The Sun.
London, England, 1863-04-06 00:00:00

THE MONT CENIS TUNNEL.

A letter from Turin, dated March 31, says, the Minister
For Public Works, General Menabrea, has given the Lower

House of the Italian Parliament most interesting particu-
lars respecting this great undertaking. He thus reported

progress:--
The lowest pass of the Alpine chain on this side is about
2,100 metres above the sea level, and the tunnel will enable
the railway trains to cross the mountain at a height of

about 1,333.8,—i.e,, 766.2 metres below the present
pass. The tunnel will be 12,220 metres in length. Its
southern opening at Bardonneche in the Valley of Susa is
1,335.38 metres above the sea level ; from this point the
tunnel Hies 0.5 per metres up to a distance of 6,100 metres
—that is, to about the middle of the gallery, when it again

slopes down at a declivity of 22.2 per 1,000 to its northern
opening near Modane in Maurienne, which lies at a height
of 1,202.82 above the sea. An English engineer, Mr.
Bartlett, set to work a boring machine, by which a tunnel
could be pierced with a rapidity eight or ten Vines greater
than any hitherto obtained by ordinary means;

but Mr. Bartlett's contrivance was wrought by steam, and

could not be applied to a tunnel where air could not be had
for combustion. The Italian engineers proposed to sub-

s flute compressed air instead of steam; and, notwithstand-
ing long opposition on the part of foreign scientific men,
their method is now in full operati n, and their success
exceeded the most sanguine expectations.
The tunnel was begun in 1857, with ordinary means.

That year and the two following were spent in prelimi •
nary operations, such as the construction of houses, work-
shops, &c , for in that inhospitable region there was all to
be done, The first experiments with the boring machines
were made in 1861 at Bardonneche, on the Italian side;
but even on this side the regular work only proceeded un-

interruptedly in 1862. The invention of the new machine
was yet in its infancy ; its occasional failures, and events
of gradual improvements could not fail to cause consider-
able delays. The tunnel at Bardonneche, on the Ist of
January, 1863, was 1,274 metres. In the years 1857, 8,9,

and 18661, 724 metres had be n_achieved by ordinary means.

By the aid of the new m ?chines 170 metres were added
in 1831 and 380 in 1862. On the Savoy side, at Modane,
from 1858 to January 1, 1863, only the ordinary means
were employed, and the result was for the whole of
that period only 925 metres. The tunnel, there-
fore, calculating the work achieved at both ends up
to the beginning of the present year, has attained a
length of 2,199 metres, 550 of which have been made with
the new machines. What was done at Bardonneche in
1862, in spire of the imperfection of a half-developed me-

thud—namely, 380 metres—must surely be possible in
1833; nay, it is quite certain that the result of the present
year will be no less than 400 metres. On the side of
Modane, again, the new method was applied on the
25th of January last, and, as there the errors which
retarded the work at Bardonneche will r e av,dded, the re-
sult of the work on both sides for 1863 will be no less than
00 metres. The engineers are very confident that the
work will proceed with even greater speed, but the Minister
would base his calculation on the most certain data, and, by
limiting the results of our yearly progress to 800 metres, he
thought the whole undertaking would be achieved in 12}
years. _

On IVIAy 7, 1862, a convention was signed with France,
by virtue of which the latter State undertook to pay the
sum necessary for the construction of 6,101 metres of
the tunnel. half its length, at the rate of 3,000
francs per metre, or 3,000,000 francs per kilometre, on
condition that this compensation should not, taken alto-
gether, exceed 19,000,000 francs. The French, how-
ever, reckoned the work upon the understanding that it
should be executed by ordinary means, and allowed a period
of 25 years as necessary for its completion ; but they stipu-
lated that in the event of the tunnel being accomplished in
less than 25 years, beginning with the Ist of January, 1862,
the capital of 19,000,000 f. would be increased at the
rate of 500,000 f. for every entire year that might
be deducted from the maximum of 25 years. If the works

were to last less than 15 years the premium would be raised
to 600,000 f. for every entire year's reduction ; so that if the
work were actually achieved in 12i years the Italians would
gain a premium of more than 16,000,000 f. Moreover, as
the French Government does not reimburse the Italians im-
mediately, but pays the interest of the sums due, and these
interests may be reckoned at 6,500,000 f., the Minister
calculates that Francs will, at the end of the work, be in
debted to Italy to the amount of aboouot,
0301:f
falls to
ranee fF ;
.
The Victor Emmanuel Railway Company is obliged to
pay a sum of 20,000,0004 of which 7,0
the 13,000,000 f. which will be paid by the Victor Em-
manuel Company is,therefore,to be added to the 31,700,000 f.
contributed by France. The total expense will be about
65,000,000 f. Deducting the French share and that of the
Victor Emmanuel Company, there will then be only about
20,000,0001. left to the charge of the Italian Government,
and this will include the railway line from Susa to Bardon-
neche, a line 40 kilometres in length, which will cost no
less than 14,000,000 f. or 15,000,009 f.
It is important to observe that by the treaty of the 24th
March, 1860, which made Savoy over to France, it had
been agreed that the Italian Government took upon itself
the accomplishment of the work of the Mount Cenis
tunnel. These words of the treaty were differently
construed by the two States, inasmuch as Italy only reserved
the power to have in her hands the whole execution of a
work which reflected so high an honour upon her en-
gineers, Grandis, Grattoni, and Sommeiller, whereas France
conceived herself entirely exonerated from her own share in
the costs. It was the technical, not the economical, charge
of the work that Italy intended to reserve exclusively to
herself. The engineer Grattoni and the Deputy Parsini
were therefore sent to Paris for some explanations with the
French Government, when, after long discussions, and upon
the production of documents irrefragably proving what was
Count Cavour's real mind at the time of the conclusion of
the treaty of 1860, France handsomely acknowledged the
reasonableness of the Italian claims, and entered into that
new convention of May, 1862, to which the Minister
referred, and by which France engaged not only tO
bear her own share of the expense, but even to allow the
Italians a premium, should the skill of their engineers suc-
ceed in hastening the consummation of that undertaking
by which the Alps shall cease to be a barrier to the inter-
course between the two neighbouring countries.
The Minister added some important facts which will give
an idea of the magnitude of the work in band. In 1862. he
said, in order to pierce 380 metres of the tunnel on the side
of Bardonneche, the men were employed 582 times, each
time 7 hours and 39 minutes for boring, and 6 hours and 2
minutes for loading and exploding the mines and clearing
away the rubbish. In these 582 operations, 45,751 holes
were bored, from 75 to 80 centimetres in depth ; 72,538
chisels were set to work; there were 54,875 blasts, 18,622
kilogrammes of gunpowder were fired, 76,000 metres of
match-line were burnt, and 1,334,000 cubic metres of com-
pressed air were consumed, equal to 8,004,000 cubic metres
of atmospheric air. The workmen on Jan. 1, 1863, were 720
at Modane and 900 at Bardonneche—altogether, 1,620. The
grants for the work were as follows ;—For 1857, 1,000,000£;
1858, 3,509,000 f; 1859, 600,0001; 1863, 2,500,000 f; 1861,
3,000,000 f ; 1862, 2,000,0001; 1863, 2,000,000—altogether,
up to this day, 14,500,000 f. The expense up to the end of
February has risen to 13,182,6031 18c, and the Minister has
in hand 1,317,3961 82c. lle, theerefore, thought that it
would be necessary to apply to the Chamber for an addi-
tional grant of 500,000 f. to enable him to finish 600 to 700
metres of tunnel, which were to be completed before the end
of the present year.

Sivori, the famous violinist, has been decorated
by the King of Prussia.

The ship Result, from Australia, passed up the
Channel yesterday morning, with 41,000 oz. of gold and 50
passengers, 11 of whom were landed at Plymouth,