Page:Popular Science Monthly Volume 68.djvu/316

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312
POPULAR SCIENCE MONTHLY
But to whatever cause we attribute the phenomena of the superficial detritus of the fourth district, the whole surface has been permanently covered by water, for it seems impossible that partial inundations could have produced the uniform character and disposition of the materials which we find spread over the surface.

Under the caption 'Description of a Singular Case of Dispersion of Blocks of Stone Connected with the Drift, in Berkshire County, Mass.,' Dr. Edward Hitchcock came forward in the American Journal of Science for 1845 with a description of that remarkable train of boulders extending from Fry's Hill in the Canaan Mountains of New York, southeasterly into Massachusetts for a distance of some fifteen or twenty miles, which have since become more generally known as the Richmond Boulder Train. The lithological nature of the boulders was such that they could be traced to a common source and were described as forming three somewhat meandering trains, extending from Fry's Hill, through the adjoining valley, and upwards over an elevation of eight hundred feet at the state line, across the Richmond valley, over Lenox Mountain, six hundred feet in height, to and over Beartown Mountain, one thousand feet in height. Naturally, so striking a phenomenon excited investigation, and, naturally, too, Dr. Hitchcock, in the then existing condition of knowledge, found difficulty in accounting for the same. He recognized the similarity of the trains to the lateral moraines described by Agassiz, but he could not conceive of a glacier traveling directly across the intervening ridges, even were there mountains in the vicinity of sufficient altitude to give rise to the same. Neither did the consideration of river drift or floating ice afford him a satisfactory conclusion:

In short, I find so many difficulties on any supposition which I may make that I prefer to leave the case unexplained until more analogous facts have been observed.

Unsatisfactory and apparently unimportant as this paper may at first thought seem, it is questionable if the contribution were not worthy of greater commendation than the one put forward three years later by the Rogers brothers, to which I now refer.

According to the descriptions given, the trains start, each from its particular depression in the summit of a high ridge in Canaan, N. Y. Taking a direction south 35° east, they cross the higher ridges and their intervening valleys, the longer for a distance of twenty miles and the shorter for ten miles. The individual trains are none of them more than three hundred or four hundred feet in breadth and not over half a mile asunder. The transported blocks of all sizes up to twenty feet in diameter, sharply angular, free from scratches, and all of the same lithological nature, identical with that of the ridge whence they start. That such a dispersion of boulders from a single point should have taken place regardless of contours is certainly enough to excite the interest of any one. It is the means invoked by the two workers which have excited our wonder, however.