166 



CEMENTS, LIMES, AND PLASTERS. 



TABLE 68. 

 COMPRESSIVE STRENGTH OP SOREL STONE. 



sible and then to crystallize. From this test it is evident that your 

 stone will withstand the action of frost more perfectly than any sand- 

 stone or ordinary building stone now in use. I see no reason why it 

 will not stand as well as granite/ 



" A perfect resistance to the freezing and thawing of one winter may 

 safely be accepted as conclusive evidence of the durability in the open 

 air of an artificial stone of which the matrix is any kind of hydraulic 

 cement. At no subsequent period will it be as likely to fail, from freezing 

 and thawing, as during the first winter. A stone suitable for all kinds 

 of building purposes on land might, however, fail under the solvent 

 action of sea-water. On this head it can be said that magnesian com- 

 pounds are understood to resist the immersion in the sea better than 

 the compounds of alumina or lime. 



"For these reasons this new stone has, with some exceptions, been 

 limited in its application to articles of small bulk and great comparative 

 value, for which other approved and less expensive artificial stone is 

 either not suitable or of less practical value. Although for architectural 

 ornaments of elaborate design it is perhaps less costly, even now, than 

 granite or marble, it cannot hope to compete successfully for general 

 adoption and use by engineers and architects with the beton agglomere* 

 and the softer kinds of natural stone until the market price of the oxide 

 of magnesium is greatly reduced. For the peculiar purposes to which it 

 is adapted, it supplies what has heretofore been felt as a great want, 

 and in this field, which is neither narrow nor unvaried, it has no prominent 

 rival. 



