602 MR. A. R. DWERRYHOUSE ON THE GLACIATION OF [ Aug. 1902, 
across West Allendale, across the spur between the West and East 
Allen, at a height of 1600 feet, across East Allendale above Allendale 
Town, across Harwood Side (98) at 1450 feet, over Lilswood Moor 
(99) at 1400 feet, across the Valley of Devil’s Water over Blanchland 
Moor (100) at 1300 feet, and so into the Valley of the Derwent. 
Continuing the line farther south-eastward, we find it skirting the 
Millstone-Grit fells by Kdmondbyers Common and Muggleswick 
Park (about 1200 feet), and finally passing over Whitehall Moss 
(101) into the Valley of the Wear, at 1100 feet above sea-level. 
(5) Glacial Lakes and Drainage-Channels. 
The ice of Alstondale produced several small lakes in the tributary 
valleys by closing their lower ends. The highest of these was in the 
valley of Garrygill Burn (102), on the right bank. The water of 
Garrygill Lake stood at the level of 1800 feet, and was drained by a 
channel (now dry) over Black Moor into the Valley of the Nent. 
Below Alston, on the same bank, were two lakes in the valleys of 
Ayle Burn (103) and Barhaugh Burn (104) respectively. Barhaugh 
Lake stood at a level of 1575 feet, and overflowed by a channel 
over Willyshaw Rigg into Ayle Lake (1500 feet), which in its turn 
drained over the col at the head of Ayle Burn into West Allendale. 
This must have taken place after the period of maximum 
glaciation, when the waters of the lake in West Allendale, which , 
will subsequently be shown to have stood at 1600 feet at that 
period, had subsided somewhat. 
The most important system of lakes and channels, however, is that 
produced along the southern border of the South-Tyne Glacier at the 
period of maximum glaciation, and by means of it I have been able to 
trace the level of the margin of the ice at that period (fig. 7, p. 600). 
The uppermost of this series was at the head of West 
Allendale. ‘The water stood at a level of 1600 feet, and drained by 
a channel at that level over Kevelin Moor (106) into a similar lake 
occupying the valley of the Kast Allen. / 
he lake in East Allendale stood at a level of 1450 feet, and 
overflowed by a channel at that elevation over the ridge to the east 
into a small lake occupying the upper part of the valley of Linn 
Burn, a tributary of Devil’s Water. This was continuous with a 
larger lake occupying the upper part of the Devil’s- Water valley, and 
its overflow cut the deep notch known as Rowantree Cleugh 
(the highest point of which is at 1260 feet) at a somewhat later 
period, when the water of the latter lake had fallen in level owing 
to the cutting-down of its overflow, Beldon Cleugh. 
The lake in the Devil’s-Water valley stood at a level of 1250 feet 
at first, but fell during the period of maximum glaciation to about 
1100 feet, by the cutting-down of its overflow-channel over Bulbeck 
Common by way of Beldon Cleugh. This channel is 150 feet deep, 
it has a flat bottom 100 yards in width, and is now quite 
dry. The watershed, which is at the northern end of the 
