CHAP. IV.] THE CRUISES OF THE 'PORCUPINE.' 



191 



ture, there being no further dimimition to the bottom. 

 This serial sounding and all the subsequent tempera- 

 ture observations taken during the Mediterranean 

 cruise showed that the trough of the Mediterranean 

 from the depth of 100 fathoms downv^ards is filled 

 with a mass of water at almost exactly the same 

 temperature throughout, a temperature a little above 

 or below 12°'75 C. 



The following instances have been cited by Dr. 

 Carpenter from the earlier observations in the Medi- 

 terranean basin, to show the great uniformity of the 

 bottom temperature for all depths : — 



At this last Station (No. 47) a serial sounding was 

 taken, which entirely confirmed the results of the 

 first (No. 40) :— 



Surface 20° • 9 C. 



10 fathoms 15-2 



20 „ 34-4 



30 „ 13-8 



40 ,,. . 13-3 



50 „ 13-1 



100 „ .12-6 



845 „ . . . . . 12-6 



