1869.] 



on the Scientific Exploration of the Deep Sea. 



471 



water nearer the surface, has lost the extreme frigidity which characterizes 

 the current at a comparatively small depth when it comes fresh from the 

 Arctic basin. And just as the rapid descent of temperature between 150 



and 300 fathoms in the Cold area may be taken to indicate that this is 

 the stratum of intermixture between the warm superficial stream coming 

 from the Southward and the deep flow of ice-cold water coming from the 

 Northward, so may the like rapid diminution between 500 and 1000 fathoms 

 in the Atlantic basin be taken as indicating that this is the stratum of in- 

 termixture between the great body of surface-water carrying a higher tem- 

 perature from the Equatorial towards the Polar regions, and the diluted 



