The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1894-08-25

4
season the rise was certain to become more
rapid. Mr.. Holland estimates that thu
lake will overflow the top of the bar abou
the middle of this month";
A most interesting question is the effec
the water will have on the dam, and The
Government of the Northwestern Pro
vinces has already provided for recording
this effect BY means of instantaneous pho
tographs. When the lake fully breast:
the barrier it will overflow at point $3.50
feet above sea level. At first the stream is
quite certain to rapidly cut through the
mud and loose stones on top. Before long
however, it must reach the large blocks Of
dolomite that are buried at no great depth,
and then the rate of erosion will be vastly
reduced. All lakes are doomed to destruc-
ton, in the course of time, by the sitting
up of their beds and the deepening and
widening of their outlets, which, at last
viii carry off the water faster than it is
received, until the lake is drained This
fate will, of course, overtake the new Him
alayan lake, but, in the opinion of Mr..
Holland the destructive agents will operate
very slowly. The lake will endure for
many ages, though as time is counted in
geological epochs its period of life will be
very short. If rapid erosion is arrested
before channel 100 feet deep has been
cut through the top of the dam, there will
be left a lake about three and quarter
miles long and a mile wide, which is likely
to be practically unchanged for some
generations of human life.
This is no ordinary avalanche dam, and
there is no ground for the fears expressed
in India that the lake will burst the bar
rier and cause enormous destruction. All
the horizontal pressure the water can exert
is estimated at 1850 tons; and the weak
est section of the dam is at least twenty
three times as strong as it need be to
Withstand all the pressure that the water
can bring against it. 1t is quite certain
that some of the other hills will, sooner or
later, slip into the lake, but even this ca
tastrophe would not seriously menace either
the existence of the lake or the hamlets in
the valley below it. A slip of 12,5O0,0OO
cubic feet would be the maximum posi-
bility, and this would raise the surface of
the lake only seven inches.
So the new lake has come to stay for
ages-all the result of the fact that when
this mighty hill was thrust into the air
by the crumpling of the earth's surface,
the big beds of limestone were steeply
tilted from their horizontal position, and
there was only needed loosening of the
strata by water, changes of temperature,
and other natural causes, and little un-
dermining at the foot of the hill, to send
the big beds of rock laundering into the
valley below. Such work as this is going
on all the while throughout the Himalayas
Conway Godwin-Austen and other travel
lers tell of being kept awake at night by
the din of ROCKS dropping over precipices
or bounding down the slopes. On some
Of the glaciers the ice is hidden from view
by the masses of rock that have fallen from
above. Everywhere the dwelling process
is going on. The debris all came from
above, and the lowliest rock in the bed of
mountain torrent may once have been
the pinnacle of needle overlooking, far
and wide, the mighty realm of Snow
There is evidence that some of the Him.
alayan valleys have been filled, for thou
sands of feet, by The rocks and mud streams
that have come from on high. In the
course of time the Himalayas will be worn
down, as our Appalaehiars have been, by
the denuding forces. Then their heights
will be far less than now; their tops will
be rounded, instead of rising in jagged
peaks, their slopes and outlines will be
gentler, and the thunder of landslides and
avalanches will be seldom or never heard,
for the material that might most easily be
detached from the mass will all have tum-
bled down the mountain sides to help fill
up the valleys.