The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1866-11-27

Wnefe
hold against the northeastern horizon. At o'clock
on the morning Of that day the mners had reached out
the lake % distance Of s2o6 feet from the shore
| third the total distance accomplishedf
/ sscRiH,"
II was feared from the inception Of the great under
taking that the one nsurmounaba obstacle to
would be the difficulty OF sinking the outer shaft through
bed OF the lake to the level Of the tunnel This
indeed obstacle OF incalculabe magnitude. When II il
considered that the waters OF Lake Michigan, when
dashed into fury by the gales peculiar to their region
RAGE with violence hardly equaed BY that Of an ocean
OF the prime difficulty Of sinking and maintain
ing In position the mammoth s'crib" which
ont the lake from the shaft Bear il
mind that without shaft extending downwards from
the lake the tunnel would be as yalueless the limb
man crippled by paralysis. Remember, too, that the
shaft could only be constructed downwards and that Il
was necessary, In order to reach down through the
protection 70 shut out the waves from the progress Of
operations In other words, necessary to sink
shaft directly from the surface Of the lake. This nclos
ure or protection against the water was termed the
scrb and second only, in interest and importance "a
the tunnel itself s the crlb which, while forming the
lake terminus Of the tunnel and being really part OF the
tupnel is yet a separate and distinct feature ! ~
Tho crib is forty feet high and pentagonal in form
Zach Of its five sides is eight feet in BREADTH making
Va diameter Of ninety feet. In the centre the swell =
open at the top and bottom, and twenty five feet in d.
ameter. Between the wall of this central space, OF
s'we y third WALL that the structure had three
walls-the outer wall the centre wall and the inner
walleach constructed of timbers twelve inches square,
firmly boed together, aud made perfectly water tight
The space between these walls divided into fifteen
separate tight compartments There were used in
the construction oil this gigantic structure 6S CPS feet Of
lumber 65 tons Of iron belts and 400 bales Of oakum
The whole structure not far from 500 0O0 nearly
one third the contract price OF the TUNE.
The crib was built on the North Pier at the mouth OF
the Chicago river whore was launched in the presence
OF an immense multitude OF spectators on the Oath Of
July 1885, II was towed the day TO its present
position. The work Of sinking II was somewhat delayed
In consequence OF defective arrangements and dents
TO the anchors. Owing rough weather which inter-
vened us az the crib reached bottom much anxiety
felt for its safety but by Of wrecking pump 1t
filled nearly full OF water and thus kept very nearly
in It's true position. After the storm had subsidized
the crib was found TO have worked thirteen feet
north Of the correct line, and TO have mbedded
itself firmly into the clay At the bottom OF the lake. II
thought best not 10 attempt TO raise again. but
proceed Immediately with 6lng 1t with stone, the
variation from the exact position intended could be of
practical Importance. The work of filling the water
tight compartments was continued for several weeks
after which the crib was securely moored by immense
cables reaching in every direction to Mtcheis patent
marine noorng forced far into the hard blue clay
The crib since il was thus loaded sunk and moorcd
has been thoroughly tested BY violent sors aud in The
winter By moving fields Of ice. II withsood the shock
both of storm and ice without injury, and the least
change OF position since II fairly loaded has not
been discovered
THE LAKE TERMINUS.
II has been already stated that the crib Tempo
rary structure Before tunnel fully competed the
loose stones placed in the watorght compartments OF
the crib will be removed and spread upon the top,
keep the huge structure from being displaced They will
u
foundation rising from the bed OF the lake half way
the surface of the water. Above this the masonry will
consist OF massive blocks o. granite boted together
with It's massive masonry and numerous bolts and bars
running from portion TO the other and firmly binding
the whole together the lake terminus, II Is
sonabe to suppose will resist for the derces gales
and storms Of Lake Michigan. Upon the top OF the
structure viii be erected permanent lighthouse. con-
sructed and maintained al the expense of the city.
TIE LAKE SHAFT
The next step in the progress Of the work. and by
means the least difficult, the sinking OF the iron
cylinder or shaft through the interior OF the crib This
cylinder Is sixty three feet length and two hundred
and three thousand pounds in weight II Is divided
Into seven sections, each OF which is nine feet in length
nine feet la diameter and two and half inches thick
ness These seven iron cylinders, making the
connected and lowered to The bottom Of
the lake. within the open space or swell" in the
centre Of the crib The cylinders then, after having
wards into the clay, to depth Of twenty-five feet Tho
powerful pressure necessary 10 the accomplishment Of
water being wholly excluded from the cylinder, and
vacuum being created by means OF air pumps. TN
The masonry was then commenced. In the meantime
made ready and the bricks and cement and other
materials and supplies which were expected be
lnred during the winter, were collected and stored on
the crib. s@
THE LAST STAGE THE WORK.
much longer period than had been anticipated
consumed in these preparations so that It was as late
the first day % January of this year whom the shaft had
boen constructed and the work fairly begun in the
tunnel proper Then the rate OF progres Of the work
was doubled. Miners commenced woxing nj both ends
pushing the tunnel farther and farther from opposite
directions 10 the 1na point Of junction, which was
yeached to-day, when Mr. Chesbrough, the faithful
Responding father and chief Of the undertaking. pierced
through the last thirteen inches Of clay which separated
the worknen.
The tendency OF the clay SWELL together with tho
small size of tho tunnel and the difficulty Of getting
clear Atmosphere made the alignment Of u matter Of
great dinlcuy. But successfully this difficulty
overcome that when the miners reached zach other
dsv the alignment had a deviation of only eighteen
inches the sides and OF only inch the bottom
HOW r'M WATER Is TO M RECEIVED INTO AND DISTRIBUTED
NA N from THE TuSNF1.
in order that nothing Of Importance in connection with
the crib the gates for the entrance OF water
Mr. +. s. Chcsbrough City Engneer-under
whose personal direction aud supervision the
work has been constructed--in January last
made visit to New York. Boston aud Phiadephia for
the purpose of securing further information and OF adj
ysng with Mr. Erastus w. Smith chief engineer OF the
bridge Harlem and consulting engineer OF the
Chicago Board Of Public Works The result OF this visit
the adoption Of Mr. Smiths plans or inlet gates in
tho outer shaft Those received much steady and care
fu els5oron since Is necessary that the gates shall
be constructed as 10 adm OF necessary repairs with
out shutting of the supply Of water from the city.
II is needless 10 give full scientific description
of these gates They at Ingenious massive and
perfect Through the masonry three openings fumes
extend from the water to the iron cylinder or shaft
which desccndR to the tunnel and connects with the
cylinder by means OF iron gates which freely and
easily opened or shut by simple but highly ingenious
Continuance Of rods and wheels worked from the TOP.
Each Hume -four feet high hy 6ye feet WIDE and they
placed different sides OF the crib One is placed
Owe feot from the botom OF the lake. another ten feet
and the third fifteen feet y
1t is not intended 20 keep more than one OF these
gates open nj tho saine time When the wind Is blowing
from the south the northern nune will he opened the
others remaining closed; when gale comes sweeping
from the norib the southern gate will be opened and
on water being always eceived through the fune which
opens on the side opposite the OF the wind One
Of the fumes being open. the water descends rapidly
into the SHAFT fng the tunnel completely and rushing
rapidly through the bores 10 the land shaft where rises
70 the top and thence s received into mmcnse
vor From this reservoir IL will bc distributed by pow
erlnl force pumps to all parts OF the CITY.
r CAPACITY OF TIE TuSskI~
IL Is calculated that the tunnel under the different
heads Of two eight and eighteen feet. win deliver nine.
teen million, thirty eight million and nfy-seven million
gallons or water daily so that u 10 only necessary IN
order 10 increasc the supply 80 open higher fume In
ihe lake terminus Of the tunnel These figures show
that the tunnel will furnish under head OF eight feet
water enough 70 supply population or twothrds Of
million Of people with fifty gallons daily for eacil
Inhnbitant. or n whole million with the same quantity
FOR each inLabitant with head Of eighteen feet
THE cost. M
II has been stated that the conrnci provided that
the work should $685. 1872 hut owing 90 the agn
al. xfe .(