Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1853-11-19
TALBoTs TUNNELLING MACHINE.

The successful operation Of this pondcrous mechanical
engine has at length demonstrated the feasibility of
cayatng rock and tunneng through mountains by
of machinery The slow and expensive process of per-
forang by of the drill and blast will be done
away with forever the dangerous force Of gunpowder
being superseded by the equally resstless but more
manageable agency of steam. Mr.. Tabots invention,
unlike that employed ruessy upon the Hoosac tunnel
entirely dispenses with the basthe whole excavation
seventeen feet in diameter, being made simply by cutting
and crushing the rock The cutting tool in the case
of the Hoosac machine, is the weknown invention of
Charles Wilson, which has long been employed to advan-
tagc both in this city and elsewhere in the business of
dressing stone for building purposes This however, is
the first instance it is believed in which it has been sue
cessfuy applied to boring excavatng. Mr.. Wilson's
invention consists simply of rotating disc of STEEL with
its periphery cutting edge properly adapted cut
away the surface of stone by rolling against it. Mr. Tai
bots machine applies sets series of these rotating
discs to the surface of rock mountain in such
that they describe in their action segment circle
from the centre to the circumference of the tunnel to be
eIcavated in combination with slow motion around said
centres while at the same time the entire machine which
carries the cutters advances forward In the direction Of
the axis OF the tunnel in order to keep the cutters to
their work as the face of the rock is away by the ope
ration of the machine The distinctive popularity Of the
invention is the simple but very ingenious method by
which these several motions combined as to cause
the different sets Of cutters in succession on the
entire surface of the proposed excavation.
machine embodying the features of this invention
and constructed for the purpose Of expermentay testing
Its value has just been erected upon the line the Harlem
railway, about miles distant from the city, 1t was
Connecticut under the immediate supervision Of the in
venor 1t is composed entirely of ron and weighs ex-
elusive Of the steamengne and boiler employed to ope-
rate it, upwards Of seventy Through the courtesy
of the propretors witnessed its operations day or
two SINCE and were as much grated by the successful
issue of its conflict with the rock by the wonderful in
genuity and mechanical skill displayed in its continuance
and construction. The rock to which Il is applied in
point of texture and compact solidty scarcely yields
precedence to the hardest granite 1t is therefore ad
raby adapted to test the power and capacity of the ma
oh he nngiti Of ha a.
chine approached it, Of necessity in the FIRST instance in
oblque direction Its face too was inclined from an
exact perpendicular the base projecting forward several
feet further than the summit At first therefore the
sectors arms which carry the cutters did not oil strike
upon the surface to be cut and the machine accordingly
operated at disadvantage the opposition being but par
tal and the strain unequal So massive, however was
the structure that the shock scarcely percepble
and the huge seemed to advance through the oppos
ing rock with motion facile and regular that Of
their neghbors which played unressted in the above
Slowly but steadily and unnchingly the cutters descrb
ed their curve the great face plate seventeen feet in
diameter revoved and the machine advanced throwing
out and drawing in its arms like the claws and eelers Of
an immense iron lobster at every motion graphing with
the everlasting rock and crumbing successive inches Of
ii into dust II spectacle to be contemplated in 81
lent admiration, almost with and wonder.
The machine has advanced about twenty feet be-
yond the point where it originally struck the rock at its
base and is already operating with all its cutters upon
the entire surface to be cut away 1t goes forward from
five to six inches per hour Only four required
in operating it, two Of whom employed exclusively
upon engine by which it is propelled and there
would appear to be reason why the work should be
suspended day night at occasional intervals for
the purpose of sharpening the cutters.
The immense importance and value Of such inven-
ton readily suggests itself to the mind In oil the
rious departments of civil engineering its want is felt
and the best mechanical talent Of the land has long been
seeking for solution Of the problem it fully eucdates
The public indebted for its development to CHAs T.
SHELTON Esq., who hns been identified with cutting
machinery from its infancy.-N T. Jour. Of Commerce