There is a narrow sand-bar running into it--wedding cufflinks

The pond rises and falls, but whether regularly or not, and within what period, nobody knows, though, as usual, many pretend to know. It is commonly higher in the winter and lower in the summer, though not corresponding to the general wet and dryness. I can remember when it was a foot or two lower, and also when it was at least five feet higher, than when I lived by it. There is a narrow sand-bar running into it, with very deep water on one side, on which I helped boil a kettle of chowder, some six rods from the main shore, about the year 1824, which it has not been possible to do for twenty-five years; and, on the other hand, my friends used to listen with incredulity when I told them, that a few years later I was accustomed to fish from a boat in a secluded cove in the woods, fifteen rods from the only shore they knew, which place was long since converted into a meadow.
But the pond has risen steadily for two years, and now, in the summer of '52, is just five feet higher than when I lived there, or as high as it was thirty years ago, and fishing goes on again in the meadow. This makes a difference of level, at the outside, of six or seven feet; and yet the water shed by the surrounding hills is insignificant in amount, and this overflow must be referred to causes which affect the deep springs. This same summer the pond has begun to fall again.
It is remarkable that this fluctuation, whether periodical or not, appears thus to require many years for its accomplishment. I have observed one rise and a part of two falls, and I expect that a dozen or fifteen years hence the water will again be as low as I have ever known it. Flint's Pond, a mile eastward, allowing for the disturbance occasioned by its inlets and outlets, and the smaller intermediate ponds also, sympathize with Walden, and recently attained their greatest height at the same time with the latter. The same is true, as far as my observation goes, of White Pond.
This rise and fall of Walden at long intervals serves this use at least; the water standing at this great height for a year or more, though it makes it difficult to walk round it, kills the shrubs and trees which have sprung up about its edge since the last rise -- pitch pines, birches, alders, aspens, and others -- and, falling again, leaves an unobstructed shore; for, unlike many ponds and all waters which are subject to a daily tide, its shore is cleanest when the water is lowest. On the side of the pond next my house a row of pitch pines, fifteen feet high, has been killed and tipped over as if by a lever, and thus a stop put to their encroachments; and their size indicates how many years have elapsed since the last rise to this height.