shown that the apparent exceptions to the absence of erratic boulders
in certain countries, are due to erroneous observations; several
statements there given I have since found confirmed by various authors.
[17] Geographical Journal, 1830, pp. 65, 66.
[18] Richardson's Append. to Back's Exped., and Humboldt's Fragm.
Asiat., tom. ii. p. 386.
[19] Messrs. Dease and Simpson, in Geograph. Journ., vol. viii. pp. 218
and 220.
[20] Cuvier (Ossemens Fossiles, tom. i. p. 151), from Billing's Voyage.
[21] In the former edition and Appendix, I have given some facts on the
transportal of erratic boulders and icebergs in the Atlantic Ocean.
This subject has lately been treated excellently by Mr. Hayes, in the
Boston Journal (vol. iv. p. 426). The author does not appear aware of
a case published by me (Geographical Journal, vol. ix. p. 528) of a
gigantic boulder embedded in an iceberg in the Antarctic Ocean, almost
certainly one hundred miles distant from any land, and perhaps much
more distant. In the Appendix I have discussed at length the
probability (at that time hardly thought of) of icebergs, when
stranded, grooving and polishing rocks, like glaciers. This is now a
very commonly received opinion; and I cannot still avoid the suspicion
that it is applicable even to such cases as that of the Jura. Dr.
Richardson has assured me that the icebergs off North America push
before them pebbles and sand, and leave the submarine rocky flats quite
bare; it is hardly possible to doubt that such ledges must be polished
and scored in the direction of the set of the prevailing currents.
Since writing that Appendix, I have seen in North Wales (London Phil.
Mag., vol. xxi. p. 180) the adjoining action of glaciers and floating
icebergs.
CHAPTER XII
CENTRAL CHILE
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