Page:The New International Encyclopædia 1st ed. v. 20.djvu/405

* WATER. 335 WATER-BOATMAN. is allowed, in the satunited state, to escape into the cold air, wlicii condensation causes tlie forma- tion of minute bubbles that produce the char- acteristic appearance of steam. BiULiooRAWiY. Deherain, Etudes pour servir it I'hisloire do la chiinie. La dvcouvcrte de la composition dc. I'eau (Paris, 1860) ; Nichols, Water Supply (New York, 1882); Davis, A Treatise on Stcam-lioiler Incrustation, and Meth- ods for Preventiny Corrosion and the l<'onnation. of Scale; also a Complete List of all Aiiierivan Patents issued hi) the Goccrnment of the United States from ll'M to July 1, 18S-'i, for Compounds and Mechanical Devices for Purifying Water, and for Preventing the Incrustation of Steam Boilers (Philadclpliia, 1884) ; Davis, An Ele- mentary Haiidljook on Potable Water (Boston, ISUl) ; VVanklyn and Chapman, Water Analysis (London, 18U1): Greenwell and Curry, Rural Water Supply (London, ISOo) ; ^[ason, Water Supply (New York, 189(!) ; Thresh, Water and Water Supplies (London, 1890) ; Fuertes, Water and Public Ucalth (New York, 1807) ; Rideal, Water and Its Purification (London, 1807) ; Crook, The Mineral Waters of the United States (New York, 1809) ; Leffmann, Examina- tion of Water for Sanitary and Technical Pur- poses (4th ed., Philadelphia, 1809). See Water Purification; Water Supply; Water-Work.s ; Well-Sinking, etc.; together with the accom- panying bibliographies. WATER BABIES, The. A fanciful tale by Charles Kingsley (1863). WATER BED. A rubber bed-tick, designed to be filled with water and to take the place of an ordinary mattress on a sick-bed. Its use de- creases the probability of the formation of bed- sores (q.v.). Objections to it are its great weight when filled, necessitating a very strong bedstead, and its liability to become cold, thus chilling the patient, and the difficulty of draw- ing oil' the contents and replacing them with warmer water. The air l)ed, constructed on the same iirinciple, meets all the indications and is free from all the objections. It is provided with a valve-stem through which it may be inflated with a bicycle air-pump. WATER-BEECH. See Hora'beam. WATER-BEETLE. Any beetle which lives in or vipon the water; more specifically, one of the true water-beetles or 'water-tigers' of the family Dytiscida". They live in the water both as larvie and as adults, although they are prob- ably modified terrestrial insects resembling the ground-beetles of the family Carabidne. The pupa is terrestrial. They are elliptical convex insects with the hind legs formed for swimming. The wing-cases fit perfectly to the body except at the tip, so as to form an air-tight space above the body proper. This space is the aif-chamber, and the beetle rises to the surface of the water, exposing the tip of its body and drawing in a supply of air wbich will last it for some time, when it goes below the surface again. The larvfe of the true water-beetles are very ra]iaciou3, and suck the juices of small, soft aquatic insects. The mandibles are hollow, with a liole near the tip and another at the base, thus being fitted for suction. The water-beetles are more numer- ous in temperate and boreal than in tropical regions. Abouf 1800 species are known, of which nearly three hundred inhabit the United States. Whirligig beetles of the family Uyrinida' are small oval forms which swim about on the sur- face of the water, usually darting in curious curves, from which habit the pojiular name is derived. They can dive, carrying with them a small supply of air, but their proper life is on the surface. The two hind pairs of legs are so modified as to form jiaddles. Tlie larvse are a(|uatic and are elongate with sharp mandibles. They are carnivorous in the larval stage as well as in the adult. About ;iOO species an' known, of which nearly forty occur in the United States. The water-beetles of the family Ilydropliilidas are sometimes called 'water scavenger-beetles.' The larva; are predaceous and carnivorous, but the adult beetles are, as a rule, vegetable feed- ers, though they will prey upon small aquatic animals. They are usually dark-colored, of elliptical shape, and do not swim as readily a3 do the other water-beetles, nor is the supply of air which may be carried as extensive as with the others. .Many species construct egg-cocoons, which are sometimes attached to the body of the beetle and sometimes to aquatic plants, and fre- quently iinattaclied, floating on the surface of the water. Prom 20 to 100 eggs are laid in each cocoon. About 1000 species are known, and of these 150 are found in the United States, and about 90 in England. Other beetles, such as the AmphizoidiP and Pelobiida'.. live in the water in their early stages. The strangely modified para- sitic beetle, Platypsyllus rastoris, found com- monly upon the beaver, might also with justice be called a water-beetle. Consult Miall, The Natural Bistorif of Aquatic Insects (London, 1805). WATER-BIRDS. A group of birds alike in their adaptations to an aquatic life. Such are the sea-birds, or Steganopodes. well represented by the cormorant ; the auk tribe, gull tribe, and other marine groups; and the great tribe of fresh-water aquatic birds represented by the swans, geese, and ducks. All water-birds are swinnners and divers, and are more or less completely web-footed, furnishing them both with paddles and with broad supports in walking upon muddy shores. All get their food mainly from the water — fish, amphibians, reptiles, shell- fish, and small aquatic animals; or else aquatic vegetation. Their plumage is dense, oily, and, except in the ducks, usually of plain black, white, and brown colors ; they nest on the groimd, as a rule, laying iraspotted eggs, except auks, gulls, etc.; and the fresh-water section atTords many birds most esteemed for food and sport, and several domesticated species of great value. See Colored Plate of Water-Birds. WATER-BOATMAN. An aquatic bug of the family Corixidie. in which the head is free, capable of great rotation, and attached to the thorax only by a narrow area. The water-boat- men, as a rule, are mottled bugs of oval shape, found commonly swinuning on the surface of ponds and streams. They are quite at home be- neath the water as well as on the surface, and remain there for a long time, since the fine hairs which cover the body retain a film of air. They hibernate in the mud at the bottom of ponds or streams. The eggs afe laid under water, and are attached to the stems of aquatic plants.