( 4 ) 



FIG i. 



II. PHYSICAL FEATURES OF THE IRISH SEA. 



i. AREA. 



The Irish Sea is roughly a large quadrangular area lying between latitudes 52 and 55 

 North, and longitudes 3 and 6 West. Its northern wider "part, in the centre of which the 



Isle of Man lies, is bounded by Scotland, 

 England, Wales, and Ireland, and forms 

 a rude square, averaging rather more 

 than loo miles each way, and containing 

 slightly over 10,000 square miles of 

 surface. The narrower southern portion, 

 between Wales and Ireland (Fig. i), is 

 about 100 miles in length to St. George's 

 Channel (lat. 52 N.), and varies in width 

 from about 50 to nearly 100 miles in 

 Cardigan Bay. Its area, as determined 

 with the "Amsler" planimeter is 7,246 

 square miles. Important extensions in 

 the northern area are the Sol way Firth, 

 Morecambe Bay and Liverpool Bay, and 

 in the southern part Carnarvon Bay and 

 Cardigan Bay. The whole area, reckoned 

 from the Mull of Galloway to St. David's Head, contains about 17,250 square miles, and has a 

 coastline, not including estuaries, of about 850 miles. Although communicating with the 

 North Atlantic, round the north and south of Ireland, by the North Channel and St. George's 

 Channel, these entrances form together only about one-tenth of the circumference of the area ; 

 and so the Irish Sea may be regarded as a landlocked or inland sea, surrounded on all sides 

 by British territory. In this respect the Irish Sea is unique. There is, at least in Europe, 

 no other sea of equal extent so completely closed in where the bounding territorial waters 

 belong to one nation. Consequently the Irish Sea seems peculiarly well fitted for those 

 experiments in Fisheries administration and cultivation which depend upon identical fisheries 

 regulations. The territorial waters and the ports of this large area are all under British 

 jurisdiction : no international questions are involved. Although at present in parts under 

 different regulations, and controlled by different local authorities, it would only require a 

 certain amount of mutual accommodation and arrangement between the English District 

 Committees, the Irish Department of Agriculture, the Fishery Board for Scotland, and the 

 Manx Fisheries Committee, to ensure uniformity of regulation and administration, and, what 

 is at least as important, an identical scheme of observation and investigation over the whole 

 area. 



2. DEPTH. 



Furthermore, the physical conditions are very varied. The greatest depth exceeds 100 

 fathoms, and there is a very considerable area of over 50 fathoms in depth, which forms a deep 

 channel running throughout the length of the Irish Sea to the west of the Isle of Man, and 

 communicating by means of the North Channel with the deep water of the Clyde sea area and 

 off the west of Scotland, and by St. George's Channel with the floor of the North Atlantic 

 south and west of Ireland. This deep channel varies in width from 4 to 24 miles, and there 



