And then, my dear child, I fell into a more serious mood.  I said to myself, “If that stream had been a little, only a little stronger, or if the rock above it had been only a little weaker, it would have been no laughing matter then; the village might have been shaken to the ground; the rocks hurled into the torrent; jets of steam and of hot water, mixed, it may be, with deadly gases, have roared out of the riven ground; that might have happened here, in short, which has happened and happens still in a hundred places in the world, whenever the rocks are too weak to stand the pressure of the steam below, and the solid earth bursts as an engine boiler bursts when the steam within it is too strong.”  And when those thoughts came into my mind, I was in no humour to jest any more about “young earthquakes,” or “Madam How’s boilers;” but rather to say with the wise man of old, “It is of the Lord’s mercies that we are not consumed.”

Most strange, most terrible also, are the tricks which this underground steam plays.  It will make the ground, which seems to us so hard and firm, roll and rock in waves, till people are sea-sick, as on board a ship; and that rocking motion (which is the most common) will often, when it is but slight, set the bells ringing in the steeples, or make the furniture, and things on shelves, jump about quaintly enough.  It will make trees bend to and fro, as if a wind was blowing through them; open doors suddenly, and shut them again with a slam; make the timbers of the floors and roofs creak, as they do in a ship at sea; or give men such frights as one of the dock-keepers at Liverpool got in the earthquake in 1863, when his watchbox rocked so, that he thought some one was going to pitch him over into the dock.  But these are only little hints and warnings of what it can do.  When it is strong enough, it will rock down houses and churches into heaps of ruins, or, if it leaves them standing, crack them from top to bottom, so that they must be pulled down and rebuilt.

You saw those pictures of the ruins of Arica, about which our talk began; and from them you can guess well enough for yourself what a town looks like which has been ruined by an earthquake.  Of the misery and the horror which follow such a ruin I will not talk to you, nor darken your young spirit with sad thoughts which grown people must face, and ought to face.  But the strangeness of some of the tricks which the earthquake shocks play is hardly to be explained, even by scientific men.  Sometimes, it would seem, the force runs round, making the solid ground eddy, as water eddies in a brook.  For it will make straight rows of trees crooked; it will twist whole walls round—­or rather the ground on which the walls stand—­without throwing them down; it will shift the stones of a pillar one on the other sideways, as if a giant had been trying to spin it like a teetotum, and so screwed it half in pieces.  There is a story told by a wise man,