How the summer time flits away, even while it seems to be loitering onward, arm in arm with autumn!

September 18th. -- How the summer time flits away, even while it seems to be loitering onward, arm in arm with autumn! Of late I have walked but little over the hills and through the woods, my leisure being chiefly occupied with my boat, which I have now learned to manage with tolerable skill. Yesterday afternoon I made a voyage alone up the North Branch of Concord river. There was a strong west wind blowing dead against me, which, together with the current, increased by the height of the water, made the first part of the passage pretty toilsome. The black river was all dimpled over with little eddies and whirlpools; and the breeze, moreover, caused the billows to beat against the bow of the boat, with a sound like the flapping of a bird s wing. The waterweeds, where they were discernible through the tawny water, were straight outstretched by the force of the current, looking as if they were forced to hold on to their roots with all their might. If for a moment I desisted from paddling, the head of the boat was swept round by the combined might of wind and tide. However, I toiled onward stoutly, and, entering the North Branch, soon found myself floating quietly along a tranquil stream, sheltered from the breeze by the woods and a lofty hill. The current, likewise, lingered along so gently that it was merely a pleasure to propel the boat against it. I never could have conceived that there was so beautiful a river-scene in Concord as this of the North Branch. The stream flows through the midmost privacy and deepest heart of a wood, which, as if but half satisfied with its presence, calm, gentle, and unobtrusive as it is, seems to crowd upon it, and barely to allow it passage; for the trees are rooted on the very verge of the water, and dip their pendent branches into it. On one side there is a high bank, forming the side of a hill, the Indian name of which I have forgotten, though Mr. Thoreau told it to me; and here, in some instances, the trees stand leaning over the river, stretching out their arms as if about to plunge in headlong. On the other side, the bank is almost on a level with the water; and there the quiet congregation of trees stood with feet in the flood, and fringed with foliage down to its very surface. Vines here and there twine themselves about bushes, or aspens, or alder-trees, and hang their clusters (though scanty and infrequent this season) so that I can reach them from my boat. I scarcely remember a scene of more complete and lovely seclusion than the passage of the river through this wood. Even an Indian canoe, in olden times, could not have floated onward in deeper solitude than my boat. I have never elsewhere had such an opportunity to observe how much more beautiful reflection is than what we call reality. The sky, and the clustering foliage on either hand, and the effect of sunlight as it found its way through the shade, giving lightsome hues in contrast with the quiet depth of the prevailing tints, -- all these seemed unsurpassably beautiful when beheld in upper air. But on gazing downward, there they were, the same even to the minutest particular, yet arrayed in ideal beauty, which satisfied the spirit incomparably more than the actual scene. I am half convinced that the reflection is indeed the reality, the real thing which Nature imperfectly images to our grosser sense. At any rate, the disembodied shadow is nearest to the soul.

There were many tokens of autumn in this beautiful picture. Two or three of the trees were actually dressed in their coats of many colours, -- the real scarlet and gold which they wear before they put on mourning. These stood on low, marshy spots, where a frost has probably touched them already. Others were of a light, fresh green, resembling the hues of spring, though this, likewise, is a token of decay. The great mass of the foliage, however, appears unchanged; but ever and anon down came a yellow leaf, half flitting upon the air, half falling through it, and finally settling upon the water. A multitude of these were floating here and there along the river, many of them curling upward, so as to form little boats, fit for fairies to voyage in. They looked strangely pretty, with yet a melancholy prettiness, as they floated along. The general aspect of the river, however, differed but little from that of summer, -- at least the difference defies expression. It is more in the character of the rich yellow sunlight than in aught else. The water of the stream has now a thrill of autumnal coolness; yet whenever a broad gleam fell across it, through an interstice of the foliage, multitudes of insects were darting to and fro upon its surface. The sunshine, thus falling across the dark river, has a most beautiful effect. It burnishes it, as it were, and yet leaves it as dark as ever.

On my return, I suffered the boat to float almost of its own will down the stream, and caught fish enough for this morning s breakfast. But, partly from a qualm of conscience, I finally put them all into the water again, and saw them swim away as if nothing had happened.