The Idaho world. [volume] (Idaho City, Idaho Territory) 1864-1918, 1871-02-09
THE MOUNT GEMS TUNNEL.

Il "A caOle dlspatcn mas informed us tnaC TIT
. Mount Gents tunnel, one of the most tremen
dous engineering feats of the age, would bs
completed yesterday. 1t is an internationa
Italian Governments; and the fact that the
French are just now occupied in task with
their German neighbors, more difficult even
than the boring of the Mount Gents tunnel, led
us to suppose that the latter enterprise would
be neglected, or ut least retarded. It's com.
pletion in the midst of great war that would
seem to exact all the resources that the French
have ut command, is an impressive proof 0l
the eminent Importance that this age attaches
TO works of cheap inter-c0mmunication.
The Mount Gents tunnel, whose completion
Wa now witness, has been before the eyes OF
the world for thirteen years, is not on the line
of any railroad, ana is not a part of any rail.
road, and is not part of any railroad scheme,
but is, as we have stated, a great tunnel be-
tween France and Italy, drilled through the
Alps. 1t has been talked of for quarter of u
century, but it was not until the year 1857 that
the work was actually commenced on the Ital-
ian side. 1t is bored through three peaks of
the Savoy Alps. Col. de Frejus, Grand Vallon
and Col. de Ia Roue-and, in fact, has no con-
nection with Mount Gents, seventeen miles dis
tant, whose name 1t bears. Before the begin
hs
gineers of high standing aud reputation who
gravely declared that the undertaking would
prove failure-that the workmen would per.
lsh by fire, water or noxious gases, aud that all
sorts of insurmountable obstacles would meet
them as they approached the heart OF the
mountains. In spite ot all these dscouraging
professional predictions, tho work was begun
IN 1857, and steadily prosecuted for four years,
when the perforators were called into requsi.
ton.
The usual method OF sinking shafts along the
line of the proposed tunnel. aud working
through from one To the other. was not appli.
cable 10 this work. on account of the great
height of the mountain. The only feasible plan
was to begin boring both ends, and continue IL
steadily until the opposite drills should meet
and give complete aperture. This made 1t
difficult to supply the workmcn with suffi.
cient quantity of fresh mir at n distance of two
or three miles from entrances. To overcome
this. machine that was a perforaior and air
pump combined was devised, which moved BY
air compressed to oHe.sixth its usual bulk A
portion OF this was conveyed into the tunnel.
and released for the consumption of the work.
men. ana another portion was applied directly
10 the drill which bored into the mountain at
the average rate of nine feet day. Ter, per-
torators were kept constantly at work. The
motive power was conveyed to the drill by a
flexible pipe. throwing the compressed air into
cylinder in which worked n piston driving
the drill into the face OF the rock. The drill
made two hundred revolutions minute, each
having n stroke OF two hundred pounds weight
The hardest substance it encountered was
white quartz. and every stroke against this
brought forth shower Of sparks that caused
the work TO resemble display of fireworks
IN the dark cavern. As preparation for |
blasting about ninety holes. three ieet in depth
and two or three inches in diameter, were
bored with the drill. charged with powder, |
tampcd, aud exploded. The shock would
brink down the face of the rock 10 the depth |
of several feet when the debris would be re-
moved. other holes drilled. charged and ex-
ploded; and thus the work kept steadily on for
years. The workmen were divided into three
relleis. eight hours being given to labor and
sixteen to rest. The most skltLi of them
were paid five francs day, and the other only!
three. The directors of the work declare that
only fifty or sixty workmen lost their lives by
accident during the boring; but as accidents,
such as premature explosions, and the falling
of rocks were frequent, it Is thought that these
figures fall far short of indicating the injuries
suffered by the men engaged in the work The
hardness OF the rock made the wear aud tear
ot machinery very great and it was necessary
to replace the drills every few minutes The
estimated average progress was about nine
feet day; but in the white quartz only dis.
tance of sixteen to nineteen inches per day
was made. The distance between Fourneaux
and Bardoneche, the two extremities of the
gallery, is 14,000 yards, or nearly as miles
The estimated cost Of the entire wsrk is
50,O00,000 francs, or about S30,000,000. The
on the French side is % feet wide,
and about as many in height A double rail.
way track running into it was used to convey
ools and supplies to the workmen, and to
,ring out the shattered rock {aa&
The next greatest work of this kind in the
world is the Hoosac tunnel in Massachusetts,, l
which was begun four years before the Mount q
)enis gallery, aud is not yet completed The =
french and Italian engineers. who had SUPER
ntendence of the enterprise. often had their
ingenuity severely taxed to devise methods for
the many unusual difficulties U
hey encountered, and they certainly are en- n
tiled to high credit for the patient assiduity b
With which they prosecuted their slow and
aborious task. AS q means of avoiding long
nd difficult crossing Of the Savoy Alps, in the :.
assage from France to Italy, the tunnel Ia a =
whose value cannot be estimated, IL
,hile, as work Of engineering, it will rank G.
ext to the Suez canal---Mo Rep. Dec. 81.
N
A CoLoRED woman, who had been lately q
inverted, was so unfortunate as to fly into a !,
asson over the misdoings Of one of her neigh =