VALVE

a contrivance for controlling the movement of a fluid along a pa age. The arrangement may or may not be automatic. The non-automatic variety is illustrated by the ordinary water-tap. This may be a simple cock consisting of a conical plug, fitting into a corresponding seating. ‘There is a hole in the plug which coincides in one position with the pa age in the seating. The other and commoner type consists of an ordinary lift valve, raised and lowered by a screw spindle working in a nut. Automatic valves are of various designs. The flap valve consists of a hinged metal plate with a piece of leather forming the joint. The butéerfly valve is formed of two flat valves placed back to back. The poppet or mushroom valve is a disk raised by pre ure and generally closing by its own weight. Double-beat and four-bect valves: in these the number of seats has been increased so as to reduce the shock of closing. The tndia-rubber disk valve rests on 2 gun-metal grid, and is held at the center by a bolt, a saucer-shaped guard limiting the rise of the rubber disk. A corresponding guard limits the opening of all the valves mentioned above. The admi ion of steam to the cylinder of an engine is usually regulated by a slide valve (see Ewaines), frequently modified, as in the double-ported valve or the Meyer valve, with variable expansion gear. Other valve gears enable the engine to be reversed. 50’ E.), town, Serbia; plum-growing center. Pop. 7,000. Hungarian traveler and Orientalist; traveled through Armenia and Persia, — 1861-4; prof. of Oriental languages in univ. of Budapest, till 1905; author of autobiographical and philological works, bet The Story of My Siéruggles, a large family of bats, with about 150 species, distinguished either by a well developed ‘leaf’ above the nose, or by skin folds or warts beneath the chin; the middle finger of the wing has three joints; they are confined to the tropical and sub-tropical regions of the New World, where they inhabit forest areas, the majority feeding on fruits, or on fruits and insects. ‘Two species, Desmodus and Diphylla, are bloodsuckers.