§ 478. THE SALTS OF THE SEA. 249 



its fastenings and move 5| miles a day all through the winter and 

 spring a disc of ice seven feet thick* and 1800 geographical miles 

 in diameter. Yet such seem to be the conditions which the ab- 

 sence 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 Bafiin'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 toward the south, have 

 been forming toward the north at the edge of an open sea (§ 459). 

 And toward the north De Haven saw a water-sky, and toward the 

 north Penny found an open sea and sailed upon it. 



478. Upon the supposition that the ice which drifts out of the 

 The drift explained. Arctic Occan 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,t and the Eeso- 

 hite. Upon no other theory can these well-known and well-au- 

 thenticated facts be reconciled. If there be no open water during 

 this winter drift, which there is reason to believe takes place an- 

 nually, both the Advance, Fox, and the Kesolute 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 occa- 

 sions at least, to set each vessel a thousand miles on her way to- 

 ward 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 pfoved.:f 



* De Haven found the ice upon which his vessel was brought out 7 feet 2 inches 

 thick. t In the Fox, 1857-1858. 



t "The Fox accomplished another of those remarkable drifts which can be ex- 

 plained upon no other hypothesis but that of an open water in the Arctic 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 18th day of 

 that month she fell in with ice, in which she was finally frozen up, and remained so 



