A
friend observed for me the ledges on the Alps of Switzerland, and
states that they ran at 3 or 4 ft. one above the other, and were
about a foot in breadth. They had been deeply pitted by the feet
of grazing cows. Similar ledges were observed by the same friend
on our Chalk downs, and on an old talus of chalk-fragments (thrown
out of a quarry) which had become clothed with turf.
My son Francis examined a Chalk escarpment near Lewes; and here on
a part which was very steep, sloping at 40 degrees with the
horizon, about 30 flat ledges extended horizontally for more than
100 yards, at an average distance of about 20 inches, one beneath
the other. They were from 9 to 10 inches in breadth. When viewed
from a distance they presented a striking appearance, owing to
their parallelism; but when examined closely, they were seen to be
somewhat sinuous, and one often ran into another, giving the
appearance of the ledge having forked into two. They are formed of
light-coloured earth, which on the outside, where thickest, was in
one case 9 inches, and in another case between 6 and 7 inches in
thickness. Above the ledges, the thickness of the earth over the
chalk was in the former case 4 and in the latter only 3 inches.
The grass grew more vigorously on the outer edges of the ledges
than on any other part of the slope, and here formed a tufted
fringe.
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