75 



fairway of the channel, a vessel will be carried about 9 

 miles by the stream during spring tides and about 6 miles 

 during neaps. Near the land the velocity of the stream 

 becomes much greater. The direction taken by the stream 

 is now pretty well known in almost every part of the Irish 

 Sea, and but for the varying influence of the wind, which 

 it sec-ms quite impossible to estimate, we should be able to 

 trace the course of an object liberated at almost any place. 

 We have tried to estimate the effect of the wind, and are 

 much indebted to Mr, W. E. Plummer, of the Liverpool 

 Dock Board's Observatory at Bidston for a complete series 

 of readings of the Bidston instruments for the time during 

 which most of the bottles were at sea. 



It will be seen from the chart that there is a general 

 northerly trend in the destination of the earlier lots of 

 bottles. Nos. 1, '2, and 3, which were set free between the 

 N.W. light ship and a point off Little Orme Head, have all 

 been found either on Walney Island or in the Duddon 

 Estuary. The direction of the streams about this point is 

 nearly easterly and westerly, and we fcihould expect that in 

 the absence of wind the bottles would have oscillated back- 

 wards and forwards in this direction and finally gone 

 ashore in the Mersey or Dee at the next spring tides. 

 But the wind during the four days that these bottles were at 

 sea came from the E.S.E. and S.W. with an average force 

 of about 21 miles per hour, and it is this influence which 

 determines the direction taken by them. Lot No. 4, of 

 which four bottles were recovered, went as far north as St. 

 Bee's Head. 



The remaining- bottles picked up seem to have 

 behaved in a fairly regular way — Nos. 5 to 12 have 

 gone successively further north. The number of bottles 

 washed ashore on the portion of coast with Drigg as a 

 centre is very noticeable. Mr. J. Grice, to whom we are 



