Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/436

Rh 410 W A T W A T DISTRIBUTION. The water is led from the service-reservoir through cast- iron mains to the branch mains, from which the service pipes convey it to the several houses. Lead is generally preferred for house connexions, owing to the facility with which it can be adapted to structural requirements. The only objection to it is that it is attacked by some very soft waters, oxide of lead being formed, which is partially soluble and very injurious to health. With free carbonic acid, however, the pipe becomes coated with carbonate of lead, which is insoluble in water and protects the pipe from further action. Peat also in water protects the lead pipes, by depositing a surface film. In the case of hard waters, the lead soon becomes coated with sulphate of lime. Accordingly, it is only under exceptional conditions that the employment of lead for pipes is deleterious ; but it should be prohibited for the lining of cisterns where the water may be stored for long periods. Domestic niters are very valuable for local well and spring supplies, and afford an additional safeguard against accidental impurities in public supplies (see FILTER). Intermittent and Constant Siqiply. Formerly the com mon form of supply was on the intermittent system. On this plan, each house is provided with a cistern, into which water from the main is admitted for a short period, once or twice a day, by means of a valve on each service main, which is opened and closed by the turncock for each separate district. When the cistern is filled, the inlet pipe is closed by the rising of the floating ball shutting the ball tap. The supply is, accordingly, limited to the contents of the cistern, except during the short period the water is turned on ; and the cistern is proportioned to the accommodation of the house. The water in these open cisterns is liable to contamination from impurities of various kinds settling in them and not being cleaned out ; and it is often exposed to heat, a smoky atmosphere, and dust, and sometimes to sewage gas. Moreover, in the event of a fire, the turncock has to be summoned before a supply of water can be obtained. Accordingly, the adoption of the constant system has been urged, and in many places carried out. The advantages of drawing a fresh supply always direct from the main, and of having an ample supply constantly at hand to meet any emergency are unquestionable; but the constant supply of water -necessitates the strengthening and very careful inspection of the pipes, joints, and fittings, to prevent fracture and avoid leakage under a continual and increased pressure, and is liable to lead to a careless waste of water if unchecked by a meter. Before substituting a constant for an intermittent supply, it is essential to overhaul thoroughly the pipes and joints, and to substitute screw- down taps, which close gradually, for the leaky suddenly- closing plug-taps, which throw a sudden pressure on the pipes. Waste in water-closets can be stopped by the insertion of a waste preventer, which only allows a definite quantity of- water to pass each time the plug is raised (see SEWERAGE). The detection of accidental waste from leakages has been much facilitated by the introduction of a waste-water meter, which records graphically, on a revolving cylinder, the amount of water which is passing the place where the meter is fixed. By fixing the meter on one of the district mains at night, when most of the recorded flow is running to waste, and shutting off suc cessively the service pipes through which water is heard to be flowing, the change in the diagram of flow at each closing of a service pipe localizes the position and extent of each source of waste, showing at what places leaks must be occurring, and which are the worst, needing attention first. This method of inspection was first adopted at Liverpool in 1873; and, besides effecting a considerable economy, it enabled the constant service to be restored, which the previous waste had rendered impracticable. Water-Meters. There are two classes of water-meters, the positive and the inferential. The positive meter, such as Kennedy s and Frost s piston meters, measures the actual quantity of water passed through it, as recorded by the strokes of a piston working in the cylinder, which is successively filled from the top and bottom, and affords a measure of the water introduced ; whilst the inferential meter, such as that of Siemens, measures only the revolu tions of a turbine actuated by the flow of the passing water, of which the quantity is deduced from the velocity. The posi tive meter is more accurate, and measures very small flows ; whereas the turbine meter may sometimes not be turned by very small flows which are gradually increased. Measure ment by meter would seem naturally to follow the adoption of the constant service for domestic supply, as well as for manufactories. Its general adoption has, however, been hindered by the fear that a charge by quantity, instead of by rental, might press unduly upon the poorer classes, and induce them to stint themselves of a proper supply, and also the difficulty of obtaining a very cheap and at the same time a perfectly trustworthy meter of adequate durability. To avoid the possibility of checking a suffi cient use of water in the poorer tenements, it has been proposed to allow a definite supply at the ordinary rate, and only to charge by meter for any excess over this amount. (L. F. V.-H.) WATERTON, CHARLES (1782-1865), naturalist and traveller, descended from a very ancient English family, was born at Walton Hall, near Pontefract, Yorkshire, in 1782. After being educated at the Roman Catholic college of Stonyhurst, and travelling a short time on the Continent, he went to Demerara to manage some estates belonging to his family. He continued in this occupa tion for about eight years, when he began those wander ings upon the results of which his fame as a naturalist principally rests. In his first journey, which began in 1812, and the principal object of which was to collect the poison known as curari, he travelled through British Guiana by the Demerara and Essequibo rivers to the frontiers of Brazilian Guiana, making many natural history collections and observations by the way. After spending some time in England he returned to South America in 1816, going by Pernambuco and Cayenne to British Guiana, where again he devoted his time to the most varied observations in natural history. For the third time, in 1820, he sailed from England for Demerara, and again he spent his time in similar pursuits. Another sojourn in England of about three years was followed by a visit to the United States in 1824; and, having touched at several of the West India islands, he again went on to Demerara, returning to England at the end of the year. In 1828 he published the results of his four journeys, under the title of Wanderings in South America, consisting largely of a collection of observations on the appearance, character, and habits of many of the animals to be found in British Guiana. Waterton was a keen and accurate observer, and his descriptions are of a graphic and humorous character, rarely to be found in works on natural history. He married in 1829, and from that time lived mostly at Walton Hall, devoting himself to the improvement of his estate, to country pursuits, and to natural history observations. Waterton also published three series of essays on various subjects connected with natural history. He died May 27, 1865, from the result of an accident. WATERTOWN, a city of the United States, the county seat of Jefferson county, New York, is situated upon both