ee a ee ee eae 
Se ee ee ee ee a 
ee ae 
E'xperiments on American and Foreign Building Stones. 7 
ee 
hig sient in 
ind of stone. Ibs. per. square inch. 
6.. Patapsco granite, 941 
(z ) nother spec ime 2593 
8. Seneca sandstone, ( Smithsonian Dealings ) 2691 
9: db. another  ApeOeT 2691 
$6 Stakbridee imarbls, Mas - 2410 
i any oo (casing of monument ) average 
2334] 
12. Bieckbridec marble, 2d specimen ; 
13. York road freestone, (a friable brown sandstone, pee: 
14. oh oe Creek sandstone, (Patent Office, ) 093 
do. do, 
15. specimen, 187 
16. a0 do. do. d do. 1441 
_:. do. - do: do. Ath = do. 1234 
18. Common building brick, 1000 
Arranging in order of the average strength, we have the follow- 
ing succession, a column of relative values being added in which 
the alum limestone is represented by 1 
 Aoeran rei ay 
: per square inch. Relative value. 
J. Maryland fine-grained marble, 48 192 
2. East Chester (N. Y. as marble, 3993 171 
3. Italian marble, . 3156 135 
A. Patapsco granite, 2767 118 
5. Seneca ( Smithsonian) stone, 2691 115 
_ [6. Alum limestone { ae 2334 100] 
7. Stockbridge ma wit, Bool 96 
8. York-road heelon: . 2126 91 
9. Aquia See (Patent Otlice) sandstone, 1660 71 
10. Common b : 1000 42 
Note.—The . sandstones, hectare 5 and 8, have a mean 
aaa of 2408, which is three per cent. higher than that oe 
‘alum limestone,” which has its place between them in the 
above series, 
an average strength of 1660 pounds, and th 
ments of Dr. Page on the alum limestone wae. an average of 
1521 pounds, showing the inferiority of at least some portions of 
this limestone to that “ material which. now disfigures ihe archi- 
tecture ad the Treasury building and the Patent Office 
Mr k Se ciments on different building materials, ubliched by 
t. Specimens of the same size as the gpa 
No. of trial, 
of stone. : ve inch, 
Ls : 
2, Balmer gr Regina es 
arble, 4 
More granite (‘Sanewak and Grayson’ s), 6250 
* Hints on Public Architecture, p. 114. 
The four trials of the Aquia wie Lgcwithes give 
three experi- 
t Mills, architect of the Washington National Monu- 
Strength per — 
* 
in aes 
ot 
i ie 
< 
