222 REPORT ON THE SURFACE DRIFT OF THE ENGLISH CHANNEL 



of drift-bottles would have led one to the conclusion that the eastward 

 drift of these bottles was a more or less steady and continuous one from 

 March 16th, when they were off the Isle of Wight, until the middle of 

 May, when they were stranded on the French coast. The recovery of a 

 bottle at Seaford in April points clearly to such a conclusion, and 

 the direction of the resultant winds at Dungeness during the latter half 

 of April (E.N.E., light) and the first half of May (W. by N., moderately 

 strong) appeared to me at first sight to accord with the view that all the 

 Calais bottles were in the neighbourhood of Seaford in mid-April. It 

 was not until I made the extensive calculations required for the above 

 analysis that I finally convinced myself of the serious error of this 

 view, and of the certainty that the Calais bottles had already made the 

 passage of the Dover Straits in the last week of March, owing to 

 the production of a current along the coast of Sussex at an angle with 

 the direction of the wind during the last fortnight of March. 



In order to explain the case of the Seaford bottle we must go back 

 to the position of the Calais bottles prior to the southerly gale of 

 March 16th, which drove so many ashore. On March 16th and 17th 

 several bottles were stranded on the S.E. coast of the Isle of Wight by 

 this gale, but one, at least (XI. 1), was stranded about the same time on 

 the S.W. coast of the same island, and another was recovered in the 

 Solent on March 31st (XIII. 1.). Now this latter batch did not arrive 

 at Calais until June 18th. It is probable, therefore, that the cause of 

 retardation in this case was that these bottles had not easted sufficiently 

 by the 15th March to be able to round St. Catherine's Point when the 

 southerly gale of the 16th overtook them. Those which were to the 

 eastward of the Point, and escaped stranding, were driven rapidly along 

 the Sussex shore to the Straits of Dover; but those which were to 

 the westward of the Point were either driven ashore on the west coast 

 of the island or into the Solent. Their course through the Solent and 

 Spithead to the eastward would be distinctly slow, as they would lose a 

 considerable portion of the direct effect of the westerly gales ; and I 

 imagine that the Seaford bottle may have been retarded in this way, 

 while others of the same batch succeeded in clearing St. Catherine's 

 Point, and pursuing an unobstructed course. A difference of a few 

 miles between the positions of bottles on the 15th of March would 

 be sufficient to determine whether they would be carried to the east- 

 ward or westward of St. Catherine's Point. If the Seaford bottle 

 actually took the course here suggested it must have slowly drifted 

 eastwards through the Solent and Spithead, and emerged off Selsea Bill 

 during the last few days of March, pursuing a course along the Sussex 

 coast under the influence of the westerly winds. The resultant westerly 

 wind of April 1st to 17th was estimated from the winds at Dungeness 



