Water-Works denote all manner of works employed in raising or sustaining water; in which sense water-mills of all kinds, pumps, wheels, hydraulic engines, sluices, aqueducts, etc, described in various parts of the work, may be called water-works. The various water-works in and about London consist of pumps worked by steam-engines. The principal are those of the New River Company, whose works at Clerkenwell and Upper Thames-street, are said to furnish daily to 67,000 houses, 13,000,000 of gallons; the East London waterworks, situated at Old Ford, also daily supply to 42,000 houses, 6,000,000 of gallons; the West Middlesex works at Hammersmith, to 15,000 houses, 2,250,000 gallons; the Chelsea works to 12,400 houses, 1,760,000 gallons; The Grand unction, also at Chelsea, to 7,700 houses, 2,800,000 gallons. From which statement it appears that the portion of the town on the north side of the Thames, is supplied daily with about 26,000,000 gallons of water, and that the total number of buildings of all kinds receiving this supply amounts to about 144,000 The water is, from the great demand of certain factories, and various other circumstances, very unequally distributed; but the average consumption for each house is about 180 gallons.
Of this water, more than one half of which is derived from the Thames, a large portion is delivered at very considerable elevations above the level of the river, even to the tops of the highest houses in the highest parts of London, by means of force pumps, called the high service, for which distinct service fifteen steam-engines are employed, exerting a power of 1105 horses.
On the south side of London, there are three water-companies, namely, the Lambeth, the Vauxhall or South London, and the Southwark. The Lambeth water-works are situated upon the banks of the Thames, and the water is forced immediately from the river into the mains, and thence distributed to 16,000 tenants, who consume 1,244,000 gallons daily. The Vauxhall, or South London works, situated in Kennington Lane, have about 10,000 tenants, who daily consume about 1,000,000 gallons. The Southwark works, upon the banks of the river, between Southwark and London bridges, supply about 7,000 tenants with 720,000 gallons of water. Each of these establishments has two engines, the aggregate power of which is about 235 horses. The whole of the water amounts to nearly 3,000 000 gallons, supplied to 33,000 tenants. The total quantity of water required for the whole metropolis, north and south of the Thames, is therefore about 29,000,000, supplied to 177,000 houses or tenants, making an average quantity of 170 gallons to each daily!
We have thus given a summary of a more voluminous statement that has appeared in most of the scientific journals, professedly derived from the printea report of a parliamentary commission, appointed a few years ago to inquire into the subject. But we think that every resident of London, after a moment's consideration of the statement made out by the water companies, of their supply, will deem it to be a most overcharged statement of facts. Our own observation upon a great number of houses, leads us to the conclusion, that instead of 170 gallons to each house daily, there is not that quantity delivered weekly in a majority of cases, or upon an average of the whole. If the water were turned on daily to all the tenants, and the discharge-cocks to all the pipes were prevented from shutting during the period of "laying on," the pipes would be capable of delivering the quantity mentioned. But the facts are, that a great number of the cocks are shut, the cisterns being full; that the majority of them are only open for a few minutes, to receive an addition of a few gallons; and that, so far from being a daily supply to all, the third, fourth, and fifth-rate houses (which constitute the majority,) receive their supplies but twice a week at the utmost, and many of them but once.
The official statements appear to us to be so grossly incorrect that we have not thought it needful to enter into a minute investigation. Nevertheless, we consider the supply generally to be abundant for all the purposes of health and comfort. We have already observed, that pumps are the machines now usually employed in water-works, for raising the water; and these pumps are generally worked either by steam or a fall of water. Having in other parts of this work treated of the constituents of water-works, we shall conclude this article by a brief notice of the water-works lately erected to supply the city of Philadelphia with pure fresh water, and which have been described in the recent scientific journals. "These works," Dr. Jones states, "have been admired by all who have seen them, as monuments both of the taste and skill of the persons concerned in the plan and erection of the buildings, and in the construction and executing of the machinery." The establishment is at Fair-mount, five miles above the city, at the Falls of the Schuylkill. The entire expense, including the purchase of the site, is 426,330 dollars.
The water power created is calculated to be equal to raise into the reservoir, by eight wheels and pumps, upwards of ten millions of gallons daily, and it is estimated that 40 gallons upon the wheel will raise one into the reservoir. There are two reservoirs, one having the capacity of three millions of gallons, and the other of four millions. The water is raised 56 feet above the highest ground in the city, and is conveyed and distributed in cast iron pipes of American manufacture. A plan and section of the pumps and water-wheels are given in the foregoing page. The pumps are what are called double forcing-pumps, (see the article Pumps,) producing an equal effect in raising water, in whichever way the piston moves. The working barrel is 16 inches in diameter in the clear, and the half stroke of the pump is five feet, giving a ten-feet stroke for each revolution of the water-wheel, of which there are thirteen in a minute. The water is forced to a perpendicular height of 96 feet, through mains of nearly 300 feet in length.
The quantity raised by one pump, in 24 hours, is upwards of 1 1/2 millions of gallons, ale measure.
A, plan of the water-wheel.
C, connecting-rod from the wheel to the pump.
D, plan of the pump.
E, the fore-hay, which supplies the wheel and pump. .F F the gates to the fore-bay and water-wheel.
Dr. Buchanan, in his Journey from Madras through the countries of Mysore, etc. gives a description of the Saymbrumbacum tank near Madras, which appears to us well deserving of the attention of persons interested in the construction of water-works, as there are probably situations in this country where similar advantages might be taken of the natural configuration of the hilly districts. The Saymbrumbacum tank has not been formed by digging, like those in Bengal, but by shutting up, with an artificial bank, an opening between two natural ridges of ground. The sheet is said to be seven or eight miles in length, and three in width, and in the dry season is let out in small streams, as wanted, for irrigation. In the rainy season it receives a supply of water from the river Chir-nadi, and from several small streams that are collected by a canal. It is provided, in different places, with sluices or weirs, of stone, which are from 20 to 30 feet wide, and some feetlower than the other parts. On the surface they are strongly fortified by large stones, placed in a sloping direction, so that the water rushes over without undermining the bank, and is conveyed away from the fields by a canal.
This is a matter of the utmost importance, as there are instances where, the banks of these large tanks having given way, whole villages have been destroyed of the torrent. In order, however, that when there is plenty of rain the tank may be completely filled, a row of stone pillars is placed on the top of the sluices (weirs); and on the water rising to a level with their base, a temporary wall is formed of mud, sticks, and straw, placed between the pillars so as to confine the water till it rises as high as the top of the bank. People watch this night and day, in order to break down the temporary bank should any additional rain endanger the whole. The water is let out to supply the fields, by a sluice lined with cut stone or bricks, formed through the bank, on a level with the country. The inner end of this sluice is covered by a fiat stone, in which is cut a conical opening, that can be shut or opened by a conical plug or valve, fixed to a bamboo staff, and which is secured in its place by passing through holes made in cross guiding-bars, let into two pillars of stone, which rise above the level of the water in the tank.
This tank is said to be sufficient to supply with water the lands of thirty-two villages, for eighteen months, should the rains fail; such a reservoir is therefore of inestimable value.