National Republican. (Washington City (D.C.)) 1872-1888, 1882-03-25
THE CHANNEL TUNNEL.
From England 60 France Under the Eng.
Ifah Channel.

Ahnh NnnnmcN.
Not so very many years ago, when IL was pro
posed to tunnel the Alps for distance OF four or
FIVE miles, the suggestion was laughed at by some
and by others looked upon as piece Of engineer
ing folly, which, II persisted in. could only result
In utter failure. And yet to-day trains OF cars
are passing TO and fro daily, almost hourly, far
below the snow clad submits, whose towering
heights have thus been happily circum-
vented by mans skill and industry. Since
that as then considered siupenduous UNI
dertaking was successfully accomplished many
others Of scarcely inferior importance have been
projected and carried out or advanced far toward
completion, and recently what is destined to be
the browning triumph of the engineers art has
been commenced by the Submarine Continental
Railway Company almost simultaneously in Eng
land and France. The object OF this latest scheme
is 10 unite the two countries by tunnel, which
Is now III process OF construction under the British
channel. The distance TO be traversed I'M ID or
water Is about twenty two miles, 10 which must
be added, according to estimate four miles on
ench side for land approaches, thus making when
finished tunnel
THIRTY MILES IN LENGTH.
From an interesting description of this great-
work which recently appeared in the WuarUed
London Nous we oondenso tho following; The
shaft upon the English side Of the Channel is sunk
in the chalk cliff between Folkestone and Dover,
and Is about one hundred and sixty feet in depth
Tho opening Is circular, with boarded sides, and
cited with steam holsting apparatus. AT the bot
tom Of this shat Is a square chamber dug in the
gray chalk, the sides Of which are heavily TIM
bored, and In front Is the experimental boring,
low rooted, circular tunnel, about seven feet in
diameter, the floor Of which is laid with a double
line Of tram-rails This tunnel is admirably ven
tllated, and OH visiting days is lighted with cleo
trio lamps. The beginning Of the tunnel proper
is one hundred feet below the surface OF the sea,
and a heading, now about
THREE QUARTERS OF A MILE LONG,
has been driven entirely through a hard gray
chalk, impenetrablo to water and yet Of such a
character as to be easily worked. The present
heading. as already stated, is seven feet in dia-
meter, but machinery has been devised to cut an
| annuar space three feet six Inches around
| H. thus enlarging 1t to fourteen feet
The boring Is done by machinery propelled by
compressed air, and progresses at the rate Of
nearly an inch minute while In operation IL IL
now going on at the rate Of three miles year
which speed Of working, providing borings on The
French side progress as rapdy VII ,ns
years and half. The geological experts assoei-
istenco of a great bed OF gray chalk, which
stretches in an irregular curve
FROM ENGLAND To FRANCE,
starting from below Dover and reaching TO point
on the Fron CHI coast little to the east OF Cape
rlsnez not far from Calais IL is the intention tc
drive the tunnel along or through this bed
The tunnel. when completed, will be In the shape
Of circle ID feet In diameter but anttened at the
bottom to receive the rails. II VIII be lined win
2 feet thickness OF cement concrete, not that II
is necessary to insure the stability Of the work. but
TO prevent accidental falls of chalk. The gradi'
ents win be to so on each side until the depth o.
| 100 feet
BELOW THE BOTTOM OF THE SEA
ia reached after which the line will be level, sub
ect only TO very slight inclination from the cen
ire outward, TO prevent the lodging OF water
when the tunnel Is opened TO tratc.the trains vii
| be run through by engines driven by compressed
| air, which not only furnishes motive power but
also ample ventilation as 1t IS discharged
| The approaches to the completed tunnel upon the
| English side will be strongly guarded agains
hostile invasion by numerous fortiheauons
many Of which now exist and, az an addihom
| recautiop, means will be adopted for
| SPEEDILY FLOODING 1T
! the entire length IN case the necessity should
arise Similar precautions will also be adopted b.
| France. But these are chiefly matters for ate
| consideration. To build the tunnel IS the frs
| tn ing, and now that matters are so well unde
way there is every reason to believe that befort
many years continental tourists will be safely ant
| In comfort travelling more than score of mile
| under the sea, while the winds and the waves are
angrily tossing the vessels that ply above thei
| heads