Wichita eagle. [volume] (Wichita, Kan.) 1886-1890, 1888-03-17
CAMEO CUTTING.
DESCRIPTION OF A PROCESS GEN.
ERALLY LITTLE UNDERSTOOD.

Two Kinds Of Cameos-Trsatmene OF
Shells and stone.-Tho Round Chalced.
onous Pebble of Braril-Msthods OF the
''Celorsr"-rhe Engravcr.
Canoes are Of two kinds-tkose cut in
stone, or in petra dUra, and those cut on
mollusk shells. The latter are found chiefly
on the African and Brazilian coast. They
show, as rule, two layers-a pale coffee
color, or deep red and white. They are clas-
sifisd in tao trade as the Bulls Mouth, the
Black Helmet, and tn. Queens Conch- The
first has red or sSrdonyx inner coat, the
second blackish ground and the third a
pink ground. The first are found mostly
at Madagascar and Csylon, and the second
at Jamaica. Nassau and Now Providence.
| They are formed Of TIRES distinct layers of
calcareous matter, and their peculiar struct-
ure, while II affords the greatest protection
to tbs animal, serves also TO give the cutter
secure foundation for his work.
Designs upon shell canoes which are very
much softer than stcre canoes, may be
effected by the process necessary in the treat
! nlsHt Of the latter. Or, when the shell
yields readily, the cutter does not resort to
the engine, bat, having drawn an outline
upon the prepared ground, cut. away from
1t as the wood ensrsrer does, with tools care
| fully made for this particular industry. They
ars files and Eravsrs. The tool most used is
fiat on sids ard round on the other, and
serves therefore either es gouge or chissl.
OF Sicilian origin, the manufacture of she'll
canoes was carried from Italy to Paris; and
more than ons-half tie output of the lapi-
DIARIES goes TO England and is thence sent to
the United States Ths she'll cameo is, Of
course, Inferior both in durability and ar
tistic quality, to IL. ston. canoes. which
enable tia engrsvo. to give considerable
rel md remarkable fidelity to any design
whioI may &c placed upon them.
The prize stones are those which show four
or five distinct layers Of different colors.
! Thus, FOR q heroic head, tho face would be in
the liEhtart color, tho helmet dark, the crest
. shade lighter, and tbs ground gray. Art
lists like to cut Nsdusa on stones having .
red layer, % - to use that shade on tho
snakes. The stones now in favor ere those
showing layers Of black snd white Of equal
breadth. Before process OF c0lorinG was
! founder rebound, rather, for # Is now
known 10 have been in use and lost IN an
| tiGuisy-Gsrman ayasss Of two shades Of gray
u
designs were engraved upon thsrn. Very few
canoes seen in jewelers. cases confess to the
careless observer that their beautiful colors
| and high polish arc due more to chemistry
than to nature. The ooloripg process is very
! curious
Tina round chalcedonous pebble Is the orig
! inal stone cameo. In Brazil it is found in
river beds. At Oberstsin it is found under
tia rocks that ere tho great ribs Of the high
! formation, and 1t lies freely also in the
/ ground ike Tint stones in chalk From tho
Iaills OF Obsrstsin and 1dsr the lapidaries Of
/ tas world ara supplied. When the psbbls is
first tested the trisr breaks of q small bit
and noiztsns the fragment with his tongue
He watches keenly ths rapidity with which
! the moisture 10 absorbed and WHISTLER the
! absorption il In bands, and in one band more
rapidly than IN another. Thus he cen;sct-
urss its capacity to receive color. The peb-
bic may be nothing but what We call agate;
but chsRistry II going to make ii onyx or
sardonyx. By its ssnsisiveness to moisture
he rates its commercial value, and then it
goes not TO the sngravsr but 10 the Sitting
mill, where it's roushness 10 ground oil, and
it Is cut 50 a. to bring the white stratum or
layer uppermoSt Then 1t is ground with
emery and polished with water and rotten
stone on pewter lap.
1t goes next to the colorer. He immerses
It in honey and water, and for several weeks
ID Is kept in its bath at . temperature Just
bslow boiling. When done it is transferred
10 another tub, and covered with sulphuric
acid heated TO $50 or 400 dsss After ten
hours it i. finished. It goes next into clean
water and is dried in an even. After polish
ing it lies in oil, which removes the appear
a0cs Of flaws and adds to the brilliancy of
the polish. Bran roHoves the oil Tbs So
crcts Of the coloring have mover been fully
underwood, and tbs operation of the various
influences Is Uncertain. II Is taken for
granted that tho honey fnvades the pores and
il carhoai7ed By tho sulphuric scid. The de-
position Of the carbon increases the color Of
each band which the honey has psrneatsd
II the celor Of the stone Is uniform through
out it is natural; il it has been chemically
heightened or produced by sulphuric acid,
which makes tho black ground, or nitric
acid which produces the carnelian ground,
the color will be found on examination
superficial and uneven. Only expert. can
detect pure chalcsdony from colored egates
II a portrait IL to be engraved upon the
stone, many artists prefer first to make the
model in wax and prove it in plaster as the
engravsr Of cid tested the design he intended
to pat in enamel upon gold The model
ing accepted, and the ston. selected Of the
size and strata desired, 1t is placed upon q
corA and leather handle. which holds it so
firmly that it will not be displaced in the
slightest degree By the action II the engine
Then the artists task actually begin. Tho
slightest error Of eye, thu least infruity of
hand, and the failure is complete. The en-
sraver and etcher apply sharp instrument
to the ground, upon which they operate.
The canso sngraver applies the ground to a
sharp instrument, which does the cutting
and which, in Amsterdam, in the diamond
factories, is run by steam power.
The engine is . miniature latho head. II
stands on solid table before the engraver,
and it is confronted by rows Of small iron
tools, some Of which look like little wheels
on the ends Of iron stems; and most Of them
like dentists tools Of half the common
length. A microscope would be necessary
to discover that the smallest of them ends in
a disc: for some Of the discs are les. than the
one hundredth part OF an inch in diameter
These little wheels are the cutters on the
cameo ground. They receive touch Of oil
and diamond dust just before the operation
commences: and the diamond dus. cuts while
the oil polishe.. The artist must change
them frequently, according to the depth Of
the incision, the nature Of the grain. and the
direction of the line Ills training must,
therefore, be slow and accurate, his eye true,
and hi. sense Of form developed into aic-os-
copic exsc,n.s.. Many sculptor. prefer the
training for cameo portraiture as az invalu-
able part Of their education 81. Gaudens
was q CAMEO cutter.-Chic.Eo Iribune.