82 A Retrospect of Oceanography 



stations. Some remarkable results were thus obtained in the 

 equatorial regions of the Central Pacific. 



"'Challenger' Reports, Narrative I. p. 772. The axis of greatest 

 velocity of the equatorial current was on the parallel of 2 N., where 

 its speed amounted to 3 miles per hour. Such an exceptional velocity 

 has, so far as is known, only been recorded once before, viz., by the French 

 corvette "Eurydice," in August, 1857. The astronomical observations 

 taken at frequent intervals showed even a greater velocity than 3 miles 

 per hour. By these observations it appeared that the vessel was in still 

 water between the equatorial and counter-equatorial currents on 

 September 2, in lat. 5 54' N., long. 154 2" W. From this position to 

 lat. 4 32' N., long. 147 28' W., the velocity of the equatorial current 

 was mile per hour S. 53 W. ; from thence to lat. 3 55' N., long. 

 148 10' W., its velocity was i mile per hour; thence to lat. 3 32' N., its 

 velocity was ij mile per hour; thence to lat. 2 34' N., long. 149 9' W., 

 its velocity was 3 miles per hour S. 76 W. ; thence to lat. 2 10' N., long. 

 149 34' W., its velocity was 4 miles per hour; thence to lat. i o' N., 

 long. 150 30' W., its velocity was 3 miles per hour S. 85 W. ; thence 

 to lat. o 25' N., long. 151 W., its velocity was 2^ miles per hour; thence 

 to lat. o 43' S., long. 151 32' W., its velocity was if mile per hour 

 S. 81 W., and then it gradually decreased." 



Observations of this kind require good will, good eyesight, 

 good instruments, and a good use of them all. The ocean water, 

 which was thus proved to be moving at the rate of 4 miles 

 per hour, appeared to the eye to be motionless. There was 

 no trouble on its surface, yet it is a fact which may astonish 

 the casual observer, that there are very few of the apparently 

 most violent mountain-torrents which get over the ground 

 at as great a speed. Of this I have assured myself by many 

 measurements in Switzerland and other countries. 



A time-honoured method of measuring the movement of 

 oceanic waters is by throwing overboard floating-bodies, 

 generally empty corked bottles containing a paper with the 

 date and position of their starting-point. If suitably ballasted 

 so as to be protected from the influence of the wind and be 

 exposed to the action of the current alone, very valuable 

 results can be obtained in this way. The most remarkable 

 are those obtained by H.S.H. Albert, Prince of Monaco. His 

 floats were especially made for the purpose, and were thrown 

 over in series on a definite system from his schooner yacht 

 "Hirondelle" in the course of his scientific cruise round the 



