In Search of the Castaways by Jules Verne — Read

For two hours the tree floated on the immense lake without reaching terra firma. The flames had gradually died out, and thus the principal danger of this terrible voyage had vanished. The current, still keeping its original direction, flowed from southwest to northeast; the darkness, though illumined now and then by flashes, had become profound, and Paganel sought in vain for his bearings. But the storm was abating, the large drops of rain gave place to light spray that was scattered by the wind, while the huge distended clouds were crossed by light bands.

The tree advanced rapidly on the impetuous torrent, gliding with surprising swiftness, as if some powerful propelling means were enclosed within its trunk. There was as yet no certainty that they would not float on thus for many days. About three o'clock in the morning, however, the major observed that the roots now and then struck the bottom. Tom Austin, by means of a long branch, carefully sounded, and declared that the water was growing shallow. Twenty minutes later, a shock was felt, and the progress of the tree was checked.