The Texas Republican. [volume] (Marshall, Tex.) 1849-1869, 1850-08-10

.. EDlros:
The power OF water, charged with for
IN matter, to excavate rocks, will mostly
ecupy this lecture.
Il is astonishing with wha, rapidi'y earth
I'd even hard rocks are excavaled by
nall streams Central France presents MS
hth many illustrations Of the excayat!ng
pxer Of water, where the channels OF
xer, have been barred up by solid currents
lava, through which the streams have
.excavatcd a passage from twenty 10 sew.
n,y five feet, and of great width We
kould bring forward many OF these Illus
L.tions, but perhaps your readers would
refer those nearer home
The Falls of the Niagara afford one Of
he most perfect examples of this. That
.rr flows from lake Erie to Ontario the
A,mer lake being three hundred and thirty
%, above the latter aud the distance be.
~een them being only thiuy.two miles,
living considerable descent On flowing
~, Of the upper lake the river is almos, on
level with It's banks so tina, ii it should
~ egh, or ten feet it would 'nnndate the
kd,accnt flat country of | PIPER Canada on
/, west, and of the State of New York on
10 east. The river where it issues is about
hree quarters of a mile in width. Before
pachipg the falls, it is propelled with grca,
apidity, being one nils broad. about TWEEN
I. five feet deep, and having a descent of
nv fee, in half a mile An island at the
Acrye of the catalact divides il into two
1heets Of water. One Of these, called the
Horse. Shoe Fall, is six hundred yards wide
and one hundred aud iiity.cght feet perpen.
Aicular; the other. called the American
Falls, is abou, two hundred yards in width
Ind one hundred and sixty four fee, high,
This great sheet Of water is preciptated
hycr ledge of hard limestone, horizontal.
N below which is soft shall of somewhat
krester thickness, which decays and crum.
kIes away more rapidly. so tina, the cal.
rocks form an overhanging msss
projecting forty feet or more above the hol.
p~ space below. This hollow shall is
oasly worn Off by the spray. so that there
n formed underneath the lime stone large
arch. The river below the Fall, runs
through narrow channel with its sides
Perpendicular, the bed and sides of lime.
Stone rock, giving evidence that the water
Aas worn this channel through the strata OF
tock, and that the Falls were once as low
hown AS Queenstown. As another evil
hence of this fact, the table land which
6lopes insensibly from the present location
bf the Falls to Queenstown, at this point
ZONES to Sudden termination, at this
boint also there is n considerable ot fall
Fhc same species Of rock extends from
Queenstown 10 the upper lake. W hen We
kyaune the sides OF the rirer, we find that
lhev give evidence of being excayatcd by
Abe action OF running water The concu.
eion is. then tha, the Niagara Falls were
bncc at Queenstown, seven miles below
Aher present location The geological
formation OF the country from Queenstown
j. lake Erie. The upper deposit is fresh
al.
b. fragments OF lime stone, and other trans
h,orted rocks. with few feet Of fine clay
below. The next strata undo, the above
formation is hard ime.s,onc rock about
hine,y feet thick. stretching nearly in a hor.
ilouial direction over the whole country,
and forming the bed of the river about the
Falls The recession Of the Falls is calcu.
lated 10 be fifty yards in forty years and
hence, il such be true, it would have re,
CURED ten thousand years in the cxca.
<aticn from Queenstown to their present
point But there is no certainty about this.
a. different causes from the present might
have carried them much more rapidly.
We nigh, give many more examples OF
fhe excavatiug power of running waier'
,u, we think this sufficient to prepare us for
Further investigation OF the subject In
|Dur next we shall branch out upon some of
the formations aud changes OF the Missls'
sippi and the river Po.
EORiO\.