))
is certainly an instance of the cleavage-laminae of a hornblendic schist
dipping inwards on both sides, for I examined this hill carefully
with compass in hand and notebook. I entirely admit, however, that a
conclusion drawn from striking a rough balance in one's mind is worth
nothing compared with the evidence drawn from one continuous line of
section. I read Studer's paper carefully, and drew the conclusion stated
from it; but I may very likely be in an error. I only state that I have
frequently seen cleavage-laminae dipping inwards on mountain sides;
that I cannot give up, but I daresay a general extension of the rule (as
might justly be inferred from the manner of my statement) would be quite
erroneous. Von Buch's statement is in his "Travels in Norway" (537/3.
"Travels through Norway and Lapland during the years 1806-8": London,
1813.); I have unfortunately lost the reference, and it is a high crime,
I confess, even to refer to an opinion without a precise reference. If
you never read these travels they might be worth skimming, chiefly as an
amusement; and if you like and will send me a line by the general
post of Monday or Tuesday, I will either send it up with Hopkins on
Wednesday, or bring it myself to the Geological Society. I am very glad
you are going to read Hopkins (537/4. "Researches in Physical Geology,"
by W. Hopkins. "Phil. Trans. R. Soc." 1839, page 381; ibid, 1842, page
43, etc.); his views appear to me eminently worth well comprehending;
false views and language appear to me to be almost universally held by
geologists on the formation of fissures, dikes and mountain chains. If
you would have the patience, I should be glad if you would read in my
"Volcanic Islands" from page 65, or even pages 54 to 72--viz., on
the lamination of volcanic rocks; I may add that I sent the series
of specimens there described to Professor Forbes of Edinburgh, and he
thought they bore out my views.

There is a short extract from Prof. Rogers (537/5. "On Cleavage of
Slate-strata." "Edinburgh New Phil. Journ." Volume XLI., page 422,
1846.) in the last "Edinburgh New Phil. Journal," well worth your
attention, on the cleavage of the Appalachian chain, and which seems far
more uniform in the direction of dip than in any case which I have met
with; the Rogers doctrine of the ridge being thrown up by great waves
I believe is monstrous; but the manner in which the ridges have been
thrown over (as if by a lateral force acting on