LTE PROPER ES OF SULE DINGS LONES, LLC. WY 
the time that has elapsed since absorption, the condition of the 
atmosphere, the size of the pores, and the position of the stone. 
It is only in exceptional cases that the stone in the wall of a 
building is saturated. However, if the pores are of greater than 
subcapillary size the water of saturation will, as a rule, be quickly 
removed, except in the lower courses below the water line. 
It would, therefore, appear that the most important factor in 
estimating the danger from freezing and thawing, is the size 
of the pore spaces, which controls the rate at which the interstitial 
water is given up. The second factor of importance is the 
amount of water contained in each of the pores at the time of 
freezing. The third and last in importance is the total amount 
of pore space. 
1. S. Hunt, in “Chemical and Geological Essays,’ says: 
“Other things being equal, it may properly be said that the 
value of a stone for building purposes is inversely as its porosity 
or absorbing power.” This statement has been quoted by vari- 
ous authorities, one of whom says: ‘Other things being equal, 
the more porous the stone the greater the danger from frost.” 
The mistake has often been made of estimating the danger from 
freezing by the capacity which a stone has to absorb water. 
Likewise the capacities which two stones have to withstand 
weathering are constantly being compared from the standpoint 
of the ratios of absorption. Such estimates and comparisons are 
very misleading, for one should not only know the capacity 
which a stone has to absorb water, but he should, above all, 
know and consider the relative size of the pores. 
The injurious effects of the freezing of the ‘quarry water,” 
as the interstitial water is called by quarrymen, has long since 
been known to contractors, who generally refuse to accept stone, 
especially sandstone, which has been exposed to the action of 
freezing before being seasoned. Where it is possible, quarrymen 
sometimes flood their quarry during the winter months, in order 
to protect the stone immediately at the surface. 
The openings formed along bedding, jointing and other fissile 
planes, permit a freer circulation of water than the pores in the 
