Year: 1863

A contract for the construction Of tun-
mel, extending some two miles under Lake
Michigan ct Chicago, for the purpose OF
supplying the city with pure wafer, was
awarded day or two since; the lowest
bid for completing the same being SSl5, 10y.
There were i've other bids, ranging from
that figure up to O million Of dollars. The
matter has been under discussion for some
months. The Times gives the following
description Of The proposed work 20 ~


The contract is for tunnel OF tVe feet
internal diameter, Infd with brick, com
menciug at the present Water Works, and
extending a distance Of two miles under
Lake Michigan, in direction nearly at
right angles to the shore line, and about
two points to the north Of due east. The
tunnel is TO be excsvsted thirty i've feet
below the bed Of the lake, and to have four
feet Of dip landwsrd. A bricked shaft is
to be sunk at the Water Works, and, at the
other extremity, crib, about eighty five
feet in diameter, is TO be sunk and filed
with stones, an iron shaft Of nine feet in
diameter to be built inside it and this crib
and cylinder TO be afterwards surmounted
By s light. house, as a guide tovessels and a
protection to the works. Between this and
the shore 8 number Of intermediate shafts
will be sudk, similar in construction TO
the outer one, except that the cribs will not
be quite so firmly built, and that the cyl
inders will be somewhat lighter. There
will not be less than one nor more than
four Of these intermediates. The number
will be determined by the circumstances
which develop themselves during the pro.
grsss Of the work. The contractors have
agreed to furnish as many as may be re-
quired without claiming extras. The OBJ
ject in sinking these is to enable the men
to work in several different places at once;
they will be removed after the tunnel is
completed so ss to present no obstruction
to the navigation Of the lake. The tunnel
will then be one continuous channel Of two
miles in length. The water, entering at
that distance from the shore, may reason
ably be expected to be clear and free from
those impurities which now infect the wa
ter supplied for city use. Strainers will
be fixed over the outlet to keep out the fish
which have at times troubled us so ex-
tensively. The total area OF the tunnel
will be nearly twenty square feet an area
amply large enough to furnish water con-
tinuously TO q city I've or six times the size
Of Chicago in the present day. The fall
Of four feet towards the shore end Of the
tunnel will 6 We ample facilities for empty
ing it occasionally In case Of fouling, and
its permsnenoe is aimed to be secured In
the most satisfactory manner, the specif-
cations being very explioi; as 70 the mode
Of construction, providing that eight inches
Of bricks shall be laid all around It and
that these bricks shall be firmly imbedded
in the soil, which must be rammed in and
puddled, il not otherwise sufficiently firm
TO fulfill the requirement of absolute solid.
ity. If this contract be faithfully execut-
ed there can be no doubt that Chicago will
have secured an unfailing supply OF pure
water, ample enough to supply her utmost
needs for fifty years to come, and that few
If any repairs will beneeded in the course
Of that time. The whole is to be completed
in two years from the date of signing the
contract.