Evening star. [volume] (Washington, D.C.) 1854-1972, 1895-03-06
MARBLE CUTTING A SCIENCE.
Some OF the Sights to De Seen at the
New COrcOran Gallery.

Some of the Sights to be Seen at the
New COrcOrnn Gallery.
They do wonders in cutting marble now
adays. II you want to be convinced of it
GO and see 1t done at the building now in
process of erection for the new Corcoran
Art Gallery, near the State. War and Navy
building. Thirty thousand cubic feet Of
marble are to be put into the structure, and
the stuff is brought by rail in huge blocks
from Georgia. Some of the chunks weigh
as much as fifteen tons. 1t takes twelve
cubic feet to make a ton.
To begin with. you will see great block
being sawed into slabs. The saws are
mere strips Of steel, arranged in a frame
30 as to work back and forth on the block.
1t is as II you would cut a cake into slices
with several knives at once, holding the
blades parallel. The saws have no teeth,
strange to say, but a nick is filed on their
edges here and there to mako them catch
the sand better. They are kept constantly
supplied with water and sand and the lat
ter really does the cutting.
A Planning Machine.
Just beyond is what is called a planning
machine. 1t is gigantic, horizontal screw,
on which carriage runs back and forth.
Upon the carriage is placed a block of
marble. As 1t runs along 1t is cut by a
knife of the finest and most highly temper
ed steel. Thus the holdings for cornices
are cut. The knife make a hideous noise.
but it does the work ever SO much quicker
than would be possible by hand tools. The
planer is quite new idea, having been
used for marble only within the last year.
Marble, though only a form Of limestone.
Is extremely hard. In respect to hardness,
however. even that from one quarry vari, $
very much, and a single block will be
harder quite often on one side than on the
other. The harder 1t is the better, because
the hardest marble will take the finest
finish. OF course all marble is made up
of the shells of mollusks, foraminifera and
other animals which once lived in the sea.
You cannot see any traces of forms of the
shells in 1t, because the stuff has been
altered since 1t was laid down as a sedi-
mentary deposit, being crystallized by the
action of heat.
Cutting Out "Dentals."
Another machine in this temporary mar
BILE shop looks almost exactly like the con-
trivance that is used at the bureau of en-
craving and printing for perforating post
age stamps, only that It is on a very much
larger scale. It is a series of steel wheels
strung on a single, long axle. Against
these wheels a block Of marble is showed.
and they cut out Of 1t pieces at regular in
tervals so as to leave sort Of ornamental
ing points are left to form a border and
relieve the eye. Architects call these teeth,
rather appropriately, 'dentals.' This
work also is done at a rate of speed much
quicker than would be practicable by hand
labor.
Speaking of "dentals," there is another
machine that is used for finishing off the
dentals and for other similar purposes. 1t
looks exactly like the continuance employ
ed by dentists for boring out decayed teeth.
Nor is this surprising, inasmuch as the
idea was taken directly from the dentists
appliance referred to, being merely a modi-
flcation thereof, and very much magnifed-
The drill is held at the end of a rubber
tube, through which air pressure is sup
piled. and all the workmen have to do Is
to grasp it with one hand and direct 1t, as
the dentist employs his little tool.