New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1896-02-07

CANAL BY Archibald Ross Colquhoun ASSOC:
Numerous Illustrations. Plans and Maps. PIP
xvii. 443. Longmans. Green CO.
As Mr. Colquhoun is an Englishnan. ne might
pe expected to advocate English interests III
Nicaragua but his book is really an argument
for an effort by the United States to complete
the Nicaragua Canal. He examined all three
~ the great TRANSPORTATION schemes-the Panama
Canal the Tehuantepec Ship Railway and the
Nicaragua Canal. The first as appears PLAINLY
from his remarks, he would not approve IL
the money were ready to build It, The floods
Of the Chagres River would destroy 1t, II IL were
a tidal canal, and there is no store OF water 10
supply It IL ii is made with locks. Inc pan ol
Eads's ship railway he manifestly approves-aS
much perhaps from the brlliancy end dash OF
the idea as from conviction Of its feasiDilty.
But the Nicaragua Canal combines all the feat-
ures that attract him % an engineer ana as
man interested in promoting every form OF IN
ternational commerce.
In the first place, considering the length OF
the route. he finds that only small part Will
have TO be excavated-about twenty -seven miles
in a total length of 10. Besides the fifty-seven
miles through Lake Nicaragua, the remainder OF
the route will lie through series OF basins or
artificial lakes, the only question about THESE
being as to the most suitable engineering de-
vices for creating them. Thus throughout the
greater part Of the canal, If it is ever completed
whole fotillas Of vessels may pass each other
with indifference Only at certain points Will
ships have to move slowly In single file There
is an unlimited supply Of water for lockage; IN
fact each lock will have a basin OF It's own
which will greatly facilitate the movement OF
vessels and allow the withdrawal Of large
volume Of water in a short time without IN
furious current or marked fluctuations of level in
the basins
Mr. Colquhoun reduces the serious engineer
ing problems of the canal to three. One OF
these Is the cut through what is called the Great
Divide, where a trench three miles long VIII
have to be cut through volcanic rock at an aver
age depth of 141 feet and maximum depth OF
1928 feet While more than usual care has been
taken with borngs to learn the character or the
rock through which tie excavation must De
made Mr. ColquhOun would double the precau-
lions From the borngs that have been made
the inference is that the rock Is Solo ana uni
form Under such conditions the plan is to
make the cut with almost perpendicular sides, as
was done with the Corinth Canal in Greece. But
unfortunately the Cornth Canal was damaged
by a slip In its almost upright walls. and so the
author argues that the engineers in Nicaragua
should take warning. He even goes so FAR as
to suggest that. If the rock is broken with horl-
zontal or inclined measures. a tunnel would be
better and cheaper than an open cut. He limits
his tunnel, however, to a heading Of 12O feet.
The slips in the mines at Kimberley South
Africa which usually occur at a depth of 100 or
$50 feet are among the things he thinks of with
dismay when he looks at the cross-section of
the proposed cut through the Great Divide.
The next great problem is dam which is 10
be built across the San Juan Valley at place
called Ochoa Here he finds that thoroughly
American device, which has been used in other
parts of the world. but is best known in the
Western United States. has been adopted. He
agrees with those who think that to divert the
course Of the San Juan River would be impos-
sible, and he comedies the difficulty of building
q dam OF masonry or concrete, though he says
that English engineer would certainly try to
build such structure. But what he finds pro-
posed is a "rock-fll" dam, in which masses of
rock Of all sizes. but each weighing tons if OBJ
tainable. are TO be dropped into the bed of the
stream. The process Of dropping these rocks
is to be kept up until in spite Of floods and all
other vagares of the river. the long heap holds
its place A particular advantage of this de-
vice for making the river build its dam is
that earthquake which would shatter
masonry dam would only render rock fill dam
more substantial. The expense Of the dam will
be comparatively light, it will be made Of
material from the Great Divide which will have
to be hauled away from the excavation. 1t is al
most unnecessary to say that Mr.. Colquhoun is
sceptical as to the efficiency of work that looks
irregular.
Finally, he considers the harbor al Greytown
Over two hundred years ago attempt made
to divert the San Juan River from its course The
result fatal 10 the harbor. which has gradu
ally filled up with sand under the steady blowing
q lie winds u
wonderful rapidly, the channels shift with ap-
palling suddenness, and all the work done with
breakwater and dredges barely serves when act
lively prosecuted to keep up with the natural
growth of the obstruction Dredging done as late
as 1893 is II it had never been done al all.
Vessels aground on the coast sink ont Of sight in
the sands In incredibly short space of time.
Altogether, Mr.. Colquhouns description Of the
harbor of Greytown is more disheartening than
otherwise. He cunts the various plans that
have been suggested for restoring the roadstead,
and. after ALL adds: considering everything /
believe this creation Of harbor at Greytown to
be the weakest feature in the whole canal scheme,
and that requires further serious considera-
ton"
While Mr.. Colquhoun advocates strongly the
neutrality OF the canal II it is completed, he
nevertheless attaches much significance to the
Monroe Doctrine. The influence of the United
States must preponderate not only in the building
but in the use Of the canal. Maps and tables Of
distances show that a passage from the Caribbean
Sea to the Pacific Ocean would not distance
for the Western European ports which can now
the Suez Canal But It would thousands
OF miles for the American cities of the Atlantic
and Gulf coasts. 1t Is the population of these
cities and OF the Mississippi Valley to whom the
completion OF the Nicaragua Canal would be
boon, not the people Of Great Britain. This con-
clusion does not tally exactly with the object Of
the book professed at the outset. which was to
strengthen and support the authors previous ar