268 



CEMENTS, LIMES, AND PLASTERS, 



500 



g 200 



100 



0123 

 AGE IN YEARS 



FIG. 54.* Tensile strength of Louisville cement, St. Louis Waterworks, 1896. 



1 



-g 400 

 p 



Neat 



1 



1 



i 



- J - ; 



t III 6 = 



* 13 -d S 



FIG. 55. Tensile strength of Lehigh district natural cements. 

 (Philadelphia tests, 1893, 1894, 1895, 1896.) 



* From Johnson's "Materials of Construction ", p. 570. 



