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THE POPULAR SCIENCE MONTHLY.

or did he write under the influence of divine inspiration?

Rev. J. C. Mahin.
Peru, Indiana, June 21, 1875.
 

 

THE MECHANICAL POWER OF LIGHTNING.

To the Editor of The Popular Science Monthly:

In the afternoon of June 26, 1874, a thunder-storm passed over the town of Cummington, Hampshire County, Massachusetts, during which an exhibition of the mechanical power of lightning was displayed, which I believe is extremely rare, at least in this latitude.

A sugar-maple tree (Acer saccharinum), thirteen feet in circumference four feet from the ground, was struck, and split in several places, apparently throughout its diameter, from the ground to a height varying from twelve to twenty feet. On reaching the .earth, the main portion of the shaft passed to a piece of wet ground several rods distant, in its way ploughing a furrow from one to over three feet in depth, tearing seven trees, the largest six inches in diameter, from the ground, and throwing them several feet from their former places, A rock containing thirty-six cubic feet was torn from its bed, and rests on the surface, three feet from its original position. In its course it passed under another maple, two feet in diameter. The tree was not thrown down, but the earth was thrown up from beneath its roots, in places, to the depth of three feet. This tree stood about sixty feet from the one struck. It then passed thirty or forty feet farther, through earth so wet in some places that the trench made by it filled with water. After making a cut eight feet wide at the surface, and three feet deep through a knoll, it divided, and, after passing a short distance farther, struck at three points a half-inch lead water-pipe, running at right angles with its centre, filled with water at the time, and covered with about two feet of wet earth, which was thrown out, and the pipe destroyed for a distance of 200 feet. No trace of the pipe could be found in many places, excepting scattered gray oxide of lead. In its way from the tree to the pipe, large masses of mica-slate rock were shattered, and one observer saw large stones which were thrown above the top of the surrounding trees.

Nearly the whole distance traversed by the lightning was woodland, and the soil was firmly bound together by interlacing roots; many of these, large enough to resist the power of the strongest yoke of oxen, were snapped like pipe-stems, the fracture being almost as smooth as if cut with a saw. Lighter portions of the electricity radiated in various directions from the tree, turning up the earth like a plough, for a distance of from 40 to 100 feet. The tree was struck while the rain-cloud was at least two or three miles distant. Many people were out, making preparation for the coming shower at the time, and the bolt was seen by several persons as it darted from the coming cloud. I visited the place nearly a year after the event, but all that I have described is yet visible. I can only account for this tremendous force by supposing that the water in the soil, converted instantly to steam, produced these results.

Dewey A. Cobb.
Providence, R. I., June, 1875.
 


EDITOR'S TABLE.

RELATIVITY OF TRUTH.

AMONG the higher influences of science to be realized in the future, will be its inculcation of more correct views concerning the relation of the human mind to truth. The effect of partisanship in politics and theology—the two great schools in which people are chiefly educated—is to establish the idea that truth is something absolute, that can be got once for all, and then can be comfortably held and professed forever afterward. There are only truth and its opposite error sharply divided off to choose from; and a "yes" or "no" is demanded for all propositions. In some things this is no doubt true; there is only one side to the multiplication-table.