Memphis daily appeal. [volume] (Memphis, Tenn.) 1847-1886, 1867-02-20
80 - u -. .l..aaN.
Lecture Of Professor AGassIz al fise
Cooper institute.


h The first Of the course of lectures by
Professor AGAssTz at the Cooper Insti
tute, New York, before the association
4 for the advancement of science, wa,
given Tuesday evening the l2th inst
- Tie audience was large, select, and in
!. teIecuaI. many OF the best known citi-
zels being among the audience. The
- su lieet for the evening was, Tile Geo.
logical Formation Of the Valley Of the
l Amazon
!. Professor AgAssTz was introduced by
E the chairman of the association, and he
b spoke as follows:
= Ladies and Gentlemen This year viii
witness an event Of no small Importance
. iu reference % the progress of commerce
b ana civilization. It has pleased the en-
pe'0r of Brazil 10 decree that the valley
Of the Amazon shall be opened to The
commerce Of the world on the 9TH Of
September next a day memorable in
Brazil, as it is their Fourth Of July. This
: fact has suggested some lectures upon
that valley, that our community may
become acquainted with its physical fea-
/ lures and with its natural products, so
/ that those who care may be prepared TO
avail themselves Of the advantages
which hencef0rth will be particularly
uuIs. in reference to the navigation of
that inland sen. To-day I shall sketch
the geographical constitution of that re
giOn, and in my next lecture enter more
fully upon an exposition OF The climate
and character Of the river and its
tributaries, its banks, and its capacities
r. a. .
other inequalities of the surface Of the
earth, the valley Of the Amazon owes
its present appearance to a Succession Of
events which have taken place at long
intervals-st those successive geological
periods which have made our earth what
10 Is now. In order, therefore, tu under
stand the few facts ] have. been able to
collect In a short SURVEYS that extern
-ive tract Of land, it Is necessary that !
should recall "A few principles bearing
upon the appreciation OF the geological
constitution Of any country. L wish ]
could dispense with this accessory part
of my subject, bat, unfortunately, geo.
I .ugy Is NOT yet part of our elementary
! education. ] c * not even always part
of an advanced education, and yet, as "a
sci snce. it has made such progress that
its fundamental principles should be un-
deIstOOd by ali, just as all understand
certain elementary facts concerning
4 every branch of human knowledge.
have lust said that the physical
| features of any country, as far
[ as determined by tine geological Cunsttu-
/ lion of zuch lands are owing 10 a success
I sion OF events which have taken place at
] long intervals. 30 part g.! OCT globe has
I assumed lis present appearance at once
/ bv "A sudden feat j, has grown to be
/ what IL Is. There is no point of Our sea- .
shore which does not owe its cOnfigura-
/ tion tD lle gearing action of the waves.
/ There is no inequality au de --r.ace of
] tho earth which does not owe ils outline
/ to the disiutegFatiou OF that suriucc
I during ages, and SO There is mo- extensive .
/ trscl of land which does not owe it's pc
( cU.iar c0u-tiiGtian 90 those geological
( agents whicbahaye framed the z'one, and
I iH the course OF time made i. sUCCessIvely .
villa. it has been at different periods .
/ st one Gme bali If igueous ma F..
I terials, without even an Amos
phcre' or drop uf water on its
surface nj a later time, q BAH of ma
teiials IN a state of igueous fusion then
with a tAiu sond crust at the surface; at
"A later time, that crust thicker-So thick .
I that FapUr could Condense on i,s surface
and form the lgSt ocean and then II F.
was an obl0ng sea sending back TO the .
atmosphere constantly the waters which .
10 lad condensed then it cooled, and, IN .
the process Of cooling, more cOndensa-
tiCn look glace. and that water being
now attracted by the moon, usgan to
move iU regular ebD and low, and SO
began Ja wear upon the consolidated sur
face anl 10 carry OF materials which .
we're deposited at some distances TO form
new beds. When this statEiiied crust
hod been added 10 "a solid nucleus owing
its existence % the cooling OF melted
materials, then by the agencies Of heat .'
and waller. Or rather fire and wafer the
crust OF our earth h4s gruWn ln thickness,
and finally has become so thick that shut
out from the effect Of the internal
neat, the surface has become iuHab!iable.
From that time il has been inhabited,
first 10y aquatic animals, and then
through z succession of changes these
iiIst-bOrn nEge been modified, new ones
have come in ana others haze qied ana
the process Of cooling mas modified the
cCuiguTatiOn OF the surface, and On this
process gradually came, first, islands
iErD extensive tracts Of land, then con-
tl0euts have risan gh9re the sea. Then
these lands have become modified by
turlher upheavals aud 10y further changes
until in the course Of time the earth has
II-l'Nll4E llt u Is INV iatltA AreN'ilIlN
Inhabited by the animals and plants
Ahich exist on iis surface. Now, this
rapid sketch concerning the changes
" hirh oar gluDs aae undergone will
enable me tD explain more uilg the man
uer in which TIE valley of the Amazon
has been made. i,DoE Bt ibis map
pointing iO q map of south America
hung in sight OF the audienceJ one
moment May / ask you for yOur
saue3 To a gentleman on the pat
Orm. The cane was used 10 point
I'D the different sections Of The map
=ferred fol. In this map Of South
america, which is one nf the beautiful
series made boy Prof GuEOJ in which
the physical features are distinctly re-
produced, you have al once an image OF
the physical condition ofSDuih America.
You see, at The backbone Of the eonti-
itenl along the Pacific ocean, the chain
of the Andes, rising in It's middle and
southern portions 10 o very great hight,
tO table lands ten, twelve, iogrteen
thousand feet and forming the wall Of
The continent against tGe Pacific. Then
guu have these high lands called the
Liable lands of Brazil, and these shore
lands, Or tIc table lands pf Guiana, and
between them you have these low lands
which are only Eve or eight hundred
feet above the level of the sea. The val
'eys Of the Amazon, the Paraguay, and
of the Guiana, communicate with each
other, making, a. IL were, three Islands,
Guiana Oh the one side, the tahle lands
pf Brazil on the other, and the chain Of
he Andes in another direction, con-
stitute the three great inequalities Of
hat continent. But these three Unequal
ties are Of q very different age. The
oldest part OF that continent is the table
and Of Guiana. ii is as old probably
as the northern portion Of our continent
North America compares In striking
manner with South America, both in
orm and geological constitution, and
ihall allude repeatedly 20 the physical
features OF our continent with view OF
giving more precise idea Of the cOnti-f
Ient Of South America, as } take it for
granted That the aspect of this continent
S more generally known. The next
oldest part Of the continent Is the table
and Of Brazil. The next is this. point
ng to the southern part Of South Amer
lca.) IL IS oi comparatively recent date,
and presently ] ski show you how
biologists have succeeded IN determin-
ing the relative age of different noun
tain chains. There was q time when
Guiana existed as an island; when
he table land OF Brazil existed
As an island but when the whole range
IF the Andes did not exist. The ocean
;0uld probably sweep between these
5wo islands, from the Atlantic TO the Pa
sific, just as we see that there was a time
when what constitutes now Canada. and
he whole extent Of land TO the north Of
.he great Canadian lakes, was large
island, stretching from Labrador in the
direction Of the Rocky mountains. and
when no other part Of the continent Of
North America existed. The geologists
who were charged by this government