162 
THE PHYSICAL GEOGRAPHY OF THE SEA. 
322. Then, since there is salt always flowing out of the north 
polar basin, we infer that there must be salt always flowing into 
it, else it would either become fresh, or the whole Atlantic Ocean 
would be finally silted up with salt. 
It might be supposed, were there no evidence to the contrary, 
that this salt was supplied to the Polar seas from the Atlantic 
around North Cape, and from the Pacific through Behring's 
Straits, and through no other channels. 
323. But, fortunately, Arctic voyagers, who have cruised in the 
direction of Davis's Straits, have aflbrded us, by their observations 
281), proof positive as to the fact of this other source for sup- 
plying the Polar seas with salt. They tell us of an under current 
setting from the Atlantic toward the Polar basin. They describe 
huge icebergs, with tops high up in the air, and of course the 
bases of which extend far down into the depths of the ocean, rip- 
ping and tearing their way, with terrific force and awful violence, 
through the surface ice or against a surface current, on their way 
into the Polar basin. 
Passed Midshipman S. P. Griffin, who commanded the brig 
Rescue in the American searching expedition after Sir John 
Franklin, informs me that, on one occasion, the two vessels were 
endeavoring to warp up to the northward, in or near Wellington 
Channel, against a strong surface current, which of course was 
setting to the south ; and that while so engaged, an iceberg, with 
its top many feet above the water, came "drifting up" from the 
south, and passed by them "like a shot." Although they were 
stemming a surface current against both the berg and themselves, 
such was the force and velocity of the under current, that it car- 
ried the berg to the northward faster than the crew could warp 
the vessel against a surface but counter current. 
Captain Duncan, master of the English whale-ship Dundee, 
says, at page 76 of his interesting little narrative :* 
'■^December 18th (1826). It was awful to behold the immense 
icebergs working their way to the northeast from us, and not one 
drop of water to be seen ; they were working themselves right 
through the middle of the ice." 
And again, at page 92, &c. : 
* Arctic Regions ; Voyage to Davis's Strait, by Dorea Duncan, Master of the Ship 
Dundee, 1826, 1827. 
