484 MR. P. F. KENDALL ON A SYSTEM OF [ Aug. 1902, 
where unmodified by subsequent stream-action, possess very broad 
flat floors. These features are exhibited in their highest perfection 
in those cases where the valleys have been excavated in very soft 
rocks, such as the shales of the Lower Estuarine Series: they 
indicate rapid cutting by a large stream. 
The same deduction may be drawn from the character of the 
‘meanders.’ In a large valley of normal drainage, the sinuosities 
of the valley bear little or no direct relation to the meanderings of 
the stream, and this independence is the more conspicuous the 
flatter the floor of the valley is. It is only the banks of the 
stream that show such a relation, the well-known one that the 
steep bank is on the outside of a bend, while a gently shelving bank 
is on the inside. The reason for this is obvious, and need not be 
enlarged upon. Now, in the valleys which I am describing, the 
glacial stream fitted the valley so closely that the valley-walls were 
also the banks and follow the rule just cited. 
In each meander of one of these valleys the outer curve is steep, 
sometimes precipitous, while the inner curve has a more gentle’ 
slope. These features are nowhere more beautifully displayed than 
in the upper portion of Newton Dale above Raindale Mill. Here, 
for several miles, the railway from Pickering to Whitby runs 
through a superb canon having a depth of 300 or 400 feet, and 
occupied through a part of the distance by a small stream, the 
Pickering Beck. ‘The outsides of the meanders here are in many 
places so precipitous as to be unscalable. 
It is a noteworthy circumstance, that at Raindale Mill a tributary 
stream of large size belonging to the normal drainage enters Newton 
Dale, and below this point the valley takes a nearly rectilinear 
course without meanders. This may imply that the valley above 
this confluence has been produced mainly by the lake-overflow, 
while below it a pre-existing valley of considerable size has simply 
been deepened and perhaps broadened, its main lines being pre- 
served. The neighbouring normal drainage-valleys on each side of 
Newton Dale exhibit no such features as the upper part of that 
valley. 
The head of an overflow-valley generally shows some very cha- 
racteristic features, which may be well studied by the aid of contoured 
maps where the contour-lines are drawn every 25 feet." As arule, 
in ascending such a valley, the sky presently shows through the 
clear-cut notch of the intake, and on the map successive loops of 
the lower contours are replaced by lines of the higher elevations 
passing right through and round the hillsides. On the lakeward 
1 [ would here remark that the extremely detailed work which I have been able 
to do in Yorkshire has been rendered possible only by the very perfect 6-inch 
contoured maps of the Ordnance Survey. In this favoured county the contours 
are drawn every 25 feet, whereas in such counties as Northumberland, Cheshire, 
Westmoreland, and Norfolk, they are drawn at each 100 feet. In comparatively 
flat Norfolk there are doubtless sheets without a single contour-line. The 
counties that I have mentioned can never be satisfactorily studied by glacialists, 
unless a new survey be made. ° 
