1869.] on the Scientific Exploration of the Deep Sea. 457 



latioQ between Depth and Temperature in the Warm area is represented 

 diagrammatically in the accompanying Figure ; in which (omitting frac- 

 tional parts) each line marks a descent of 1° Fahr. : — 



Diagram L 



Further, on comparing this Series with the bottom-soundings taken in 

 various parts of the same area, the accordance is found to be ex- 

 tremely close ; no difference of more than a degree presenting itself any- 

 where, except at depths of less than 200 fathoms, the bottom-tem- 

 peratures of which are higher by from 1° to 2 0, 2 than the temperatures 

 at corresponding depths in the serial sounding. This accordance be- 

 comes at once evident when the upper curve of Diagram IV., which is 

 constructed from twelve bottom -soundings in the Warm area, is compared 

 with the upper curve in Diagram III. which represents the serial soundings 

 at Station 87 ; while the slight difference is just what might be expected, 

 when it is borne in mind that the superficial stratum is not here underlaid 

 by colder water. 



97. Turning from these to the Series of Temperature-soundings taken at 

 Station 52 in the Cold area (distant less than 60 miles from Station 87), 

 which begins from nearly the same surface-temperature (52° - l), we see 

 (1) that the descent during the first 50 fathoms corresponds so closely 

 with that observed in Series 87, that the two temperatures at that depth 

 are almost precisely the same; (2) that at 100 fathoms the temperatures 

 in the two series are identical ; (3) that at the depths of 150 and 200 

 fathoms there is only a very slight difference ; but that (4) whilst the re- 

 duction between 200 and 300 fathoms in the Warm area is only 0 o, 2, 

 it amounts to not less than 14 Q, 8 in the Cold area, bringing down the 

 temperature at that depth to 30 o, 8 ; and that (5) this is further reduced 

 to 30 o, 6 at the bottom of 384 fathoms.— Thus it is evident that a tempe- 

 rature of 32° would have been reached at somewhat less than 300 fathoms, 

 and that the temperature of the water occupying the 100 fathoms beneath 

 was absolutely below the freezing-point of fresh water. 



