The Cape Girardeau Democrat. (Cape Girardeau, Mo.) 1876-1909, 1894-11-24
RAPID STONE SAVING.
The Process As Accomplished by Chilled
Metallic Shot. f.

1he Process ~ Accomplished by Chilled
Metallic Shot.
The use of chilled metallic shot has
completely revolutioned the stone-saw.
ing trade, by reason of the rapidity
with which the work can now be &C.
acomplished as compared with the times
when h saving material consisted
only of quartzose sand. It is obvious
that in saving granite, for instance,
the sand alluded to, not being harder
than quartz, was incapable of doing
much work, as that mineral exists SO
a~bundantly in granite. What was want
I'd was something harder than quartz.
several minerals answered the purpose,
among which were corundum (emery)
and the diamond. The former of these is
occasionally used for saving, and large.
dy for rubbing granite, marble and
the like, preparatory to the polishing
process; the latter has for some years
been employed to a limited extent for
saving the hardest kinds of stone, and
diamond disks may be found in the
workshops of every lapidary. But
these minerals are rather expensive,
especially the latter, and until within
RECEIPT years sharp sand was still almost
universally employed. Then a new
material, known as chilled shot, was
introduced and was rapidly taken up.
During our visits to various granite
,enters in 1ss6-S7 we found it had al
ready gained a firm foothold, as the
rate of saving was greatly increased
oy its use; it was also very economical
IN working. and has been much
employed to this day. The fore
going observations were suggested
by some samples and a trade descrip-
lion of 'Krushite," which is said to be
4 new material. 1t appears to be
chilled metallic shot, and is very SINH
lar to, though probably not identical
n composition with. what we saw in
nse some eight years since. At any
rate, the use of chilled metallic shot
Cor saving hard stone is by no means a
new idea. "K~rushite" is said to be
capable of saving blocks of granite at
The rate of four inches and hard grit
stone at nine inches in depth per hour,
with twelve blades in the frame.
1t is manufactured in several differ
ent sizes. the largest about the size of
small rabbit shot being suitable for
sandstone and the smallest Zine DUST
for the rubbing bed. The material is
used in sand blast apparatus in lieu of
sand, and in substitution for diamonds
in boring and drilling. 1t is described
as being absolutely without points OF
edges, though we do not find this state
ment borne out by samples sent us.
However, there can be no question that
the chilled metallic shot is by far the
best and most economical material
hitherto discovered for saving the
hardest descriptions of stone and for
use in the initial stages of rubbing.
1t must be handled with great
care, though, in the manufacture OF
marble. Only the other day we saw a
beautiful slab utterly ruined during
the final polishing with putty powder,
by reason of a few chilled shots having
found their way under the felt pol
Usher, with the result that the smooth
surface of the stone was deeply scored
before the machinery could be stopped.
That, of course, is sheer carelessness;
the fact that the chilled shot was capa-
BILE of scratching SO deeply in such a
short space of time is distinctly in its
favor as a saving material.-Londop
Builder.