Page:Popular Science Monthly Volume 2.djvu/366

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350
THE POPULAR SCIENCE MONTHLY.

discovery, in the Madras Presidency, of implements of quartzite of true drift-type, found on the cliffs at an elevation of 300 feet above the sea, in a bed of ferruginous clay, which forms the coast-line for several hundred miles, and is intersected at right angles, at various intervals, by the rivers of the country in making their way to the sea.

In all these cases, all traces of the ancient rivers, if indeed they ever existed, have been entirely effaced; neither channels, nor outlets, nor adequate water-sheds, nor a single land or river shell, remaining to testify of them; and not only so, but we find many deposits of quaternary gravel (which Mr. Evans justly concludes to be of the same geological period as those of the implements, and to owe their existence and position to the same causes) on hills which could not have been reached by modern rivers. The whole country would have been a vast lake before such heights could have been submerged; and under such circumstances it may be fairly assumed that the same forces, whatever they were, that covered the hill-tops, may have partially filled up the valleys; the presence of gravel may suggest, but cannot prove, that the river brought it, however much it may have rearranged and sorted it; both valley and gravel may have had an existence before the river began its course. We have many valleys and gravels without rivers, and rivers without gravels; they can very well exist apart, and doubtless have often done so.

Fig. 6.—Spindle-Whorl, from Holyhead.

One of the arguments usually relied upon, in support of the belief in fiuviatile, as opposed to diluvial, agency in the formation of the deposits in which the stone implements are found, is founded on the assumption that the constituents of these quaternary gravels are petro-logically such, and only such, as belong to existing river-basins; and this fact, Mr. Evans says, holds good in France and England, and cannot be too often reiterated. Without pausing to consider how far this argument might avail as against those who, like Dr. Buckland, believe in a simultaneous and universal cataclysm, it seems hardly applicable