Vol. 58.] GLACIER-LAKES IN THE CLEVELAND HILLS. 555, 
formed by an artificial dam at the eastern end. The western intake 
however is closed by so slight an elevation, that I think a flow has 
taken place in both directions, the last being that to the eastward. 
The cutting of the valley was probably commenced at about 275 
feet, and ceased at about 235 feet. Hackness Lake, therefore, stood 
between those levels for a short time. 
An earlier stage is represented by a very small notch 100 yards . 
to the northward, which shows a slight fall in both directions 
from acentral watershed about 385 feet above O.D. This overflow 
is cut through gravel. The flow seems to have occurred in both 
directions, the eastern being the last. There is a bench like a 
beach at the 300-foot contour on the south side of the hill. 
To the westward a well-marked marginal channel, with a fall 
towards Forge Valley, occurs in a gravelly tract above Ox- Pasture 
Hall. The intake is a little below 225 feet O.D., and it is trace- 
able to a point about a quarter of a mile to the westward, where it 
cuts the 175-foot contour. 
Turning back towards Scarborough again, we fad a channel cutting 
the 300-foot contour behind (west of) Hatter bord Hill. This hillisa 
portion of a fine moraine, which projects forward from the escarpment 
at the farmhouse called Row Brow. ‘he channel drained north- 
- ward towards Forge Valley, and it was modified considerably by 
subsequent morainic accumulation. On the eastern side of the same 
hill a long shallow channel exists, which is in my judgment clearly 
an overflow. It cuts the 225-foot contour, and falls to the south 
towards the Seamer escape: it is quite streamless. Lady Edith’s 
Drive is another related drainage-valley having an easterly. fall. 
Taken in conjunction with the last, it seems to indicate a recession 
of the ice-front to the eastward and northward. 
Four remarkable valleys cut through the ridge of Kellaways 
Rock to the eastward. At Northstead the northernmost cuts the 
ridge with a fall to the westward down almost to the 225-foot - 
contour. The intake hasa southerly curvature, probably indicating 
that the water was flowing from that direction, and this is confirmed 
by the fact. that the hill falls away to the northward. The ice must, 
as in the former cases, have stood to the northward. 
The next, Peasholm Valley, is now occupied by a stream flowing 
eastward, and, ipso facto, I should have concluded that the 
Glacial drainage of which it is certainly a relic had the same 
direction. Nevertheless, J] am inclined to the opinion that a reversal 
of the drainage has taxen place since Glacial times, mainly perhaps 
by the action of springs. 
The Scalby-Road valley, which cuts well through the 200-foot 
contour, was formed by a stream flowing westward; the last, the 
Stepney-Road valley, which also falls westward, cuts through the 
225-foot contour. 
The group of four I should regard as a connected or parallel 
sequence; but it is necessary to assume, what is by no means 
improbable, that there were. fluctuations of the ice-front. These 
fluctuations may not only have closed with an ice-barrier a channel 
