ADDITIONAL NOTES ON THE DEEP CURRENTS 

 OF THE NORTH SEA AS ASCERTAINED 

 BY DRIFT BOTTLES. 



By Captain C. H. BROWN. 



In continuation of former Reports, I deal in this short paper with 

 additional drift bottles from om- earlier experiments, which have 

 come to hand since the main results of these experiments were re- 

 ported on ; and also with a recent series of experiments, the success 

 of which has been much interfered with by the exceptional conditions 

 of the last year and a half. 



In om' first series of experiments, between June 1906 and September 

 1907— 



1012 bottles were put away, and of this number 



200 were recovered up to January 1909, and these formed the 

 basis of the First Report on the Deep Currents, published 

 in the Fourth Report (Northern Area), 1906-1909. 

 112 more bottles were recovered up to October 1913, the 

 results being included in the Second Report on the subject 

 (Fisheries Scotland Sci. Invest., 1913, II. (August 1914)). 

 Since then another 

 16 have been returned to us, making a total of 328. 



These 16 additional bottles have been under water for periods 

 ranging from 6 years 5 months to 8 years 3 months, while the distance 

 between the positions of their departirre and recovery only varies 

 from 10 to 60 miles. The rate of drift of the sixteen is therefore very 

 small, and so they add but little to the knowledge we have already 

 gained from the other bottles of this series. The additional informa- 

 tion they convey to us, on being incorporated in the previous statistics, 

 does not appreciably change the direction or velocity of the currents 

 as already determined and published. 



The actual route followed by these dilatory messengers is obscure 

 owing to the long time they have been adrift. They may" have fouled 

 something on the bottom, and so got held up on the way ; some may 

 have been drifting to and fro, or even carried round in a complete 

 circle. A record of these additional bottles is herewith attached. 



Second Experiment. — There were 787 bottles in this series, numbered ■ 

 consecutively from 100a to 387a and from 1100 to 1598, and all of 

 them were put away at intervals between August 1909 and July 1911. 

 Two hundred and four of them were recovered up to October 1913, 

 and the information derived therefrom was discussed in the Second 

 Report on the subject. The results indicated a slight modification, 



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