AND NEIGHBOURING SEAS DURING 1897. 



207 



of the wind at the time. The currents produced on this occasion must 

 have profoundly modified the course taken by those of our bottles which 

 were in the southern part of the North Sea at the end of November and 



befrinning of December. 



o o 



It will at once be seen that there was a close correspondence in 1897 

 between the direction of the surface drift in the Channel at different 

 times of the year and that of the winds for the same periods. It is 

 unnecessary to go into details, but I may point out that, in view of this 

 general correspondence, the non-recovery of drift-bottles in January and 

 February is probably to be explained by the marked northerly element 

 in the winds of January, liottles sent adrift off the Eddystone in this 

 month must have drifted out towards mid-Channel, requiring the strong 

 south-westerly winds which prevailed during the whole of February to 

 bring them ashore at the beginning of March. By a method to be de- 

 scribed below, moreover, I have calculated that by the end of February 

 the bottles sent adrift between the 15th and 18th of that month had 

 in all probability been carried north-eastwards into the great bight 

 formed by Lyme Bay, where the conditions as regards wind and tide 

 differ considerably from those prevailing in the fairway of the Channel. 



An equally complete analysis of the northward and southward drifts 

 is unnecessary, since the recovery of almost all the bottles on the 

 northern coasts of the Channel speaks for itself. Almost all the drifts, 

 whether to eastward or to westward — but especially in the former case 

 — had a northward element, which carried the bottles to some part or 

 other of the English coast. Two cases of due northward drift are 

 included in the preceding table, one for April, the other for August. In 

 the former case the drift was short and rapid (ten miles in 27 hours, no. 

 XXXII.); in the latter the resultant distance was equally short, but the 



