from below being spent
and [relieved?] in eruptions. On this view, I do not consider these
so-called craters of elevation as formed by the ejection of ashes,
lava, etc., etc., but by a peculiar kind of elevation acting round and
modified by a volcanic orifice. I wish I had left it all out; I trust
that there are in other parts of the volume more facts and less theory.
The more I reflect on volcanoes, the more I appreciate the importance
of E. de Beaumont's measurements (480/3. Elie de Beaumont's views are
discussed by Sir Charles Lyell both in the "Principles of Geology"
(Edition X., 1867, Volume I. pages 633 et seq.) and in the "Elements
of Geology" (Edition III., 1878, pages 495, 496). See also Darwin's
"Geological Observations," Edition II., 1876, page 107.) (even if
one does not believe them implicitly) of the natural inclination of
lava-streams, and even more the importance of his view of the dikes,
or unfilled fissures, in every volcanic mountain, being the proofs
and measures of the stretching and consequent elevation which all
such mountains must have undergone. I believe he thus unintentionally
explains most of his cases of lava-streams being inclined at a greater
angle than that at which they could have flowed.

But excuse this lengthy note, and once more let me thank you for the
pleasure and encouragement you have given me--which, together with
Lyell's never-failing kindness, will help me on with South America, and,
as my books will not sell, I sometimes want such aid. I have been lately
reading with care A. d'Orbigny's work on South America (480/4. "Voyage
dans l'Amerique Meridionale--execute pendant les annees 1826-33": six
volumes, Paris, 1835-43.), and I cannot say how forcibly impressed I am
with the infinite superiority of the Lyellian school of Geology over
the continental. I always feel as if my books came half out of Lyell's
brain, and that I never acknowledge this sufficiently; nor do I know how
I can without saying so in so many words--for I have always thought that
the great merit of the "Principles" was that it altered the whole tone
of one's mind, and therefore that, when seeing a thing never seen by
Lyell, one yet saw it partially through his eyes--it would have been in
some respects better if I had done this less: but again excuse my long,
and perhaps you will think presumptuous, discussion. Enclosed is a note
from Emma to Mrs. Horner, to beg you, if you can, to give us the great
pleasure of s