Omaha daily bee., 1912-06-02
24NTy LT.1ZGTQES QRLZNE LEDGES

Of the cut near Culebra, which covers
| twenty-eight acres and another on the
east side north Of Gold Hill where about
seventeen acres have broken off begin
ming 1900 feet back from the center line
Of the canal. So far an area something
! like 157 acres of slides has been taken
OUT and there are many acres still In
| motion. Colonel Gaillard, who has seen
tho glaciers of Alaska, tells me that
these slides move just like them. The
earth flows down the sloping surface Of
the bed rock, the lateral support of the
masses having been removed by the dig
cling. 1t is just as though the earth were
made Of molasses and held back by dams
at the sides. These dams were taken
away by the digging of the canal.
Squeezing Old Mother Earth.
In addition to these surface slides or
flows there is another class of earth
motion which is carrying great masses
OF rock into the canal. These masses
do not come from the top, but from the
strata of which the canal banks are
made Sometimes they come from below
the canal bed and force themselves up
in humps through 1t, overturning steam
shovels and throwing down the railroad
tracks.
During my walk through the cut this
morning, at point just opposite Gold
Hill, saw a hump or great hill which
had risen UP in the bed Of the canal dur
ing the night, moving the four railroad
tracks which ran parallel across 1t. The
rails were pulled out of the earth. Colonel
the men who were getting ready to re-
pair the tracks and were bringing up
shoves to take out the hump, when 10,
right under our eyes, we saw the eartn
rise and throw the railroad, ties and
all, to one side. / had my camera ready
and made photographs of the ground
while it was moving. l had just finished
taking my last picture when one of the
tracks fell clear over and rolled down
the side of the hill. This hump was right
in the bed of the cut and almost. on the
bottom of what will be the permanent bed
of the canal
Where Rock Moves Like Water.
Shortly after this went with Colonel
Gaillard to one side of the canal where
the rock was such that the strata could
be plainly seen. The walls of the cut
contained many different layers Of rock
Of varying degrees of density. lying one
upon the other Here was stratum of
shale, there one of lava, and above 1t
one Of limestone or layer Of volcanic
dust hardened to stone There were also
strata of Ignite and other soft rocks
Now, before we began excavating, as
these strata lay one upon the other, the
weight of the mass was equally distrlh,
uted, bed upon bed, so that 1t was not
possible for any of the strata to move
no matter what lay above them. Thhn
the great ditch was cut and the weight
and pressure on that side were taken
away. This allowed the great weight
above to exert,its force on the weaker
strata beneath, and 1t has squeezed some
Of them out into the canal. You may
imagine how this could be IL you will re-
gard some of the weaker strata as like
thick fluid. say nolasses, or the jelly
in layer cake. The layers above will
force the molasses out at the sides, and
II you press on the cake the jelly WI.
ooze. Now, the Ignite strata especially
are Of this nature. These give way to the
weight above and force themselves OUT
into the canal bed, or II the stratum is
under the bed Of the canal 1t is squeezed
out so that 1t humps up and throws the
railroad as l have described.
Slides Can he Controlled.
Slides Of strata such a. ! have de-
described are common, but the engineers
know how to control them. They have
occurred so often that they are now
taken as matter Of course. The hump
saw today will be all out Of the way