evident that he could go back through the forest wherever he had been during the day.
After this rough walking in the dark woods it was an agreeable change to glide down the rapid river in the canoe once more. This river, which was about the size of our Assabet (in Concord), though still very swift, was almost perfectly smooth here, and showed a very visible declivity, a regularly inclined plane, for several miles, like a mirror set a little aslant, on which we coasted down. This very obvious regular descent, particularly plain when I regarded the water-line against the shores, made a singular impression on me, which the swiftness of our motion probably enhanced, so that we seemed to be gliding down a much steeper declivity than we were, and that we could not save ourselves from rapids and falls if we should suddenly come to them. My companion did not perceive this slope, but I have a surveyor's eyes, and I satisfied myself that it was no ocular illusion. You could tell at a glance on approaching such a river, which way the water flowed, though you might perceive no motion. I observed the angle at which a level line would strike the surface, and calculated the amount of fall in a rod, which did not need to be remarkably great to produce this effect.
It was very exhilarating, and the perfection of travelling, quite unlike floating on our dead Concord River, the coasting down this inclined mirror, which was now and then gently winding, down a mountain, indeed, between two evergreen forests, edged with lofty dead white pines, sometimes slanted half-way over the stream, and destined soon to bridge it. I saw some monsters there, nearly destitute of branches, and scarcely diminishing in diameter for eighty or ninety feet.
