IiVI. 



W. E. COOK. 



in-Chief for Sewerage construction, short lengths of pipe were 

 specially manufactured, so that they might be tested by Professor 

 Warren, at the University. Using the results so obtained as a 

 guide, the following specification was drawn up : — 



" 20. Stoneware pipes and junctions to be of well-ground and 

 mixed materials of tough, tenacious, impervious quality, well burnt, 

 sound, hard, uniform in thickness, true in section, straight longi- 

 tudinally, uniformly glazed both inside and outside, free from fire 

 or other cracks, flaws and ash holes, the collar and barrel to be 

 made in one piece, and in every way equal to sample pipe to be 

 seen at the Engineer's office. 



"21. Pipes to be of the following thickness and depth of collar, 

 viz. : — 

 Pipes inside diameter, 4-in.; thickness, f-in.; depth of collar, If -in. 



JJ 



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6-in.; 



j j 



fin-; 



lf-in. 



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9-in.; 



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il-in.; , 



, 2-in. 



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12-in.; 



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1 -in. j , 



2-in. 



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15-in.; 



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li-in.i 



2fin. 



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16-in.; 



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lf-in.; 



21-in. 



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18-in.; 



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ll-in.; , 



2£-in. 



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21-in.; 



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If -in-; 



2|-in. 



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24-in.; 



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l|-in.; 



2|-in. 



"All parcels of pipes used in these works will be tested in the 

 Departmental testing machine, and submitted to the following 

 crushing strains applied to the centre of the pipe : — 



24-inch... ... 110 R)s. per square inch of bearing surface. 



100 „ „ 



"0 ,, ,, ,, 



80 ,, ,, ,, 



18 



16 



12 



9 



6 



100 

 100 



" If the Engineer deems its necessary, the pipes will also be 

 tested for porosity. Should the pipes fracture under the foregoing 

 strains, or be found to absorb more than two per cent, of water, 

 then the Engineer may reject the whole of the parcel from which 



