Experiments on American and Foreign Building Stones. 13 
as proved both by Dr. Page and Mr. Wyatt, is among the sand- 
stones, er among granites, marbles or compact limestones. 
6. In addition to the foregoing comparisons, the writer is en- 
abled to vadd two experiments of his own on the Quincy syenite, 
the stone of which the Bunker Hill Monument is built. These 
experiments were made July 28, 1843. 
Lbs. pr. sq. inch. Rel. value. 
* 1. A 15 inch eube (2°25. 54. wre bp bor , 
2. A block having a base 2°5X 1°15==2°87 sq. os hiohes anda 
length of 5:2 25 5 inches, proved endwise, bore . 12,890 530 
[3. Alwm limestone—Dr. Page’s trials on 2 inch cubes, ‘ 2,834 100] 
Note.-—The block proved by compressing it endwise was not 
crushed, but only splintered or slightly ‘“spalled” along the cor- 
ners. ‘This was one at two successive applications of the same 
compressing force. The 1:5 inch cube was crushed with the 
force above given. 
From these experiments it appears that the Bunker Hill Monu- 
That a coarse, loosely aggregated rock like the alumstone, is 
far inferior in strength to rocks of the same chemical constitution 
and specific gravity but of fine texture, was long since prove 
by Rondelet. We may cite one or two of his proofs and add by 
‘Way of comparison, two others derived from the preceding sec- 
tions of this paper. 
ie Experiments on coarse, and on fine-grained stones of the 
same class. Specimens tried in two-inch cubes. 
1. ite ssard stone, coarse grained, ie whe A aS en a 
Choin de Villeburg, Jine grained, Deep ise ‘ meee : 8300 
2. j Saillan court stone, coarse grain, i gee 
Stones of Passy and Va ugirard, fine grain, - 4484 
3. i3 Symington’s — a pein eg (11 _— a Dr. Page) : 2334 
Symington’s fine gra arble, (2 do. hie 5 ee 
«| Alum en ae f Dr. Page’s pe a 
Fine gr arble, highest result by Mr. Mills, . oy eee 
The a 
2830, ses of the ‘oteee nee grained ones, 5982. The ratio of 
these numbers is 100 to 911 
Arranging the several iciads of stone in the order of their rela- 
ting values as determined by their power to resist crushing, ve 
; against each the number of square inches on the 
= the Specimens tried, with the name of the experimenter, we vis 
2 the ‘ing rank, as indicated by a comparison.with the alum 
| a used in casing the Washington National monument, 
: ee oa of which is taken as 100. 
