CHAP, vii.] DEEP-SEA TEMPERATURES. 321 



A series of temperature soundings, at depths in- 

 creasing progressively by 250 fathoms, was taken to a 

 depth of 2,090 fathoms, on the 24th of July, lat. 

 47 39' N., long. 11 33' W. 



Surface . . 17'08C. 



250 fathoms . 10-28 less than Surface . . 7- 5 C. 



500 . 8-8 250 fathoms . 1 5 



750 . 5 17 500, .3-6 



1,000 . 3 - 5 750 .1-7 



1,250 . 3 17 1,000 .0-3 



1,500 2 9 1,250 .0-3 



1,750 . 2 61 1,500 .0-3 



2,090 . 2 4 1,750 .0-2 



The same two Miller-Casella thermometers were 

 employed as in the previous observation. 



Another serial sounding was taken a few days late^ 

 in water 862 fathoms deep, somewhat nearer the coast 

 of Ireland. In this case the temperature was taken 

 at intervals of 10 fathoms from the surface to a 

 depth of 50 fathoms, and thence at intervals of 

 50 fathoms to the bottom. This was done to deter- 

 mine exactly the rate of diminution of temperature, 

 and the exact position of the most marked irregu- 

 larities. 



Surface . . 17' 22 C. 



10 fathoms. 16 72 less than surface . '. . . 0- 5 C. 



20 . 15 22 less than 10 fathoms . 1-5 



30 . 13 33 20 .1-9 



40 . 12-44 30 ;, 0-9 . 



50 .11-8 40 .0-64 



100 . 10 6 50 .1-2 



150 . 10 5 100 .0-1 



200 . 10 3 150 .0-2 



250 . 10.11 200 .0-2 



300 9-8 250 ; 3 



