convinced that this was not the sole cause of their formation. Sir J.
Hooker saw such ledges on the Himalayan and Atlas ranges, where there
were no domesticated animals and not many wild ones; but these latter
would, it is probable, use the ledges at night while grazing like our
domesticated animals. 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 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. Their middle part was
bare, but whether this had been caused by the trampling of sheep, which
sometimes frequent the ledges, my son could not ascertain. Nor could he
feel sure how much of the earth on the middle and bare parts, consisted
of disintegrated worm-castings which had rolled down from above; but he
felt convinced that some had thus originated; and it was manifest that
the ledges with their grass-fringed edges would arrest any small object
rolling down from above.
At one end or side of the bank bearing these ledges, the surface
consisted in parts of bare chalk, and here the ledges were very
irregular. At the other end of the bank, the slope suddenly became less
steep, and here the ledges ceased rather abruptly; but little embankments
only a foot or two in length were still present. The slope became
steeper lower down the hill, and the regular ledges then reappeared.
Another of my sons observed, on the inland side of Beachy Head, where the
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