THE SALTS OF THE SEA. 253 



table affords data that show the proportion of rain and river 

 water that the Arctic Ocean receives annually. The qiiantity 

 may be inferred from the fact that average sea water lias ten per 

 cent, more salt than attained by Eodgers in the Arctic. 



481. Tlie ice-hearing drift from the Arctic liJce the ordinary drift 

 from the Baltic. — Eeturning now to the drift of the ice, and the 

 drift of the Advance and her followers, we see that, so far as 

 currents are concerned, we have in the Arctic Ocean a repetition 

 merely of the more familiar phenomenon that is seen in the 

 Baltic, where (§ 383, note) an under current of salt water runs in, 

 and an upper current of brackish water runs out. 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 become 

 more and more briny, and 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 

 Xorth Cape, and from the Pacific through Behring's Straits, and 

 through no other Channels. But, fortunately, arctic voyagers 

 who have cruised in the direction of Davis' Straits, have con- 

 firmed by their observations a law of nature (§ 474), and aff'orded 

 us proof positive as to the fact of this other source for supplying 

 the polar seas with salt. They tell us of an under current setting 

 from the Atlantic towards 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, ripping 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. 



482. Icebergs drifting north. — Passed Midshipman S. P. Griffin, 

 who commanded the brig Rescue in the American searching ex- 

 pedition after Sir John Franklin, informs me that, on one occa- 

 sion, the two vessels were endeavouring, when in Baffin's Bay, to 

 warp up to the northward 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 " drift- 

 ing 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 carried the berg to the northward faster than the 

 crew could warp the vessel against a surface but counter current. 



