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 



Conipressive Strength of Grout Mixed icith Different Proportions of Water 

 Containing Hydrogen Sulphide 



(Average of three specimens, age 28 days) 



Pounds pei- 

 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 days 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. 



TABLE 22 



Analyses of Rock Waters 



Parts per million 

 E W 



CaO 85 943 



MgO 159 156 



SO S ' 73 172 



Cl 1380 3420 



Total solids . 2978 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 irith Various Saline Waters 



