USES OF SALT SEAS. 25 



zone. This double vertical current facilitates and prepares the grand 

 horizontal current which puts these submarine reservoirs of heat in 

 communication with the lower beds of the glacial sea. In the Arctic 

 basin the clouds, the melted snow, and the great rivers, which have 

 their mouths on the north of both continents, produce considerable 

 quantities of fresh water, which, mixing with the waves of the Polar 

 Sea, form a bed of mean density light enough to maintain itself and 

 flow off towards the Atlantic Ocean. These surface movements deter- 

 mine in the lower regions certain contrary movements, whence origi- 

 nate the powerful counter currents which ascend the Straits from 

 Baffin's Bay and reappear in the mysterious ' Polynia ' of Kane, diffus- 

 ing there its treasure of heat brought from intertropical seas." Dr. 

 Kane, in his interesting Narrative, reports an open sea north of the 

 parallel of eighty- two degrees, which he and his party crossed a barrier 

 of ice eighty miles broad to reach, and before he reached it the ther- 

 mometer marked sixty degrees. Beyond this ice-bound region he found 

 himself on the shores of an iceless sea, extending in an unbroken sheet 

 of water as far as the eye could reach towards the Pole. Its waves were 

 dashing on the beach with the swell of a great ocean ; the tides ebbed 

 and flowed. Now the question arises, Where did those tides have their 

 origin ? The tidal wave of the Atlantic could not have passed under the 

 icy barrier which De Haven found so firm ; therefore they must have 

 been cradled in the cold sea round the Pole ; in which case it follows 

 that most, if not all, the unexplored regions about the Pole must be 

 covered with deep water, the only source of strong and regular tides. 

 Seals were sporting and waterfowl feeding in this open sea, as Dr. 

 Kane tells us, and the temperature of the water which rolled in and 

 dashed at his feet with measured beat was thirty-six degrees, while 

 the bottom of the icy barrier of eighty miles was probably hundreds 

 of feet below the surface level. 



" The existence of these tides," says Maury, " with the immense 

 flow and drift which annually take place from the Polar Seas and the 

 Atlantic, suggests many conjectures as to the condition of these unex- 

 plored regions. Whalemen have always been puzzled as to the breed- 

 ing place of the great whale. It is a cold-water animal, and, following 

 up the train of thought, the question arises, Is not the nursery for the 

 great whale in this Polar Sea, which is so set about and hemmed in by 

 a hedge of ice, that man may not trespass there ?" 



