Read it through once

The next few months showed me strange things. On the same day that we held the conversation above narrated, we met a great rise coming down the river. The whole vast face of the stream was black with drifting dead logs, broken boughs, and great trees that had caved in and been washed away. It required the nicest steering to pick one's way through this rushing raft, even in the day-time, when crossing from point to point; and at night the difficulty was mightily increased; every now and then a huge log, lying deep in the water, would suddenly appear right under our bows, coming head-on; no use to try to avoid it then; we could only stop the engines, and one wheel would walk over that log from one end to the other, keeping up a thundering racket and careening the boat in a way that was very uncomfortable to passengers. Now and then we would hit one of these sunken logs a rattling bang, dead in the center, with a full head of steam, and it would stun the boat as if she had hit a continent. Sometimes this log would lodge, and stay right across our nose, and back the Mississippi up before it; we would have to do a little craw-fishing, then, to get away from the obstruction. We often hit _white _logs, in the dark, for we could not see them till we were right on them; but a black log is a pretty distinct object at night. A white snag is an ugly customer when the daylight is gone.