Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1867-01-09
Thu Chicago Tunnel Completed

The last brick has been formally iais
by the Mayor of Chicago, completing
the tunnel which is to supply that city
with $4,000, 600 gallons Of water per day
which is an ample supply for million
of inhabitants. This tunnel EXTENDS
two miles and seven feet under the bot
tom of the lake, and is lined with brick
laid in cement, throughout; and as
specimen of civil engineering and ma
sonry, coupled with convenience, IS the
foremost thing Of the kind in the world.
As SUCH it is certain to be examined,
criticised, and to produce effects upon
the future that make it worth study and
thought No doubt some of the gigantic
railway tunnels now in process OF con-
struction are destined 10 surmount' far
greater obstacles. Indeed, the excellent
nature of the soil, stiff yellow clay,
that can be cut like cheese, has been
peculiarly favorable both by its uniform
ity and compact character The Thames
tunnel might have presented the same
advantage in this respect had the same
care been taken. All the comparisons
show how much more worthy of study
and admiration is the American work
than the English.
The former has been completed IN
about two years /; the latter, after several
previous attempts and failures, occupied
about twenty, and was only completed
for foot passengers in lS43, having been
undertaken in 1928. The Thames tun-
mel was but 400 yards long; that at
Chicago is 1927 yards. The Thames
tunnel, while only one-ninth as long, is
of course much greater in diameter, but
il cost Just as many pounds sterling as
the Chicago tunnel did dollars of our
deprecated currency. The entire cost
will be under half million Of dollars,
and yet it viii supply larger amount of
water daily than the Croton aqueduct,
which, at a first cost of about 81, 900, 900,
will supply, at the lowest stage OF water,
about 27,OOO,OOO gallons, and at the
highest IS, OO0,000
In carrying this tunnel thirty one
feet below the bottom Of the lake there
have been no serious irruptions OF water,
although the escape of gas under heavy
pressure has at times created apprehen-
sions. The Thames tunnel has been a
costly failure, but this at Chicago bids
fair to be one of the cheapest and most
remunerative public works any city
could conceive or desire. There can
be no doubt that the effect Of this sue
cess will be very great in stimulating
other and similar improvements.
The Chicago river, which runs through
the heart of the city, and has to be eros
sed AZ ali the principal streets by draw
bridges, which greatly obstruet travel,
will now probably be tunneled in seve-
raj places where the travel is greatest.
Whether tunnel under the Ohio river
would have cost more than the recently
constructed bridge from Cincinnati to
Covington, depends, probably, much
upon the nature of the soil: but when
the danger from freshets and ice OBJ
structior s, the hindrance Of navigation,
and many other things, are taken into
the account, there can be but little doubt
that communication under such river
would be most advantageous aEEgt
1t is we'll known that for half cen
fury past there have been famous pro-
jects for passage under the sea from
Dover to Calais. The chalk formations
might not prove hard to penetrate, and
would probably be firm enough, without
any brick or cement, for the walls The
Incas of Peru constructed aqueducts
among the Andes, under far greater diff
ficuties, except in the matter of ventila-
ton. Yet the devices used in coal mines
successfully show how readily even this
might be overcome. The rest is simply
a matter of engineering and of expense
If for half million of dollars we carried
the Chicago tunnel two miles, surely
where labor is so much cheaper, as in
England and France, they might carry
tunnel twenty miles under the British
Channel for sum that would be incon-
siderable compared with the advantage.
Even for canal purposes the more diff
ficult ground Of tie Isthmus of Panama
will, we have no doubt, he penetrated
eventually by the energy and industry of
our American engineers, and the sooner
men Of sufficient enterprise and capital
resolutely set to work and accomplish
thus, the more rapid and complete will
be the prosperity of the American CONT
tent