The Manitowoc tribune. [volume] (Manitowoc, Wis.) 1866-1878, 1875-03-04
THE PROPOSED TUNNEL UNDER
THE BRITISH CHANNEL.

France by submarine tunnel is said
to have been the subject of conversation
between the Lord Mayor and the Minis
ter of Public Works in Paris, and an az
rangement is reported to have been
come to between the governments Of
England and France sanctioning pre-
liminary experiments. The idea is by
no means new one, for as far back as
1888 M. Thomas de Gamond interested
himself in the subject, and spent both
time and money in studying on the spot
the nature of the strata through which
the proposed boring would pass. In
1867 that gentleman exhibited plans and
models of a channel tunnel, and two
years previously Sir John Hawkshaw
had commenced series of practical re-
searches, causing borings to be sunk on
both coasts, and examing the bottom of
the channel all cross in a great number
of places, by meanes of apparatus con-
trived for the purpose. Since that per-
namely, in 1S72-the Channel Tun-
mel Company has been incorporated;
and Sir John Hawkshaw, Mr.. James
Brunless, and M Thome de Gamond
have been appointed the engineers OF
the undertaking. Mr.. William Low, a
gentleman much interested IN the scheme
previous to the formation of the COM
pany, has, we understand, now ceased
to have any connection with it IN an Of
fetal capacity. The assent in principle
of the governments of England and
France has been obtained; but until the
time arrives for constructing functions
with the railways terminating at Dover
there viii be no occeason to apply to
Parliament. On the English coast, st.
Margaret's Bay, depression in the
chalk cliffs, about four miles east of
Dover, has been selected as the point of
departure; and and the French side, a
spot about midway between Calais and
the village Of Sangatte has been fixed
upon. By adopting this line, it appears
from observations which have been
made by Sir John Hawkshaw that the
tunnel can be almost wholly excavated
in the lower bed of homogeneous chalk;
and this stratum IS upwards of 500 feet
deep on each shore from high water
mark. It is believed, on apparently
good grounds, that the chalk is continu-
Gus and that it stretches beneath the sea
uninterruptedly across the Straits. The
maximum depth of water on the line of
the proposed tunnel nowhere exceeds
$50 feet below high water mark, the
water being deepest in the center, and
gradualls diminishing in depth towards
the sides. The tunnel itself would be
placed by the engineers at such q level
that the depth of strata over it would
never be less than 20 feet; and this
depth, which is amply sufficient for Sc
curity, would permit the railway ap-
proaches to be formed with tolerably
easy gradients. It has been ascertalned
by actual experiments that, provided the
chalk be solid, the water will not per
meate it; and it has also been shown on
more than one occasion that compare
lively little subterranean water exists in
that formation. But the illustration of
the possibility of tunneling beneath the
sea level is to be found at Brighton.
Sir John Harkshaw has there completed
tunnel 81 miles in length along the
sea shore, in close proximity to the
margin of the sea. The tunnel is Who'll
ly in the upper chalk, where the mat
erial is not very compact; and it is II
feet at one end, and 20 feet at the other
end, below high-water mark. Considera-
BILE quantities of water, chiefly fresh,
were encountered in the progress of the
work, and as much as O,OO0 gallons per
minute had sometimes to be pumped out;
but the works were not prevented from
proceeding. As pumping power ten
times the magnitude of that employed
at Brighton could, if necessary, be ap-
piled, the entry of small quantities of
water during the construction of the
channel tunnel would not be in the least
dangerous. Nothing, probably, could
hinder the completion of the work but
but the existence of open, untitled ifs
sures, reaching from the sea to depth
of at least 200 feet. It is believed that
such assures, if at any time existing,
will be found to have been filed up in
the lapse of ages.
IT is stated that the remains of a
gigantic steer have just been found in