lic, which are deemed of so great importance as to outweigh the consideration of private ownership. The most important of these rights are the right of the public to use the shore at low water as a highway for passing and repassing, to land, dry nets, and dig for shell-fish there, and, when the shore is covered by the tide, to pass in boats and to fish therein. These rights are not inalienable, however, and may be released by the Crown or State, acting in behalf of the public, and vested exclusively in the private owner of the shore. It is on this principle that the numerous and important exclusive rights of sea fishing, and many of the rights of erecting piers, bulkheads, and breakwaters, and the like, have become vested in private persons or corporations in the United States. Consult Gould, Waters.

WATER-SCORPION. Any one of the waterbugs of the family Nepidæ. These insects have swollen forelegs fitted for grasping, thus distantly resembling the cheliceres of a true scorpion. The anal end of the body is furnished with two thin, long, grooved, terminal bristles or sheaths, which when pressed together form a tube, through which the insect obtains its supply of air from above the surface of the water. The water-scorpions are carnivorous, feeding upon fishes' eggs, small fish, and water-insects. They are of two types: flat and oval or long and thin. The former belong to the genus Nepa and the latter to Ranatra. The eggs are pushed entirely within slits made by the ovipositor in the stems of aquatic plants. From these slits and attached to the eggs protrude two (in Nepa) or five (in Ranatra) long supposedly pneumatic filaments.

WATERSNAKE. A harmless colubrine ser

pent of the genus Natrix (or Tropidonotus), closely related to the garter-snakes (q.v.). The common watersnake of the United States is Natrix fasciata of Cope, who names six varieties of the species, of which all are Southern except variety sipedon. This form, known in the older books as Tropidonotus sipedon, is the numerous and well-known watersnake of the Northern and Eastern States as far West as the dry plains. Its average adult length is three feet, but it frequently grows larger. The color is a variable brown, with large dark brown markings on the back and sides, and with the belly yellowish or reddish, spotted with reddish brown rounded spots (absent in some Southern varieties). These

HEAD AND ANAL PLATES OF WATERSNAKE.

colors, together with its habits and somewhat broad head, lead to its often being mistaken for the venomous moccasin snake (q.v.), of which some naturalists consider it a mimic. (See MIMICRY.) This snake is semi-aquatic in its habits, being usually found on the borders of the water,

especially quiet millponds and sluggish streams, where it takes refuge when alarmed. It is an expert swimmer and diver, and skillful at catching fishes, on which it mainly subsists; it will also eat dead fishes. When cornered it is pugnacious, but its bite is insignificant and harmless. Its young, 16 to 33 in number, are born alive, when about eight inches long.

The watersnake of Europe is Natrix natrix, which in several varieties is to be found all over Europe, Western Asia, and the Mediterranean Basin. It is much like the American snake in form, colors, and habits, but very variable. This is the only snake except the viper in Great Britain, and there it does not occur in Ireland or Scotland, and is commonly known in England as 'grass snake.' The main difference between it and our watersnake is that the English one is more active on land, and lays eggs, which are buried in loose loam, or in manure or dust It is deheaps, and hatch after some time. scribed at length by Gadow, Amphibia and Reptiles (London, 1901); and by Leighton, British Serpents (Edinburgh, 1901). Several other species of the genus occur in the Malayan Archipelago and two in Africa ; some of them are large and of savage appearance, but all are harmless. Consult Cope, Crocodilians, Lizards, and Snakes of North America (Washington, 1900), and other authorities cited under SNAKE.

WATERSPOUT. A small, rapidly whirling column of air, extending from a cloud down to the ocean or lake, and whose central axis becomes visible as a column of water or cloudy vapor. In some regions, in warm weather, waterspouts are of very frequent occurrence. As they frequently occur in calm weather, it is evident that they are not necessarily produced by wind, but them is the result of the same process that forms that, on the contrary, the wind that accompanies the spout. The formation of a waterspout is due to a strong indraught upward beneath the base of a cumulus cloud. The air that supplies this indraught easily acquires a rapid rotary motion as it ascends. This rotation, by reason of the resulting centrifugal force, produces a very decided low pressure in the central axis of the eddy. The rising air flowing into this region expands by reason of the low pressure, and is therefore cooled dynamically so as to become a visible cloud. One may see a perfect axial cloud formed in a precisely analogous manner in the midst of a rapid dust whirl over a city street. The permanence of the waterspout axis depends largely upon the humidity of the inflowing air. A large waterspout is attended by a cloud of flying salt water spray at its base, but the spout proper consists of fresh water in the form of cloud-particles or rain. Heavy rain generally falls upon any vessel that runs into a waterspout, but the only real danger in that case is from the whirling wind. The firing of cannon to break up a distant spout has often been tried at sea, but it is an error to believe that it has any appreciable effect. Spouts generally last but a few minutes, individually, but many of them may form and disappear in succession, owing to meteorological influences. The term 'waterspout' is often erroneously applied to any very heavy fall of rain from a cloud causing local destructive floods. Such rains may deliver five, ten, or fifteen inches of water in depth

over a small region within an hour's time, and cause great destruction. The popular term 'cloudburst' should be applied in these cases, and not the term 'waterspout.' Consult: Ferrel, Recent Advances (Washington, 1885); id., Popular Treatise on the Winds (New York, 1889).

WATER-STRIDER.

A slender, long-legged water-bug of the family Hydrobatida. They live upon the surface of quiet waters and dart about with great rapidity. They prey upon other insects and may even leap into the air in pursuit of their prey. The numerous species are found upon both salt and fresh water. They have prominent eyes, a stout beak, long antennæ, and an abdomen which usually tapers to the tip. Many species are dimorphic, one form being wing less and the other winged. Their eggs are attached to submerged parts of plants. A common species upon ponds and in the United States is Hygrotrechus remigis, a moderately stout, dark brown insect about half an inch long. It hibernates in mud, beneath leaves upon the banks, or at the bottom of the water under stones. A very strange form common in certain portions of the United States is Rheumatobates Rileyi. While truly aquatic, water-striders are structurally more nearly related to the landbugs than to the other water-bugs.

WATER SUPPLY. Water for irrigation, navigation, water-works, and other industrial and domestic purposes, derived primarily from the rainfall and secondarily from running streams and lakes, or surface water; and from springs, wells, tunnels, and infiltration galleries or underground sources. The quality of water supplied for irrigation, water power, and navigation is of comparatively small consequence, except that a badly polluted stream might be a general nuisance, and that the mineral contents of certain waters are harmful to crops. The water made available by water-works should be above all question as to sewage pollution and should possess other qualities, natural or artificial, discussed under WATER-WORKS and WATER PURIFICATION. A gravity flow is generally an essential in the case of supplies for navigation and water power. The same is often but by no means always true of water for irrigation. These limitations are due to the cost of pumping and do not apply to supplies for domestic and manufacturing purposes. Besides volume, there is a further essential to water for power, namely, sufficient fall to yield the requisite amount of energy to accomplish the desired work. (See WATER POWER.) As has been stated, the common source of all water supplies is the rainfall. Some of this finds its way to the streams, ponds, and lakes; some sinks into the soil to be utilized by plants, or to percolate through the soil to lakes and streams; some is stored in the soil and the permeable layers below it ready to be tapped by wells; and a large part is evaporated directly from the surface of the ground, only to fall to the earth again, in the form of rain, dew, or snow. With a given rainfall in any locality the amount of water naturally available will depend upon the extent, surface slope, and geological formation of the gathering ground, or drainage area, and the nature of the vegetation on that surface. The steeper the slope and the

greater the proportion of the rainfall reaching the streams, the less the amount available as underground supplies. With very steep and impervious drainage areas, the streams rise and fall suddenly, leaving comparatively little water available for any useful purpose, and threatening the stability of such water-supply works as are built. Forested and other well-covered areas retain the rainfalls for longer periods, but, in common with all vegetation, they make their own demands upon the water stored in the soil. stretches of country, tend greatly to equalize the Nevertheless, such areas, and also flat, sandy seasonal yield of drainage areas. Temperature and humidity are important factors in all waterhumidities increasing the evaporation from both supply calculations, high temperatures and low land and water. When the ground is frozen water cannot percolate into it and the surface. flow, or run-off, is so rapid that but little of the rainfall is available, unless there is ample storage. The percentage of water surface to total drainage area plays a very important part, since the evaporation from water surfaces, particu larly in hot and dry climates, is much greater than that from land areas.

The excellent maps and reports of the United States Geological Survey and some of the State geological surveys often afford sufficient data relating to the extent, surface, and subsurface character of drainage areas for at least preliminary studies of water supplies. Where these maps are lacking or insufficient, special topographical surveys are necessary, but it may not be so easy to secure geological data. In like manner, meteorological statistics (see RAIN) may be secured from the United States, State, and local weather bureaus or meteorological stations. Still further aids are the observations on the flow of streams made for a number of years past by the Hydrographic Department of the United States Geological Survey, by some of the State engineering bureaus, by municipal water departments, and by owners of private water powers. The New Jersey Geological Survey, the State Engineer of New York, the cities of Boston and New York, the private corporations which control the water power of Lawrence and Lowell, Mass., the East Jersey Water Company, in northeastern New Jersey, and the Spring Valley Water Company at and near San Francisco, Cal., afford the most notable examples of valuable records of this sort. Observations on the amount of water required for various crops, and various phases of ground-water investigation, have been conducted for years past by the United States and the various State agricultural ex periment stations, under the control or leadership of the United States Department of Agriculture.

In developing a water supply for any purpose, the first step is to determine the approximate relation between the quantity needed and the vari ous supplies that are or appear to be available. Where the source is to be some large river or lake, or say an artesian well from a basin of known capabilities, and in general where the re quired supply is obviously only a small part of the minimum yield of the source, no preliminary investigation as to quantity available will be required. But in the majority of cases this point demands at least some consideration. The

cardinal principle in estimating the quantitative fitness of a source of water supply is to compare the maximum demand with the minimum supply. Averages are also of great importance, but the foregoing is the crucial test. There should be determined not only the actual or estimated yield of the source of supply during the driest month on record, but also the corresponding yield for the driest two or three years in succession. This will enable those concerned to calculate what storage will be necessary for use during droughts, what supplementary steam plants may be required in connection with water supply developments, and what delays to navigation may be expected in case it is not feasible to provide all the storage indicated as necessary to maintain the levels of navigable canals or rivers. Although the yields of both surface and underground supplies depend primarily upon the rainfall, other factors vary in the two cases. Streams and lakes are supplied partly from the water that flows into them directly from the surface of the ground, hence the name surface water, and partly from water that soaks into the ground, then percolates through the soil to brooks, rivers, and lakes. The underground supplies are replenished from time to time from that portion of the percolating water that does not find its way to the surface supplies, or else is intercepted by artificial means. The drainage areas of surface supplies are well defined and the flow of streams may be readily measured.

The drainage areas of underground sources are not so easily determined, particularly deep seated waters, and the determination of their volume is often extremely difficult and generally only an approximation. Instead of a stream flowing in a well-defined channel, as is true of surface supplies, underground waters are hidden in the earth and follow a tortuous course through thousands of tiny channels in the voids between the separate grains that compose their water bed. The size of these channels, the general slope of the underground water surface, the depth of the water-bearing stratum, or absence of the pressure that gives rise to artesian conditions, all play their part in the possible yield of wells and springs. Some or all of these factors are but poorly known and their ascertain ment may be surrounded with grave difficulties. The safest and often the only practicable means of determining the yield of an underground source of supply is to measure it, or a portion of it. In the case of springs this may be done by means of a weir (q.v.). Where wells are proposed one or more may be sunk and tested experimentally, but unless the test is for a long period and the deductions are made in the light of the best engineering and geological knowledge the results are quite certain to be misleading and the future yield grossly exaggerated If a relatively small supply is all that is required one or more test wells may settle the question of capacity with sufficient definiteness at the outset, with the understanding that when the supply, as finally developed, proves inadequate, the plant will be enlarged. If, however, a quantity close to the probable safe yield of the underground basin be desired, the test wells may be so located as to determine approximately the slope of the water level and the porosity of the water-bearing material. From

these facts, combined with other valuable data, an estimate of the available supply may be made. The effect of a well is to lower the water level for a greater or less distance around it as a centre, so the new water level in this zone assumes the shape of a flat inverted cone, which has had its surface curved somewhat in the vicinity of the well. The more the water is lowered the flatter becomes the cone and the greater the area of the zone influence, until the water practically fails through exhaustion, or through diminution due to increased friction. Obviously, if wells are placed too close together their zones of influence will overlap and one will rob the other.

In determining the possible yield of surface supplies the first step is to ascertain what gaug ings, if any, of the actual flow are available, and particularly whether such gaugings cover a series of years of minimum rainfall. Where no gaugings are to be had it is desirable that a gauging station or stations, should be established. If this cannot be done all the available rainfall records in and near the drainage area should be gathered and studied. These figures may be compared with the rainfall and corresponding yield, or run-off, of other drainage areas, as nearly similar as possible. Deductions may then be drawn as to the average, minimum, and maximum yields. The latter must be known to make possible the provision of adequate means for the passage of flood waters without damage to any of the structures connected with the supply works.

Storage reservoirs may often be provided to make good the deficiency of run-off or stream flow in dry periods. The extent to which this is feasible will depend partly upon the character of the available reservoir sites and largely upon the economic value of the water thus conserved. Absence of proper reservoir sites frequently turns the scales in favor of some other source of supply. The yield of underground water supplies may be supplemented by storage, also, but to a very small extent, as compared with the storage of surface supplies, since most underground waters would have to be pumped as well as stored, and since the conditions for water storage on a large scale are rarely favorable in the vicinity of underground sources. Moreover, underground sources are chiefly used for public water supplies, and ground water in storage for more than brief periods is liable to deteriorate unless protected from the light. The expense of covering large reservoirs would be prohibitive. Relatively small supplies of well water are sometimes stored for irrigation (q.v.).

The yield of drainage areas is expressed in a variety of ways, depending somewhat upon the uses to which the water is put. For preliminary studies the yield may be stated in inches of depth, or in percentage of the total rainfall. The former is readily converted into cubic feet per second, hour, or day, per mile of drainage area, or into millions of gallons per square mile. The gallon is the most convenient unit where waterworks are involved, and the cubic foot where water is to be applied for power or navigation. In the case of irrigation either cubic feet or acre feet may be employed. (See IRRIGATION.) Stream gauging are recorded, primarily, in cubic feet per second.

not so great as to render some other source of supply cheaper. The amount of storage will range all the way from nearly the whole run-off of very small streams, to a few months' supply for medium-sized ones, and nothing for large rivers. But whenever an attempt is made to utilize a large percentage of the total run-off, storage will also have to be provided in large quantities. With adequate storage an average daily yield of 500,000 to 700,000 gallons per square mile may be expected in the New England States, New York, and New Jersey, where all the problems involved have been most carefully studied.

In a brief paper on Storage Water Supplies presented to the American Water-Works Association in May, 1901, L. J. Le Conte submitted the preceding estimates as to the capabilities and requisite storage of the drainage areas which supply Boston, New York, San Francisco, and Oakland, Cal.

BIBLIOGRAPHY. Consult: F. E. Turneaure, Public Water Supplies (New York, 1901), and other general reference books under articles on Irrigation and Water-Works; Water Supply and Irrigation Papers, and recent annual Reports of the United States Geological Survey; and vol. iii. (Water Power) of the Final Report of the State Geologist of New Jersey (Trenton, 1894). For further information on the natural sources of water supply, see WATER; ARTESIAN WELLS; RAIN; RIVER; SPRINGS. For the development of water supplies and their useful application, see AQUEDUCTS; DAMS AND RESERVOIRS; IRRIGATION; WATER POWER; WATER PURIFICATION; WATER-WORKS; and WELL-SINK

ING.

WATER-THRUSH. A name very suitably applied in Great Britain to the ouzel (q.v.), and transferred in the United States to the terrestrial warblers of the genus Seiurus, also better called 'water wagtails.' They are large, handsome birds, golden or olive brown above and satiny white below, with spotted breast. Three species are observable during the irrigation seasons in the eastern United States, where one remains during the summer as a numerous and familiar resident (see OVEN-BIRD). All show a fondness for the vicinity of water, frequently ponds and forest-streams, near which they make their nests and practice songs surpassed by few American birds in brilliance and melody.

America against arbitrary taxation. In 1775-76 the second and third Provincial Congresses of Massachusetts met here, and here the people of Boston, driven from their homes by the British, held several town meetings. Population, in 1890, 7073; in 1900, 9706. Consult: Francis, An Historical Sketch of Watertown (Cambridge, 1830); Hurd, History of Middlesex County (Philadelphia, 1890).

WATERTOWN. The county-seat of Jefferson County, New York, 70 miles north by east of Syracuse, on the Black River, and on the New York Central and Hudson River Railroad (Map: New York, E 2). Among the prominent buildings are the county court house, State armory, county jail, post office, and the Young Men's Christian Association building. A memorial library to ex-Governor Roswell P. Flower and a handsome high school building are in course of construction. The charitable institutions include the Henry Keep Home for the Aged, two hospitals, and two orphans' homes. There are several small parks, and a new park covering 650 acres is being laid out. Watertown is of considerable commercial importance as the cendeposits of iron and limestone. tre of a fertile farming section having extensive It also has large industrial interests. In the census year 1900 the various manufacturing establishments had an invested capital of $8,281,845, and a production valued at $7,881,977. The city is especially known for the manufacture of paper and wood pulp, and foundry and machine-shop products. The New York Air Brake Company ments include carriage and wagon factories, flourhas an extensive plant here. Other establishing and grist mills, lumber mills, steam engine works, farm-implement works, etc. Under the amended charter of 1903, the government is vested in a mayor, chosen biennially, and a unicameral council. The majority of the subordinate officials are appointed by the mayor, subject to the confirmation of the council. The water-works are owned and operated by the municipality. First settled in 1800, Watertown became the county-seat in 1805, and was incorporated as a village in 1816. It was chartered as a city in 1869. Population, in 1890, 14,725; in 1900, 21,696.

WATERTOWN. The county-seat of Codington County, S. D., 140 miles north by east of Yankton, on the Big Sioux River, and on the

WATER TOWER. See FIRE PROTECTION. WATERTOWN, wa'ter-toun. A town, including several villages, in Middlesex County, Mass., seven miles west of Boston, on the Charles River, and on the Boston and Maine Railroad

(Map: Massachusetts, E 3). It has a public library with 26,000 volumes, and a United States arsenal. A prominent residential suburb of Boston, it is also largely interested in manufacturing. The leading products are paper, paper bags, rubber goods, shirts, soap, woolen goods, waste and shoddy, starch, stoves, furnaces, etc. The water-works are owned and operated by the town. Watertown was settled and incorporated in 1630, and in 1632, when called upon to contribute toward the erection of a fort at Cambridge, made the first protest ever made in

VOL. XVII.-37.

Island and Pacific, the Great Northern, and the Minneapolis and Saint Louis railroads (Map: South Dakota, H 5). It is in a region of attractive scenery, but three miles from Lake Kampeska, one of the most picturesque lakes in

the State.

The city is an important shipping point for the farming and cattle-raising section adjacent. There are large grain elevators and warehouses, flouring mills, and manufactories of leather, foundry and machine-shop products, agricultural implements, carriages and wagons, oatmeal, etc. Population, in 1890, 2672; in 1900,

3352.

WATERTOWN. A city in Wisconsin, on the boundary line between Jefferson and Dodge counties, 44 miles west by north of Milwaukee (Map: Wisconsin, E 5). It is on the Rock River, and on the Chicago, Milwaukee and Saint