of the Fishery Board for Scotland. 



355 



the North Sea, and continued the following day. It has also to be noted 

 that during the preceding months the effective winds in the southern part 

 of the North Sea blew, as a rule, from an easterly direction ; for example, 

 at Yarmouth they blew from E.S.E. J S. in October; from N.E. f 

 E., strong, in November; from S.E. \ E., strong, in December; in 

 January they blew from E.N.E. The existence of the strong winds and 

 gales from the N.E., E., and E.N.E. no doubt explains the westward 

 movement of the bottles, and it is noteworthy that they also went north- 

 wards along the east coast, some, as we have seen, being got in Yorkshire. 

 Strong north-east and easterly winds appear to heap up the water on this 

 part of the east coast, and owing to the configuration of the coast and the 

 bottom it escapes in a north-westerly direction along the coast. 



2. Seasonal Variations. 



It is evident from the description given of the course of the drifters 

 throughout the period covered by the experiments that the surface water 

 in the North Sea has a general movement southwards along the western 

 side and northwards along the eastern side. Before considering how this 

 movement is related to the effective winds it will be well to consider 

 whether any variation is apparent at different seasons. In the Moray 

 Firth, east of the third degree of west longitude, the drifters put away in 

 October (1894 and 1896) were found on the south coast of the Firth in 

 the same month and in November ; those put away at the end of February 

 (1895) were found in March; those put away in March (1895, 1896) 

 were picked up in the same month and in April ; and those set adrift in 

 July were found in July and August. The drifters put away on the east 

 coast in February, March, April, May, June, July, August, September, 

 October, November, December, in the various years, were found to the 

 south in the same month or later, with the exception of those at the end 

 of December 1896, when the reversed movement began. None were 

 set adrift on the east coast in the month of January. In all the months, 

 then, during which the drifters were thrown in on the east coast (except 

 December 1896), they moved southwards, which seems to prove that the 

 southward movement of the surface waters on the western side of the 

 North Sea is practically continuous and does not vary with the seasons. 



There is not the same regularity or continuity shown in the times when 

 the drifters were found on the coasts of Holland, Germany, and Denmark. 

 This is clear from the following table ; and for comparison the months 

 during which drifters were stranded on the English coast, south of Durham, 

 where the coast line begins to project markedly eastwards, are included. 



From this table it will be seen that while bottles were recovered on 

 the coast of Yorkshire in January, February, May, June, July, August, 

 November, and December, they were found in Holland in February, 

 June, July, and August, and in Germany only in July. On the coast of 

 Denmark they were found in January, April, July, August, September, 

 October, and November, but in very different proportions. Thus, only 

 one was found in January, July, October, and November respectively ; 

 while twenty-one were recovered in August and twenty-nine in September. 

 It will also be noticed that it was only in 1895 that they were stranded in 

 August and September on the Danish coast ; in 1896 only one was found 

 in August and none were found in September. Further, it will be seen that 

 those found in August 1895 in Denmark were set adrift in the previous 

 November, February, and March, and those found in September, in 

 February, March, April, and May. These facts point to the conclusion that 



