The Port Gibson herald, and correspondent., 1850-12-06
WASHINGTON NATIONAL MONU-
MENT

The following is an extract of a letter from
Elisha Wittlesey, addressed to DR.. A. V. Rowe,
Agent for the "National Monument" for the
4th Congressional District of Mississippi, and
who is now in this county, receiving donations.
1t will be seen from the letter, and the circular
following, that there need be no fearful ap-
prehension as to the material and foundation
of the edifce.
"The Board of Managers have taken every
| possible precaution to secure beyond the sha-
| dow Of doubt, a good foundation, and supe-
rior material for the Monument, previous to
commencing the edifce they consulted emf
nent Architects and builders, and had the
ground bored, they have thus satisfied them
selves and the public that if the Monument
| had a solid rock for its base, it could not be
more secure, nor has it settled the thickness of
a sheet of paper, as has been proven by obser-
yations taken. l send you a report made in
reference to the tests of the marble, and
subsequent report which has been copied by
paper with an editorial. We have exhausted
our supply, but will send you others in few
days. We are pleased to learn of your sue
! cess"
Washington National Monument Office,
/ NOVEMBER 9, 1850
To THE AMERICAN PEOPLE:
statement made by Prof. Johnson in lee
ture delivered by him some twelve or fourteen
months ago, that the marble forming the exter-
or facing of the great National Monument now
building in the City of Washington, in honor of
the illustrious Father of his Country, wanted
strength and durability, and would be crushed
by its own superintendent weight, induced the
, I orlar IN fha ar-
ror into which he had fallen, and in justice to
the Board of Managers, as well as to arrest the
mischief it was calculated to produce, to cause
the strength of this marble to be accurately tes-
ted by powerful Hydrostatic press at the
Washington Navy Yard. A series of expert
/ ments were accordingly made under the direc-
I ton of the superintendent of machinery at that
b Yard and the architect Of the monument, and
they reported as the result of these tests, that
: the marble was equal in strength to the gran
4 ties, and that base of A inches, or one foot
square, would bear pressure of 100000 lbs. be-
[ fore it could be crushed or four times the per-
Y pendicular weight of a column OF marble 50C
feet hgh and that the atmospheric action on this
material was only the fifteenth part of one grain
or the muiety Of that on the large crystal marble
!. Of New York, A repetition of the erroneous
If statement referred tohaving been recently made
by Mr.. Johnson and noticed in some distant pa
h pers of this country, circumstance which il
operating, it is believed to the injury OF the pa
? triotic object of the Monument Association, the
!. Board of Managers, with view more fully tC
O satisfy the public mind as to the strength anc
durability of the marble objected to, ordered ad
e ditional experiments to be made with the same
powerful press, and the result has been still more
e demonstrative of the absurdty Of the opinion en-
}. tertained and promulgated by Mr.. Johnson
q The following is statement of these expert
e ments by Mr. Dougherty, the superintendent
II the Monument:
i 'sThe experiments were conducted by WIN
NJ. ELLIS, Chief Engineer L. S. Navy Yard, ant
:. A. B. SToUGHToN, Esq, Machinist, Unitel
10 States Patent Office, whose certificates are at
" tached.
It mo. l.-I-:nch cube crushedat 2, pound
I pressure; which is equal to 28S,000 pounds, o
ST l28. 1880 2240 tons to the square foot.
mo. 2.--l-inch cube (natural bed) fracture
at 1000 pounds pressure, same as No. l..
"No. 3.--3da-inch cube (natural bed) crushe
at 46, ,l25 pounds, equal to 1888 pounds, Q
#. 241. 1893. .2240 tons to square foot.
"No. 4.--31-inch cube (natural bed1 irac
tured at 10000 pounds, equal 20 Adj pounds
: or 201.l328 .2240 tons to square foot.
OF "No. 5--SIab inches thick, AZ by inches
a! az crushed $4,000 pounds, equal to 77O,O2
10 pounds, or 343. .l701 2240 tons TO square foot.
IN "No. 6.-Four-nch cube, crushed at 90
rs pounds, equal to $4,000 pounds, or 365.l40
~ 224O tons to square foot.
p Mr.. Dougherty, practical and skiltul mi
~ chanic, also observes that
ct $50 far from there being any apprehension
ol this marble not bearing the pressure upon it,
CD can with great@con6dence say that, from Il
lat manner in which it is bound in with the ma
IN, BODY of the wall, which is gneiss rock, that
whole course of the marble casing, eightet
u inches thick, could be taken out and the edifit
re- carried up to its full height without endsDgerir
W the safety of the work.
!, "The size OF the obelisk at the base o. Il
marble work is 55 feet square, at the top 80 lie
All square, the walls are feet thick at the botto
Try four feet at the top, and 500 feet high, makiI
eh the superficial area covered by the walls at I
nc base 2 400 square feet; the mean square OF I
snl walls is "A feet, and thickness 9 feet incht
es which, multiplied by the height, $500 feet) Civ
en- 65550O cubic feet, which, at II feet to the tc
!. will make the whole weight of the obesk D.
u, 625 tons, giving pressure of22.76lO0 to ca
'no square foot of the base.
not sBy taking the average of the above expe
iGe on,S !, would rooniro q snressure of more IN
it, oo5 TINS IL the SQUARE foot TO crush them
=
nearly ten times the actual pressure at 300 L
the high. Whereas the highest would require SO
ect tons pressure to The square foot or Is times
I'M actual height, and the lowest 1881 tons. or o'
Tor 81 times the pressure so that instead Of 500 e
the he monument could (if it were possible to bu
on. it) be carried 5000 feet high without any ds
and ger whatever of the marble crushing under
ave weight. WM. w DoUGHERTY
lor- Sup. Washington National Monument
de- "WAsmNGToE, Sept. 6, 1850
cy. aWe hereby certify that we applied the cru
ing ino mower of the hydrostatic press at the Uni
OF States Navy. yard to the large crystal mar
OF used at the Washington NATIONAL Monnme
ion and that the results above stated are correct
opt "WM NJ. ELLIS,
'est "Chief Engineer U. S. Nauy Yard
and IA. B. SToUGHToN,
nMachinia u. s. Patent Office.
rict
IL 4. II