down upon it. It would be difficult for those who oppose the existence of an open water here in the Arctic Ocean to discover a force there which, during the extreme cold months of the northern night, when the ice is making all the time, could tear from its fastenings and move 5½ miles a day all through the winter and spring a disc of ice seven feet thick[1] and 1800 geographical miles in diameter. Yet such seem to be the conditions which the absence of open water would require; for, when the Advance was thawed out, there was a thousand miles of ice to the northward of her, and between her and Wellington Channel. This 1000 miles of ice had drifted out of the polar basin during her journey to the south; for when she was liberated there was doubtless a continuous sheet of ice between her in lat. 65°, and Wellington Channel in lat. 75°. This tongue of ice is what the whalemen call the "middle ice" of Baffin's Bay. When the Advance was at Wellington Channel, this thousand miles of ice must, according to the anti-polynians, have been to the north of her; or, according to the other school, it must, as it drifted towards the south, have been forming towards the north at the edge of an open sea (§ 459). And towards the north De Haven saw a water-sky, and towards the north Penny afterwards found an open sea and sailed upon it.
478. The drift explained.—Upon the supposition that the ice which drifts out of the Arctic Ocean in the dead of winter is formed on the edge of an open water not far from the channel through which it drifts, we can account for all the known facts which attended the celebrated drifts of De Haven M'Clintock,[2] and the Resolute. Upon no other theory can these well-known and well-authenticated facts be reconciled. If there be no open water during this winter drift, which there is reason to believe takes place annually, both the Advance, Fox, and the Resolute indicate that the whole icy covering—the frost-shell of the polar sea in winter—must have drifted bodily far enough, on these three several occasions at least, to set each vessel a thousand miles on her way towards the south. And thus, without bringing in again the long chain of evidence from Chapter IX., the physical necessity of an open sea in the Arctic Ocean is proved,[3]
