STRENGTH OF CONCRETE. 

 Fig. 6. 



XXIX. 



2S0 320 360 days 



Abscissae = Aae in da\s. Ordinates = Crushing force in lbs. per square inch. 



(Mean of two tests ) 

 Cement, 'Tripod brand'; Nepean sand ; sandstone 2 inch gauge. 



Fig. 7. 



40 80 120 If 6 200 240 2S0 320 360 days 



Abscissae = Age in day*. Ordinates = Crushing force in 100 His. per sq. inch. 

 Cement, 'Tripod brand'; Nepean sand; pebbles 2\ iuch gauo-e. 



