Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1889-12-06
ynE HELIcolDAL SAW
New and Very satisfactory sYS'e" luz
saving stone.


- w;ra cord has been adopted in many
European quarries. While retaining
sand as the cutting agent nj. fanlih
t,av of Marseilles. has succeeded III
applying it by mechanical means anu
no continuously as the sand blast ana
band saw, with both OF when aPpii-
ances his system-that OF the neil
coidal wire cord"-has considerapie
analogy. H..
An engine puts in motion contlnu-
Gus wire cord (varying from nve "
seven thirty seconds of an inch In diam
eter, according to the work., composed
of three mild steel wires twisted al d
certain pitch, that found to give Tue
best results in practice, at speeu VI
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 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 II 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 Tie cord causes it, while travelling,
to turn upon ITSELF and thus become
worn evenly. A cord of $50 yards in
length will cut about 70 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 adj
vance of inch in granite or porphyry
and inches in marble is regu' arly OBJ.
tanned in blocks of Is or 16 feet long.
At the Brussels Exhibition of last year.
where the system was awarded prize,
the same cord which cut marble also
cut block of concrete composed oil
quartz pebbles.
Not merely does the helicoidal core
saw blocks of stone. but it even cuts
them out of the solid rock in the quar-
ry. To do this it is necessary to sinh
shafts of 2 OF q feet in dian eter in or
der to introduce the photographers
If there is free side TO start from on,
, shaft is sufficient for a triangular
block, but for a quadrangular one
, which is preferable, two shafts are nee
, essary- They are bored by mechan
| ical perforator, consisting of hollow
t plate-iron cylinder, having at its lowe
I end slightly thicker collar which act
! with sand and water in its latest devel
, opment. The cylinder is made to re
t volve at a speed OF 140 revo
3 lutions minute by means O
q ie'e-dynamic cable advancing abou
! an inch per hour in marble. An an
nular space is cut in the rock, leavin!
0 a core, which may be utilized as a col
t umn. The diameter of the shaftwa,
: depends upon the diameter of column
: most in demand, provided a sufficen
0 number be sunk. and the intervenin,
e angles broken down, so as to affor
r sufficient room for the pulley carrier
t lu the case of stratified rocks tn
t shaft-cutS are carried down to a mai
o ural parting; but in unstratifed rock
e nearly horizontal cut nay be mad
d with the cord, sufficient inclination
l. being given to insure the flow of san
s and water to the bottom of t cut.
), Such is the method of working prac
d tlced at the Traigneaux quarry. nea
> Philippeville, in Belgium. where Is.
n 0OO cubic feet Of marble are extracted
!. yearly with thirty horse power en-
= CINE, and only thicty hands in summe
! and twenty in winter, besides the lad
who tend the wire-cords The syster
Is also employed at granite and MAI
!, D equarries in Ftance, Germany, Spain
Italy, Algeria, Tunis, and other cour
l. tries, where it is said to be giving sat
n lsfactory and economical results.