STRENGTH OF CEMENT MORTAR AND CONCRETE. 303 



crete consisted of one part of Portland cement, two parts 

 of sand, and two and a half parts of broken blue metal 

 f gauge. The results are recorded in Table VIII. and 

 fig. 20. 



The triangular pile showed about the same modulus of 

 rupture as the square pile on a span of 5 feet 6 \ inches, 

 but the square pile tested on a span of 15 feet was 50°/° 

 stronger than a similar pile tested on a span of 15 feet, due 

 probably to the more complete distribution of the stress in 

 the longer pile. 



In the experiments recorded in Tables I. to VI. the 

 specimens were removed, after hardening in air for 24 

 hours, into water where they were kept until they were 

 taken out for testing. The experiments recorded in Tables 

 VII. and VIII. were allowed to harden in air. 



The author proposes to read a paper early next year 

 dealing with the application of these results to the design 

 of reinforced mortar and concrete constructions, and he 

 wishes to acknowledge the assistance of Mr. A. Boyd, 

 b.sc, b.e., in connection witli the testing and recording of 

 the results. 



