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 side, the cliff itself, is—why, the whole cliff is composed of the very same stone as the pebble ridge.
Now, my good friend, how did these pebbles get three hundred yards across the lake? Hundreds of tons, some of them three feet long: who carried them across? The old Cymry were not likely to amuse themselves by making such a breakwater up here in No-man’s-land, two thousand feet above the sea: but somebody or something must have carried them; for stones do not fly, nor swim either.
Shot out of a volcano? As you seem determined to have a prodigy, it may as well be a sufficiently huge one.
Well—these stones lie altogether; and a volcano would have hardly made so compact a shot, not being in the habit of using Eley’s wire cartridges. Our next hope of a solution lies in John Jones, who carried up the coracle. Hail him, and ask him what is on the top of that cliff . . . So, “Plainshe and pogshe, and another Llyn.” Very good. Now, does it not strike you that this whole cliff has a remarkably smooth and plastered look, like a hare’s run up an earthbank? And do you not see that it is polished thus only over the lake? that as soon as the cliff abuts on the downs right and left, it forms pinnacles, caves, broken angular boulders? Syenite usually does so in our damp climate, from the “weathering” effect of frost and rain: why has it not done so over the lake? On that part something (giants perhaps) has been scrambling up or down on a very large scale, and so rubbed off every corner which was inclined to come away, till the solid core of the rock was bared. And may not those mysterious giants have had a hand in carrying the stones across the lake? . . . Really, I am not altogether jesting. Think a while what agent could possibly have produced either one or both of these effects?