STRIDES TIOIR, Sy Tay DINIES 
Pitta Ors whl SOL GS UMeEDING  SLONES AND 
VEO DS tO rh DE ViTNUNG ae Wks VATU ES 1, 
In selecting a stone for building or other economic purposes, 
one should be familiar with the 
i Color 
( Mineralogical, 
) Chemical. 
Tl, Suenedn, | Semone 
| Transverse. 
II. Composition, 
IV. Hardness. 
V. Elasticity. 
VI. Porosity (including fissile planes). 
VII. Specific gravity. 
VIII. Weight per cubic foot. 
IX. Effect of temperature changes. 
(a) Freezing and thawing of interstitial water. 
(0) Effect of extreme heat. 
X. Effect of gases, | ee 
XI. Quarry conditions. 
There are three important methods of obtaining these facts: 
(1) observations at the quarry and adjacent natural exposures ; 
(2) examination of buildings, monuments, or other construc- 
tions built out of the stone; (3) laboratory examination. If a 
geologist were obliged to choose between the three, he would 
probably consider the first method most satisfactory. The archi- 
tect and builder, on the other hand, would undoubtedly choose 
to examine buildings already constructed out of the stone. 
However, the value of opinions based solely upon quarry obser- 
vations or the inspection of buildings depend largely upon the 
333 
