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ANNALS NEW YORK ACADEMY OF SCIENCES 



Temperature records of the percolating water were not kept, since these 

 tests represent a part of a larger series in which this would have been 

 impracticable. The other aggregates tested showed results from which it 

 was quite difficult to draw any legitimate conclusions as to the relative 

 : suitability of different rocks in concrete subjected to these conditions. 



Concretes containing different aggregates. A scries of tests on con- 

 cretes made up of different aggregates but with the same cements gave 

 results which may be tabulated as follows : 



TABLE 14 



in Grams of Water passing in 10 Minutes through Concrete Specimens 

 subjected to continuous Water Pressure for 52 Weel-s 



