(.4,) 
Il..-PHYSICAL, FEATURES OF THE IRISH SEA. 
1. 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 100 miles each way, and containing 
slightly over 10,000 square miles of 
surface. The narrower southern portion, 
between Wales and Ireland (Fig. 1), 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” 
square miles. Important extensions in 
planimeter is 7,246 
the northern area are the Solway Firth, 
Morecambe Bay and Liverpool Bay, and 
in the southern part Carnarvon Bay and 
Fic 1. 
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 
