326 THE DEPTHS OF THE SEA. [CHAP. vii. 



fathoms in thickness ; and finally the deep cold layer 

 into which these soundings do not penetrate very far, 

 through which the temperature sinks almost imper- 

 ceptibly from 4 C. The difference between these 

 soundings and those of the year before at the mouth 

 of the Bay of Biscay is that the temperatures at all 

 depths are somewhat higher. 



I refrain for the present from going into any detail 

 with regard to the distribution of temperature in the 

 Mediterranean, further than to give a mere outline of 

 the remarkable conditions which were observed there 

 by Dr. Carpenter. 



Dr. Carpenter's observations were principally con- 

 fined to the western basin of the Mediterranean, and 

 during the months of August and September the 

 surface temperature averaged between 23 C. and 

 26 C. On two occasions only the surface tempera- 

 ture fell considerably lower, and the fall was attri- 

 buted in both cases to the influence of the colder 

 surface current passing from the Atlantic through 

 the Straits of Gibraltar. The following table of the 

 series taken at Station 53 gives about the average rate 

 of fall of temperature for the first 100 fathoms : 



Surface ~%/ / . . 25- C. 



5 fathoms , 24 5 



and Dr. Carpenter made the remarkable observa- 

 tion that " whatever the temperature was at 100 



