238 



THREE CRUISES OF THE " BLAKE. 



its way north between the Bahamas and the Bermudas, and 

 that there is a deep hole in ^hich the enormous depth o£ 

 4,561 fathoms has been sounded by Lieutenant - Commander 

 Brownson, with a temperature of 36°. The same temperature 

 (between 36° and 37°) is found to be the bottom temperature in 

 the sections taken to the northward, the only exceptions being a 

 few colder soundings (a temperature of 35°) met within the lines 

 off Norfolk, off Cape May, and off Nantucket, at a distance of 

 about three hundred miles from the coast. At a depth of 600 



Fig. 167. 



fathoms, off San Domingo, the temperature is 42° ; at 500 fath- 

 oms, it is 45°. Off the northern extremity of the Bahamas it was 

 about the same. Owing to the abruptness of the slope and the 

 absence of serial soundings, we have no data regarding the thick- 

 ness of this body of cold water, with a temperature of about 36°, 

 which covers the bottom. Farther north this temperature begins 

 at a depth of about 1,500 fathoms. In the sections taken off 

 the Middle States, the temperature falls very rapidly, being 75° 

 at the surface, while at a depth of 1,000 fathoms it is not more 

 than 38° ; and judging from the single section to the eastward 



