on 
84 MR, A. R. DWERRYHOUSE ON THE GLACIATION OF [ Aug. 1902, 
buried beneath the great sheet of ice pressing over from Edenside, 
though a large part of Mickle Fell (44) and Green Fell were free 
from ice. The effect of this pressure is well seen in the case of 
the valleys of Great and Little Eggleshope Becks. Here the ice 
was forced for scme distance up-stream and stood against the 
shoulder of Middle End (45), which separates the two valleys at a 
height of 1250 feet, in such a manner as to block the mouths of 
both of them. 
In the case of the Blackton-Beck Valley, the Teesdale ice was 
forced over the watershed into the Wear-Valley drainage, and to 
the south of Langleydale Common (25) the country was completely 
overridden, as shown by the striae at Holingside Wood, Hawksley 
Hill, and Roger Moor, and by the occurrence of a large boulder of 
Shap Granite near the village of Lynsack (p. 592). 
The following are some of ‘the levels of the ice in different parts 
of the valley-system at the period of maximum glaciation :— 
At the head of Teesdale the ice appears to have stood at about 
2000 feet above sea-level; while on Herdship Fell, between Tees- 
dale and Harwood Beck, which was a nunatak, it stood a little 
lower. 
At Green-Fell End the ice stood at the 1750-foot contour-line, 
and at Harter Fell (46), where it became confluent with the Lune- 
dale ice, its level was about 1500 feet. 
This gives a total fall of 500 feet in a distance of about 15 miles, 
or a surface-gradient of 33 feet per mile. 
At the head of Lunedale the ice stood at a level of 2000 feet, 
and fell to 1500 feet at Harter Fell, where it joined the Teesdale 
Glacier, giving a fall of 500 feet in 9 miles, or 55 feet per mile. 
The foregoing heights are obtained from that of the upper limit 
of the Drift, and therefore refer to the edges of the glaciers. The 
central parts of the glaciers would doubtless be somewhat higher— 
how much higher it is impossible to ascertain. 
(5) Glacial Lakes and Drainage-Channels. 
It will have been seen from the foregoing observations that, even 
at the period of maximum glaciation, the highest parts of the 
district were not covered with ice. 
These more elevated parts of the country appear to have been 
comparatively free from snow, at all events in the summer-time, 
inasmuch as traces of the existence of lakes and of copious streams 
of water are to be found in several parts of the area. The largest 
of these lakes occupied the valley of Maize Beck, and appears to have 
had ‘its overflow at the head of Hilton Gill (47), or at High-Cup 
Nick (48), or at both these places, the watersheds being at about 
the same level. 
As has been already stated (p. 583), the Drift of this part of the 
area is of a type different from that occurring in the main valley, 
scratched stones being very uncommon and striated surfaces absent. 
