ons.

Pray give my best thanks to Lady Lyell for her translation, which was as
clear as daylight to me, including "leglessness."

LETTER 486. TO C. LYELL.

Down [November 20th, 1849].

I remembered the passage in E. de B. [Elie de Beaumont] and have now
re-read it. I have always and do still entirely disbelieve it; in such a
wonderful case he ought to have hammered every inch of rock up to actual
junction; he describes no details of junction, and if I were in your
place I would absolutely dispute the fact of junction (or articulation
as he oddly calls it) on such evidence. I go farther than you; I do not
believe in the world there is or has been a junction between a dike and
stream of lava of exact shape of either (1) or (2) Figure 2].

(Figures 2, 3 and 4.)

If dike gave immediate origin to volcanic vent we should have craters of
[an] elliptic shape [Figure 3]. I believe that when the molten rock in a
dike comes near to the surface, some one two or three points will
always certainly chance to afford an easier passage upward to the actual
surface than along the whole line, and therefore that the dike will be
connected (if the whole were bared and dissected) with the vent by a
column or cone (see my elegant drawing) of lava [Figure 4]. I do not
doubt that the dikes are thus indirectly connected with eruptive vents.
E. de B. seems to have observed many of his T; now without he supposes
the whole line of fissure or dike to have poured out lava (which
implies, as above remarked, craters of an elliptic or almost linear
shape) on both sides, how extraordinarily improbable it is, that there
should have been in a single line of section so many intersections of
points eruption; he must, I think, make his orifices of eruption almost
linear or, if not so, astonishingly numerous. One must refer to what one
has seen oneself: do pray, when you go home, look at the section of a
minute cone of eruption at the Galapagos, page 109 (486/1. "Geological
Observations on Volcanic Islands." London, 1890, page 238.), which is
the most perfect natural dissection of a crater which I have ever heard
of, and the drawing of which you may, I assure you, trust; here the
arching over of the streams as they were poured out over the lip of
the crater was evident, and are now thus seen united to the central
irregular column. Again, at St. Jago I saw some horizontal sections of
the bases of small craters, and the sources or feeders were circular. I