Peninsula enterprise. [volume] (Accomac, Va.) 1881-1965, 1900-10-13
HUGE GRANITE COLUMNS.
They win Adorn the Episcopal. Ca
thedraI In New York City.

They win Adorn the Episcopal. Ca
thedraI In New York City.
For the Cathedral Of ST. John the Dr.
vine, In this city, 80 magnificent gran-
lite columns are to be supplied, each as
high as four story house, and to
shape them a remarkable piece Of ma
chinery has recently been constructed
in Philadelphia and sent to the quar-
ries of the Bodwell Granite company.
In Vinalhaven, Me. 1t is nothing less
than n turning lathe Of unparalleled
strength and proportions.
A good illustration Of the objects and
operation Of lathe is found in shop
where wooden balusters are manufac-
tured. A stick Of wood, three or four
inches square and two or three feet
long, Is adjusted In a horizontal posi-
ton, with its ends firmly held by metal
disks. which are intended to revolve
rapidly. The stick being thus set IN
rotation, a workman applies to 1t the
edge of a chisel or other cutting tool.
which rests on a fixed support, but
may be shifted from one end OF the
stick to the other. The result Of this
treatment Is to make the stick perfect
ly round in a very short time. Its d.
ameter at different points may be va
ried, II this is desirable. so that In one
place there Is a graceful bulge and In
another a slender taper. Lathes arc
also built for working metal, and the
cutter IS usually shifted automatically
by a screw motion, so that the lack or
uniformity which results from hand
work Is eliminated and absolute adher-
ence to model insured.
The same method Is now employed
in shaping long blocks Of stone Into
columns like those in front Of the New
York Life building. In Broadway. The
stone is suspended horizontally be-
tween the head stock" and tail
stock" both Of which can rotate. As
In other lathes. the power which causes
the stone to revolve Is applied to the
head stock. By arranging suitable cut
ting tools on the side the superfuous
material is Clipped Off by degrees. and
the column Is reduced to the desired d.
mensions as surely, though. Of course
not so rapidly, as wooden baluster.
The finished columns Of the Episco-
pal cathedral are to be 81 feet long and
have a diameter Of 6 feet When
finished, each will weigh l60 tons. But.
TO begin with, block Is Quarried out
that is 81 feet long. measures S1a by I
feet In cross section and weighs about
80 tons! This burden must be sus-
tanned by the two rotating ends OF the
marvellous machine recently sent to
Vinalhaven. Before the lathe Is put
In operation 1t Is intended that little
Of each rectangular edge shall be TAX
en- of from the block by hand. Eight
cutting tools will be adjusted close to
each other. one going little deeper
than its predecessor. Each Is designed
to cut off three inches Of stone. so that
together they would be capable Of
making a cut "a inches In depth. By a
suitable mechanism these cutters are
slowly shifted from one end OF the
lathe to the other, so as to traverse the
whole length of the column. But they
are set In such a manner that they
cannot make the diameter less than
six feet.
When q column has thus been brought
down to the proper size, 1t still has a
rather rough surface. The stone must
now be polished. This second opera
ton is conducted with the lathe also,
but the rotation Is effected at some
what higher rate Of speed. There are
two polishing processes. The first, or
rough" polishing, is done with a cup
shaped device that has lot Of hard
ened steel shot In contact with the
moving surface. In the final opera
ton sand and emery are employed. A
period Of about six weeks Is required
for each column. 1t will take nearly
four years, therefore, to get out the
whole 80 columns.
This machine is sc feet long and
weighs 1875 tons 1t Is much larger
than any other stone cutting lathe over
before constructed. 1t is driven by a
80 horse power engine. When engaged
In cutting it's speed is ~ revolutions a
minute and when used for polishing.
The change Of speed Is effected by
gearing. The work Of constructing
the lathe was begun In December last,
and 1t was delivered to the Bodwell
Granite company in May. But 1t was
not put into operation until few
weeks ago.-New York Tribunes