TESTING STONEWARE PIPES USED IN RETICULATION SEWERS. LIX» 



The following table gives the average percentage by weight of 



water absorbed by test pieces of pipe after twenty-four hours 



immersion in water. 



Porosity. 



Size in 

 inches. 



Passed or 

 Failed. 



2 % Standard. 



Percentage 



increase in 



weight. 



4 % Standard. 



Percentage 



increase in 



weight. 



6 



i Passed 

 I Failed 



1-46 



5-52 



1-36 



4-DO 



9 



I Passed 

 \ Failed 



1-48 



4-27 



2-30 



6-18 



12 



C Passed 

 I Failed 



1-66 

 334 



2-37 

 5-13 



16 



| Passed 

 1 Failed 



1-15 



2-39 



5-58 



18 



( Passed 

 (. Failed 



2-12 

 3-57 



2-15 



4-78 



21 



< Passed 

 I Failed 





3-14 

 4-55 



24 



( Passed 

 I Failed 



1-18 

 5-52 



2-85 



General average — passed 1'97 per cent.; failed 4-85 per cent* 

 The percentage of failures under 2 per cent, standard was 27. 

 The percentage of failures under 4 per cent, standard was 18. 



The following figures show that the pipes which break the more 

 easily are also the more porous : — Average crushing strain of pipes 

 which passed for porosity, 6,317 lbs.; average crushing strain of 

 pipes which failed for porosity, 5,990 lbs. ; or a little more than 

 5 per cent, less strength in pipes that failed for porosity. 



In 103 cases, test pieces have been weighed both after twenty- 

 four hours and after forty-eight hours' immersion, with thefollowing 

 result: — No. of pipes, 103; percentage increase in weight after 

 twenty four hours, 2*14 ; percentage increase in weight after forty- 

 eight hours, 2-35; or 10 per cent, more for forty-eight hours than 

 for twenty-four hours. Two 9-inch pipes have been tested with 

 an internal pressure of 100 lbs. per square inch without fracture,, 

 the joint having failed at this pressure and not the pipe. 



Another set of tests was undertaken as follows : — Instead of 

 selecting one pipe only, two were chosen as nearly as possible alike 



