322 KEPORT OF THE COUNCIL. 



The number of stations at wliich observations are made has been 

 sliglitly increased, three stations having been added at the eastern end 

 of the Channel. At the same time tlie plankton programme has been 

 somewhat reduced at certain of the shallower stations where no marked 

 ditt'erence in the organisms found at different depths could be proved 

 by the methods employed. 



In addition to the work done on the cruises, samples of sea-water 

 and of plankton are being regularly taken on a number of lightships 

 in the Channel and on the Irish coast, and samples of water are obtained 

 every fortnight from steamers crossing the Channel from Newhaven to 

 Caen and from riymouth to the Channel Islands. A number of samples 

 have also been taken at the mouth of the Englisli Channel and in the 

 Bay of Biscay l)y officers of steamships navigating those waters. 



The hydrographic observations during 1903 and the first three months 

 of 1904 show that the direction of the flow of the waters of the English 

 Channel is from west to east, and that they are derived from a northerly 

 current of about o5'6 7oo S. from the Bay of Biscay and from a southerly 

 current of about 35"2 7oo S. or less from the Irish Sea and Bristol Channel. 

 The meeting-place of these waters may be roughly fixed as south of the 

 Scilly Islands in mid-channel, and it will be generally found that the 

 salinity of the water increases as we pass this point from west to east. 

 Owing to the varying salinity and temperature of these two currents it 

 has been found that at the entrance to the Channel the water is often 

 divided into distinct layers, while the changes of their relative velocity, 

 combined with the general drift up Channel, give rise to alternate areas 

 of high and low salinity which follow one another eastward. On the 

 line between the Isle of Wight and Cape Bartieur the salinity has been 

 low on all five cruises, a state of things due in all probability to the 

 amount of fresh water discharged from Southampton Water and the 

 Seine. The presence of denser water south of Beachy Head, however, 

 points to the occasional passage of a high salinity current across this 

 line. 



In February (1903) the Channel from the Land's End to the Isle of 

 Wight was filled witli water of 35-4 7oo S., bounded by fresher water on 

 the west and east, and by water of 35-5 7oo i^ear Ushant, the general 

 features pointing to a quick movement. No observations were made 

 east of the Isle of Wight. 



In May the area of 35*4 7oo S. had diminished in size, being encroached 

 upon by water of 35'6 7oo on the south-west and by fresher water on the 

 east. In this month the area of 354 7oo S. south of Beachy Head was 

 first observed, and the increased distance between the isohalines indi- 

 cated a slower movement. 



In August the low-salinity water of the Irish Sea had spread south 



