El Paso herald. (El Paso, Tex.) 1901-1931, 1913-08-23

the Culebra cut alone. A million Gu
bic yards is equal to a solid block SOC
| feet square and 500 feet high. Such
/ a block would have base Of more
the height of a % or so story build
ing. Twenty such blocks would be
| more than mile high Talk about
the pyramid of Ghizeh! That is es-
timated to contain 100000 cubic
! yards Six or seven such pyramids
have slid down into the Culebra cut,
and we have had to move them out
How the Mountains Flow.
What are these slides?'
They are of two kinds" said Col.
GaiIard. "One is the slide proper,
| which consists of the movement of
] material lying on the bed rock. They
3 are composed of clay and earth, and
may have a great deal of rock mixed
| with them. They are masses of earth
moving by gravity on smooth in
! clined surface of harder underlying
/ material. The other class is known
| as the break 1t comes from the
/ weakness of the various strata far
under the surface. They are squeezed
out by the enormous weight of the
material lying above them.
Take first the slide proper. In this
case the motion is very like that of
a glacier, and it ranges in speed from
a few inches a month to IA feet a
day. In the large slides the motion
is uniform. In one instance the speed
was about 10 feet per day, and the
the movement did not amount at any
time to more than 10 per cent. That
was the famous Cucaracha slide,
which covered Al acres and carried
down a mass of moving material of
several million cubic yards"
The Danger to Ships.
as there any possibility of one of
those slides dropping down on
steamer in transit and swallowing it
Il think not" replied Col Gaiilard.
THE, slide would have to move far
more rapidly than any we have had
to fall upon a steamer in transit. The
only way that ship could be at
fected would be one Of the breaks,
where the material in the bottom of
the canal might rise up and the ship
go aground. You remember the hump
that occurred when we were together
in the canal. Had that taken place
when a steamer was passing over the
place she might have gone aground if
her keel had been within six feet of
the bottom. AS to the speed at which
the slides proper come down into the
canal we have not yet had a man
killed by any of them So you see,
they do not go very fast. Indeed, we
do not look for any danger as to slides
and breaks, more than a temporary
blocking of the channel, and that may
not occur"
Rock which Flows Like HOIasses.
TEL me something about the
The breaks are caused in every
case by the crushing OF a weaker
underlying layer of rock through the
enormous pressure of the high bank
on the side Of the canal above It. If
this weak layer runs across under the !
canal at few feet below the level of !
the bottom OF the material is forced /
laterally toward the center Of the
canal and is heaved up through the I
bed. II it is above the bottom level !
it may be squeezed out from the sides /
or walls OF the canal 1t is just as I
though you had some jelly in a. layer \
cake. If you press on the cake, the /
Jelly viii oOZe. Now the pressure Is 1
so great upon these weaker layers OF /
rock that they oOze out as il were, |
or are forced up into the bed of the !
1T is caused by the disturbance of j
the equilibrium Of the earth's strata !
by the digging of the canal. AS long !
as the strata lay one upon another I
the weight of the mass was equally
bed upon bed. so that it
was not possible for any of the strata
to move. When the great ditch was
cut, and the material taken out, the
lateral pressure which held the weaker
strata in place was taken away and
the great weight above squeezed the !
weaker materials far below out in
the canal
There viii probably be slides until
the excavation is entirely completed, /
but they ought to stop shortly there
after. The water will aid in preserV-
ing equilibrium, and the vibrations /
-GU6eQ Dy the Ilrl0S OH OF charges or :
dynamite, and that of the hundreds
IF loaded trains which are passing /
through the cut every day will then
be removed. The humps which come,
f any ever should come, after the
work is completed can be removed by
hedging"
a Sea-LeveI Canal Impossible.
do not the slides show that we
could not have built a sea-leYel
,anaIT'
TT would seem so to me. The IN
,OTeseen increase indicates clearly
that the construction of a sea-level
sanal would have been practically i'm
possible within any reasonable time
md at any reasonable cost For such
/ canal the excavation at Culebra cut
would have had to be IS feet more
han the present depth and this would
have caused a much greater relative
addition by slides than has been the
,ase up to the present time During
he month of April last 81 per cent of
he total excavation made in that cut L
vas necessitated by slides"
Had you known the possibility Of