The Ouachita telegraph. [volume] (Monroe, La.) 1865-1889, 1883-04-07
THE EGYPTIAN OBELISk IN CENTRAL
PARK.

To the Editor of the Scientific American
During a recent visit to New York
took occasion to examine the obelisk
in Central Park, and the opinion /
formed is so at variance with the gene
raj and accepted one in regard to its
construction, that after several days.
reflection on the subject, have deter
mined to write you. 1 have been
looking up in the Scientific American
Supplement (of which have copy
of every issue), and find in February,
1881, you wrote up the whole thing,
giving illustrations, etc. In that ar
taken from certain granite quarries,
thus showing it to be natural stone.
Yet in spite of all this, to me, excel
lent authority, cannot believe it to be
a natural stone, and l want to give
my reasons for so thinking and if
you find enough in what l have to
say to induce you to take any notice OF
it, whether to substantiate or upset my
theory, makes no difference; l only
want to get at the facts. My reasons
for believing the obelisk to be a mass
of concrete are as follows
1 have spent lifetime in the manu-
facture of lines and cements, and in
the study of mortars, concretes, ETC.,
and after thirty years spent in this
line, it seems as though I ought to
know concrete when see it.
Invent around on the back side of
the obelisk, climbed over the wire
fence, mounted the masonry work,
took out strong magnifying glass and
q sharp pointed steel, and went at it.
could see what looked at distance
to be gray, reddish, uniform tint,
was, on close inspection, granite broken
into pieces from the size of q walnut
down to corn or wheat size, and these
broken stones were intimately mixed
with some bituminous matter, black
and seamy, something of the nature of
asphaltum. The black substance and
broken stone were thoroughly mixed
with hydraulic lime; by the latter I do
not mean hydraulic cement, but lime
which contained sufficient clay to rem.
der it hydraulic, but not enough to pre-
vent it from slaking if kept under
water eight or ten days. The hydraulic
lime is light in color, with slight yell
lowish tinge peculiar to all true n.y.
u1RullC ouNll llluSS "lAuS1dlu
the action of the weather much better
than the best Portland cements. With
my steel point | could plow out this
hydraulic lime, and with my knife I
cut and shaved the black substance,
which lay in all conceivable ways, the
grain in some bits presenting their flat
sides, sometimes their ends, sometimes
vertical, sometimes horizontal, show
ing it to have been mixed up with the
lime and broken stone haphazard.
The lime showed in such thin streaks
that it is evident that the men who
had made the obelisk knew how to
make concrete. l think, if I had time
enough and no policemen to nose
around and bother one, l could have
taken out bit Of granite with my
steel.
The hieroglyphics show, as plain as
anything can show, that they were
formed by fastening the proper forms
on the inside Of the box into which the
concrete was rammed, and when the
concrete had hardened sufficiently, the
boxes were taken away, and the pat
terms of the hieroglyphic were with
drawn, leaving their impression on the
face of the concrete, exactly as is done
every day by manufacturers ofartiticial
stone. Such work cannot be mistaken
for work done by the chisel by any
one familiar with that class Of work.
Every letter is made to "draw," and
in no place could T find spot among
all the hieroglyphics where a pattern
would not "draW." Such structure,
made in concrete as 1 have described,
could be safely carried up at the rate
of from IL to Is inches per day, and SO
positive am that it is concrete, that
I would not hesitate to enter into con-
tract to erect exact duplicates of ii in
any city for $4,000 each. ! think /
can find granite in Connecticut Of the
same color, the bituminous matter in
New York, and the hydraulic lime in
Buffalo, and with these make Just as
good obelisks as were ever turned out
in Egypt. AS to the durability Of the
obelisk in Central Park, of (which much
has been written lately, think it will
stand for ages where it is. Some por-
tions may get loose that were not per-
tectly cemented, but as a whole the
material is Of that class that will out
last anything else we have. If it were
Portland cement or Roman cement in
the place of the hydraulic lime, i
should say it would disintegrate in
few years, but not so with the true
hydraulic lime, of which that in the
obeIisk seems to be an excellent type.
u. CUMMINGS.