Mower County transcript., 1889-11-06
THE HELICOlDAL SAW.
Anew and Very Satisfactory SYstcm for
Saving Stone. =

THE HELICOlDAL SAW.
q New and Very Satisfactory sYstcln for
Saving Stone.
A new plan Of cutting stone by means
I. .of wire cord has been adopted in many
European .quarries. While retaining
sand as the cutting agent, NJ. Panlin
iay.. OF Marseilles. has succeeded in
applying it by mechanical means, and
rs continuously as the sand blast and
band saw, with both of which appli-
ances his system--that of the "heli-
coidal wire cord"-has considerable
analogy.
An engine puts in motion continu-
ous wire cord (varying from five to
seven thirty of an inch in diam
Rter. according to the worlz). composed
of three mild steel wires twisted at q
certain pitch, that found to give the
best results in practice, at Il speed of
from Is to II feet per second, the higher
speed being adopted for the smaller
diameter.
Instead of the stone being brought
to the saw, the wire cord, which may
be of indefinite length, is led to the
stone, being guided by grooved pull
leys, mounted on bearings with uni
versal joint, which permits of their
adapting themselves to any change Of
direction. The same cord. which is
kept at uniform tension by q weighted
truck on an inclined plane. may act
upon: any number of blocks. provided
sufficient space be given between them
to allow for cooling.
The pulleys are mounted in stand
ards, and are fed down by endless
screws rotated automatically if the
stone is uniform. but preferably by
hand If there is reason to suspect ir-
Irregularities in its texture. Sand and
water is allowed to flow freely into
the cuts. the sand carried along by the
cord in the spiral interstices between
the wires. causing a uniform at
triton of the stone. The twist
of the cord causes it, while travelling,
to turn upon itself, and thus become
worn evenly. A cord of $50 yards in
length will cut about 20 feet deep in
blocks Is feet long, or produce 400
square feet of sawn surface before be-
ing worn out.
The sand must be sharp, and not
used more than three times The nat
ure, of the sand is determined by the
hardness OF the stone; thus quartz sand
will cut granite and porphyry, which
it has hitherto been found impossible
to saw. Or indeed cut in any other way
than by pick or chisel. An hourly ad-
vance Of inch in granite or porphyry
and inches in marble is regularly OBJ
tanned in blocks of Is or l6 feet long.
At the Brussels Exhibition flast year,
where the system was awarded prize,
the same cord which cut marble also
cut a block of concrete composed of
quartz pebbles
Not merely does the helicoidal cord
saw blocks of stone, but it even cuts
them out of the solid rock in the quar-
ry. 10 do this it is necessary to sink
shafts of 2 or q feet in diameter in or
der to introduce the pulley-carriers.
If there is a free side TO start from one
shaft is sufficient for a triangular
block. but for a quadrangular one,
which is preferable. two shafts are nec-
cssary- They are bored by a mechan-
ical perforator, consisting of hollow
plate-iron cylinder, having at its lower
end a slightly thicker collar which acts
with sand and water in its latest devel-
opment. The cylinder is made to re-
volye at a speed of 14O revo-
lutions a minute by means of
a tele-dynamic cable advancing about
an inch per hour in marble. An an
nular space is cut in the rock, leaving
core, which may be utilized as a COL
umn. The diameter Of the shaftway
depends upon the diameter of columns
most in demand, provided a sufficient
number be sunk. and the Intervening
angles broken down, so as to afford
sufficient room for the pulley carrier.
1u the case of stratifed rocks the
shaft-cuts are carried down to a nat
ural parting; but in unstratified rocks
8 nearly horizontal cut may be made
with the cord, sufficient inclination
being given to insure the flow of sand
and water to the bottom of tle cut.
Such is the method of working prac-
ticed at the Traigneaux quarry, near
Philippeville, in Belgium. where 15.-
900 cubic feet Of marble are extracted
yearly with a thirty-h horse power en-
gine, and only thirty hands in summer
and twenty in winter, besides the lads
who tend the wire-cords. The system
/ is also employed at granite and mar
b b'equarries in France, Germany, Spain,
Italy. Algeria, Tunis, and other coun-
tries, where it is said to be giving sat-
isfactory and economical results. .-Sci-
ence.
CLUBBING BY POLICEMEN.
Usually 1t Produces Mere Confusion