124 The Philippine Journal of Science wis 



show consistently an average reliable strength of over 400 pounds 

 per square inch. 



10. In Manila the total bonus would average about 1 per cent 

 of the cost of concrete. It would secure at least 10 per cent 

 greater concrete efficiency, and practically eliminate the necessity 

 of rejecting cements. 



11. Cement manufacturers have expressed their willingness to 

 cooperate on such a basis. 



