different shape than these, if it run over soils of a different kind. We
will make a Hartford Bridge Flat turned upside down--a cake of sand with
a cap of clay on the top; and we will rain on that out of our watering-
pot, and see what sort of glens we make then. I can guess what they will
be like, because I have seen them--steep overhanging cliffs, with very
narrow gullies down them: but you shall try for yourself, and make up
your mind whether you think me right or wrong. Meanwhile, remember that
those gullies too will have been made by water.

And there is another way of "verifying my theory," as it is called; in
plain English, seeing if my guess holds good; that is, to look at other
valleys--not merely the valleys round here, but valleys in clay, in
chalk, in limestone, in the hard slate rock such as you saw in
Devonshire--and see whether my guess does not hold good about them too;
whether all of them, deep or shallow, broad or narrow, rock or earth, may
not have been all hollowed out by running water. I am sure if you would
do this you would find something to amuse you, and something to instruct
you, whenever you wish. I know that I do. To me the longest railroad
journey, instead of being stupid, is like continually turning over the
leaves of a wonderful book, or looking at wonderful pictures of old
worlds which were made and unmade thousands of years ago. For I keep
looking, not only at the railway cuttings, where the bones of the old
worlds are laid bare, but at the surface of the ground; at the plains and
downs, banks and knolls, hills and mountains; and continually asking Mrs.
How what gave them each its shape: and I will soon teach you to do the
same. When you do, I tell you fairly her answer will be in almost every
case, "Running water." Either water running when soft, as it usually is;
or water running when it is hard--in plain words, moving ice.

About that moving ice, which is Mrs. How's stronger spade, I will tell