Evening capital journal. (Salem, Or.) 1888-1893, 1889-12-07
EAc1s ABOUT MARRLE.
How the Rugged Rock Is Converted Into
Polished vsriegated Slabs.


Polished vsriegated Slabs.
Few people who stand before a finished
monument or mantel, or even soda. water
fount In drug store, and admire the high
ly-polished variegated marble, says the New
York Commercial Advertiser, realize the
amount of time and labor that has been ex-
pended in the evolution Of the completed
structure from the raw materials. The
biphly-colored varieties are found chiefly in
Italy, Spain, France, Belgium, or Portugal,
though sometimes in Mexico or Algeria.
The white stone is common in this State
Among the marbles which most frequently
enter into composition of fancy apparatus
are;
Italian-white, vernal and clouded with blu
ish gray; Etrurian-pure porcelain white, Sara
possa shaded cream white, veined with dark
gray; Algerian and Mexican onyx-translucent
white, veined with opaque white, yellow, or
pink Bardiglio-delicately veined gray 'Sarran.
col,n--shaded pearl gray, dashed with carmel
ian red; Sienna-golden yellow, clouded with
white and veined with olive and brown; Ten.
nessee-chocolate, frosted with white; Genoa
green; Brocatel-richly notified yellow, pur.
pie, brown, white and red; Violet Brocatel--
purple mottled and veined with golden yellow:
Lisbon-redd.sh; Gryotte OF France deep red.
shaded with red and brown; Gryotte Fleure-
purplish red, mottled with pearl white War
wick brilliant red, veined with white; Bel
gan-velvety black; African - yellow, with
purple veins; Rouge Antique-deep red; Knox
yllle-grayish pink, with light blue veining,
The colored marbles retain their fresh
ness longer and can be repolished after
many years. use.
The marble is extracted from the quarry
in oblong blocks cut out by means of
wedges.
Except when designated for statuary or
building purposes the first thing the manu-
facturer does is to place the block of marble
under a gang-saw in order to saw it into
slabs. The gang-saw consists merely of a
series Of parallel saws, to which an oscilla-
ting motion Is impaired while they are kept
fed with sand and water. When they come
from the gang-saw the slabs are generally
about IN inches thick, so that they NAV
dress to one inch when rubbed on both
sides. The slabs are then inspected. To the
inexperienced eye the rough slabs are much
alike, and while the good qualities of the
slab are only fully brought out under the
polisher's mop, the imperceptible defects
are also magnified very much. It is there
fore necessary to detect flaws before the
polishing begins.
The perfect slabs are cut into required
lengths by rip-saw and passed to the rub
bing bed to be rubbed smooth. The rubbing
bed consists Of a solid horizontal cast-iron
wheel about four inches thick and usually
about twelve or thirteen feet in diameter.
This wheel is fixed in vertical shaft which
revolves on two chilled steel friction balls,
placed one upon the other, and inclosed in
cast-iron box which is kept well supplied
with oil. The box itself is firmly imbedded
in a stone foundation, and the entire struct-
ure is made as true and as steady as pos
sible. 1t requires great deal of care and
attention to keep the rubbing-bed perfectly
true; and it is sometimes necessary to rub
it down Tor whole week with bluestone in
order to keep the surface smooth.
When the slab leaves the rubbing-bed it
is comparatively smooth, and is ready to be
cut out by hand into its final shape. 1t then
passes into the hands Of the polishers, who
are provided with rubbers made of ordinary
ticking rolled up into mop Of about three
or four inches in diameter and sewed firmly
through and through. With these they rub
the surface Of the slab back and forth, hour
after hour, until they bring out the high
polish - much admired. The marble is
first rubbed with grit, then with pumice-
stone, and then with hone. On some white
marbles oxalic acid is then used, and finally
the finishing touches are given with putty
of zinc. On colored marbles emery and
French putty, prepared with sulphur and
lead, are used. It is estimated that each
square foot Of surface polished costs one
man four hours Of steady work.
In gliding, four or five gold leaves are
blown into a cushion made of board COW
cred with chamois. The glider cuts it into
strips quarter of an inch wide, lays it on
the marble with his "tip," then ''cottons"
1t on, after which he rubs it down with
fine hair brush in order to smooth the laps
and form an even and continuous surface.
He then cleans off the edges with cutie fish.
Great dexterity is acquired by gilders, and
they seem to handle with the greatest ease
the delicate gold leaf which the slightest
breath Of air is sufficient to carry of, and
which in inexperienced hands is utterly un-
manageable.
The variegated, dark-colored marbles are
most expensive, but they are also generally
harder and more durable, as well as more
beautiful, than those that are white or light
colored The common white marble, which
is not so valuable from an ornamental point
Of view, has a separate value as being the
best basis for the production OF carbonic
acid gas for the manufacture of "soda" wa
ter and all other carbonated beverages, and
large trade is done in it for this purpose.
1t has succeeded whiting and bicarbonate
Of soda in this respect on account OF It's
cheapness. A barrel of good marble-dust,
weighing about 400 pounds, costs sl.25. An
equal quantity of whiting costs about $3.50,
and produces no more gas. A like weight
Of bicarb6nate of soda produces double
amount of gas, but costs about 81.
As far as chemical composition is con-
cerned marble and whiting are analogous
both are carbonates Of lime, and when
equally pure both contain the same amount
Of carbonic acid. Whiting, however, is
rarely, if ever, as pure as marble. 1t con-
sists chiefly Of the remains OF extremely
small animalcules.
Fire-Proof Building Material.
The Real Estate Record says that fire ruins
,hox.. 49,. eoxxo l,r;clro and