42 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



streams or currents in the Irish Sea is that for nearly six 

 hours after low-water at, say, Liverpool, two tidal streams 

 pour into the Irish Sea, the one from the north of Ireland, 

 through the North Channel, and the other from the south- 

 ward, through St. George's Channel. Parts of the two 

 streams meet and neutralise each other to the west of the 

 Isle of Man, causing the large elliptical area, about 20 

 miles in diameter and reaching from off Port Erin to 

 Carlingford, where no tidal streams exist, the level of the 

 water merely rising and falling with the tide. The 

 remaining portions of the two tidal streams pass to the 

 east of the Isle of Man and eventually meet along a line 

 extending from Maughold Head into Morecambe Bay. 

 This line is the " head of the tide." During the ebb the 

 above currents are practically reversed, but in running out 

 the southern current is found to bear more over towards 

 the Irish coast. 



There is some reason to believe that, as a result of the 

 general drift of the surface waters of the Atlantic and the 

 shape and direction of the openings to the Irish Sea, more 

 water passes out by the North Channel than enters that 

 way, and more water enters by the South (St. George's) 

 Channel than passes back, and that consequently there is, 

 irrespective of the tides, a slow current passing from south 

 to north through our district. The fact that so many of 

 our drift bottles have crossed the " head of the tide " from 

 S. to N., and that of those which have gone out of our 

 district nearly all have gone north to the Clyde Sea-area 

 supports this view, which I learn from Admiral Wharton 

 is a priori probable, and which is believed in by some 

 nautical men in the district from their experience of 

 the drift of wreckage. 



It may be objected to our observations by means of 

 drift bottles that they are largely influenced by the wind 



