The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1856-1888, 1883-01-27
Professor C. Il. Hitchcocks's Lecture on
Niagara Falls"

lecture at the Lyceun1, his subject being
Niagara Falls. This was the first of a
series of lectures relating to geology. The
object of this lecture Was to give a definition
of the science of geology. The subject was
treated in an able manner, and by the kind
courtesy of the lecturer we are enabled to
lay before our readers the following
synopsis:
The Niagara River is only So miles long, con-
Meeting Lakes Erie and Ontario along the bound
AIRY between the United States and Canada. It
is of enormou5dimensions, however, 100. 600, 900
tons of water pour over the precipice every hour,
to the average depth of 100 feet above the sur
face of the stream beneath, to the bottom of the
river it may be as much more. Looking down
upon it as from a balloon, we can see the whole
course of the stream, with its rapids, Whirlpool
and quiet flow. By so doing, as Is shown in the
diagram, we find the country to be an elevated
plateau, nearly 600 feet above the ocean. The
edge of the plateau is the highest portion of it.
as it slopes southeriy- l will present a few
figures for convenience OF description.
From Lake Erie, above, near Buffalo, lit is 22H
miles to the Falls.
Length of the gorge or canon below the Falls
to Lewiston, it is Z miles.
From Lewiston to Lake Ontario, it is go
miles. Total SO miles.
Elevation of Lake Erie. 573 feet above the
ocean.
From the Lake to the Rapids-l3 feet descent
Rapids (4-mile long, 81 -
Cataract 1854 ;,
Descent in the gorge 100 ,
Lake Ontario is 245 feet above the ocean and
1913 feet below Lake Erie.
The Fall is divided by Goat Island, giving
what is called the American Fall upon the east,
1900 feet wide and l64 feet deep, and the
Canadian or Horseshoe Fall, 2400 feet wide and
15S feet deep.
The river is 3 miles wide, at 21l miles above
the Falls, and 400 feet at the Whirlpool, mid
way in the gorge. The river has therefore been
gaming in width from the mouth of the gorge
to the Falls.
The edge of the plateau has been called the
niagara e~scarpment. 1t is a precipice facing
Lake Ontario, and may be traced as much as
200 miles through New York and Canada.
The rocks composing it are finely shown in
the gorge. The materials lie in their original
horizontal position where they were laid down
in the primeval oceaL-belngc composed partly
of beach sand, partly of mud and partly of
coral rock. Having been cut through by the
Niagara River, it will be easy for us to examine
their nature, upon either bank. Is these rocks
have a wide extension, they have been carefully
studied and we know their thickness entirely
through the gorge. and have collected the differ
emit sorts of corals and sea shells distributed
through them. 1t would be like studying the
beach and coral reef at Honolulu. Special
names have been given to the rocks as shown
upon the diagram.
They are the Niagara limestone at the top.
20 feet at the escarpment, increasing to l64 at
the Falls, of this quite a large part rises above
the river. Next is the Niagara shale, so feet
lnlCh. II A1oL a lHO NOA6A ASNAB ~ -
marine Maud, and others are the only rocks ex-
posed at the Falls. Below,i in the cliff, we notice
the Clinton shale, 20 feet thick, and the Medina
red sandstone, $50 feet thlck-maklng q total OF
675 feet at the cliff.
In proceeding from Lake Ontario to Lake
Erie other.groups are seen above the falls, as
shown upon the diagram-the whole in their
order from below. upwards being as follows
Medina sandstone, Clinton shale, Niagara shale
= ,sz.Hnes Salt group, Heidelberg limestone.
,sE-JoH THE GORGE
Now we can nlT nnderstana Hv vbSS5 has Aeen done
st Niagara. With n plateau inclined to the SoSs-
it is clear, there must have been at first a lake
behind it. The waters from the various rivers
in Pennsylvania, HOhio, Indiana and Canada
would fill up the basin to its very edge. At
Lewiston there would seem to be a slight de-
preston where the water would begin to dis
charge-and here the Niagara began to run.
Presently the rock would disappear and the
gorge begin to be eXcavated, then commenced
the gradual falling of the water over the cliff,
pounding, hammering the rocks below and
washing out the pulverized material into the
lower lake. The common opinion is that the
falls had an existence as distinct as to-day when
the wearing action commenced, and that the
cataract has gradually cut its way back for
several miles at the rate of one foot annually,
thus requiring a period OF about 80, 900 years
for it's accomplishment. AS fast as the falls
receded the great lake would become drained
for the cliff is $50 feet high while the present
cataract only $50. 1t seems q very simple mat
ter to accept this general conclusion-but there
are several facts going to show a great many
steps in this progress. First, we have to con-
slider that the existence of a cataract in q canon
is an exception to the usual method of erosion.
You have heard of the immense canons of the
western United States-of hundreds of miles of
gorges, but no cataracts like Niagara. The
descent is greater and yet Niagara has hardly its
g double " PIN any part of the world. A river
will naturally wear a uniform channel in a
plateau country. If the rock varies in char
acter then the gorge will wear faster in the soft
places. If the softer rock is found l at the lower
part of the river there may be a cataract where
the hard rock joins it. That is the case at the
present Niagara. The everything limestone is
quitefhard and the shale beneath is very soft,
and the rate of excavation of the top just bal
ances the pounding of the soft shale beneath,
and thus the recession is uniform at present.
Now on recurring to our diagrams We can see
where variations might have existed. The bot
tom rocks at Lewiston are much harder than
those above. The Niagara shale and limestone
are found at the top just as now at the falls.
Hence q cataract might follow these two layers
back at nearly constant rate. But the two lower
layers are of unequal hardness, the lowest being
the most unyielding. Hence there may have
been three different cataracts in early times,
cutting back at unequal rates of speed. The
first would be in the upper shale and limestone,
the second in the Clinton shale, and the third in
the hard red sandstone. In the Genesee river,
runs parallel to the Niagara several miles
to the east, over the same rocks there are three
corresponding falls. Now as these rocks all
GILL SOutAGIINJ II idyCIo presently
pass below the line of erosion, and hence the
lower falls will disappear after a while,
leaving only the upper cataract, and we can
know of their existence only by the process of
employed above.
Another popularity is shown by the existence
of the Whirlpool. The river changes it's course
abruptly at this point, and it is very much mar
rover below. The water is very swift, and any
floating object may rush with railroad speed
around it for days before passing out below.
The residents fear the Whirlpool as much as
they do the rapids, and will not venture so much
as to put hand or foot into the water at either
locality for fear of being drawn in.
On sorutinizing the walls OF the Whirlpool We
a part of it composed of sand and gravel.
and on looking further discover the outlines of
an ancient gorge filled up with earth running to
stand this ancient gorge corresponds in width
the wider part of the ebasm above the
Whirlpool. Here is an additional fact in the his
tory Of Niagara, and it indicates the former dis
- IL - = no-slE. o. r. -