Read it through once

Sometimes, in the big river, when we would be feeling our way cautiously along through a fog, the deep hush would suddenly be broken by yells and a clamor of tin pans, and all in instant a log raft would appear vaguely through the webby veil, close upon us; and then we did not wait to swap knives, but snatched our engine bells out by the roots and piled on all the steam we had, to scramble out of the way! One doesn't hit a rock or a solid log craft with a steamboat when he can get excused.