Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1842-02-28
AIISCELLANY v.
G E o L o G Y
PROFESSOR sIILIMAN'S FIRST LECTURE

PROFESSOR SITLIMANS FIRST LECTURE
Reported for the New York Tribune.
Prof. Sillimun commenced his Lecture by al
ludng to the peculiarly interesting character of
the subject Of Geology, and TO the extreme diff
Gully OF presenting in the compass oftwo lectures
INV thing like an Ineligible statement of liz prin-
cipu facts, and the process by which they ARE es-
tablished. The beautiful orb on which we dwell
belongs, as every one knows, to the Solar System;
and it is the business of Astronomy 10 point out
the characters and relations Of the other bodies
of this system We are now concerned however
solely with our own planet, and thus in many inn
portant particulars the science OF Geology is much
more interesting than Astronomy; for the results
presented by the latter, although far more magnl-
fcent and imposing than those of any other de-
parment of human enquiry, yet depend wholly
on the evidence of single sense, that of sight /;
and even this is not available until we add 10 it
the aid of Mathematics and Geometry. The
suits OF Astronomy, moreover directly contradict
the evidence of the senses. The Sun does not re-
volve around the Earth eyes tell us it does,
nor do the stars that sparkle in the heavens roll
around our planet as they appear to do.
The object of the Science to which ! invite
your attention is simply to ascertain the structure
of the planet which we had our birth, the scene
on which our actions are performed, from the
dawn of being in which at the night OF life we
shall I've entonbed, and from which we hope to
arise IN uuOllet uilu DtlteT w Ieu We IOON
over its surface we find projecting from it lofty
clilfs--along the ribbed sides of mountains we
behold solid strata of rock shooting forth, and far
inland we find cliffs which we know have in form
err ages lwelt alongside the sea- / he rocky beds
Of which the Earth is composed do not lie lIorl-
zontally in every case stratum that in one place
may be hundreds of miles beneath the surface, at
another may creep out above it and thus the trav
eler though he has no knowledge OF the internal
structure Of the Earth, as he crosses these projec
ting strata, may read as in book the nature and
position Of the rocks below. Thus the means Of
geological investigation are by no means rs scanty
as they are generally supposed 10 he. But the
facts have stated do not contribute by any means
the sole, indeed, the greatest aid in thesetnqur-
ies The internal fires of the Earth, which were
kindled when the planet was born, which nave
burned ever since IRE burning now, and will con-
iinue to burn until The end, by the matter they
throw up from the deep ubyss,gve us some knowl-
edge of the nature of our planet and though no
man can say that he is perfectly acquainted with
the chemical and mechanical properties OF lis IN :
most contents, still have fair representation oil
their character. BY these various means il is be
lieved that we have arrived at toIerably accurate
knowledge of the Earth for a depth of al least ten
mies-which is at least twenty times the depth 10
which any mines have penetrated That may
acquire 10 some extent, your implicit confidence
in what shall advance without which no prog
ress can be made, may say that no science has OF
late been cultivated with more zeal aud unring
industry, or by higher class of intellect than Ge-
ology.
We behold upon the surface of the Earth vari
GUS astonishing phenomena inland sea cliff, &c.
as have already mentioned. The question of
course arises slow came they there what are
the causes Of these phenomena? 1t may occur
that the answer God made them thus is sufh
cent bnt it is not, Tor it is not true. There is
not cubic foot OF our EARTH that is now precise.
4 Il la thnt has pt h.pn puh,
over and over again. Mighty powers are inces-
sanity ut work transforming by their own laws the
structure aud condition of our planet Here as
elsewhere it las pleased the Great Creator 10 cal
these substances into being, and TO establish GER
tain laws to whose dominion they are left These
continue ever the same they are now MS at the
dawn of their being and as they will be at the enc
Of all things. They never change; and from The
time the first bright star twnked in the blue firm
ament to the last syllable of recorded time the
operation is The same.
Two great agents are continually at work upor
our globe fire and water the former including al
substances which fire can melt and the latter al
that water can dissolve. These two involve al
the agencies ut work upon the Earth and to thes'
may all others be attributed Let us look first a
the gneous agencies. There is no one presen
who has not heard Of volcanoes. We have III
deed general knowledge of only iew-snch "A
are found in countries which are much visited, a
Vesnvius Ktna, &C.. aud these are to be regard
ed only specimens of ihe whole. or thes
magnificent valves, these breathing holes for tn
in-dWelliug fires Of the Earth, exist in an activ
state OF least The number OF three hundred tho
il must be borne in mind that we include in the lie
of active or erup!iye volcanoes oil those OF who's
eruptions history or tradition gives us any accoun
for if by history we know they once have bee
active we have every reason to believe they will b
again, though long ages may intervene. oh
serve that Mr.. Lyell, n distinguished English &c
ologst, now in this country, reduces their numbe
to one hundred hut he includes in this humble
only those which are now really in action. a
their geograp hical position can only give hast
glance; and first all along The Western side q
this continent from Bherlng's Straits TO Cape llor
we have vast line Of volcanoes extending thrC
Mexico Central America, Peru, Chill, and Pata
gonia. We often read OF their terrible eruplion
OF the cities swallowed up and the vast desrut
ton of life and possessions caused by their agef
cy and we pass them by without the sllghle
thought of their real relation to our own comic
and well being. We little dream how much W
owe TO their agency, nor does it once occur to I
that were these vents sealed as they will he by
and bye, by the sulid masses falling into the
mouths, the seat of the volcanic fire must then i
transferred to our side of the Continent nor ca
we hope TO parry off this result.
If we look at the Pacific Ocean find 1t a
dotted over with volcanic islands. In the Islam
Of Owyhee is one of the most remarkable in ,f
world. There is no mountain there; hut an in
mense gulf yawns from the surface. The ira
eller approaches, descends little, then comes
a plane-descends again, and arrives at anoth
plane; where the gaping gulf-sevsn m'lesn CT