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of water, like Windermere or Ullswater, and irregular expansions 
of alluvium, such as would result from the silting-up of such lakes. 
When, therefore, we meet with similar chain-like expanses of alluvial 
flats occurring in connection with the courses of rivers, we are 
justified in regarding them as evidence of the former existence of 
lakes on their present site. This kind of evidence amounts to 
little short of absolute proof, if it can be shown that the termination 
of the alluvial tract coincides with the occurrence of a rocky 
channel in the river bed. If, in addition, that rocky channel is 
hemmed in on each side by steep walls, of the same rock, little or 
no further proof is needed, and we may safely regard the alluvial 
tract above the barrier as occupying the site of a veritable rock- 
basin, which, at a period not very remote, once contained the 
waters of a lake. 
It is hardly necessary to point out that the essential conditions 
I have referred to are all present in the case before us. Looking 
in the direction of Carlisle, we find here a rocky gorge, wherein the 
Eden is chafing its way seawards through some of the very toughest 
and least-easily eroded beds of the Penrith Sandstone, and the 
rocky walls that hem it in at this point occur in such a way as to 
suggest that at no very remote period the channel of the river lay 
many feet higher than its level is at present. Turning our attention, 
from our present standpoint near the rock barrier, in the direction 
of Appleby, we find a great alluvial flat, which is, as the farmers 
know to their cost at the present day, very often converted into a 
series of small lakes during heavy floods, when the quntity of river 
water flowing seawards is partly dammed back by this barrier. 
With minor narrows, this alluvial flat can be traced all the way up 
to Appleby, where it is found to terminate against the end of the 
gorge below Appleby Castle ; a gorge in that case, as in this before 
us, consisting of a hard barrier of Penrith Sandstone, notched into 
a deep groove by the action of the river. The lakes do not 
terminate at that point, however, for if we follow the Eden up as 
far as Clint Scar, the point where the Midland Railway now 
crosses, we come upon a very beautiful scar that evidently extended 
quite recently right across the river, The barrier here, and the 
