Rock Island Argus., 1899-12-26
EXHIBIT OFCHALC LCEDONY
Process of Preparing Petrified
Wood For Paris Exposition.
WORK Is COSTLY AND TEDIOUS.
Slabs From ArizOna's stone Forest
by the Mills at Sioux Fa1ls-Three
Years Already Spent In Preparing


Years Already Spent In Preparing
the Exhibit.
at the plant of the Sioux Falls Pol
ishing works in Sioux Falls is being
prepared for the Paris exposition an
exhibit of chalcedony, or petrified
wood, from the famous petrified forest
of Arizona. says the Chicago Record.
The exhibit will embrace specimens
aggregating in value several hundred
thousand dollars. The polishing works
in Sioux Falls is the only Institution in
the world which makes speciality of
saving up and polishing this petrified
wood, which is third in hardness TO
diamond.
Thus far 10 carloads of the petrified
wood have been shipped TO Sioux Falls.
This alone represents large outlay OF
money, owing to the great weight OF
the logs, the distance the petritied for
est is from d railroad and the difficulty
Of loading and unloading the wood
from the cars. On the Arizona end OF
the line the 10 carloads had TO be haul
ed by team a distance OF % miles TO
the nearest railroad point. The freight
rates were also enormous, as the wood
then had no classification in the freight
tariffs of the railroads and had to be
shipped as bullion.
1t was shipped to Sioux Falls in
great logs and stumpS. some OF them
weighing many tons each. The largest
log shipped TO Sioux Falls was eight
feet long and about four feet in diane
ter. From this the logs run from three
and four to six feet in length, the pet
ritied stumps varying from eight or
ten inches high and about the same in
diameter to two or three feet high and
two feet or so in diameter. The wood
as shipped to Sioux Falls was IN eX-
actly the condition in which it was
found in Arizona, where the logs and
stumpS have doubtless lain for ages
during the process required by nature
to turn the wood into stone of the most
beautiful and variegated coIors.
The process OF saving the stone up
in proper form for polishing is most
tedious. Three years already have
been spent in preparing the exhibit.
which will not be completed until
early in the summer of 1900, when it
will Immediately be shipped to Paris.
When sections of the wood or
stumps are selected for cutting up.
they are first roughly polished TO see
If they are perfect. Some of the larger
logs. it is found, have decayed in the
center before petrifying. To roughly
polish the sections they are placed.
with the smoothest side up, in an up
right position in huge circular recep-
tacle. known as the Drake bed, invent
ed especially for the purpose for which
it Is used. and imbeddeG in cement to
prevent their moving.
Huge arms, between which are Sc
curely placed other sections of petri-
fed wood in a horizontal position and
lying on the upright sections imbedded
in the cement. are carried around in 4
circle of powerful machinery. Thus
the tops of the upright pieces of petri-
fed wood are roughly polished by 9th
er sections of the same material When
stumps or logs are found to be without
serious flaws. they are placed under
the saws to be sawed into slabs from
an inch to an inch and a half in thick
ness. The logs and stumps are sawed
straight through. leaving the bark in
its natural state around the edges OF
the slabs.
The saw blades are without teeth.
The petrified wood being SO much
harder than the saw blades. chilled
steel shot is placed under the blades
These become imbedded in the edges
of the saws and do the cutting. The
process is n very weariSome one, as
many as two complete sets of the saw
blades being worn out in saving
through a section OF the wood no more
than 30 inches in diameter. The saws
do not cut into the logs more than an
average of an inch day. thus con-
suming a month in cutting through a
80 inch log.
When the slabs are cut from the logs,
they are taken to what is known as
the rubbing bed" where they are pol
ished ready for the final finish. This
is also done by rubbing the slabs
a against blocks of petrified wood y pc
riod of from 10 to Is days is required
to complete this portion of the polish
ing. FROM the rubbing bed" the slabs
are taken TO the polishing wheels,
which give them the final finish. This
is also very tedious. slabs so inches in
diameter being kept under the polish |
ing wheels from three to four weeks.
In this final process the best quality !
Of Turkish emery is used. as it is found |
TO give a much finer polish than any /
other grade. Columns are cut from |
the logs or stumps by circular saws. |
These saws. like those used in saving |
the slabs, are without teeth. and the |
steel shot which become imbedded in |
the edges of the saws do the cutting |
as in the other case. The columns I
are cut from them across the grain 4
They vary in diameter from few up ;
TO ten inches.
No two of the hundreds of slabs are
exactly alike. the markings and color
ings I'm each case being entirely differ
ent. One slab of l or IL inches in
thickness. when sawed off a log. may,