338 SINYDIUDS IROIR SINGUDIEINIES 
The grade of stone that has been used in the construction of 
the building under inspection should be known. Nearly every 
quarry contains more than one grade of stone. However, it is 
not an uncommon occurrence for the stone from an entire dis- 
trict to be condemned because second or third grade stone has 
not proved as satisfactory as number one stone from another 
district. The poorer grades of stone are sometimes used in the 
fronts of buildings or even carved for the finer parts of the 
architectural work. 
After the stone once becomes a part of a building people do 
not stop to distinguish different grades, but charge all weaknesses 
or imperfections against the quarry as a whole. Sometimes an 
entire area including several quarries suffers in consequence. 
It is also important to know the manner in which the stone is 
quarried, handled, dressed, and laid. Much stone is still being 
laid on edge, especially in veneer work. Where the bedding 
planes are prominent and the stone is only of moderate strength, 
this practice is dangerous. An observer should ascertain if pos- 
sible whether the flaking and scaling is due to improper methods 
of laying or to inherent weaknesses in the stone. 
Stone used for ornamental and monumental purposes will 
show deterioration in proportion to its age, position, etc., the 
same as stone in the walls of buildings. For these reasons, the 
same care should be exercised in passing judgment on its dura- 
bility. 
The oldest monuments are built out of marble, it being only 
within a comparatively few years that granite has come into very 
general use. Nevertheless, some of the important granite monu- 
ments, in spite of the comparatively recent data of their erec- 
tion, are gradually losing their polish and even now have finely 
pitted surfaces. Monuments that are exposed for years to dust 
laden winds frequently have their polished surfaces dulled and 
the lettering obscured. The sides exposed to the direct 
rays of the sun often deteriorate most rapidly owing to 
the diurnal expansion and contraction caused by heating and 
cooling. 
