246 THE PHYSICAL GEOGRAPHY OF THE SEA. 



mendous forces of all the steam and water power of the world, 

 could not, in centuries of time, move even so much as an inch this 

 matter which the sunbeam, the zephyr, and the infusorial insect 

 keep in perpetual motion and activity. 



474. If these inferences as to the influences of the salts upon 

 Deductions. the currcnts of the sea be correct, the same cause 



which produces an under current from the Mediterranean (§ 471), 

 and an under current from the Eed Sea into the ocean, should 

 produce an under current from the ocean into the north polar ba- 

 sin ; for it may be laid down as a law, that whenever two oceans, 

 or two arms of the sea, or two sheets of water, differing as to salt- 

 ness, are connected with each other, there are currents between 

 them, viz., a surface current from, and an under current into the 

 sea of lightest water. In every case, the hypothesis with regard 

 to the part performed by the salt, in giving vigor to the system 

 of oceanic circulation, requires that, counter to the surface current 

 of water with less salt, there should be an under current of water 

 with more salt in it. That such is the case with regard both to 

 the Mediterranean and the Eed Sea has been amply shown in 

 other parts of this work (§ 471), and abundantly proved by other 

 observers. That, in obedience to this law, there is a constant cur- 

 rent setting out of the Arctic Ocean through Davis' and other 

 straits thereabout, which connect it with the Atlantic Ocean, is 

 generally admitted. Lieutenant De Haven, United States Navy, 

 when in command of the American expedition in search of Sir 

 John Franklin, was frozen up with his vessels — the Advance and 

 the Rescue — in mid-channel near Wellington Straits ; and during 

 the nine months that he was so frozen, his vessels, like H. B. M. 

 ship Resolute and the Fox (§ 431), each holding its place in the 

 ice, were drifted with it bodily for more than a thousand miles to- 

 ward the south. 



475. The drift of these vessels is sufficient, were there no other 

 Drift of the Reso- Gvidencc, to cstablish the existence of an open sea 

 ^"*®- in the Arctic Ocean ; for this drift can not be ac- 

 counted for upon any other hypothesis, as a slight examination 

 of the arctic regions on a terrestrial globe, and a careful study of 

 the facts p. 231-3, and other phenomena of the case, will show. 



476. About the middle of September, 1850, being in latitude 

 De Haven's drift. 74° 40', and in the fair way of Wellington Channel, 



