Burlington free press. [volume] (Burlington, Vt.) 1827-1865, 1852-03-12

rapidly. Now suppose hoop "a feet in dam
ser to be armed Of one edge with these cuts
ting wheels or rollers, and to be turned on its
axis with the armed edge pressed against the
face OF the rock, and we shall see that it will
cut groove or channel Of its own dimension
Such channel or heading the machine is to
carry in three feet and also drill hole in the
centre. 1t will then, being mounted on trains,
be moved back, and a charge of powder or gun
cotton, will be exploded in the central hole,
which will tear out the rock.
The mechanism by which the cutting of,hs
channel aud the drilling Of the central hole sre
to be effected, At the same time, seems we'll
adapted to the purpose. The immense hoop is
mounted % a strong wheel, like tire project
ing forward in front three feet beyond tue fell
ioes. There are on its periphery ten of the
small cutting wheels, placed al d.f-reEt angles
so as 10 cut The groove arger than the hoop
itself, and let it work freely. These cutters
are disposed ia lour groups Of two or three
each, and behind each group IS a scrsper which
collects the chips, and carrying them off on an
inclined plane, loads them at intervals into a
cart winch stands underneath on one SIDE.
THIS great wheel or augul-5t is mounted on
a large hollow shaft or arbor, from the centre
Of which drill works TO make the central
hole. Motion is given to the great wheel not
through its arbor, but be a shaft parallel with
that arbur and above It, bearing pinon which
tootns into the inside of the great hoop.
And fixed ring, toothed on lis inside, gives
motion to the drill in the centre OF the main
shaft. The same shaft which drives the great
wheel, also drives a feeding screw, which car
rIes the main shaft and vince. forward on ways,
oue-eighth Of an inch for each revolution Of
the cutting hoop. The whole Of this gigantic
machinery is borne upon mammouth railway
carriage ot four wheels, which, when the ma
chine Is boring, is TO be braced firmly against
the walls OF the tunnel.
The driving power may be either stajioua-
ry steam engine at the mouth of the tunnel
Connected by bands Of it may be locomotive
mounted on the trans.
As the boring machine is already set up on
lis broad guage wheels, 1t begins to develope
lis mighty proportions 1t looks as if it might
walk through mountain. When finished It
will weigh eighty tons, every ounce Of it Of
iron, steel and brass, unless it be the babbitng
, OF soft metal which lubrcates its enormous
loints. To move 1t TO the scene Of its opera
/ tIons it will be taken 10 pieces. The heaviest
piece will weigh only eight tons.
| As the cutting quality of the invention has
been tested satisfactorily on granite, there is no
reason TO believe tat It will fail on softer
rock-and AS to the adequacy of the proposed
machinery to turn the cutting quality to good
account in the tunnel, We thiuk there cannot
be two opinions among practical mechanics
who inspect lie model. Il has every appear
ance OF having the living eo-ahead principle in
it, TO say nothing oi the Hooslck tunnel,
which it is expected to reduce to feasibility
it can hardly tail TO produce revolution in re-
gard to deep cut ing Oh railroads generally.
II this machine should work as well as the
experiments on Quincy granlte have given
reason to hope it wlli, two such, working al
both ends, will finish the Hoosick tunnel in
two years, and keep most of the Sabbaths, il
required,