Vol. 58.] TEESDALE, WEARDALE, AND THE TYNE VALLEY. 585: 
The valleys now occupied by Hudeshope Beck and Great Eggles- 
hope Beck were also the sites of lakes at this period, the former 
haying its overflow into the latter between Carrs Hill and Monk’s. 
Moor. 
In the case of Little Eggleshope Beck, the ice standing against 
Middle End, as already described, caused the ponding-up of the 
drainage of that valley; and it would also appear that a large 
volume was discharged into this lake from the ice-front, as there 
is a deep and wide gorge (now practically streamless) connecting 
this valley with Eden Beck (49), a tributary of the River Wear. 
The best-marked series of glacier-dammed lakes in the area 
is that which occurs in the Mickle-Fell and Green-Fell range 
(Pl. XXIX)}. The uppermost lake of this series occupied the area 
now known as Philip-Reed Moss; it received the drainage from 
all the southern side of Mickle Fell, and probably also waters from 
the eastern edge of the Eden Glacier. Its waters found an outlet 
over the col between Closehouse Hush and West Hush, at an 
elevation of about 1700 feet (51). The waters of this lake flowed 
into a second lake which occupied the valley of Arngill Beck; this, 
in its turn, overflowed by way of the col at East Hush into the 
valley of Hargill Beck. 
This valley was also occupied by a lake, and overflowed by way 
of the col between Cock Lake and Bink Moss into Wemmergill 
Beck. At the period of maximum glaciation this lake not only 
received the whole of the drainage from its own side of the Mickle- 
Fell watershed, but also the overtlow from a lake which occupied. 
the broad upland valley known as Howden Moss and Bleabeck 
Grains (53). The overflow of this Bleabeck Lake was through the 
channel of Dry Gill (54), between Hagworm Hill and Bink Moss, 
the level of the lake being about 1750 feet. There was still one 
more in this chain of lakes, and this occupied the valiey of Wemmer- 
gill Beck. Its overflow at its maximum was at an elevation of 
1600 feet, between How Top and Scarsett Rigg, by way of Merry 
Gill (55). 
About a mile below the foot of Merry Gull the ice appears to. 
have stood at a level of 1500 feet, that is to say 100 feet lower than 
the outiet of Lake Wemmergill, and therefore the water probably 
flowed on to the ice, or may have found its way under or through 
the glacier, as do some of the streams on the Malaspina Glacier in 
Alaska. 
(6) Phenomena during the Period of Retreat. 
Having seen what was the probable state of affairs at’ the time 
of maximum glaciation, we may now consider what took place 
during the period in which the ice dwindled. Of course, we can 
learn nothing directly of the sequence of events during the period of 
advance, as the traces of this advance were necessarily obliterated 
during the period of greatest extension. By a careful study of the 
phenomena of retreat we can, however, learn something of that 
