table affords data that show the proportion of rain and river water that the Arctic Ocean receives annually. The quantity may be inferred from the fact that average sea water has ten per cent, more salt than attained by Rodgers in the Arctic.
481. The ice-hearing drift from the Arctic like the ordinary drift from the Baltic.—Returning 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 North 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 confirmed by their observations a law of nature (§ 474), and afforded 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 expedition after Sir John Franklin, informs me that, on one occasion, 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 "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 carried the berg to the northward faster than the crew could warp the vessel against a surface but counter current.
