The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1913-08-26

Canal al a few feet below the level Of
NE bottom. the material is forced
Iai'rallH toward the center Of the ca
nal and ; heascd up through the bed.
II IL IS above ths bottom level i; may
BE- squeezed olt from the sides or
walls Of The canal 1t i Just a. though
YOU hao some jelly III u LAYER cake.
II y"u press on the cake. the Jelly
viii oozs. Now. the pressure Is SO
sreat upon these weaker layers II
rock that they ooze out, as it were.
or are forced up into the bed az the
canal"
But ho~ does tina, come" II
asked. |
1T j. caused by the disturbance Of
the equilibrium Of the eaFth'> strata
by the digging OF the canal. AS long
as the starta lay one upon another
the weight Of the mass was equally
distributed bed upcn bed. so that IL
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 weak
CT strata in place. was taken away.
and the great weight above squeezed
the weaker materials far below out
into the canal. I might explain il
more scientifically. but that IS a
rough, simple idea of how these
breaks occur. Where they come up
through the bottom we dig the heavi-
est portion away. and often the hrok-
en- part Of the high bank settles again,
causing another hump in the same 10
cality. After a time. however. the
weight Of the broken portion Of the
bank is so reduced that it cannot
move again. i look for all such
breaks and slides to disappear grad
ually. They Will stop as soon as the
earth has accommodated itself to the
f~changes in equilibrium made by the
digging"
How long do @ think they will
Continue?"
There will probably be slides until
the excavation is entirely completed
but they ought to stop shortly there
after. Thew alter will aid in preserv-
ing equilibrium, and the vibrations
caused by the firing off Of charges of
dynamite. and that Of the hundreds
OF loaded trains which are passing
through the cut every day will then
be removed. The humps which come.
If any should come, after the work is
completed can be removed by dredg-
fng?"
a Sea-Ievel Canal Impossible.
DO not the slides show that we
could not ave built a sea-level ca
nal?'
1T would seem so to me. The un-
!, foreseen Increase indicates clearly
that the construction Of a sea-level
, canal would ave been practically i'm
!, possible within any ole time
!, and at any reasonable cost. For such
a canal the excavation at Culebra cut
: would have had to be eighty-five feet
! more than the present depth. and
! this would have caused a much
greater relative addition by slides
! than has been the case up to the
: present time. During the month Oh
I April last ga per cent Of this total e X
; cavation made in that cut was neces-
STATED by slides"
lilac you known the possibility OF
slides at the beginning and changed
your angle Of excavation, could you
AVE done the work more cheaply?'
I'VE might have made more regu-
+ lar slopes, but | doubt whether any
v material diminution in the quantity o.
q the excavation would lave occurred.
"On May /, 1913, we lac still 81,
and one-half million yards to take
: out. If no new slides should come
we ought to be able to complete tina
e work before January. 1914. II, how
: ever, the waite. is turned into the ca.
r nal in October, as is anticipated
there will remain still two or three
million cubic yards which will hav,
to be removed by dredges.
when do you really expect to se'
a the water flow into the cut?'
a Prior to my departure the chair
a man n chief engineer said it wa
lS | Ills lIllC1IN4Oh ~ NAAH ~ NOkCi Iht'
d the cut early in October, 1913"
e Does that mean that the canal vii
II be ready for use them"
v Il do not like to p%rophesy as t
1t that. There are all kinds Of est
mates. ! see that one big steamshil
d line is advertising that it will sem
= tourists through OF a sixteen thousan
ton ship early in February. 1914.
will only say, however, that it seem
# certain that it will be possible to pas
2 ships through the canal severa
months before the date Of the officia
opening. that is. bly, IN ad
4 vance Of ~anuar l, 1915
- The Men at Work.
- What force have you now in Pan
-, anna? 7 suppose that the men wi
- soon be leaving Ia find other job. ?"
-. During the past year We have ha
= more men at work than ever before
- May /. 1913, the number was $500
81 That is the largest in the history {
~ the canal
.Whaf can Uncle Sam do with tn