USE, CONSTRUCTION, AND COST OF SERVICE RESERVOIRS. 



161 



plate to be protected by first coating the plate with a solution of 

 bitumen and kerosene, and then laying on the sheet asphalt and 

 rolling it with a paper-hanger's roller; it adheres well, indeed it 

 can only be removed by chipping ; this system for plane surfaces 

 appears to be almost perfect, but much trouble was experienced 

 in getting the asphalt to adhere closely all round rivet heads, this 

 may yet be overcome, but so far as the experiments were carried 

 it was not satisfactory, the asphalt sagged from the underside and 

 left a space to which water might gain admittance, and serious 

 corrosion would go on unseen. The system is nevertheless ingenious 

 and may yet be turned to good account. 



Four tanks of the foregoing type F have been constructed, their 

 dimensions, capacity, and cost being as follows : — 



No. 



Dimensions. 



100' dia. 33' deep 

 100' „ 33' „ 

 100' „ 22' „ 

 75' „ 26'6"„ 



Avail, cap. in gals. 



1,543,500 



1,543,500 



1,029,000 



707,900 



Cost per 1,000 gals. 



£3 15s. 7d. 



£3 15s. 7d. 



£4 4s. lOd. 



£4 2s. 2d. 



It is clearly shown by comparing this table with previous ones 

 that the Reservoirs are very economically designed. 



Type G., Plate xvm. — This type comprises circular, uncovered 

 Reservoirs or tanks, with brick or concrete vertical walls and con- 

 crete floors. These are mostly constructed about two-thirds in 

 cutting, and one-third above ground level, the upper wall being 

 well backed up with the earth taken from the excavation. In 

 most cases tanks of this description are used for receiving river 

 water and allowing it to settle before pumping up to a higher level. 



Eight tanks of this type have been constructed, their dimen- 

 sions, capacity, and cost being as follows : — 



No. 



Dimensions. 



Avail. Cap. 

 in gals. 



Cost per 1000 gallons — Remarks. 



1 



100' diam. 11' deep 



502,300 



^£3 3s. 2d., concrete walls and floor. 



2 



100' „ 11' „ 



502,300 



£3 3s. 2d., 



3 



100' „ 11' „ 



502,300 



£3 13s. 9d., 



4 



100' „ 11' „ 



502,300 



£3 13s. 9d., 



5 



60' „ 13' „ 



211,700 



£4 9s. 6d., brick vert, walls, con. floor. 



6 



56' „ 17' „ 



245,900 



£5 0s. lid., 



7 



100' „ 14'6"„ 



750,000 



£4 10s., „ 



8 



140' „ 22' „ 



1,950,000 



£3 4e. 4d., concrete vert, walls & floor 



K— October 7, 1891. 



