of the North Atlantic and Northern Oceans. 117 



American coast, the other keeping out and forming the main 

 Gulf Stream. Sometimes where they met they interlaced in 

 alternating stripes of hot and cold water ; sometimes their 

 meeting caused a deflection, — as, where one branch of the 

 Gulf Stream was sent down to the south-east of Europe and 

 north of Africa, and another branch sent up past the British 

 Islands to Norway and Scandinavia by the polar current set- 

 ting down to the east of Newfoundland. The author next 

 proceeded to consider the uses in the economy of Nature of 

 these great oceanic currents. The first that he noticed was 

 the equalizing and ameliorating influence which they exer- 

 cised on the temperature of many countries. Of this he gave 

 several examples. Thus, our own country, though usually 

 spoken of as a very variable climate, was subject to far less 

 variations of range of temperature than many others in simi- 

 lar latitudes, — which was chiefly from the general influence of 

 the northern branch of the Gulf Stream setting up past these 

 islands. He had himself on one occasion, in the month of 

 November, known the temperature to rise no less than 52° in 

 forty-eight hours, having previously descended in a very few 

 days through a still greater range ; while in these countries 

 the extensive range between mean summer and winter tem- 

 perature scarcely in any instance exceeds 27°, and in many 

 places does not amount to nearly as much. Another advan- 

 tage derived from these currents was, a reciprocation of the 

 waters of high and low latitudes, — thus tending to preserve a 

 useful equalizing of the saltness of the waters, which otherwise 

 by evaporation in low latitudes would soon become too salt 

 to perform its intended functions. Next he pointed out their 

 use in forming sand-banks, which became highly beneficial as 

 extensive fields for the maintenance of various species of the 

 finny tribe, as in the great banks of Newfoundland. Next, 

 this commingling of the waters of several regions tended to 

 change and renew from time to time the soil of these banks, — 

 which, like manuring and working our fields, was found to be 

 necessary for preserving these extensive pastures for the fish. 

 Lastly, bv bringing down from polar regions the enormous 

 masses of ice which, under the name of icebergs, were at 

 times found to be setting down towards tropical regions, they 



