Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1875-03-12

CUTTING MARBLE BY SAND BLAsTs.-Mes'rs
Sheldon & Slason, of Rutland. have con-
tractwith the government for Supplying 24o'-
600 headstones for the Nationa. Soldiers
cemeteries. The Rutland Herald describes
the way in which the stones are cut py
means of sand blast, which takes OH the
surface of the stone with astonishing rap'-
dity. The Herald explains
If for the blow of the hammer IN me
hand of the workman is substituted tne
blow of grain OF sand csrrieo " q iaPd-
current of air the same effect Will De pro-
dured only of course in a much smaller de-
gree. lust as the grain of sand IS smaller
and lighter than the hammer. One grain.
ot sand does not accomplish much. but
when millions are rained upon the surface,
thick and fast, it is worn away even faster
than by hammer and chisel. Ii portion
of the surface be protected from the impact
of the sand and the rest be left exposed, the
latter will be cut away and the former re-
main projecting.
The headstones furnished by Sheldon
& Slason are about three feet in height,
fifteen inches in width and five inches thick:
On the face of each, is cut shield shaped
depression in which is the inscription IN
raised block letters about anlnch In lengtn'
After being sawed 10 the right Dimensions
the blocks are dressed to the right shape
upon the top, which Is u section oil a GYM
der, running from front TO back oil the
stone. They are then sand rubbed py inge-
nious and very effective ruboers erected Tor
| the purpose After this they pass INTO the
| hands of a number Of boys whose business
| it is to prepare them for the sand blast
| This preparation consists IN fastening upon
their face the proper letters to form the IN
scription which they are TO bear when COM
pleted. The letters. or rather the shields
which are to form them, are of cast ZION
and are fastened upon the stone by shellac.
The apparatus of the sand blast Is quite
simple Steam is used 10 furnish q motive
mower to propel the sand. THIS is dis
charged through an iron tube like gun
| barrel. into which is led stream OF sand
| The tube is connected with machinery
which moves it slowly back and forth acros,
the face of the stone. while this Is carried
forward on rollers 80 that the whole Is al
fected by the blast. The amount OF steam
set free prevents much of the process beln9
seen. but hand placed in the neighbor
hood of the stone feels as though 1t wa
acted upon by innumerable neeGle-p0ints
and on being taken away is found to b.
covered with minute shining particles o
marble and .aud After about four minute
of this treatment the stone is removed. HI
iron letters are taken of by boys, who hea
them with a req not iron enough to soitel
the cement, and there Is the Inscription
complete. The shield j. depressed from one
fourth to one-halt an inch, leaving the let
tiers in bold relief The sand leaves the sur
face upon which it acts slightly rough, pro
ducing an effect Ike hammered stone.
Each one Of these machines will cut th
inscription upon store IN about four min
utes. and there are ;broo Of them, 50 tina
when all are working theY are capable q
turning out over FIVE hcudred day III
pressure of steam used is about eight
pounds.