574 
between it and the older drift last described. On the lower 
side we find terrace after terrace, till we get to the modern 
alluvium. Now, although it is quite possible that some of 
these terraces may be due to an older formation, a gravelly 
drift, planed off by the river, it seems far more natural and 
simple to suppose that we have here the records of a con- 
tinuous fluviatile action back to the Glacial period; for, as 
soon as the glaciers began to recede, the streams which 
flowed from them must have commenced their work, and 
sudden flushings must have resorted and carried down the 
mixed moraine debris, leaving it often on steeper slopes than 
the gentler flowing rivers of modern times can ever form. 
In these gravelly deposits we often find deep hollows with 
no outlet, as for instance the curious hole known as Hollow 
Basin, or Devil's Punch Bowl, in Underley Park, near 
Kirkby Lonsdale, and others near the gardens at Underley ; 
and, on a smaller scale, in several places north of Grimes 
Hill, and near Sedbergh. Looking at the hole in Underley 
Park, last year, Sir Charles Lyell told me that similar 
% phenomena were produced sometimes by a glacier receding 
unequally, and so at one time depositing but little moraine 
matter on a given area, and at another time more, and so, 
by unequal deposition, hollows would be left. Another way 
Sir Charles said they have been sometimes produced was by 
the breaking off of large masses from the end of a glacier, 
which would take so long to melt, that the glacier would 
recede too far ever to fill the hole occupied by the fallen ice. 
About a mile ~N. of Austwick, there are some very interest- 
ing points connected with glacial phenomena and subsequent 
denudation. Resting on the mountain limestone plateau of 
Norber, there are a number of large blocks of Silurian grit, 
some to twenty or thirty feet in longest diameter. These 
have been forced along from beds at a lower level in Crum- 
mack valley, and left often on a bare table of limestone. 
