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MASONRY 



The resistance to crushing varies within wide limits, owing 

 to the great variety in the structure of the stones; the method 

 of preparing and finishing the test pieces also affects the results ; 

 hence, the great variations found in the values given by differ- 

 ent experiments. The accompanying table shows the average 

 resistance of the principal building stones to crushing and to 

 rupture when used as beams. 



CRUSHING STRENGTH AND MODULUS OF RUPTURE 

 OF BUILDING STONE 



Absorptive Power of Stone. The absorptive power of a 

 stone is a very important property, a low absorption generally 

 indicating a good quality. The accompanying table gives the 

 average percentage of water absorbed by stones. 



ABSORPTIVE POWER OF STONE 



Durability of Stone. The following rough estimate, based on 

 observations made in the city of New York, indicates the num- 

 ber of years a sound stone may be expected to last without 



