The Mediterranean Sea 229 



order thoroughly to investigate this matter, as well as the 

 biological conditions of the deep water of the Mediterranean, 

 H.M.S. "Porcupine," Captain Culver, with Messrs Carpenter 

 and Gwyn Jeffreys, visited the western basin of the Medi- 

 terranean in the autumn of 1870. A large number of tem- 

 perature observations were made in the western basin near its 

 southern coasts, and one sounding with temperature observation 

 in the eastern basin a short distance from the Sicilian coast, 

 the result of which was to confirm the conclusion arrived at 

 from earlier observations, that, however high the temperature 

 of the surface may be (and it may reach 90 F.), the water 

 becomes rapidly cooler as we go below the surface until we 

 reach a depth of about 100 fathoms, where a temperature of 

 54 to 56 F. is found, and persists without sensible variation 

 to the greatest depths. The average of all the bottom tem- 

 peratures in the western basin was 54-88 F. Three soundings 

 were made in the intermediate basin to the eastward of Pantel- 

 in depths of 266, 390, and 445 fathoms, and in each case 

 the bottom temperature was found to be 56-5 F., or about a 

 degree and a half warmer than in the deeper western basin. 

 This is precisely what might have been expected from what we 

 know of inland seas divided into several basins. In summer 

 the shallower basin has usually a higher temperature at the 

 l>"ttom than is found at the same depth in the deeper one. 

 Only one observation was made in the eastern basin, namely 

 off Cape Passaro in 1743 fathoms, with a bottom temperature 

 of 56-0 F. That the temperature in this basin should be lower 

 than in the Pantellaria basin is due to its greater depth, and 

 that it should be higher than is found in the western basin i- 

 due to its lower latitude. These researches were further 

 prosecuted in the autumn of 1871 in the "Shearw 

 Captain Nares, accompanied by Dr Carpenter. At two stations 

 in the eastern basin "serial temperatures" were taken. At 

 the tir-t, 3554 / N. latitude, 16 23' E. longitude, depth 1650 

 ms the bottom temperature was 56, or the same as had 

 1 the year before in 1743 fathoms; at the second, 

 17}' N l.ntu.ie 26*44' ' llde ' depth 1870 fathoms, 



the bottom temp, i .itui. M<1 the temperature .it all 



