Page:1902 Encyclopædia Britannica - Volume 26 - AUS-CHI.pdf/315

 BOHMISCH-LEIP A—B O I L E R S race. While the Austrian episcopacy is in an exceptionally favourable pecuniary position, the minor clergy are badly paid. The profession has therefore little attraction for the well-to-do middle classes. The consequence is that it is largely recruited among the Slav peasantry, so that the priests even of the German districts of Bohemia and Moravia are predominantly Czech. Such a priest, filled with a sense of his own dignity and authority, enters his sacred office not merely with an unenlightened racial Chauvinism, but with an almost personal grudge against the better educated leaders of the German element, and indeed against the less deferential German part of his flock altogether. The irritation produced by this attitude of the Catholic clergy accounts for a good deal in the movement in favour of wholesale conversion to Protestantism, which has made most progress in Bohemia. The motive of the promoters of the “ Emancipation from Rome ” movement, however, is to make German Austria more palatable to Protestant Germany in view of future eventualities. The Pan-Germanic movement finds encouragement and support among an important section of the German manufacturers of Bohemia on other than national grounds. These argue that Austrian industry has now reached a stage at which it can compete successfully with that of Germany. The latter, it is true, has had the start, but Austrian industry has the advantage in the matter of good taste, a point in which Germany is deficient. Moreover, Austria has numerous undeveloped resources, which, if properly utilized, would place it on a level with its rival. The most pressing requirement of the Austrian manufacturers is fresh markets and liberty for their expanding energies, and this, it is urged, would be at once provided by some form of amalgamation with the German empire. Other sections of the industrial community hold, however, that Austrian industry is not yet strong enough to dispense with the high protectionist tariff that now excludes German products. The recent aggravation of the nationality conflict has done less damage to trade in the Czech provinces than might have been expected, the prevailing system of credit having opposed practically insurmountable difficulties in the way of the threatened boycott of political opponents. Authorities.-—R. Axbree. Nationalitais-verhaltnisse und Spratfigrenze in Bbhmen, Leipzig, 1872 ; and Tschechischc Gauge, 1872 ; Bendel. Die Dcutschen in Bohmen, Mahren, und Schlcsien, Teschen, 1884; Die Oesterreichisch-Ungarische Monarchic in Wort und Bild; the histories and historical sketches of Tomek, Schlesinger, Frind ; Tomax. Das Bokmische Staatsrecht; Menger. Bohmische Ausgleich, Stuttgart, 1891 ; Turnwalb. Administrative Teilung Bbhmens; the article “Bohmen” in M ischi,erandUlbrichs OesterreichischesStaatsworterbuch, Vienna, 1895-97. Dr H. Rauchberg. Die Bev'dllcerung Osterreichs, Vienna, 1895, &c. 0>N ^ Bdhmisch-Leipa (Czech, fiesM Lipa), the chief town of a district in North Bohemia, on the Polzen, a tributary of the Elbe. It has a considerable industry, including the works of the Bohemian Northern railway, textile and calico-printing factories, and the manufacture of pianos, glass, dextrine and starch, sweetmeats and preserves, sugar, stores, the preparation of furs and skins, brewing and corn-milling. Population (1890), 10,406 • (1900), 10,674; chiefly German and Catholic. Bdhmisch-Triibau (Czech, Trebovd 6eskd), an old town in the government - district of Landskron, in North-East Bohemia, Austria, near the Moravian frontier. It has considerable textile industry (linen spinning and weaving), brewing and the preparation of malt, and trade in flax, which is extensively cultivated in the district. The inhabitants (4982 in 1890, 6040 in 1900) are Czech.' Boilers.—In the article Steam-Engine (Encydo- |

281 paidia Britannica, vol. xxii.) the general principles underlying the design and use of all steam boilers are stated, and several kinds of boilers are illustrated. The examples given still fairly agree with the present practice of the types described, but during the last few years some changes have taken place in matters of detail, and several new designs have come into use. It is with these that this article is intended to deal. Land Boilers.—The boilers most generally used in large mills and manufactories at the present time are the Lancashire ” and its modification the “ Galloway.” ^ Cross-sections of these are illustrated “Laac*’ in the Bncyclopaidia Britannica, vol. xxii. p. sbire‘ 497. They are usually from 26 to 30 feet long, with diameters from 6 feet 6 inches to 8 feet. The working pressure is in some cases as high as 200 lb per square inch, but is usually about 60 lb per square inch in the older boilers, 100 to 120 lb in those supplying steam to compound engines, bIb 150 lb to 170 lb where the engines are triple expansion, and 200 lb where they are quadruple. The furnace flues are now generally made in sections from 3 feet to 3 feet 6 inches Fl°-1-- “Adamson” Joint, long, each from one plate, the seam being sometimes riveted but more usually welded. The rings are flanged outwards at the ends, and are connected together by “ Adamson ” joints (Fig. 1). It will be seen that these joints do not expose any rivets or double thickness of plate to the action of the fire, and they serve also as strengthening rings to prevent collapse of the furnace. In such boilers the long flues beyond the firebridge form combustion-chambers in which the furnace gases may be completely burned. The amount of heatabsorbing surface provided in proportion to the grate surface is not so large as in some types of tubular boilers; and, although they are regarded as fairly economical, they do not give such good results as are obtained with some more complicated forms. The space occupied by them, and their weight in proportion to the power developed, are both large ; but their design is one which affords great facilities for easy inspection and cleaning of all the vital parts. The great amount of water they contain, and the large area of the water-level, provide a considerable reservoir of energy for fluctuations of power or of firing, and a reserve of water for variations of the feed supply. These reasons lead to their employment in situations where the feedwater is impure or very skilled attention is not available, and where in addition space and weight are not very important considerations. In some large works water-tube boilers are used. Two types of these boilers will be described. The “ Babcock and Wilcox ” boiler, illustrated in Fig. 2, consists of a horizontal cylinder forming a steam-chest, having dished ends and two specially constructed cross-boxes riveted to t,Babcoc „ the bottom. Under the cylinder is placed a sloping “ nest of tubes, under the upper end of which is the fire. „ 1 he sides and back of the boiler are enclosed in brickwork cox. up to the height of the centre of the horizontal cylinder. Suitable brickwork baffles are arranged between the tubes themselves, and between the nest of tubes and the cylinder, to ensure a proper circulation of the products of combustion. The nest of tubes consists of several separate elements, each of which is formed by a front and hack header made of wrought steel of sinuous form connected by a number of tubes. The upper ends of the front headers are connected by short tubes to the front cross-box of the horizontal cylinder, the lower ends being closed. The upper ends of the back headers are connected by longer pipes to the hack crossbox, and their lower ends by short pipes to a horizontal mud drum to which a blow-off cock and pipe are attached. The headers are furnished with holes on two opposite sides ; those on one side form the means of connexion between the headers and tubes, and the others allow access for fixing the tubes in position and cleaning. The outer holes are oval, and closed by special fittings shown S. II. — 36
 * J