breaking in upon its structure, floating off its ice-fragments in the form of bergs or floes, and, by releasing at the same time its heavier rock and gravel constituents, built up a breakwater which, as an island, now forms what is known as "Fisher's Island Sound." Fig. 2 represents a not unfrequent example of the character
Fig. 3.
of the materials which enter into the construction of this natural breakwater, as seen from the western side of this island.
But it is in the region to the east and west of the line of the Thames River, and which it has been suggested may have been the axis of the ancient glacier, and not very far removed from this line, that bowlders of extraordinary size occur most numerously; and among them is a rock which until very recently has been regarded as one of the largest, if not the very largest, bowlder that has thus far been recognized in this or any other country. This rock—of coarse crystalline granite—is situated in the town of Montville, New London County, about six miles south of Norwich, and about a mile west of the Montville Station on the New London and Northern Railroad; and, under the Indian name of "Sheegan," has almost from the first settlement of the country been recognized as a great natural curiosity. Its position is on the edge of a gentle mound or knoll, on the northeast slope of a little valley; and its dimensions, according to recent
