SEA-FISHERIES LABORATORY. 213 



1905 are plotted and isolialines drawn which seem to bear 

 out his contention that a current of water of low salinity 

 is flowing southwards from the Irish Sea. 



I have re-drawn the charts (see Plates II to V) 

 putting in the numerical values for the salinities of the 

 various points indicated on Matthews' charts. Nearly 

 all of the numerical data are given in the above-mentioned 

 Second Report, Part II, but a few of them had to be 

 obtained from the Second Report, Part I — Southern 

 Area — (London, 1907), while a few were obtained from 

 the " Bulletins trimestriels du Conseil permanent inter- 

 national pour l'exploration de la Mer " for 1905. A few 

 other figures, not utilised apparently by Matthews, but 

 also referring to the same period, were found in Part I 

 of the Second Report. These have also been introduced 

 into the charts of the present paper, but are specially 

 indicated. I have tried to draw the isohalines on the 

 charts as fairly as possible, and have also indicated by 

 dotted lines how Matthews draws the same. It seems to 

 me that my way of drawing the lines is in better agree- 

 ment with the figures, and also gives a reasonable 

 explanation of the facts, but it must, of course, be 

 admitted that the data are too scanty to enable one to 

 draw the isohalines with any great certainty. 



It will be seen at once that the isohalines indicate a 

 current of water flowing northwards up the Irish Sea with 

 a tendency to strike St. David's Head. At the same time 

 there is a small tongue of low salinity water coming 

 South round Land's End. It was the presence of this 

 water which led Matthews to think that there was a 

 southward flowing current from the Irish Sea. 



This tongue of water seems, however, relatively 

 insignificant, and is almost certainly derived not from the 

 Irish Sea, but from the Bristol Channel, and is probably 



