a few years ago) falls over some cliff, turning what had been a water-fall into a fire-fall, and filling up the pool below with blocks of lava suddenly cooled, with a clang and roar like that of chains shaken or brazen vessels beaten, which is heard miles and miles away.  Of course, woe to the crops and gardens which stand in its way.  It crawls over them all and eats them up.  It shoves down houses; it sets woods on fire, and sends the steam and gas out of the tree-trunks hissing into the air.  And (curiously enough) it does this often without touching the trees themselves.  It flows round the trunks (it did so in a wood in the Sandwich Islands a few years ago), and of course sets them on fire by its heat, till nothing is left of them but blackened posts.  But the moisture which comes out of the poor tree in steam blows so hard against the lava round that it can never touch the tree, and a round hole is left in the middle of the lava where the tree was.  Sometimes, too, the lava will spit out liquid fire among the branches of the trees, which hangs down afterwards from them in tassels of slag, and yet, by the very same means, the steam in the branches will prevent the liquid fire burning them off, or doing anything but just scorch the bark.

But I can tell you a more curious story still.  The lava stream, you must know, is continually sending out little jets of gas and steam:  some of it it may have brought up from the very inside of the earth; most of it, I suspect, comes from the damp herbage and damp soil over which it runs.  Be that as it may, a lava stream out of Mount Etna, in Sicily, came once down straight upon the town of Catania.  Everybody thought that the town would be swallowed up; and the poor people there (who knew no better) began to pray to St. Agatha—­a famous saint, who, they say, was martyred there ages ago—­and who, they fancy, has power in heaven to save them from the lava stream.  And really what happened was enough to make ignorant people, such as they were, think that St. Agatha had saved them.  The lava stream came straight down upon the town wall.  Another foot, and it would have touched it, and have begun shoving it down with a force compared with which all the battering-rams that you ever read of in ancient histories would be child’s toys.  But lo and behold! when the lava stream got within a few inches of the wall it stopped, and began to rear itself upright and build itself into a wall beside the wall.  It rose and rose, till I believe in one place it overtopped the wall and began to curl over in a crest.  All expected that it would fall over into the town at last:  but no, there it stopped, and cooled, and hardened, and left the town unhurt.  All the inhabitants said, of course, that St. Agatha had done it:  but learned men found out that, as usual Madam How had done it, by making it do itself.  The lava was so full of gas, which was continually blowing out in little jets, that when it reached the