CAPE OF GOOD HOPE. 445 



hours. We then ran out of it, having fine weather again, and a clear 

 sky overhead; leaving as it were behind us the storm, which seemed 

 to occupy half the firmament, with many beautiful and well-defined 

 rainbows. I was told, at the Cape, that this phenomenon of the sky 

 half covered with clouds, was frequently seen by those dwelling there, 

 or navigating the seas in its neighbourhood ; and, on its occurrence, 

 those in a proper situation never fail to witness the same series of 

 beautiful and well-defined rainbows. 



We were again affected by currents on the 5th ; and they showed 

 themselves in the formation of the short rough sea which we encoun- 

 tered. The deep-sea soundings on that day gave remarkable results ; 

 for, while the temperature of the water at the surface was 73-5°, that 

 at a depth of one hundred fathoms was 78°; although this may seem 

 somewhat singular, it may be accounted for by the circumstance that 

 we were within the influence of the tropical currents setting to the 

 southward along the eastern coast of Africa. 



On the 6th, experiments on the temperature of the water gave 

 similar results, although the difference between the surface tempera- 

 ture and that at one hundred fathoms depth was not so great as on 

 the previous day, the former being 75-5°, and the latter 78-5°. The 

 ascertained set of the ship by current this day was south half west, 

 forty miles. At noon the current was found, on trial, to flow in the 

 same direction, but with a Velocity of not more than half a mile per 

 hour. 



The ship continued to be tossed about most uncomfortably during 

 the 7th, and the current set us fifty-three miles in a west-southwest 

 direction. We passed close to the edge of the Aguillas Bank, where 

 the temperature of the surface water rose to 78°, and continued so until 

 5 p. M., when the water became discoloured, and it fell to 73°; we 

 then obtained soundings with sixty fathoms of line on dead coral. 

 During this time the temperature of the air had not been higher than 

 70°. In order to examine the temperature of the warm stream that 

 we were passing through, I shaped a course nearly at right angles 

 to the direction of its flow, and while sailing sixty miles made the 

 following observations : 



At noon, 



the 



temperature 



of the 



surface was 





78° 



" 1 



P. M 



. 



cc 





u 



. . 



78 



" 2 



a 





M 





a 



. . 



78 



" 3 



u 





It 





a 



. . 



77 



" 4 



tt 





ec 





tt 



. 



75 



VOL. V. 











112 







