kkndall: tiik (;lac'Iki; lakks of (u.kvklaxd. 
25 
similarly from the Stonegate Valley in an easterly direction, and 
halted on the watershed, where a series of gravelly mounds are 
seen with strongly-channelled fronts overlooking the valley. In 
the retreat many trenches were cut by streams flowing from 
the melting ice ; some of these, as tlie ice-front drew back behind 
the watershed, cut steadily backward through the crest, and 
produced a set of overflow channels for the discharge of a seiies 
of small lakelets formed along the margin of tlie ice. 
Three true lake overflows cut the watershed more deeply. 
These are. in order from east to west : — (1) Middle-Cair Slack, 
whicli makes a slight trough through tiie watershed near Lady- 
Cross CJate. but deepens to a pronounced feature in its lower 
course. (2) Stonedale Slack, a very fine ravine which now 
cuts the crest in a very marked fasliion. A curious cross-channel 
connects these two valleys near their head. The two channels 
probably weie of l)rief occupation, and their strong development 
in their lowei- parts, as compared with the heads, is consistent 
with the view here ado[)ted. that they were primarily channels- 
carrying the direct drainage of the glaciei-. (3) The third overflow 
is of a very different type — it is a great gorge 30 to 40 feet deep, 
which forms a very conspicuous breach in tlie line of watershed 
at Barton " Howl." The overHowing stream commenced ta 
cut at about 680 feet, and ceased at about 665. These, then, 
may be regarded as the approximate water-levels of a small 
lakelet on the iceward side of tlie watershed. This lakelet had 
a maximum area not exceeding three or four square miles. 
The last evidence of constrained drainage in Eskdale that 
demands notice is the actual outlet of the River Esk at Whitby. 
The river here flows through a rock -gorge about 100 feet deep^ 
and so narrow as to forbid the supposition that this was its 
ancient course. This was to the west of the town and into the 
sea at a point where the cliffs, entirely composed of drift, show 
a pre-glacial valley. The modern course may be either due 
to the obliteration of the old valley by glacial deposits, or may 
mean that the stream was comj^elled to take a course along 
the outer edge of the ice, and had cut the rock gorge sufficiently 
deep, before the ice was withdrawn, to render it the permanent 
line of drainage. 
