The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1870-10-14

Friday Morning, October IA, le7O.

CORTLAND


Correspondence of the Providence Journ1l.]
CHICAGO, ILL.,, Oct. 1O. 1870.
In the projection of the public works of this
great metropolis there is displayed bodness
ofplan and recklessuess of cost that is peculiar
to the western character. No natural obstacles
seem to daunt the resolution of the people.
The difficulties to be overcome are less taken
conservative commuuities. The presence OF
such difficulties seems to stimulate rather
than TO todiscourage. One thing, in which Chi
cago seems specially eminent among the lead
ing cities OF the world, is in the construction
of successful submarine tunnels. The water
tunnel under Lake Michigan takes rank
among the great engineering marvels Of the
continent and the age. We do not propose
TO advert at the present time to this triumph
OF mechanical skill, bat only to speak of those
minor works built for the purpose OF afIording
a.feady means of communication for the pab-
|.ie betweeN the two sides Of the Chicago river
To make such passage way under the bed OF
a deep stream which is channel OF commerce
intersacting busiest thoroughiares of great
commercial town without inconvenIencing
the fleets of vessels continually navigating its
waters, is no slight undertaking. But Cbca-
go has already once successfully accomplished
the task, and pro6ting by the experience thus
gained in overcoming difficulties at iirst I'M
forseen, will undoubtedly in its second attempt
accomplish it with greater facility and econO-
my than it did before. The tunnel Under the
river at Washington street is an object OF
much interest to the stranger, as a work of
remarkable utility, unique OF its kind and
most sasaciously planned and arranged. The
demand Tor such a roadway. connecting the
divisions OF the city which the river separates,
has become necessity at the time when II
was con- menced; for, nOtWi hstanding the
great multiplication OF bridges, travel was
1exatiously delayed and embarrassed by the
continual opening OF the draws. 1t was com
pleted on the lst of January, 1869. at cost of
S32S,5OU, and has fully subserved the purpose
es contemplated, affording very convenient
means OF transit, both tor carriages and pedes-
trians. The avenue for vehicles dips from
the open street, one block back from the side
OF the river. The extreme length OF the road
way (tOrmed of Nicholson pavement) IS 1,6O3
feet. The length between the arches is $50
feet. The distance between the entrances on
either side tor loot passengers is $40 feet The
grade OF descent eastward is one foot in eight
cen, and westward one loot in sixteen. The
height OF the chamber beneath the river is IS.
83 teet At ITO feet from the river-contre
separate double waeon-ways begin, each
eleven feet in width. Parallel with The car
riage way IS the foot passage--a separate
chamber eleven feet high at the centre. Ii is
entered fom within passenger-houses by de-
scendina shoft flights OF steps. The floor is
even and the DESCENT gradual. The gas lights
are iorty feet apart. There are ventilation
shafts by which the air is kept fresh.
The labOrs OF the men. employed in making
the excavations Tor the new tunnel farther
down the river at La Sale street, are watched
daily by curious throng, and present a very
novel spectacle. They are indeed or the mud,
muddy. these besmeaied, betraggled wallow-
ers in the noisome deposit left by waters with
which the drainage of the city has been so
long mingled. They toll on day after day,
knee-deep in the Shiny ooze, slowly removing
accumulations of filthy sediment, the amount
of which it must seem discouraging to con-
template. Before us lies great basin from
which the water has been pumped, laying
bare the muddy bOtto n two-thirds Of the way
across the stream. A gang OF laborers are
continually shOveng the mud into buckets
which are drawn out by ste IN power. The
loads are emptied INTO scows ami conveyed
away to make land for railroad purposes
TIE open area is enclosed by three sides of a
cofie dam, built OF double water-tight walls
OF heavy plank, which form massive bulwarks
to shut out the river. The spaces betW cen
the walls, three or four feet wide, are filled
with mud, giving great stability. The strdct-
ule is shored up and braced from within in
the strongest manner by masses of heavy tim
ber. The middle bulkhead. placed lengtbwise
with the stream, rests against the mouths of
the closed cylindrical chambers Of the north
ern or completed portion of the tunnel. The
foundation tor this was prepared, and its oven
like compartments of masonry built up with
in the walls Of a Golfer dam, which vas the
counterpart OF the one ABOVE described. The
river now flows above this masonry, and all
vessels passing up or down mu sail over it,
though the channel is quite narrow. The bed
Z is at present nearly prepared upon which to
lay the masonry for the first section of the
south part of the structure. The mud is
dug out to depth of twenty-four feet
The depth OF the water above the
place was formerly twenty feet, so that
the submarine roadway at this point will be
about forty-iour feet below the surface of the
river. A section comprising thirty-eioht ieet
OF the horizontal length of the structure is
built up and finished at one time. The length
of the bukheads extending to the shore is at
present one hundred and eighty teet. The
work was begun In the centre OF the river by
ietLlng DOWN large "crl0" or Golfer dam, lD
shape like square box. thus making well
in the middle OF the river, then pumping out
the water, digging out the bottom and laying
section of masonry within the box, whose
transverse sides were elongated hcm time to
time, laying bare more and more of the river
bed as the progress of the work required, un-
til they reached the shore.
The total length OF the tunnel when COM
pleted, including the approaches from Ran
| dolph street ON the sou'h and from Michigan
street on the north, will be nineteen hundred
and thirty feet. As in the Washington street
tunnel, there will be an open passage way tor
vehicles, and separate chamber for pedestri-
| a rs. For the construction of the masonry
about eight millions OF bricks will be required
| and .ery LARGE amount OF stone. The COM
| pleted portion may now be entered, although
the path wav is muddy one. In two weeks
time 1t will be more passable. The laying Of
the masonry was commenced on the fifth of
February last The first piles were driven
preparatory to building the Golfer dam on the
fifth OF November. The time fixed by the
| contractors, previous to which they propose
to have the tunnel completed, is the fourth of
July next. 1t is found that depth OF eight
feet deposit has accumu ated on tue bottom Of
| the river since the stream was widened by the
city fifteen years ago, The amount of appro-
priation tor the work is S5OO,OOO. -.
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