CHAP. IV.] 



THE CRUISES OF THE 'PORCUPINES 



L91 



ture, there being no further diminution 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 downwards 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' 



10 fathoms 15 



20 

 30 

 40 

 50 

 100 

 8 1 5 



14 

 13 

 13 



13 

 19 



9C. 



•> 



4 



8 

 3 

 1 

 6 



(i 



