§ 751. TIDE-RIPS AND SEA DRIFT. 403 



to feed the Gulf Stream. But my excellent friend, Lieutenant 

 Marin Jansen, of the Dutch Navy, suggested that this was prob- 

 ably not the case. This induced a special investigation, and I 

 found as he suggested, and as is represented on Plate IX. Captain 

 N. B. Grant, in the admirably well-kept abstract log of his voyage 

 from New York to Australia, found this current remarkably de- 

 veloped. He was astonished at the temperature of its waters, and 

 did not know how to account for such a body of warm water in 

 such a place. Being in longitude 14° east, and latitude 39° south, 

 he thus writes in his abstract log: "That there is a current set- 

 ting to the eastward across the South Atlantic and Indian Ocean 

 is, I believe, admitted by all navigators. The prevailing westerly 

 winds seem to offer a sufficient reason for the existence of such a 

 current, and the almost constant southwest swell would naturally 

 give it a northerly direction. But why the water should be ivarm- 

 er here (38° 40' south) than between the parallels of 35° and 37° 

 south, is a problem that, in my mind, admits not of so easy solu- 

 tion, especially if my suspicions are true in regard to the norther- 

 ly set. I shall look with much interest for a description of the 

 ' currents' in this part of the ocean." In latitude 38° south, longi- 

 tude 6° east, he found the water at 56°. His course thence was 

 a little to the south of east, to the meridian of 41° east, at its in- 

 tersection with the parallel of 42° south. Here his water ther- 

 mometer stood at 50°, but between these two places it ranged at 

 60° and upward, being as high on the parallel of 39° as 73°. 

 Here, therefore, was a stream — a mighty " river in the ocean" — 

 one thousand six hundred miles across from east to west, having 

 water in the middle of it 23° higher than at the sides. This is 

 truly a Gulf Stream contrast. "What an immense escape of heat 

 from the Indian Ocean, and what an influx of warm water into 

 the frozen regions of the south-! This stream is not always as 

 broad nor as warm as Captain Grant found it. At its mean stage 

 it conforms more nearly to the limits assigned it in the diagram 

 (Plate IX). 



751. Instances of commotions in the sea at uncertain intervals 

 Commotions in the ^^^ not unfrcqucnt. There are some remarkable 

 ^' disturbances of the sort which I have not been able 



wholly to account for. Near the equator, and especially on this 

 side of it in the Atlantic, mention is made, in the "abstract log," 



