New-York tribune., 1870-11-22

guide will request you to pause for while, and you will
probably sit down In the rugged gallery, not more than
nine feet wide, to await what you know must be
blast that dreary cavern, nearly three miles from
| the outer world and with more than mile OF Alps
towering above your head you expect to he almost deaf
ened by the sound OF the explosion But II is very differ
ent from what It would be in the open ara dull heavy
rumble, echong and reGchong through the gallery, ana
seeming TO shake the mountains from base to summit
One explosion follows another in rapid successon and
after eight the wooden doors, which are closed
lust before the blast opened again. and the clouds OF
thick yellow smoke pouring through the Tunnel In
such density and volume to be painful If not danger
ous to persons with weak lungs The guide then gives
you sign 90 on and you soon get beyond the sufio
eating atmosphere into comparatively fresh and
pure.
Before long you reach the end of the Tunnel and
the carriag. platform supporting the perforaors ac
lively at work They scatter sparks of fire from the
rock as to remind you Of small Catherine wheels. The
motive power OF the perfoatOr conveyed 10 from the
conduit by flexible pipe throwing the compressed air
into cylinder placed horizontally along the carriage,
which the Italians call the GGuSo In the cylinder is
piston TO which Is attached sharp drill nearly three
feet long The motion OF the piston drives the drill
against the rock and by complicated piece OF machin-
cry gives 1t a rotary motion.
TIE DRILL.
The drill makes 300 revolutions minute, and as the
force each stroke upon the rock is 200 pounds
the power the drill exercises is equivalent to about 10000
pounds minute. The hardest substance the workInen
is white quartz and through it the progress
necessarily slownOt much more than half that made
through hornblende. mica, and slate The first
difficulty in beginning the perfOratiOn Is to make
hole large enough to cOnfine the drill. That once
made the drill works back and forth and r0ates with re-
markable regularity assisted by stream OF water 10
facilitate the boring process. For blasting, about 20
holes three feet depth and two to three inches In
iu k.
charged with powder and tamped, when, the miners
Withdrawing behind the wooden doors, the slow mach
is ignited the explosion takes place So the labor
continues day and night, week after week. lncludlhg
Sundays, month after month, year after year. Ihe
workmen are divided into three reefs Eight hours are
given TO labor and l6 to rest. For all this hard unyary-
ing and perous toll in unwho!esOme and poisonous
atmosphere the common aborers receive, L have been
,od only three francs day and those who have more
skill and experience but five francs
The wear and tear OF machinery In the Tunnel Il very
great The drills have to be changed every few minutes,
and it estimated that by the time the Tunnel Is nished
at least 800 perforatOrs Will have been used up.
ACCIDENTS.
One would naturally suppose that frequent accidents
would be unavoidable in such gigantic undertaking.
and had often been told that than l,0O0 workmen
had their lives up the Summer Of 1869 The guides
and d ectors, however have a different story. They
declare that not than 30 or co men have been Killed
outright though number Of others have been seriously
wounded. Their statement, suppose, is to be taken
with allowance. have always found that casualties of
any kind diminish in proportion TO the interest or the
persons who report them. Most OF the accidents
on the railway, from the falling of rock, and from
premature explosions; but many Others which defy
classification are constantly taking place. The
day before. the day after my visit, premature
explosion killed. l informed, five men and
wounded nine Others three OF them fatally Iheard,
too that week previous a rock had fallen and crushed
aflraa sHaI huu
simple of three that II eleven lost their lives
In week, 1t hardly probable only fifty sixty
should be mOrally hurt in tweyeyears. / have men
toned the average rate OF progress through the tunnel
at nine day; but this is estimate rather than
fact. 1t is almost impossible TO give an exact aver
age owing to the difference in the material which
the drills encounter. AS the work has advanced,
the rate OF progress has diminished. Through the
quartz the w0rkmen sometimes have not made
than l6 TO 10 inches day During the month OF May,
before the quartz had been reached, advance of 80
metres "a metre is 80 3SlOO English nches during June,
when the quartz first began to appear 4s metres during
July IL and during August only r. If it had not been
the quartz IL is probable that the Tunnel would have
been completed than years ago. 1t thought
that the work would be finished early last Spring but 1t
now stated upon what claims to be good authority,
that 1t certainly will be before January 1, 1871.
the excavating gallery the temperature ranges from
70 to IS degrees Fahrenheit all the year round and the
ternal atmosphere is often from 80 to As degrees.
THE ITALIAN SIDE.
The perforators not introduced into tho Tunnel at
Fourneaux he French sde until 1863 years after
they had been in use Oh the Italian side.
IL Is said that the work from Bardoneche
has advanced about ~ miles, and the distance in
straight line between FOurneaux and Bardoneche-the
termini OF the Tunnelmeasures l2323 metres, nearly
1900 yards, almost AS miles 1t will be that the
Italian side has proted by the advantage in time.
The aircompressing establishment at Fourneaux
there is similar one Bardoneche) is the banks of
the Arc, about threequarters OF mile from the mouth
OF the Tunnel and well worth visit, especially from
those who understand and feel interest In ingenious
mechanical contrivances The machinery seems sim
pie, and yet is complicated witha that any explana-
nation without diagrams would fail to be satisfactory;
though the principle, which have briefly stated ~
the motive power remembered, the general plan of
the work ought TO be clear
The amount Of money expended, or that will he
pended, when the Tunnel is finished have heard
ousy estimated at lOOOcoOoo 5oOOooO francs; but
should suppose when tho entire footed up that
might reach nearly lTo,ooO,OoO francs,
GREATNESS OF THE woRK.
Since the beginning OF this the greatest achievement
in engineering yet undertaken at least in modern times,
the predictions have been that the work would
be finished. Time and again the report has been
circulated Of the abandonment the enterprise hope
and impracticabe and yet, have said the labor
has gone steadily and without serious interruption,
at both since the first day of its practical be-
ginning. The Italian engineers Grands, Grattoni, and
sommeller. mainly contributed with suggestions from
Bartlet's rock perforang invention TO the formation
OF the ingenious apparatus which has been success
fully employed in the construction OF the Tunnel They
speculated experimental long and oenergetcaly
upon their ideas and plans that their final triumph
hailed by their friends with much surprise rs sasfac