m
E.N.E. to W.S.W., say from Scaw Fell to Shap Fell; and a sketch map
shows us almost at a glance that Derwent Water, Thirlmere, Ullswater,
Coniston Water, and Windermere run at right angles to this axis;
Ennerdale Water is just where the boss ends and the mountains disappear;
while Crummock Water and Waste Water lie at the intermediate angles.

[Illustration: Fig. 37.--Map of the Lake District.]

So much then for the direction. We have still to consider the situation
and origin, and it appears that Ullswater, Coniston Water, the River
Dudden, Waste Water, and Crummock Water lie along the lines of old
faults, which no doubt in the first instance determined the flow of the
water.

Take another case. In the Jura the valleys are obviously (see Fig. 18)
in many cases due to the folding of the strata. It seldom happens,
however, that the case is so simple. If the elevation is considerable
the strata are often fractured, and fissures are produced. Again if the
part elevated contains layers of more than one character, this at once
establishes differences. Take, for instance, the Weald of Kent (Figs.
38, 39). Here we have (omitting minor layers) four principal strata
concerned, namely, the Chalk, Greensand, Weald Clay, and Hastings
Sands.

[Illustration: Fig. 38.--_a_, _a_, Upper Cretaceous strata, chiefly
Chalk, forming the North and South Downs; _b_, _b_, Escarpment of Lower
Greensand, with a valley between it and the Chalk; _c_, _c_, Weald Clay,
forming plains; _d_, Hills formed of Hastings Sand and Clay. The Chalk,
etc., once spread across the country, as shown in the dotted lines.]

The axis of elevation runs (Fig. 39) from Winchester by Petersfield,
Horsham, and Winchelsea to Boulogne, and as shown in the following
section, taken from Professor Ramsay, we have on each side of the axis
two ridges or "escarpments," one that of the Chalk, the other that of
the Greensand, while between the Chalk and the Greensand is a valley,
and between the Greensand and the ridge of Hastings Sand an undulating
plain, in each case with a gentle slope from about where the London and
Brighton railway crosses the Weald towards the east. Under these
circumstances we might have expected that the streams draining the Weald
would have run in the direction of the axis of elevation, and at the
bases of the escarpments, as in fact the Rother does for part of its
course, into the sea between the North and South Downs, instead of which
as a rule t