Vol. 58. GLACIER-LAKES IN THE CLEVELAND HILLS, 545 
extramorainic course along the opposite side of the valley, until it 
cleared the obstruction, at the same time that the overflow from the 
Tburndale—Robin Hood’s Bay area was sweeping down the same 
line. In this way the Jugger-Howe valley was produced. A well- 
marked range of gravelly moraine now extends along the verge of 
Jugger-Howe Beck, which here runs in a narrow gorge from 100 to 
130 feet deep, contrasting very strikingly with the broad open 
Fig. 23.—Section across Jugger-Howe Beck and Castle Becl-, 
showing the moraine. 
W.N.W. 
Eo. 
Moraine 
Castle Beck. 
«K Jugger Howe Beck. 
307 0.1). 
100 200 300 400 S00 Vertical 
Scale Feet : 
200 400 600 800 1000 Horizontal 
valley of Castle Beck which runs beside it (see fig. 23). The water- 
shed separating the head of Castle Beck from Hellwath Beck is not 
more than 50 yards from the bottom of the deep ravine in which 
the latter stream flows. At the assumed stage of maximum exten- 
sion, a small lakelet was held up by ice on the north side of Stony- 
- Marl Howe, and a fine streamless valley with a double intake now 
comes down to join Hellwath Beck. The altitude of the intakes is 
about 750 feet. A marginal channel, already noticed in the section 
on Robin Hood’s Bay, also passed down the northern face of the 
same hill, and carried its drainage into Burn-Howe Dale. The 
southern ice-lobe appears to have withdrawn somewhat rapidly, its 
margin retreating simultaneously to the south and the east until it 
fell behind the north-and-south line of water-parting through Pye 
Rigg and Hallow Rigg. So soon as this stage was reached, marginal 
lakes began to be formed. One of these was drained southward by 
means of a marginal channel, Pye-Rigg Slack, which was joined later 
by a small overflow behind Moorland House, Rudda Howe. Perhaps 
to this stage should be referred a small overflow towards Castle Beck 
which passes through a spur near Thorn Howe. A fine gravel- 
mound marks its outlet on the southern bank: it cuts the 525-foot 
contour. A slight shrinkage of the ice enabled the water here to 
escape in a south-easterly direction down the valley, at present 
carrying very little drainage, which extends into the Broadlands 
valley, cutting through a bold belt of moraine in its course. 
From this point, the retreat of the ice seems to have been very 
gradual, with long and frequent halts and even some re-advances, 
repeating in a striking way the fluctuations recorded by the Robin- 
Hood’s Bay series of overflows. The retreat produced two definite 
lakes—one at the head of Bloody Beck, the principal affluent of the 
