202, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
have been known for many years from the Admiralty 
publications* (based upon Captain Beechey’s well-known 
observations in the Phil. Trans. of the Royal Society), 
and were summarised by one of us some years ago some- 
what as follows :— 
The tidal wave coming in from the open Atlantic 
reaches the Ivish Sea round both ends of Ireland (see 
Chart, fig. 8), but mainly round the south. The 
northern entrance is narrower, and admits only a 
comparatively small proportion of the total volume of 
water. 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, the larger, from the southward, 
through St. George’s Channel. Parts of the two streams 
meet and combine to the west of the Isle of Man, where 
there is a large elliptical area, about 20 miles in diameter, 
and reaching from off Port Erin towards Carlingford, 
over which there is no perceptible tidal stream, t 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, 
“the head of the tide,” extending from Maughold Head 
into Morecambe Bay. 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. 
The tide is high at Liverpool about eight hours after 
the same wave reaches Bristol, and an hour and twelve 
* See the Charts, the Admiralty Sailing Directious for the West Coast 
of England, and for Ireland, and ‘‘ The Tidal Streams of the English and 
Irish Channels’’ (Hydrographic Office, Admiralty, London, May, 1899). 
This information was summarised, as stated above, in Herdman and 
Dawson, “ Fishes and Fisheries of the Irish Sea’”’ (G. Philip & Co., 
London, 1902). 
+ The existence of such an area is, however, disputed by the fishermen 
at Port Erin, who state that even out in the channel there is sufficient tide 
running to carry the floats of their nets and lines under water. 
