It was accompanied by inconceivable winds--the hurricanes and cyclones spoken of in many of the legends. Hence we find the loose material of the original surface gathered up and carried into the drift-material proper; hence the Drift is whirled about in the wildest confusion. Hence it fell on the earth like a great snow-storm driven by the wind. It drifted into all hollows; it was not so thick on, or it was entirely absent from, the tops of hills; it formed tails, precisely as snow does, on the leeward side of all obstructions. Glacier-ice is slow and plastic,
{p. 98}
and folds around such impediments, and wears them away; the wind does not. Compare the following representation of a well-known feature of the Drift, called
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CRAG AND TAIL.--c, crag; t, till.
"crag and tail," taken from Geikie's work,[1] with the drifts formed by snow on the leeward side of fences or houses.
The material runs in streaks, just as if blown by violent winds:
"When cut through by rivers, or denuded by the action of the sea, ridges of bowlders are often seen to be inclosed within it. Although destitute of stratification, horizontal lines are found, indicating differences in texture and color."[2]
Geikie, describing the bowlder-clay, says:
"It seems to have come from regions whence it is bard to see how they could have been borne by glaciers. As a rule it is quite unstratified, but traces of bedding are not uncommon."