226 



ACTUAL COSTS AND CAPACITY OF GASWORKS. 



tensile strain of 20 tons to the square inch of section 

 without fracture. The steel work was required to stand a 

 similar test at 28 tons. All iron castings were to be of 

 good close grey metal, to be examined by the engineer 

 before painting, after which they received one coat of paint 

 before delivery and another after erection. 



The old factors for purifying area are becoming some- 

 what antiquated, in view of the modern practice of hurdle 

 grids and working by means of the rotation method of 

 changing without opening. Although the writer is a 

 thorough advocate of both these modern devices, it was 

 decided that ordinary grids would be quite sufficient for 

 some years, i.e., until the boxes approach the maximum 

 capacity so fitted. With the present method of working, 

 they will be quite capable of purifying a maximum daily 

 make of 240,000 cubic feet, or, say, 1,000 cubic feet for 

 each 2*4 square feet of area. This is the equivalent of 

 48,000,000 cubic feet per annum, and doubtless it can be 

 considerably increased by subsequently adopting hurdle 

 grids. 



The proportionately large purifiers were adopted 



because excess of purify- 

 ing area always conduces 

 to economy in labour costs. 

 Cost of purifiers and foun- 

 dations, complete, ^"473. 



Meter and governor 

 house. This building is 

 erected in the most suitable 

 position for intercepting the 

 inlet and outlet pipes to the 

 holder, which enter the latter 

 at right angles. Its dimen- 

 sions are 18 feet 6 inches 

 by 9 feet inside, 8 feet 

 to eaves, and 12 feet to 

 apex. The walls are of 



Fig. 31. Meter and Governor 

 House : Roof, Cross Section. 



brick, 9 inches thick, with foundations as specified for 

 exhauster house. The floor is boarded so as to give 

 access to connections. Cost, i l > 





