;Y38 new yokk state museum v 



American and foreign Portland cements, one part of cement to 

 -three parts of sand: 



One week; one 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, as 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 1877. Fineness, not more than 25^ to be left 

 on sieve of 5806 meshes per square inch. 



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

 days in water, 113.78 pounds per square inch. 



Standard of 1878. Pineness, 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. Pineness same as German of 1878. 



Tensile strength, 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, 170.68 pounds per 

 square inch. 



In Austria a standard for the minimum fineness and tensile 

 strength of Roman cement was established and generally ac- 

 cepted, as follows. 



Standard of 1878. Pineness, same as Portland. 



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



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



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

 square inch. 



28 days, 1 day in air, 27 days in water, 56.9 pounds per square 

 inch. 



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



Seven days, one day in air, six days in water, 42.6 pounds per 

 square inch. 



