Experiments on American and Foreign Building Stones. 15 
TABLE CONTINUED. 
Area of l Rel, val 
No, Name of stone. ee ee Name of experimenter. aoe “a 
inches 100. 
\60,|Metamorphic blue Potomac stone, ....... BOB MAB aww chee 160 
61,|Derby grit, friable sandstone, ........... 955. [Renhie, ..1-.5.. 0 160 
62,| Portland Divs aus eRe EL bawSiEs 4 ae ee 159 
63,|Veined white marble, (Pauf,) .......... Rondelétz . ..... «+ 158 
64, Yorkshire Cromwell stone, ............. S26 | Wyatt. oo ccna: 156 
65, Bagneaux stone, (Pantheon at Paris,)....| 4 Rondelet; 4. Hae e2 149 
66. Granite of Port Deposite, ............. 4 UNG, . dices 139 
67, White veined Italian marble, ........... 1 Rormie, ois ce cee 187 
68. Steetley white dolomite, .............. 4 |Daniel & Wheatst’ne| 136 
Sir entyn granite, ... 2.2... os sac 2. 18 = Wyatt) 200+. & 136 
70. Italian Ns Re dicied 34 e 4 Oy caer 135 
71 ‘Temple OF Paestum stone, 4... as oaee os 4 Rondelet,....<.... 130 
12 ‘Patapsco hy Ap Ry Poem nie are + PONS. a es tay ee 118 
mgleith- sandstone, .6 2% 0.080 ie ces 36 Wyatt, 6.7. a 117 
4. Seneca sandstone, Smithsonian Institute, . 4 BOOS 5s alk aiers Me 115 
75. Granite of Normandy, .............00. 4 WHS. ie 112 
16. Alum limestone, (Wash’gton Nat’nal.Mon't.)) 4 PASC 2 os kee 100 
ine Stockbridge marble, ........0cceeccee 4 Oe ia eee es 96 
78.|York road brown sandstone, ..........- 4 a. whine wea Sos 91 
79. Humbie sandstone, .............sss00- 86 METAL, sta e es ces 81 
80.Aquia Creek (Patent Office) sandstone, ..| 4 PAGS, 0565603 4S 71 
81|Whitby sandstone, ...........cscccces 36 Lg 7 SE ECAR 41 
__The wide discrepancy already noted between the results ob- 
tained in experimenting on the alum limestone, in which the, 
Pressure required for crushing varied from 910 pounds to 5687 
pounds per square inch of the area of the base, must be explained 
either on one or the other of three suppositions; Ist, that the 
Strength of different specimens of the rock is thus variable, 
nd that consequently no certain reliance could be placed on its 
t th 
metease of area of base and the power of resistance of cubes of 
gtanular rocks and other materials, the writer has proposed a se-’ 
€s of trials on several stones, in cubes of different sizes from one 
he all those of the same kind of stone to be 
tom the same block and accurately reduced to the ree 
i a - At present the following comparisons seem 
,t0-a 
lrect relation between the power of resistance o 
x 
= 
at if 
* 
and the product of the area of the base multiplied 
of that area. ee » : 
& 
