big trout know well, sinks suddenly to unknown depths. On the
opposite side, that flat-topped wall of rock towers up shoreless
into the sky, seven hundred feet perpendicular; the deepest water
of all we know is at its very foot. Right and left, two shoulders
of down slope into the lake. Now turn round and look down the
gorge. Remark that this pebble bank on which we stand reaches some
fifty yards downward: you see the loose stones peeping out
everywhere. We may fairly suppose that we stand on a dam of loose
stones, a hundred feet deep.

But why loose stones? - and if so, what matter? and what wonder?
There are rocks cropping out everywhere down the hill-side.

Because if you will take up one of these stones and crack it
across, you will see that it is not of the same stuff as those said
rocks. Step into the next field and see. That rock is the common
Snowdon slate, which we see everywhere. The two shoulders of down,
right and left, are slate, too; you can see that at a glance. But
the stones of the pebble bank are a close-grained, yellow-spotted
rock. They are Syenite; and (you may believe me or not, as you
will) they were once upon a time in the condition of a hasty
pudding heated to some 800 degrees of Fahrenheit, and in that
condition shoved their way up somewhere or other through these
slates. But where? whence on earth did these Syenite pebbles come?
Let us walk round to the cliff on the opposite side and see. It is
worth while; for even if my guess be wrong, there is good spinning
with a brass minnow round the angles of the rocks.

Now see. Between the cliff-foot and the sloping down is a crack,
ending in a gully; the nearer side is of slate, and the further