XLIV. J. M. SMAIL. 



to tlie cost. The cost of covers is thus seen to be much less 

 than indicated by European experience, due chiefly to the 

 use of concrete and to a more economical design. To the 

 cost of filters will have to be added the cost of clear-water 

 reservoir, and usually sedimentation basins, amounting to 

 from £625 to £2,080 per million gallons capacity, according 

 to the circumstances. The total cost of the Albany plant, 

 including the low-service pumping station, but not including 

 the conduit, was about £81,250, or £5,420 per million gallons 

 capacity. 



The cost of filtering plant, buildings, etc., in the American 

 or rapid sand filtration, taking the cost of works completed 

 and in operation, averages £1,000 per million gallons (Imp.) 

 In this case the cost depends on local conditions of site. 

 The cost of filtering plant, inclusive of machinery, buildings, 

 etc., is given by the manufacturers at £2,000 per million 

 gallons (Imp.) 



Operation of Filters. 

 The average cost of working the filters of seven London 

 Mater Companies for fifteen years, has been stated by Mr. 

 \Y. B. Bryan, Engineer of East London Water Company, to 

 be slightly over 4/- per million gallons, the minimum being 

 3/- for the Chelsea Company, and the maximum 4/9 for 

 the Grand Junction and West Middlesex Companies. In 

 Germany the cost is higher on account of the turbid water 

 to be dealt with. At Liverpool the cost has been given at 

 4/9; at Hudson, N.Y., 3/8; and Ploughkeepsie as high as 

 11/7, due to ice. In the city of Laurence, Mass., U.S.A., 

 the cost of operation, exclusive of ice cutting, was 4*95 

 dollars per million gallons (Imp.) The work comprised in 

 cost is scraping, conveying sand, sand washing, sanding, 

 filter maintenance, extra filter maintenance, and coal for 

 pumps. Turneaure and Russell give the cost of operations 

 at Albany, N.Y., in 1900 at 84 per million gallons. In some 



