1898] THE ESKERS OF IRELAND 245 
In some places on the low ground the esker sea drifts (as 
Kinahan terms them) are spread out in undulating sheets, as in 
the County of Kildare. The famous Curragh may be cited as a 
tabular deposit of such materials. Now all these deposits point in 
the clearest manner to ‘the rushing of great waters’; and if we only 
consider the thaw of such an ice-sheet, as all admit to have existed, 
we can have perhaps floods and rushing waters enough for any pur- 
pose, without calling in the aid of subsidence beneath present sea- 
level. 
Mr Kinahan does not, however, forget that the formation of the 
eskers is a disputed point; but he thinks it probable that they are 
modifications of the banks and shoals which accumulate at (1) the 
colliding, and (2) the dividing of the flow-tide currents of the esker 
sea, similar to those that are found in the seas around Great Britain 
and Ireland at the present day. He examines three contem- 
poraneous instances of the ‘ colliding’ of currents giving origin to 
bank formations : 
(a) In the Irish Sea, in the vicinity of the Isle of Man, there is 
a meeting of the north and south flow-tide waves, or a ‘ Head of 
tide.’ Where the tidal currents meet they neutralise, forming a 
mass of currentless water that simply rises and falls, depositing silt 
and other materials. 
(6) There is a ‘ Head of tide’ in the Straits of Dover ; and 
(c) In the German Ocean, between Norfolk and Holland. 
But in the Straits of Dover and in the German Ocean the 
meeting is not precisely a case of ‘ colliding,’ as the currents pass 
for some distance ; and at their edges, or their junctions, long banks 
of gravel and shingle accumulate, 
It is also found, says Kinahan, that long banks of gravel and 
shingle may form at the dividing and splitting up of the 
flow-tide currents. We have here some resemblance between 
currents at sea and rivers on land. Just as the river-flow, dividing 
at the outlets, makes a deposit which may eventually become a delta, 
so does the ocean-current where it parts produce an accumulation 
varying in its constitution, extent and form with the nature and 
supply of materials affected by the moving mass of waters. 
As an illustration Kinahan cites the following: From Greenore 
Point (Co. Wexford) a main current runs northward up the Irish 
Sea, while secondary currents break off into Wexford Bay; and at 
the junction of these currents with the main one there are long 
banks between Greenore Head and Wicklow Head. Similar 
results, he adds, must have occurred in the esker sea. He applies 
his theory in this way : 
The flow-tide wave entering at Galway must have sent a main 
current eastward to the coast between Drogheda and Dublin. 
