NARRATIVE OF THE CRUISE. 



423 



depths with the density of the surface water at each Station. They are reduced to their 

 value at 60° F. (l5°-56 C.)— distilled water at 39°'2 F. (4° C.) being unity. 



Density of Water at 60° F. (Distilled Water at 39 0, 2 F. = l). 



Immediately on leaving the Cape, the course of the ship passed through the well- 

 known Agulhas Current, the water of which is warm and dense. The first deep sounding 

 was in 1900 fathoms, rather to the westward, or on the Atlantic side of the Agulhas Bank. 

 Here the current coming from the Indian Ocean bends round the Cape, and its waters 

 enter the Atlantic. The sounding was taken in a position where great changes of surface 

 temperature are frequently observed (see p. 290), which indicate the meeting and imperfect 

 mixture of waters brought from sources remote from each other. The densities observed 

 at this Station are given in column A of the Table. It will be seen that they are all 

 higher than those in any of the other columns. The temperatures also observed at the 

 different depths are higher than at the other Stations. The water from the surface to the 

 bottom bears evidence of having been warmed and concentrated in tropical regions. 

 Between this Station and B the temperature and the density of the surface water fall 

 at first gradually then rapidly, the great fall taking place while the ship was passing 

 through a strong current, setting to the north and east between the 40th and 45th 

 parallels. At Station B, which is already within the zone where icebergs may be met 

 with at any season of the year, the surface density has fallen to 1 "02508. During the 

 whole sojourn of the ship in Antarctic waters, the surface density varied between 1"0250 

 and T0248, except where pack ice was met with, and then both the temperature and 

 the density of the surface water were lower, the temperature being from 29° to 30°, 



