But what could change a beautiful Chine like that at Bournemouth into a wide sloping glen like this of Bracknell’s Bottom, with a wood like Coombs’, many acres large, in the middle of it?  Well now, think.  It is a capital plan for finding out Madam How’s secrets, to see what she might do in one place, and explain by it what she has done in another.  Suppose now, Madam How had orders to lift up the whole coast of Bournemouth only twenty or even ten feet higher out of the sea than it is now.  She could do that easily enough, for she has been doing so on the coast of South America for ages; she has been doing so this very summer in what hasty people would call a hasty, and violent, and ruthless way; though I shall not say so, for I believe that Lady Why knows best.  She is doing so now steadily on the west coast of Norway, which is rising quietly—­all that vast range of mountain wall and iron-bound cliff—­at the rate of some four feet in a hundred years, without making the least noise or confusion, or even causing an extra ripple on the sea; so light and gentle, when she will, can Madam How’s strong finger be.

Now, if the mouth of that Chine at Bournemouth was lifted twenty feet out of the sea, one thing would happen,—­that the high tide would not come up any longer, and wash away the cake of dirt at the entrance, as we saw it do so often.  But if the mud stopped there, the mud behind it would come down more slowly, and lodge inside more and more, till the Chine was half filled-up, and only the upper part of the cliffs continue to be eaten away, above the level where the springs ran out.  So gradually the Chine, instead of being deep and narrow, would become broad and shallow; and instead of hollowing itself rapidly after every shower of rain, as you saw the Chine at Bournemouth doing, would hollow itself out slowly, as this glen is doing now.  And one thing more would happen,—­when the sea ceased to gnaw at the foot of the cliffs outside, and to carry away every stone and grain of sand which fell from them, the cliffs would very soon cease to be cliffs; the rain and the frost would still crumble them down, but the dirt that fell would lie at their feet, and gradually make a slope of dry land, far out where the shallow sea had been; and their tops, instead of being steep as now, would become smooth and rounded; and so at last, instead of two sharp walls of cliff at the Chine’s mouth, you might have—­just what you have here at the mouth of this glen,—­our Mount and the Warren Hill,—­long slopes with sheets of drifted gravel and sand at their feet, stretching down into what was once an icy sea, and is now the Vale of Blackwater.  And this I really believe Madam How has done simply by lifting Hartford Bridge Flat a few more feet out of the sea, and leaving the rest to her trusty tool, the water in the sky.