73 



the card, and in many cases volunteering further informa- 

 tion. 



The general results of the experiment are indicated on 

 the sketch chart (fig. 2). The positions at which the 

 various lots of bottles were set adrift are indicated roughly 

 by the serial numbers in the lower portion, extending from 

 the N.AV. light ship to Cardigan Bay. The destinations of 

 the bottles are given by the same numbers in the upper 

 portion of the chart, the bracket indicating the portion of 

 coast on wliich they were picked up. The line drawn from 

 Maughold Head to the opening of Morecombe Bay 

 indicates the place of junction or separation of the tidal 

 streams in the North and St. George's Channel — the '' head 

 of the tide." When the chart and tables are compared it 

 will be seen that: — 



(1) 84% of the bottles picked up crossed this 

 imaginary line and drifted on to the Furness 

 and Cumberland coasts ; 



(2) 11% of the bottles found entered Morecambe 

 Bay; 



(3) 5% were stranded on the Lancashire coast 

 between Blackpool and Lytham ; 



(4) And only one bottle, set free on station 19, 

 failed to round Holyhead. This was found on 

 the Holyhead coast about 2 miles from the 

 place where the "Primrose Hill" was wrecked. 



It is difficult to account for the varying destinations 

 of the bottles set free in these experiments. Many factors 

 determine their subsequent course, the chief of which are 

 the wind and the direction and force of tbe tidal streams 

 near the place where they were set free. In the absence 

 of wind there stems no doubt that the course of a floating 

 object might be predicted from a knowledge of the direction 

 of the stream and the state of the tide. In general, in the 



