VALVE. 809 VAMPIKE. valve; thus a slide v:ilve may be operated by hand like the ordinary hand screw gate valve, by separate niechanisni like the hydraulic gate valves for water-works, or by nu'cluuiism con- nected with the medium operated like the slide valve of a locomotive. The construction of some common forms of valves is as follows: A jlap ralvc consists of a disk hinged at one side so as to open and close like the lid of a coffee pot. A butterfly valve consists of a disk hinged at diametrically opposite edges and slit through the centre at right angles to the hinges so that the two flaps swing upward and away from each other when the valve opens. Another construction con- sists in placing tlie hinges together on the dia- metrical slit so that the two llap upward and toward each other. A dhk r<ilvc consists of a circular disk seated on a grid and free to slide up and down for a limited distance on a rod or bolt passing through a hole in its centre. Lift or poppet valves consist of a disk with a flat or beveled edge seated on a circular disk: they operate by their own weight, like a disk valve, or by means of springs or rods. Slide Valves are of various forms. The D valve and the piston valve, illustrated in the article on Loco- IIOTIVES. are exam|)les. The f/ate valve used on water mains consists of a metal disk sliding be- tween two seats inclined toward each other so as to form a wedge-shaped slot. This disk is also wedge-shaped to correspond with the slot, and is raised and lowered by a stem attached to its upper edge and screwed up and down by a hand wheel. Cochs consist of a conical plug seated in a conical casing: both plug and casing have a hole through them in the line of the pipe, and bv turning the plug so that the holes coin- cide the valve is o]iened. Valves are usuall.v made of metal, cast iron, bronze, brass, and steel, combined with rubber, leather, or other flexible material to secure tightness. See Air CoMPHESsoK ; Gas; LocoMOTrvE; Pumps and Pumping Machinery; Steam Engine; Water- Works. Val-es in Musical Instruments are me- chanical devices in some brass instruments for lengthening or shortening the column of air. B.y means of this mechanism the older natural horns and trumpets, which had onlv a diatonic scale, were changed to chromatic instruments capable of producing every chromatic interval within their range. The number of valves is generally three, though some instruments have four. Two systems of valves are now in general use — piston valves and rotary valves. The latter afford the player a lighter manipulation of his instrument, but are more likely to get out of order than the piston valves. For valves in the organ, see Organ. VAMBERY, viim'bar-y', Arminius (1832 — ). An Hungarian traveler and Orientalist, born at Szerdahely, near Pressburg. He was largel.V self-educated. In 1S.54 he went to Constanti- nople as a private tutor, where he acquired a knowledge of Eastern languages, later becoming private secretary to Fuad Pasha. With the assistance of the Hungarian Academy he trav- eled through Armenia and Persia from IStll till 1864, visiting Khiva, Bokhara, and Samarkand. On his return to Europe he was appointed pro- fessor of Oriental languages at the Universitv of Budapest. The literary activity of V.'imlH'ry was confined, in the main, to the Ural-Altaic linguistic stocks, es|)ecially the Turkish. Among his numerous works the most important are: Travels and Adventures in Central Asia (2d cd. 1S73) ; Meine Wanderunyen and ICrlebnisse in I'crsien (1807); Vugataische Spraehstiidien (1807); Etymoloyisches Worlerbueh dcr turlco- tatarischen Spracheii (1878); Allosmanische Upraehstudioi (1001) ; editions of the Kudatken- liilik (1870) and the Scheibaniade (188.5) ; and the geograpliical, political, and historical books: Skizzen aus ilittelasien (1808); Hiissjands Machtstellung in Asien ( 1871 ) : (leschichle Hooh- aras oder Transoxaniens (1872); Cenlralasieii und die englisch-russische Grenzfrage (1873); Der Islam im ncunzelinten Jahrhundert (1875) ; tSitlenbilder aus dcm Morgenlandv (1870); Primitive Kultur des turku-latarisehen Volkes (1878); Crsprung der Uagyarcn (1882); Das Tiirkenvolk (1885); The Vominq Struggle for India (1885); The Story of Hungary ('l886) ; and A magyarsdg keletkezese es gyarapodasa (1895). Consult his autobiographical Arminius V amber y ; Ilia Life and Adventures (7th ed., London, 1889). VAMPIRE (Serv., Bulg. vamplr. Russ. ram- piru. Little Russ. vampyr, uper. White Russ. upir, vampire, probably from North Turk, uber, witch). In Slavic folklore, a corpse that rises at night from his grave, and drinks the blood of the living, which he obtains b.v sucking, with- out arousing the sleeper. He ma.v not onlv ap- pear in human form, but can assume the shape of a dog, cat, toad, or any bloodsucking animal. The victim loses appetite, wastes away, and after a few days expires without any visible dis- ease. The corpse of the destro.ver. being thus supplied, remains pliable and life-like. The veins are full, the cheeks ruddy and plump, and the mouth is gory — properties which enal>le an inquirer to ascertain the vampire quality. The most effective remedies against the vampire are cremation of the corpse, or nailing it by a thorn or aspen stake driven at one blow through the breast to the bottom of the grave to prevent the liody from wandering. Yet another mode of kill- ing the vampire is to chop off the head of the corpse with a grave-digger's shovel. Communities as well as individuals may be at- tacked bv the vampire. In general, children are first destroyed. The demon may. however, be traced by sprinkling salt on the floor of the house which it haunts. Vampirism is sel- dom a matter of choice, but a necessity depend- ing on criminal character, or some other reason which is likely to render a spirit unea.s_v in the grave. Thus witches, wizards, suicides, children of the devil, or illegitimate offspring of parents themselves illcgitinuite, are vampiri's, while the leap of a cat or the flight of a bird a<'ross a corpse may force even the innocent dead to be- come a vampire. Vam|iirism is, moreover, re- garded as infectious, since, it is believed, a man who has been the object of attack is himself thereby turned into a vampire. Tlie practice of burying murderers and other criminals with a stake through the body was evidcntlv brought about by dread of their turning into vampires: as regards suicides, this custom was onlv abolisjied in England bv a statute of George IV. A survival of the super-
