Memphis daily appeal. [volume] (Memphis, Tenn.) 1847-1886, 1867-02-22
THE GLACIERS.
Lecture ny Prof. AEaEsfE on she Ancien
Glaciers Of the Tropics

From the New York Irisune, l5
b A large and appreciative audience as
I, sem bIed last evening 10 listen to th'
third lecture Of Prof Agsssiz- The par
ticular subject selected for the lecture
y was "The Ancient Glaciers UndeE tht
~ Tropics - On coming forward the speaker
was received with applause. He theI
= said:
Ladies and Gentlemen: Under the
pressure Of materials crowdiug for pre-
sentatiOn at the close Of my last lecture
I omitted two statements which would
now supply. In the first place, I would
: saw to those who seek for relaxation and
pleasure in travel, that the valley Of the
: Amazon Is at present accessible once g
e month from New York in splendid
steamers, and from Para twice month
: for the whole length Of the Amazon,
with accommodations so comfortable
that our best river steamers have nothing
batter to offer. The other statement /
want to make, is for the benefit of those
who are looking for private commercial
relations with Brazil, and especially with
the valley of the Amazon, that all the
spices Of the east, the pepper, the Glove,
; the nutmeg, camphOr, aud the Ike, nave
been cultivated in the neighbOrhOod OF
Para. and might be cultivated to such
y
der skilltul management share the bene-
fit Of the commerce which is now eXclu-
siveIv in the hands Of European nations.
And now let me call your attention to
the subject Of this evenings lecture,
"The Ancient Glaciers under the
Tropics" And at first 1 would say a
few words upon the interest which at
taches to the study Of the glaciers. 1t is
not long since the study Of the glaciers
was an accident in the study Of physical
geography. They were mentioned as
curious accumulatIOns Of spOw formed on
the SUBMITS Of certain mountains, and
adding to the beauty Of the scenery; but
the influence of the glaciers then did not
60 beyond that which Is derived from
the picturesque beauty Of these masses Of
snow and ice. 1t is no dRnger so now.
The study OF their formation the study
Of the changes which they undergo !;
the. study OF the greater eXten-
sion and range which they have Occu-
MED in former times; the signs which
have been traced Of their presence in
/ countries where they are no longer to be
1 found. the further tracing Of their for
ruer presence very far from the regions
| where thev occur at present, have salts
fed geologists that our globe has under
gone changes Of temperature which were
not at all suspected before these lnvesu-
cations were made. And If L am not
mistaken, l shall be able today to prove
10 YOU that there was a time preceding
| Immediately the establishment OF the
state of things which prevails now upon
the surface of the globe, and follow
/ ing the last geological commissions,
which have made our earth what it is
now. during which the whole surface Of
the globe was covered by masses
OF Ice as thick, as extensive, as
| compact. as those which nOw-s-
davs are limited to the ArtiC regions
/ So that a period Of intense cold would
! have followed those hvpertropical periods
| in geological history which have pre-
/ ceded the coming OF man upon the earth.
/ And If this be so, you see that the study
| Of the glaciers may well deserve our at
I teutiOn. and that we're it only % test the
value Of the doctrine which l advance,
| you may perhaps feel inclined to give
me your bearing during this evening
/ Applause In order to be able 10 track
| the glaciers everywhere where they have
I been, and where they are no longer, it il
! necessary to become acquainted with the
signs which they leave where they have
/ been when they disappear; 10 become
/ familiar with the Indications OF their
! former presence. And this can only be
reached by a study Of the glaciers as
! they are now. l therefore call your at
/ teutiop. first, 10 the submits Of the Alps,
/ where | had the best opportunities Of
studying the glaciers Of our days, and
I then gradually invite YOU 70 travel over
/ those regions over which the glaciers
4 themselves have moved, and perhaps We
shall see that even where the tropical
sun Of 10 day shines, there was at one
I a. -. -as.r- 1e-..- It
valley Of the Amazon, extending toward
/ the Atlantic, and perhaps covering the
| sea to such an extent, th At the question
may be fairly asked, as il. is now asked
at the polar region, whether there was
open water under the equator So far,
DO I believe does the evidence go. SO
extensive, I am satisfied, have the
changes Of the temperature upon
the surface of the globe been. And
if this be so, you see al once how
this intense cold must have mOdi-
| fed the surface of the globe TO
| the extent Of excluding life
! from its surface-of interrupting
| the normal course Of the vital phenom-
eua, and preparing the surface Of the
earth for the new creation which now
exists upon It, attach great Importance,
/ in a philosophical point Of view, TO the
sAuAF Nl AA4lD aAF lA4s At-AsiA'N a. ~ liaAi
/ be demonstrated that such was once the
condition Of our earth, it will follow that
4 the doctrine of the tIaDsmutatiOu Of The
| species, and Of the descent Of the animals
/ that live bow, from those Of past days, is
/ cut at the root by this winter which put
an esd % all living beings on the surface
/ Of the globe. Applause. Now, what
| do we have? The accumulation of snow
/ aud ice gradually passing from more
snowy condition into q more icy cODdi-
/ ton, and descending from the nights
| where snow falls into the regions where
/ the ice and snow melt every summer
/ Such are the glaciers; and in their ap-
/ pearance they present UNUSUAL beauty.
The snow which accumuiates at
! certain nights above the level OF
the sea, or on the plain within Lhe Are
tics, melts only where the average tenn
perature Of the year Is above thirty-two
degrees. Where the average tempera-
ture remains below thirty-twO, the snow
may accumulate and where large
nIasses accumulate, the snow, il IL moves
/ from the place where il falls, msy be
| preserved even where the temperature is
above thiFty-tw0. This is what takes
place IN the Alps We have untortu-
nately no glacier region on the eastern
side Of this continent. There are glaciers
only in the Rocky mouutains, and on
the whole range OF high SUBMITS, which
extend from the Rocky mountains to the
southern extremity Of South America,
[ varying in hight according to the average
temperature Of the different levels.
Within the Arctic regions .he level at
/ which the snow remains perpetually
on the ground Is at the level
OF the sea. And this condition
Of things prevails on this continent, es-
pecially IN its eastern part, further TO the
south than 10 Europe and northwestern
/ Asia And from that level, which Is
about sixty degrees northern latitude in
Greenland, and about seventy or seventy
one degrees northern latitude in Europe,
the sn0gfails remain on the highlands at
higher and higher levels as you approach
nearer and nearer the tropics, 10 the eX-
tent that under the tropics, the land Of
perpetual snow rises TO II 900 feet while
ia the temperate regions, under latitude
Of fOrty-five degrees say, the hight at
which the snow remains permanently on
the ground Is about 6O00 feet above the
level Of the sea. Thag6 is the hight at
which the snow remains on the ground
throughout the year in the Alps of swift
zerland. And yet if you examine the
valleys OF tie Alps, you will find that
there is M uniformity 10 the level at
which snQw is permanent, nos al which
theg glaciers come down into the valleys, for
the obvious reasons tnRt the inequalities OF
the surface TO affect the local tempera-
ture, and in many localities, which are
a. much as eight or nine thousand feet
above the level Of the sea, warm winds
from the south may sweep in such a
manner as to melt away the winter
snow early in the summer; while in
! other regions, protected from the soften
vinds. and, on the contrary, open TO the
the cold influence OF northern winds, the
snow may remain permanently even
below tbe averaged leyel0f the perpetual
,,.,,, nd then. owing to the MOVING