Page:A Week on the Concord and Merrimack Rivers.djvu/267

Rh in the limestone rock at Shelburne Falls on Deerfield river in Massachusetts, and more or less generally about all falls. Perhaps the most remarkable curiosity of this kind in New England is the well known Basin on the Pemigewasset, one of the head-waters of this river, twenty by thirty feet in extent and proportionably deep, with a smooth and rounded brim, and filled with a cold pellucid and greenish water. At Amoskeag the river is divided into many separate torrents and trickling rills by the rocks, and its volume is so much reduced by the drain of the canals that it does not fill its bed. There are many potholes here on a rocky island which the river washes over in high freshets. As at Shelburne Falls, where I first observed them, they are from one foot to four or five in diameter, and as many in depth, perfectly round and regular, with smooth and gracefully curved brims, like goblets. Their origin is apparent to the most careless observer. A stone which the current has washed down, meeting with obstacles, revolves as on a pivot where it lies, gradually sinking in the course of centuries deeper and deeper into the rock, and in new freshets receiving the aid of fresh stones which are drawn into this trap and doomed to revolve there for an indefinite period, doing Sisyphus-like penance for stony sins, until they either wear out, or wear through the bottom of their prison, or else are released by some revolution of nature. There lie the stones of various sizes, from a pebble to a foot or two in diameter, some of which have rested from their labor only since the spring, and some higher up which have lain still and dry for ages,—we noticed some here at least sixteen feet above the present level of the water,—while others are still revolving, and enjoy no respite at any season. In one instance, at Shelburne Falls, they have worn quite through