12 Experiments on American and Foreign Building Stones. 
and sandstones, tested in cubes of about the same size as the 
largest of those above given. His investigations were made with 
the aid of the hydraulic ape of Messrs. Bramah & Sons, and in 
this respect also appear to be comparable with those, made on 
the alum limestone in a blocks. Each of his results is the 
mean st two trials* 
13. r. Wyatt's s experiments on marbles, in blocks of larger 
size a 2-inch cubes. 
Lbs. pr. sq. inch. Rel: value. 
1. Ravaccioni marble, (blocks 44% 4 inches base), - . 9632 172 
2. Veined marble ( 44x4 . 9251 163 
[3. Alum limestone in 4, and in 43 inch cubes (average), - 5658 100] 
From the above and the preceding series of trials, it appears 
that the “alum limestone” falls very far below Italian marble, 
whether tested in l-inch, 2-inch, or 4-inch cubes, and whether 
crushed under a hydraulic press, or any of the other carefully 
constructed machines which have been employed for the purpose 
ee in France and England. Compared with every other good mar- 
ble and limestone, its inferiority of strength, when the size of 
cubes was the same, @ppears still more remarkable 
14. Mr. Wyatt's experiments on granites tested in cubes of 4 
inches on a side, or in blocks of which the base measured 4'5 by 
A inches. 
Lbs. pr. sq. inch. Rel. value. 
1. Herm granite, (4-inch cubes), . ‘ . 14, 26S? 
2. Heytor do. do. ‘ : . 13,865 245 
3. Destentie granite, do. . 12,275 217 
A. Peterhead red do. (45 x4 inch base), . 10,931 193 
5. Aberdeen blue do. (425x4 do.) . . 10,393 183 
6. Peterhead blue gray do. ne 5x4 do. ) ~ 9,766 172 
7. Penryn granite, (4:5 x4 do. ) «ft 136 
pe Alum limestone, (in 4 and in 43 cubes), ... 5,658 100] 
. Mr. Wyatt’s experiments on sandstones, tested in cubes 
of 3h and 6 inches on a side. 
Ss. pr.sq. inch. Rel, val. 
E Yorkshire Cromwell stone (5:5 inch cubes), 8,825 156 
2. Craigleith stone (6 inch cubes), 6,652 117 
3. Humbie ed do. ; ; “ 4,614 Sk 
4. Whitby sand do. © 2378 a 
5. DGaelione “A and 4:75 cubes), ; 5,658 100] 
| e average strength of the above four sandstones is almost 
‘identical with that of the alumstone, as given*by these experi- 
ments. Had the cubes been 4 instead of 6 inches, the compari- 
son might probably have been more favorable to the alumstone. 
- Its true position in the seale of strength, among building stones, 
