48 THE rilYSICAL GEOGKArilY OF THE SEA. 



ITow closely these two seas of tbo nortli resemble each other; 

 and how, on account of the large openings between the Atlantic 

 and the Frozen Oceans, the flow of warm waters to the north and' 

 of cold waters to the south is so much more active in the Atlantic 

 than it is hi the Pacific. Ought it not so to be? 



14o. As a rule, the hottest -water of the Gulf Stream is at or 

 A cushion of cool wa- ncar thc surface; and as the deep-sea thermometer 



tor protects the bot- . ^ . , ^ ■"■ 



torn of the deep sea IS SCUt UOWU, it ShOWS that thcSC WatCl'S, thOUgh 



from abrasiou by its . , . ^ , , . , ' . , 



cun-euts. Still lar wamicr than the water on either side at 



corresponding depths, gradually become less and less warm until 

 the bottom of the current is reached. There is reason to believe 

 that the warm WatCl'S of the Gulf Stream are nowhere permitted, 

 in the oceanic ccononi}-, to touch the bottom of the sea. There 

 is every where a cushion of cool water between them and the 

 solid parts of thc earth's crust. This arrangement is suggestive, 

 and strikmgly beautiful. One of the benign offices of the Gulf 

 Stream is to convey heat from the Gulf of Mexico, where other- 

 wise it would become excessive, and to dispense it in regions be- 

 yond the Atlantic for the amelioration of the climates of the 

 British Islands and of all Western Europe. Now cold water is 

 one of the best iion-conductoi*s of heat, and if the warm water 

 of the Gulf Stream was sent across the Atlantic in contact with 

 the solid crust of the earth — comparatively a good conductor of 

 heat — instead of being sent across, as it is, in contact with a cold, 

 non-conducting cushion of cool water to feud it from the bottom, 

 much of its heat would be lost in the fii'st part of the way, and 

 the soft climates of both France and England would be, as that 

 of Labrador, severe in the extreme, ice-bound, and bitterly cold. 



