It soon grew very monotonous, having nothing to see but the shapes of the distant clouds, which stood out now and then like dimly-seen mountains high up above the land.  But by degrees the distant flickering of the lightning grew nearer, and went on slowly growing brighter, till from time to time, as we leaned over the bulwarks, listening to the faint rushing sound of the river, sweeping past the chain cable, and dividing again upon our sharp bows, we obtained a glimpse of the shore on either side.  Then it glimmered on the black, dirty-looking stream, and left us in greater darkness than ever.