Nashville union and American. [volume] (Nashville, Tenn.) 1868-1875, 1871-12-13
Engraving with the sand BIa.a.


The most remarkable invention brourbt
out within the past year, is that by Mr.. b.
Z. TilGhmaE, of Philadelphia, for ,norayir.r
Ca glass and stone. BY means or a iet of
quartz sand, blown through pi pe hy steam
At = pressure Of 800 pounds to. the soUara
inch, he can cut hole in solid block of
corundlIm-only inferior to the diamond in
Ear;tness-in few minuteS,. The new pro-
cess Is now exciting great. interest IN En-
rope; an English Journal. thus speaks of If:
y lis American eng .neer inst turns rpon
cogindi.m pipe VII Ich discharges sifed-
SAND, mixed WIN a furious squirting of
Steam, ana the M { shower Of particles thus
n'ih7, cuts no : egnal to the diameter Of
Jio Je,' Inc same effect is produced in
sLyjhihg eE e submitted TO the process.
here mas ne world been grinding, hammer
l'.,. cIh- ellinc, and whirling drills for cen
lures, % make holes and channels in obdu-
Ta'e substances, when suddenly the friend
OF our youth. the sqUirt-in a new form,
30 doTbt-cOmes to the rescue; and for the
future, we shall see the work done by this
irresistible jet of dust beating in ten million
millions Of fairy rans upon the object; thus
efi;scting what Is wished in a tenth Of the
previous iimt. a~i with exquisite precision.
But the clever G.sGcytrer of this ne agent
has found that so great a force Of steam is
not necessary for finer work, such as grind
in~ or engraving glass. One may employ a
blast Of air for this purpose by means Of
rotary fan. The tube is fed with sifted
sand, which the air-blast takes up and
whirls against the glass. Il will thus com
pletely dep0lish a surface, moving past at
the rate IF five inches in a minute, and the
spent sand and glass-dust can be perpetual
ly returned and re-employed. Moreover,
by covering parts Of the glass with semi
elastic material, such as paper, lace, caout-
cifoGc, or oh-paint designs Of any sort
may be engraved. The particles which eat
off the hard glass or stone, beat in vain up
on the iuterpOsed medium; and so curious
Is this resistance that even a green fern leaf
may he used, and the sand-shower will con-
sume all but the parts thus covered, leaving
delicate pattern of the frond. Again, in
that kind of glass-work where a sheet of
one color is supeT-impOsed upon another,
the upper sheet may be partially protected
by a paper stencil, while the parts left ex-
posed are eaten or bitten away into the de-
sired fiyures. The film of bichromatized
gelatine, used for Photographic negatives,
may also be thus utilized for producing an
engraving on glass or steel; and by very
simple arrangement the jet can be rendered
movable, and be handled with an absolute
artistic freedom. So effective, indeed, is
this principle of minute myriad tappings
npon any exposed surface, that small leaden
shot. driven in the same manner wear
hole in the hardest quartz rock. The ex-
hibitor of fhhe new agent showed a sheet of
glass which had been perforated by a sand
Jet under a covering Of wire gauze. The
glass was turned, as it were, into delicate
squares Of blond lace with meshes Of one
twrIflh Of an inch, and threads Of one six
teonih, u result unattainable by any other
pro 'esS.'
! may be added that the latest adaptation
of tais new Invention IS TO a peculiar process
Of raplacinG ilie art # wood engraving. 1t
consists in IringiuC upon suitable matriX
a arhotorraphc copy Of the drawing or en-
craving o. be produced. This is then
pa,sed beneath the sani-blast, and the cut
tin is thus obtained. The reverse engrav-
inc IS .icn subjected 10 the electrotype pro-
ccs-. aud any desired number Of copies are
produced.