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chamber by four down-pipes placed outside the casing. These are of comparatively small diameter, and are designed principally as part of the framework. There are also two larger outside circulating pipes at one end of the boiler. The “ Eeed ” boiler resembles the “ Normand ” in some respects, A I 'l.

but the tubes are longer and more curved, and there are no waterwalls, the products of combustion passing between all << ” the tubes as in the “Yarrow” boiler. The tubes, instead of being expanded into the plates of the chambers, are fitted at each end with specially designed screw and nut connexions,

Fio. 14.—Normand Boiler. which enable them to he quickly taken out and replaced in case of bustion to pass across all the tubes is less than one quarter need. The tubes are somewhat reduced in diameter at their lower of a second. It follows that at very high rates of working these boilers cannot be economical in coal consumption, and it is only their extreme lightness in proportion to the power they yield that determines their suitability for the special purposes for which they are employed. (j. T. Mi.) Boise, capital of Ada county and of the state, Idaho, U.S.A., in the valley of Boise river, in 43° 37' N. lat. and 116° 12' W. long. Its houses are in great part heated by water brought in pipes from hot springs situated about 2 miles from the town. Here terminates a branch of the Oregon short line railway from Nampa. Boise is a supply-point for miners in the neighbouring mountains. Population (1880), 1899; (1900), 5957. Bois-Ie-Duc, ’S Hertogenbosch or ’S Bosch, the capital of the province of North Brabant, Holland, 28 miles S.S.E. of Utrecht, at the confluence of the Dommel and Aa. It is the market of the fertile Meiery district, and does considerable trade with Dordrecht and Botterdam, Nimeguen and Arnheim, Maestricht and Liege. The industrial features include cigar factories. A new station was built in 1894. In the same year the seminary for teachers ceased to exist. In the provincial museum are interesting Roman and German antiquities. Population, 30,517. Boissier, Marie Louis Gaston (1823 ), French classical critic, and secretary of the French Academy, was born at Nimes on the 15th August 1823. The Roman monuments of the place of his birth very early attracted his attention, and drew him insensibly to the study of ancient history. He made epigraphy his particular theme, and, while still a youth, became a teacher of rhetoric in his native town. All the small-tube boilers described are worked with In 1846 M. Gaston Boissier was appointed professor of strong forced draught when full power is desired, the that science at Angouleme, where he lived and worked for air-pressure employed sometimes exceeding 4 inches of ten years without further ambition. A travelling inspector water-column. Owing to the rapidity with which the of the university, however, passing through Angouleme, products of combustion are hurried amongst the tubes, happened to hear him lecture, and M. Boissier was called where no further combustion can take place, if some of the to Paris to be professor at the Lycee Charlemagne. It was gases are not completely burned, only part of their heat only in mature years that he began to be an author. The can be given up ; for instance, in a “ Yarrow ” boiler work- Academie des Inscriptions offered, in 1859, a prize for an ing at full power, the time taken for the products of com- essay on Terentius Yarro. M. Gaston Boissier was induced