Page:Popular Science Monthly Volume 40.djvu/354

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340
THE POPULAR SCIENCE MONTHLY.
REMARKABLE BOWLDERS.

By DAVID A. WELLS.

THE calling of attention, in The Popular Science Monthly for June, 1890, to the evidences of glacial action in southeastern Connecticut afforded by the number and great size of the bowlders in that section of the country, with accompanying illustrations from photographs, has been instrumental in creating no little popular interest on the subject, and in bringing to the attention of the public many other interesting examples of like glacial phenomena that have hitherto almost escaped notice.

Accepting reported measurements, the largest erratic block, or bowlder, as yet recognized in the United States, and probably in the world, is in the town of Madison, N. H., and, according to Prof. Crosby, of the Boston Institute of Technology, has the following maximum dimensions: Length, 83 feet; width, in excess of 45 feet; height, 30 to 37 feet; contents, 90,000 cubic feet; and probable weight, 15,300,000 pounds, or 7,650 tons.

PSM V40 D354 Sheegan boulder in connecticut.jpg

Fig. 1.

Next to this in size is undoubtedly the great rock in the town of Montville, New London County, Connecticut, generally known by its Indian designation as "Sheegan," and also as "Mohegan" (Fig. 1). In the opinion of some, this rock is an isolated granite protuberance, and not a true "erratic" or bowlder; but recent examinations have seemed to completely negative the first supposition. Its approximate maximum dimensions are: Length, 75 feet; width, 58 feet; height, 60 feet; contents, 70,000 cubic feet; weight,