738 NEW YOKK STATE MUSEUM 



American and foreign Portland cements, one part of cement to 

 three parts of Band: 



One wick; oik' day in air, six days in water, from 80 to 125 

 pounds. 



One month (28 days); one day in air, 27 days in water, from 

 100 to 200 pounds. 



One year; one day in air, the remainder in water, from 200 

 pounds to 350 pounds. 



Standards of minimum fineness and tensile strength for Port- 

 land cement, a- given below, have been adopted in some foreign 

 countries. In Germany, by Berlin society of architects, Society 

 of manufacturers of bricks, lime and cement, Society of con- 

 tractors, and Society of German cement-makers. 



Standard of 1S77. Fineness, not more than 25# to be left 

 on sieve of 5S0G meshes per square inch. 



Tensile strength, 1 part cement, 3 parts sand, 1 day in air, 27 

 days in water, 113. 7S pounds per square inch. 



Standard of 1878. Fineness, not more than 20$ to be left on 

 the sieve, as above. 



Tensile strength, same mixture and time as above, 142.23 

 pounds per square inch. 



In Austria, by Austrian association of engineers and architects. 



Standard of 1878. Fineness same as German of 1878. 



Tensile Btrength, same mixture as above, 7 days, 1 day in air, 

 six days in water, 113.78 pounds per square inch. 



28 days, 1 day in air, 27 days in water, 170. GS pounds per 

 square inch. 



In Austria a standard for the minimum fineness and tensile 

 Btrength of Roman cement was established and generally ac- 

 cepted, ;i- follows. 



Standard of 1878. Fineness, same as Portland. 



Tensile Btrength (1 part of cement, 3 parts of sand) for: 



Quick Betting (taking 15 minutes or less to set): 



Seven dayB, 1 day in air, six days in water, 23 pounds per 

 square inch. 



28 days, 1 day in air, 27 days in water, 5G.9 pounds per square 

 inch. 



Slow Betting cement (taking more than 15 minutes to set): 



Seven days, one day in air, six days in water, 42. G pounds per 

 square inch. 



