Vol. 58.] GLACIER-LAKES IN THE CLEVELAND HILLS, 539 
intersected by two modern streams. ‘The first segment runs behind 
Biller-Howe farmhouse, and it is a streamless gully of about 20 feet 
in yisible depth, but is known to contain at least 15 feet of peat 
near the house. Its intake is seen as a notch in the skyline 100 
feet above the floor of Biller-Howe Dale. The second segment is a 
moss-swamp forming a deep trench across Biller-Howe-Turf Rigg. 
The third, rather less sharply-cut, segment continues in accurate 
alignment across the spur called ‘ the Island,’ and its lower course 
has been adopted by a modern stream, forming a rocky gorge 100 
feet deep at its confluence with Jugger-Howe Beck. 
Beyond this point, a breach was made in the watershed on Jugger- 
Howe Moor: this separated the Robin-Hood’s Bay drainage from 
that of the Hellwath Burn, which now flows into the Derwent 
drainage, but formerly entered the sea near Burniston. The margin 
of the ice-sheet appears to have stood for a very short time at 
its farthest point of advance, then to have retreated rather rapidly 
for a time toa position about which it lingered for a very long period, 
long enough for many large and deep channels to be cut which are, 
I think, unsurpassed in the whole Cleveland area. 
The first effect of the retreat appears to have been to produce a 
great sinuation of the ice-margin which withdrew from Biller-Howe 
Dale, and uncovered a large part of Sneaton Moor. A large channel, 
Grey-Heugh Slack, was now developed running along the western 
margin of the ice-lobe from Fylingdales Moor to Biller-Howe-Dale 
Slack. This channel would carry off the water flowing from the ice- 
front, as well as that coming from the ice-free ground on Sneaton 
Moor. As the shrinkage of the ice progressed, a series of small 
shallow trenches were worn through the gravelly eastern banks of 
Grey-Heugh Slack by water from the ice-front. The best preserved 
of these is a small slack draining to the westward from Foulsike 
Farm. 
The next phase of retreat initiated a line of drainage, second in 
importance in the Cleveland area only to the great Newtondale gorges: 
this is the valley, bearing different names in its parts, which I may 
call the Jugger-Howe Valley. The margin ofthe ice had with- 
drawn northward soas to lie upon, or entirely behind, the Sneaton-Moor 
watershed. The shrinkage to the eastward brought the edge of the 
ice along the line of the present Jugger-Howe Valley, which afi that 
time, however, had no existence. A recess in the hills at the 
northern end produced by the valley of Kirk-Moer Beck now became 
a small lake receiving the water draining from Sneaton Moor by 
the two channels mentioned, and also from its own section of the ice- 
front. A marginal channel was then initiated, which wound along 
the edge of the ice to join the Biller-Howe-Dale overflow from 
Lake Iburndale. This new channel, which I may call the Foulsike 
overflow, continued to operate for a long time, and its broad and 
steep-sided gorge, though containing a great thickness of peat, 
still shows a depth exceeding 75 feet. It opens out abruptly at 
its intake into the very dissimilar valley of Kirk-Moor Beck. No 
stream, but only swamp, occupies the upper part of the gorge. 
