, 1888-12-26

edge on October 4, 1872, and he admits
that thiss starting point can vary from four
to twenty feet with the rise aud fall of the
water below the Falls. He gave the
width of the American Fall as GOO feet
and that of the Horseshoe Fall as 1900
feet.
The Lake survey went over the ground
again in 1875, and in these thirty-three
years the southernmost point of the
Horseshoe Fall had receded 100 feet,
while in the brink of the American Fall
differences of forty feet were apparent.
When the American Association for the
Advancement Of Science met here in 1886
the section of geology decided to make Mia
CARA the problem of the session, and for
that purpose Professor Woodward, of
Washington, and some of his assistants
surveyed the brink Of the falls again.
They found an average recession for the
whole face of the Falls of about two. and
One-half feet per annum, but as the cen
trail parts of the curve, where the water
is deepest, retreated faster than the edges,
the SOuthernmOst point of the Horseshoe
Fall was found TO have travelled south
alb out 200 feet since 1875 or about $50 feet
since 1912, nearly nine feet every year.
In view of such rapid changes it seems
highly probable that the older pictures of
the Fails, which always place the Horse
shoe Falls, considerably nearer than they
are today, are practically, or at least par
TALLY correct.
If the rate of retr0CcSSiOn remains dur
ing the next 800 years as it has been for
the last forty five years, the inner edge Of
the Horseshoe Fall will have passed to
the east of Goat Island, and as the line of
deeptSt water is near the Canadian shore
all the waters Of the river will pass over
the Horseshoe Fall, Obliterating the
American Fall entirely and transforming
Goat Island into a peninsula, on which the
smaller islands of today, Bath, Luna, Cha
pin, etc, will appear as little hilltops.
The fall will then, perhaps, be higher
than to-day because the present descent of
fly feet over the rapids will be added to
the height Of the cataract, minus the num-
her of feet needed to give the necessary
current to the river below, which at present
is fifteen feet to the mile. Considering
that even now the Horseshoe Fall no long
or recedeS south but more east than south,
which recession will be more easily yet in
the course of time, it will have to travel
about five miles IN that direction before the
Niagara shale, which now occupies the
lower half Of the face of the Fail, is under
water and the retT0CeSSiOn .by means Of
undermining is stopped. For at the pre-
sent the changes that take place are due to
the fact that the upper eighty feet of the
face is formed of a hard limestone, while
the lower eighty feet is composed of soft
easily crumOled Shlle, which the spray
can wash away with ease to such an eX,
tent that the everything limestones lose
their support, break off and tumble down
with a corresponding change in the APP
pearance of the edge of the Falls. Then
the changes will be accomplished simply
by the erOding power of the water and the
Falls will remain near the northern end Of
Grand Island for a practically unlimited
time. We thus see that after the Falls Of
to-day nave receded, perhaps three,Quar-
of Il mile, there will be only one Fall
when that one Fall has travelled east and
south four miles more and reaches Grand
Island, it will again be divided into an
American, and a Canadian cataract, this
separated by Grand Island, and, like the
Falls of to-day, the western branch will
carry the largest amount Of water, will
recede faster and be the lower of the two
in height. The hope of finally having the
Falls at Buffalo must be abandoned, for
from that point of Grand Island to the city
of Buffalo only rapids can exist on account
of the nature of the underlying rock, which
is soft.
AS the retrOcession of the Falls of Mia.
CARA began in what NAV be called. pnolO.