Catoctin clarion., 1889-10-31
FLORENTINE MOSAlCS.
INTERESTING PROCESSES BY WHICH
THEY ARE PRODUCED.

StOuS - io" Inv ~ ANiuth'
Where and How the Materials Are OBJ
tained-A Royal Monopoly for ESQ Years.
In continuation of the description we gave
tho other day, from Sir D. T.. Colnaghi's re-
port, we give some interesting facts about
Elorcntiro mosaics--the "objccts of art' Of
which nearly every visitor brings back some
specimen:
The proper technical term for the SO called
Florentine mosaics is works In "commesso."
They are composed of delicate slices of stones,
carefully cut into shape, arranged and joined
together c'commessi'l with u fine cement,
and then fitted into a thin slab Of marble.
The pictures arc produced by the natural
tints of the stoncs the selection OF which, to
carry out any given design. demands great
taste and skill
DETAILS or THE WORK.
f, After the design had been prepared the thin
! slices of stone selected for tho various parts
arc distributed among Il certain number Of
workmen, each of whom completes tho por-
| ton of the design il.ri!@tad TO him, the whole
subject beng suh;tai.ltlr united. The
stones, after being cut into the required
shapes, are carefully set together wiz &C.
mcllt made OF wax and .Dslo 'prcc erc'a' ~
/ heat being used 10 hiHl them rr.4," S.Ht1
is employed to support the "uH, daring lis
progress, and 10 line it aa'H ".Hi.n:at' ~
each stage tho first hHiI" y...Emi iutHes gr'
ate part, is ground lo,.u, at.l i IlysA uo ap-
! piled, 40 that an eTcn .u.ljt, u@. ai""tSha
secured. When, finally, the ro%.i .,' d-.i~n
is fitted into the marble i.lh pr r"! tor its
reception, tue wlo.e Of tlc base is again
ground down to a pcricn, plane, tn, is lined
with fresh backing Of sia.e II i,ting i,
performed vit, the .inatnsl care, the edges
of the several parts hains files! nntj the exact
dimensions have been attained The whole
surface is afterward polished, 50 That tLo
lines Of juncluro arc rendered almost ilVl3-
iblo To bind on tho ltlng heat is used, as
also FOR uniting the smaller pieces The opera
tion is very carefully performed, 50 that no
moro cement tEar! is absolutely required
shoN!d remain between the parts that have
been joined together.
The first operation OF saving the stones
into thin Slices from ~ to mtl!i!net"rs in
thickness, is performed by means Of thin
blades of iron OF copper, emery pp"'r Civ
Ing tho required friction TIE slices arc fur.
thor sawn into the shapes required To form
the various parts of tho design by iron or
copper wire attached TO bows, and always
with the all ot caiery The finest emery
powder CpoltigIia"l IS used for polishing tho
4
for grinding down the Innings. For this lur.
pose the vor!: is place., on a HE.i slab Of
marble or slate iron plates Of various Sizes
and thickness, according TO tho CtmcnsiDns ct
the slab and having wooden handles, being
steadily worked over IL w ono Or two men,
as required.
To provide stones for the works IN real
"petre duro," Europe, Asia and the north Of
Africa havo been laid under contribution,
and the Royal factory possesses q largo col
lection Of stones, valued at somo 10000 lire.
Among the principal stones employed arc
amcth ystS agates, the sarlonyX and cha!ce-
dony, hnts, many varieties of Jasper, peb-
bes from the Arno (Which generally contain
largo proportion of l:mcI, and petrilicl
woods. Among the rocks, which arc chiefly
used for works Of decoration, are red ori-
entail, Egyptian and othor GRANTEES, verde dl
Corsica, labradorite, oligoclase 0atcly intro
ducetD, antique porphyry, green porphyry,
oriental serpentne, jade hasalt si!rious
breccia and lapis nzuli. Black marble from
Belgium is largely used as foundation, and
slate ns has already beon mentioned, is EN-
poved rs n lining for works III "commesso"
The hardness of tho materials employed, re-
quring patience to work thom accounts for
tho costlintss Of works IN "plrtre dure," of
which IS to 50 per cent. is attributed to
labor
TIE MOSAiCiSTS.
Tho outfit of a mosaicist is very simple.
With small table, d basin of water bra
zier, vice, some copper and iron blades to
be used as files Il bow strung with iron wire,
little emery powder and few stones al
ready cut into slices, which cost only few
francs his equipment is complete. 1t Is not
astonishing therefore, that, on the industry
H.. ,,,1N