420 CAPE OF GOOD HOPE. 



the same direction as that shown by our experiment. A trial of the 

 temperature at the bottom was made with the deep-sea thermometer, 

 and was found to be 56^°; while at the surface it was 69°. The land 

 to the westward of Algoa Bay was now in sight, and it was not a little 

 remarkable as we came on soundings how soon we passed into a 

 smooth and quiet sea, from a rough and tossing one, exhibiting all the 

 turbulent characteristics that are caused by the meeting of powerful 

 currents. 



On the 9th, the wind being contrary, we continued standing in 

 towards the land, and in the afternoon were not more than ten miles 

 from the coast. The temperature of the air and water was 68°. 



The next day the wind blew from the same direction, and as the 

 weather was fine, I determined to stand off to the edge of the bank 

 previously spoken of, in order to obtain the assistance of the current 

 running there, to carry us to the westward. At 4 p. m. we tried the 

 set and velocity of the current, on soundings in eighty-five fathoms 

 water, and found its direction to be east-northeast; its rate, a quarter 

 of a knot per hour. During the last twenty-four hours, while on sound- 

 ings, the set of the current was thirty-three miles N. 62° E. At 6 p. m. 

 the temperature of the water changed from 67° to 75°, and with this 

 variation of temperature, we found we were again entering the turbu- 

 lent sea. In the tacks we made, off and on, the temperature rose and 

 fell during each of them, several degrees, and the turbulent and smooth 

 water formed a well-defined line. 



On the 11th, we still continued in the rough water; the temperature 

 at the surface being 75°, but that at one hundred fathoms depth was 

 only 65° ; with two hundred and fifty fathoms of line, there were no 

 soundings. In the evening the water became remarkably phosphore- 

 scent; in fact, to a greater degree than I had ever previously observed, 

 except at the Cape de Verde Islands, while on our outward voyage. 

 After we had passed the pitch of the Cape, the direction of the current 

 was found to be changed, having set us, in twenty-four hours, forty 

 miles, on a course N. 40° W. 



I am satisfied that the use of thermometers would be beneficial to 

 those navigating around this Cape; for by keeping in water of a tem- 

 perature above 70°, they would, although exposed to a rougher sea, be 

 carried more rapidly around the Cape, and would discover that they 

 had passed it by encountering the cold water which is flowing rapidly 

 to the northwest. In fact, it is obvious to me that the anomalies of 

 current and temperature existing in this neighbourhood, can only be 

 accounted for on the hypothesis of an upper and under current of 

 different temperatures. The former of these is the warm, the latter 



