1
Conservative.
cavatiou called for iu the deep cutting
at Culebra nud Ernporador , which will
largely determine the duration of the
work. The deeper this cut , the longer
will bo the time required to complete
the Canal , and , consequently , the
greater will be the outlay in general ex
penses of administration , interest on the
funds to bo raised , loss of revenue , etc.
These are important elements of ex
pense , sometimes neglected in estimates.
Basing the rate of probable excavation
chiefly upon the experience acquired by
the old company in operating on a
large scale , checked by that of the new
company iu operating under many dis
advantages upon a small scale , it has
been computed that there will be re
quired to complete the project of Level
96 % feet about eight years , and longer
proportionally for the other projects.
But it must not bo forgotten that the
old company has been criticised , per
haps justly , for the mode adopted by its
contractors in prosecuting the work ;
rapidity of execution not having been
made an object to be specially sought.
Also that great improvements have been
introduced during the past ton years in
machines and methods. It is , therefore ,
not unreasonable to expect that , with
these improvements , and with better
stipulations in the contracts , these
estimates of time , at least for the- higher
levels , may bo notably reduced , and
excessive iucide < tal expenses for inter
est , etc. , be thus avoided. To be con
vinced of this , it is sufficient to con
sider the rapidity attained iu excavating
the ship-canals of Manchester and Kiel ,
and especially the drainage-channel at
Ohictfgo , where such great advances
were made.
It is a great merit so to have adjusted
the projects as to bo able to pass readily
from one to the other , if experience in
the progress of the work should show
this to bo desirable. But how is this
advantage to be secured ? Simply by so
adjusting the different levels as to per
mit the change to bo made by omitting
upper locks thus calling for ten , or
eight , or six looks , in the three projects ,
respectively.
All three projects require a dam at
Bohio ; transforming the Chagres River
into a vast lake , of which the bound
aries have been accurately determined.
It will extend a distance of 18 miles to
Obispo , where the Canal leaves the
River , and will cover an area of about
21 % sq. mihs , Its lowest level is fixed
at 52 % feet , its normal level at 65 %
feet , and its highest level at ( io ) feet
above mean. tide. It thus provides a
reservoir to retain one hundred and
ninety-six million cubic yards of flood-
discharge , which , with one hundred and
thirty million more held back at Alha
juela in the Upper Ohagres , will effect
ively control the torrential stream. Two
locks will admit ships coming from the
Atlantic into this lake. Thence , to at
tain the summit-level at Elevation 96 %
feet , three locks will be required all at
Obispo ; while for elevation 69 feet two
will suffice , and for Elevation 82 % feet ,
one only , or perhaps none , will be ne
cessary. The descent to + he Pacific is
made for the three projects , respective
ly , by two locks at Parniso , two at
Pedro Miguel , and one at Miraflores ; or
by one lock at Paraiso , two at Pedro
Miguel , and one at Mirnflores ; or by
two locks at Pedro Miguel , with a tidal
lock at Miraflores.
All of these looks have a rook founda
tion ; and none presents extraordinary
difficulties. All are double : one cham
ber having a serviceable length of 788
feet and a width of 82 feet , and the
other ( for smaller vessels ) the same
length divided by a sot of intermediate
gates , and a width of 59 feet. The
maximum lift is 29 feet , except that
provision for 82 % feet is made at Bohio ,
when , very rarely , and then only for a
few hours , the lake may rise to maxi
mum flood-level.
With respect to alignment of the
Canal the following are the conditions
adopted : The curves not to have a
radius less than 8,200 feet , which ex
perience has shown to bo required for
easy navigation ; the depth to be 29 } < j
feet , with provision at the locks for 81J
feet should an increase ever become
desirable ; the cross-section never to fall
below about three times the midship
section of the vessels which will navi
gate the Canal ; ample enlargements ,
at distances not exceeding 5 miles.for
ships to pass each other ; bottom-widths
of 164 feet iu Lake Bohio and 98) feet
in the central part ; retaining the exist
ing width (12 ( % feet ) in the Atlantic
level , to bo enlarged to 98 feet after
the Canal is opened to navigation , QS %
feet in the Pacific level , and 161 feet in
the channel extending through the bay
from La Boca to Isle Naos where the
Canal terminates.
Only two largo dams are required ,
the first at Bohio.creating a lake which ,
besides acting as a floodregulatoryill
obviate the necessity of encountering
strong currents where the route trav
erses the bed of the Chagres , a very im
portant matter for ocean shipping ; and
the second at Alhajuela , in the Upper
River , to assist in controlling the floods ,
to supply the summit-level in the dry
season , and to furnish hydraulic power ,
transmitted by electricity for operating
the Canal.
The dam at Bohio will be of earth
revetted with stone , with a foundation
bed of clay and abutting ogainst rock
banks- The extreme length of crest is
1,286 feet , the extreme height above the
bed of the river is 75 > 2 feet , and above
the lowest point of the foundation 98
feet. All details of construction , in"
eluding the devices for controlling the
River during the progress of the work ,
have been carefully elaborated , and
will command the confidence of engi
neers. The sites for the two overflow
weirs are remote from the dam ; and an
abundance of excellent material is found
near at hand.
The dam at Alhajuela , about ten
miles from the Canal , is to bo of con
crete masonry , founded on compact
rock , and abutting against rock walls.
The extreme length of crest is 936 %
feet ; the extreme height above the bea
of the rivpr is 184) feet , and above the
"owest point of the foundation 164 feet.
The cross-section and the practical de
tails of construction are iu accordance
with all the requirements of modern
engineering. Good rock and sand are
abundant in the immediate vicinity.
To connect this reservoir with the
summit-level , a feeder 10 miles long ,
starting at 190 } feet above sea-level , is
required. It traverses a rough country ,
and its construction will be relatively
costly ; but when compared with many
of our irrigating canals west of the
Mississippi it offers no serious diffi
culties.
The minor dams at Obispo , Paraiso
Pedro Miguel , and Miraflores will vary
in height according to the project adopt
ed ; the first , second , and fourth will beef
of concrete masonry , and that at Pedro
Miguel of earth. None of them presents
difficulties worthy of note.
The regulating weirs will bq ol
the "Stoney" design , which has given
entire satisfaction on the Manchester
Ship-Canal ; and all of them will bo
detached from the dams.
Such is a brief summary of the pres
ent condition of the studios for the
Panama Canal. It remains to compare
the project with that at Nicaragua.
The details of the latter are so fully
presented in the report of the Govern
ment Commission of 1895 and accom
panying documents , and are so well
known in America , that a recapitulation
in detail is not required hero. The new
commission , of which Admiral Walker
is president , has as yet made no formal
report ; but the individual views of the
three members were given in so much
detail at the hearing before the Senate
Select Committee in Juno last , that the
modifications likely to bo recommended
may bo inferred. The essential fea
tures of the project are the following :
The whole length of the route is 17(5 (
miles. Of this distance about 67jj
miles lie in the bed of a crooked river
through which must pass the outflow of
Lake Nicaragua , draining some three
thousand square miles , and about 5724
miles in the Lake itself , calling for from
10 to 14 miles of dredging in soft mud.
The summit-level is fixed at 110 feet
above mean tide ; and both of the Gov
ernment commissions recognize the ex
treme difficulty of regulating this level
so as to avoid , on the one hand , flooding
a valuable district on the Pacific side of
theLakeaudon the other hand .exposing
rocks in the bed of the Upper San Juan ,
where there are several bad rapids to be
drowned or excavated before a ship-
channel is possible.
The Nicaragua Canal Company advo
cates two principal dams , one at Ochoa
on the San Juan , and the other at La
Flor west of the Lake ; but as the latter
was regarded as impracticable by the
Ludlow Commission , and apparently is
not favored at the projected height by
the Walker Commission , it will be left
out of consideration. The Ochoa dam
presents serious difficulties ; and al
though the present commission has suc
ceeded in finding a rock bottom at great
depth ( Admiral Walker estimates it
approximately at 40 or 45 feet , and Prof.
Haupt at 60 feet , below sea-level , i. e. ,
at 80 to 85 feet and 100 feet respectively
below the deepest part of the bed of the
river ) , no definite plan has yet been pre
sented for modifying the loose rook and
clay dam heretofore regarded as neces
sary. This construction is without
precedent in canal engineering ; and
Admiral Walker says of it : "Of course
a dam of loose rook would have to be
enormous in size ; it would bo like mov
ing a hill into the river. "
But the alternative of digging from
80 to 100 feet to roach foundations in the
bed of a river which cannot bo tempo
rarily diverted , and then of raising a
masonry mass to a height of 150 or 170
feet above this newly discovered rook
bed , is not an easy or a safe undertak
ing. Moreover , to hold the summit-
level at 110 feet , enormous embank
ments are required in the San Francisco
basin. They are sixty-seven in number
and six miles in length ; and some of
them will rise from 60 to 85 feet above
soft mud , which must be excavated to a
depth of 80 feet to reach a clay founda
tion. The chief engineer of the Com
pany regards these embankments as
"the weakest feature of the whole
route" ; and they appear to have im
pressed the present commission , as they
did that of which Gen. Ludlow was
president , most unfavorably. Indeed ,
now surveys have been ordered to at
tempt to radically change the existing
project , with a view to reducing the
height of the dam at Oohoa and of the
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