The companies supplying this parish obtain water exclusively from the Thames, viz., the West Middlesex and Grand Junction Companies at Hampton, and the Chelsea Company at Ditton. The bad state of the water supplied by the last-named company in December appears to have been caused by the intake being “below the filthy outflow of the rivers Mole and Rye.” The total volume which may be supplied daily by each company is 20,000,000 gallons. The average daily supply during the month of December was—West Middlesex, 8,600,000; Grand Junction, 10,200,000; and Chelsea, 7,200,000 gallons—eleven to fourteen per cent. of the water (exclusive of waste, an enormous but unknown quantity!) being delivered for other than domestic purposes. The number of houses supplied in the several districts is—West Middlesex, 46,404; Grand Junction, 35,144; and Chelsea, 28,395. Only 401 houses in the West Middlesex district have a constant supply. The estimated population supplied is—West Middlesex, 348,000; Grand Junction, 316,000; Chelsea, 210,000. The West Middlesex Company possess eleven engines of 1,341 horse power; the Grand Junction, eleven of 1,820 horse power; and Chelsea, eight of 1,025 horse power. The number of miles of mains possessed by these companies in the Metropolis is—West Middlesex, 248; Grand Junction, 200; Chelsea, 170. The West Middlesex Company have three subsiding and storage reservoirs for unfiltered water—area, 20½ acres; available capacity, 57,000,000 gallons: and three covered reservoirs for storing filtered water, of an aggregate capacity of 10,922,000 gallons. This company, by means of its large reservoir capacity, avoids taking in water during floods. The Grand Junction Company have four subsiding and storage reservoirs for unfiltered water—area, 7 acres; available capacity, 19,500,000 gallons: the number of covered reservoirs for filtered water being three, their capacity 18,000,000 gallons. This company requires additional impounding and subsiding reservoirs. The Chelsea Company have no reservoirs for unfiltered water, and only two (capacity, 11,000,000 gallons) for storing filtered water. The filter beds of the several companies are as follows:—West Middlesex, five in number, area 8 acres, depth 5 feet, viz., Harwich sand 1ft. 9in., Barnes sand 1ft., and gravel (screened to different sizes and arranged in layers) 2ft. 3in. The average rate of filtration per square foot of area was, during December, 1½ gallons per hour. (It may be here observed that the quality of the water is improved by a slow rate of filtration—the rate should not exceeded 2½ gallons per square foot of filter bed per hour: this will give 540 gallons per square yard each 24 hours, and at this rate filtration should be effectual.) Grand Junction: Number of filter beds, 4; area in acres, 7¾; depth, 5ft. 6in.—viz., Harwich sand, 2ft. 6in.: Hoggin, 6in.: fine gravel, 9in.: coarse gravel, 9in.: boulders, 1ft.: average rate of filtration, 1⅓