are: Either that the great body of all the winter-formed ice of the Arctic Ocean must have drifted in an unbroken mass over towards Baffin's Bay; for these vessels were brought out upon a tongue of ice thrust through that bay down into Davis' Straits; or that this tongue must have been separated from the main mass, leaving behind that from which it had been severed. "By the latter supposition all the known facts of the case may be reconciled; by the former not one. "If we suppose this drifting field of ice to be formed upon the very verge of an open sea, and to drift to the south as fast as it is formed, then the whole phenomenon becomes one of easy solution. At any rate, we are now possessed of a physical fact which probably would have returned Captain Crozier and his companions to us all safe and sound had they been aware of its existence; and that fact is in this oft-occurring, if not regular and annual, southward drift of ice from the Arctic Ocean down through Baffin's Bay into Davis' Strait. Captain Franklin, being ignorant of it, placed his vessels out of its reach on the south, where he was frozen in and died, and where Captain Crozier, his successor, remained imprisoned for eighteen months and then abandoned his ships: their drift in the mean time, and for obvious reasons, being almost, if not quite insensible, except as influenced by the summer thaw and 'winter wedgings.' Now if those vessels, with their scurvy-riddled, frost-worn and disabled crews, could have been placed farther to the north, as in Barrow's Strait, or in the fair way of any of those channels connecting with it from the northward and westward, or with Baffin's Bay, the probabilities are that this regularly occurring
