The Helena independent. [volume] (Helena, Mont.) 1875-1943, 1890-11-07


the bottom Of the sea has been found by
soundings TO preserve the outcrops Of the
different strata in unbroken line from
coast to coast. Tho sequence Of the forma-
ton Is cherry flint ON the top, while chalk
with dints, then white chalk without flints,
under which comes the chalk mari. next
the upper greenland carrying littl water,
then considerable stratum Of Qault, be-
low which 10 the lower greenland invariably
charged with water.
The tunnel il located in the chalk mari
about twenty fest above the upper green
sand. It 10 designed 90 % to have 16O feet
between 1t and the bottom of the sea, and
az the sea il rough and over15o fest do ep,
itfollows that the tunnel will be 800 feet
below the surface. The soundings alb We
mentioned showed, from 6,oO0 specimens
brought up, that the outorops Of the va
in straight line; hence the condition Of
keeping 15O feet Of chalk cover, and being
within twenty feet Of the upper greenland,
involved the line Of the tunnel being
curved under the sea portion. The total
length of the tunnel is thirty miles, of
which twenty miles would be under the sea,
and ave under the land ON either side,
forming the approaches to the English and
French sides respectively. The latter
would join the Northern railway Of France
seven or eight miles on the Boulogne side
Of Calais and the former would connect
and Chatham lines, not far from Dover.
Whsn the work was stopped some eight
years ago, mile had boon done ON the
English side and . similar distance On the
French. Thus . eenth Of the whole dis
sanoe under the sea stands now completed
81 ht>aM A~wA Il
On the Enalish aide four-ineh plunssr
pump, working few hours 90
oasionally, keeps the heading clear
OF water, and since the ground
was opened the dew Of water, II such it
can be called, has been found to diminish.
and when the stream was cut BY the ma
chime 1t appeared 70 bs under some pressure
which rapidly disappeared a. the cutting
progressed. In fact, water was mo moro
than little reservoir which bad probably
been imprisoned since tho chalk was depos-
tied. For the advanced hsading no lining
vas required except in few. places whore
the strata were aoeidently disturbed.
A machine ID now lying below, and near
the end Of the Dover pier, with the air CON-
neotion complete and in such order that in
i've minutes the compressed air could b
turned on and the driving toward France
hour. AZ work would bs carried on from
France simultaneously, couple Of. years
would have been sulhctsnt for the heads to
have met, and had the work mot been
stopped. the trains would have been run
ming three Or fonr years ago between Lon
oGm sno fslls.
- Msca ah 1atn 1nio1 the Work was
Coils. Frederick Beaumont and English,
Of the regal engineers. It weighed about
forty tons, and was driven by compressed
~. ne msen1ne consisted OF very mas
sive oussef-nssa IN sne saape OF single
Ctoss sIns tne 0lametet OF the tunnel TO
20. Gus tDetween seven and eight
iron cutters and carried by heavy steel
snsts eesieo 20 me motor engine 30 - TO
!couce tne speed some lOO 70 !. Tho out
tef-ncao. sRa1t, gearing ana engines were
PlaSeo on cass-rsn ped, sliding longitud.
na!y On asevy steel seml-clfcular bed
Rlsse extenolnG one-tnifd OF the way round
toe oottom OF sne tunnel; the connection
oesWeen the upper and lower beds was
Iozmea oy means OF screw feed capable Of
x xss.s.a9n. so tnas eecn evolution Of the
neso sav9noeg sne neadinR given DIS
s@ ms u1aesI u forced the bed back.
ar ano acu.y y; e naro ground q keeping
rr;rad so.cs :; ;.a. MI W one which re-
.osn oa ce.. a; LcunG nest suited 70 the
VOL na ~! ~ c.Icui.I snaiP.eagsd chisel Of
csss HON. SspeccIaay eeIected Tor hard
nes' aoou! aoos !ees u "a, diameter
ana NO Ilones snicA; Ineee were
i. -. n4eS s .ns e. ~. .us esRcs Tore shey
afound sney we're eot Feoast. Inese cutters
800 -. ~ Eak.rn n, VAN ~ return
1or QUO Metsl, % ~ .on nes.
- tne S.ea ~ ~ w W. tsr :ds oot.cm
t.o suitable scoops, one on each s side Ct me