212 



ANNALS NEW YORK ACADEMY OF SCIENCES 



developed a fair set within 24 hours. The grouts mixed with the undi- 

 luted sulphide water turned a dark green, but otherwise no change was 

 noticed in these or any other specimens. Three cylinders one diameter 

 high were cut from each set of specimens, and, after storing 28 days in 

 distilled water, were crushed. 



Table 21 



Compressive Strength of Grout Mixed with Different Proportions of Water 

 Containing Hydrogen Sulphide 



(Average of three specimens, age 28 days) 

 Pounds per 

 Mixes square inch 



Distilled water 1424 



Undiluted sulphide water 1608 



10 per cent of sulphide water, 99 per cent of distilled water. . . . 2088 

 1 per cent of sulphide water, 99 per cent of distilled water 1110 



Apparently, considering the average of the last three values, water of 

 this composition will have no evil effect at 28 clays upon the grout with 

 which it is gaged. 



Three series of tests were undertaken, in which a 1 : 3 mortar of Ot- 

 tawa sand and a cement of good quality was mixed with Croton water, 

 and with two typical rock waters encountered in tunnel work. 



CaO 



Table 22 

 Analyses of Rock Waters 



Parts per 



B 



85 



159 



73 



1380 



. 297S 



million 

 W 

 943 



MgO 





156 



S0 3 





172 



CI 





3420 



Total solids . 





7929 



The normal amount of water was used to mix the mortars in each 

 case, and the briquettes were stored in the damp closet over the stated 

 periods. 



Table 23 



Tensile Strength of 1:3 Mortars Mixed with Various Saline Waters 



Mixed with— 



Pounds per square inch 



Number of 



specimens in 



ayerage 



7 days 



28 days 



3 months 



Croton water. 



302 

 297 

 296 



322 

 343 

 335 



344 

 363 

 383 



6,5,6 

 6,6,6 

 6,6,6 



Water E 



Water W 



