Las Vegas daily optic. [volume] (Las Vegas, N.M.) 1880-1908, 1907-02-23

Probably mo one whO has looked
down OF the falls of the Niagara
river and the gFand canyon they have
carved for ahemsaltes put Ut the
sold rock but rs felt his brain up.
pressed with tho idea Of eternity and
the p.shenslaHty Of II. We
come and look. - 30 away. and We
rome again after many years, and
the stmpeRd0us rush of water In stiil
going on. has been going on, during
all our absence. vas going on long
before We FIRST came. will 20 on after
We have ceased 10 be. And with NH
the apparent anehangeabieness OF
the phenomenon which excites our
wonder. the cataract itself IL the nj.
most embodiment Of constant change
and motion. III In a thought that will
BE- driven home TO those who may
read the recent pamphlet Of Mr.. G. X.
Gilbert OF the United States Geologi.
cal Survey. concerning the rate Of re-
cessiom Of Niagara Fails. Not only
does he tell us that the great falls
are not what they have been within
the memory Of man, and show us pic.
lures and maps TO prove that their
outline has changed. but he gets out
his tape line and measures. the dis.
lance that they have receded within
certain years.
The erosivc work of the cataract OF
Niagara, he says. Ia exceptionally
rapid. This depends primarily on the
great power Of the falling water. but
partly on the character Of the local
geological structure. The recession of
the American Fall II much slower
than that Of Horseshoe Fall. The
sheet of water on It's brink is compar.
atively thin, and tho force the water
acquires I'm falling 10 not sufficient 10
remove the larger Of the limestone
blocks broken from the ledge above.
The blocks are therefore heaped at
the base of the ciif and serve az a
natural riprap TO protect the shale
against wear. The rate Of recession
of the Horseshoe Fall IL desired by
biologists In connection with estim'
ates of the age of the river. The rate
Of recession of the American Fall Il
OF interest 10 biologists because some
what representative OF the rivers &C
tivity I'm gorge mailing. when the
volume OF water was much less.
The data for computing the rate
OF recession of Niagara Falls include
surveys Of the crest line made In
Is4a, 1875, 1856, 1890. and 1896. ant
c~amera-lucida sketches made In 1897
During the period covered by thes'
data the rate Of recession has no
Uttered TO an important extent from
the natural conditions. The presen
and prospective diversions OF waite
for economic uses interfere with tn
course OF nature and may be expected
10 modify the rate or recession.
The rate OF recession Of the Horse
shoe Fall. or the rate OF lengthenini
of the Niagara gorge. during the sixty
three years from 1912 to 1906 Is foun'
to be 6 feet per annum. with an nm
certainty OF / foot. For the thirty
three years from 1912 to 1875 tn
rate was apparently slower than 70
the thirty years from 1875 to 1905
The rate of recession Of the American
Fall during the seventy-eight year.
from 1927 TO 1906 was less than
inches per mum.
The time consumed In the recession
of the falls from the escarpment a
Lewiston to their present position
or the age Of the river. Is not her,
estimated. IL a not properly b.
computed without aking account o
all conditions, local and temporary
affecting the rate OF recession, ant
some of those conditions have variet
greatly from point to point and from
time 10 time.
Mr.. Gilbert's report Is published q.
Bulletin No. 3os of the Geological
Survey. It Is accompanied by a re
port on the survey of the crest. line
OF Niagara Falls by Mr.. W. Carve
Hall. who made the survey In June
1906. Tn ework was done under O
plan of cooperation between the Sur
vey and Mr.. Henry A. Van Alstyne.
state engineer Of New York. Mr.,
Hall adds two tables to his report.
one showing the artificial monuments
and other permanent reference points
connected with the triangulation of
the surveys, the other the. distance
between permanent reference points,