328
ALLPORT —ALMADEN
alloys is thus presented. Rayleigh has pointed out that Villars, Paris.—W. Spring. Bull, de I’acad. roy. de Belgique, 1878 this difference may arise from the heterogeneity of alloys. to recent years.—R. H. Thurston. Materials of Engineering. (w> c> R .A^ When a current is passed through an alloy, a series of Wiley, New York. Peltier affects, proportional to the current, are set up Allport, Sir James Joseph (1811 1892), between the particles of the different metals, and these English railway manager, born 27th February 1811, was a create an opposing electromotive force which is indis- son of William Allport, of Birmingham, and was associated tinguishable experimentally from a resistance. If the with railways from an early period of his life. In 1843 he alloy were a true chemical compound the counteracting became general manager of the Birmingham and Derby Railelectromotive force should not occur, and experiments in way, and in the following year succeeded to the same position this direction are much needed. Roberts-Austen has on the Newcastle and Darlington line. Six years later he shown that in the case of molten alloys the conduction of assumed the charge of the Manchester, Sheffield, and electricity is apparently metallic, no transfer of matter Lincolnshire (now the Great Central) Railway, and finally, attending the passage of the current. A group of bodies in 1853, was appointed to the general managership of the may, however, be yet discovered between alloys and Midland Railway—an office which he held continuously, electrolytes in which evidence may be found of some with the exception of a few years between 1857 and I860’ gradual change from wholly metallic to electrolytic con- until his retirement in 1880, when he became a director.’ duction. Laurie has determined the electromotive force of During these twenty-seven years the Midland grew to be a series of copper-zinc, copper-tin, and gold-tin alloys, and one of the most important railway systems in England, as the result of his experiments he points to the existence of partly by the absorption of smaller lines and partly by definite compounds. Explosive alloys have been formed the construction of two main extensions—on the south by Deville and Debray in the case of rhodium, iridium, to London and on the north to Carlisle—whereby it and ruthenium, which evolve heat when they are dissolved obtained an independent through-route between the metroin zinc. When the solution of the rhodium-zinc alloy is polis and the north. In the railway world Sir James treated with hydrochloric acid, a residue is left which under- Allport was known as a keen tactician and a vigorous goes a change with explosive violence if it be heated in fighter, and he should be remembered as the pioneer vacuo to 400°. The alloy is then insoluble in “aqua of cheap and comfortable railway travelling. He was regia.” The metals have therefore passed into an insoluble the first to appreciate the importance of the third-class form by a comparatively slight elevation of temperature. passenger as a source of revenue, and accordingly, in The feature of the period from 1875 to 1901 has been 1872, he inaugurated the policy—subsequently adopted the increased attention which has been devoted to the ap- more or less completely by all the railways of Great ladustrlal plications of the rarer metals. Thus nickel, Britain—of carrying third-class passengers in well-fitted applica- which was formerly used in the manufacture carriages at the uniform rate of one penny a mile on all tions. ' 0f « German silver ” as a substitute for silver, is trains, even the fastest. The diminution in the receipts now widely employed in naval construction, and in the from second-class passengers, which was one of the results, manufacture of steel armour-plate, projectiles, and, when was regarded by some authorities as a sign of the unwisdom alloyed with copper, the envelopes of bullets. Manganese of his action, but to him it appeared a sufficient reason not only forms with iron several alloys of great interest, for the abolition of second-class carriages, which therefore but alloyed with copper is used for electrical purposes. disappeared from the Midland system in 1875, the firstChromium also, in comparatively small quantities, is taking class fares being at the same time substantially reduced. its place as a constituent of steel axles and tyres, and in This innovation too has been followed by other comthe manufacture of tool-steel. Vanadium, molybdenum, panies, though not with the same unanimity as attended and titanium may be expected soon to play an important his earlier reform. He was also the first to introduce the part in the constitution of steel. Titanium is alloyed in Pullman car on British railways. Allport received the small quantities with aluminium for use in naval archi- honour of knighthood in 1884. Hd died in London on tecture. The importance is now widely recognized of con- 25th April 1892. (h, K ^ sidering the mechanical properties of alloys in connexion with the freezing-point curves to which reference has already AI mad a, a town of Portugal, district Lisbon, on been made, but the subject is a very complicated one, and the left bank of the Tagus, immediately opposite Lisbon, all that need be said here is that when considered in with manufactories of cork. It was founded by English relation to their melting-points the pure metals are con- crusaders in the reign of Affonso Henriques. Population sistently weaker than alloys. The presence in an alloy of a about 7000. eutectic which solidifies at a much lower temperature than AI made n, or Almaden del Azogue, a town of the main mass, implies a great reduction in tenacity, Spain, in the province of Ciudad Real, in the Sierra Moreno. especially if it is to be used above the ordinary temperature In the latter part of the 19th century the Almaden quickas m the case of pipes conveying super-heated steam. It mines were leased by the state to the house of Rothmay also be stated that alloys of metals with similar melting- silver schild, whose contract expired in 1900, but who still sell the points have higher tenacity when the atomic volumes of the constituent metals differ than when they are nearly quicksilver for the Spanish Government. The town has a good hospital, schools, and other buildings. Care is taken to J the same. minimize the effects of the fumes on the operatives, whose For further information the reader may refer to : —Roberts health is very rapidly and seriously impaired. Hence the 1- t0 0 the A,lo s Invtttvfimi V Research of th custom formerly was to use convicts for the labour in the Institution of Mechanical7V Engineers, London, 1891 Committee to 1899 • Intri duction to Study of Metallurgy, London, 1898 (see section devote- quicksilver mines. Owing to the deleterious effects of the atmosphere, exemption from military service is granted to t , A l0 S f r ef nCe t0 f reign J ;; ,! delivered 7 7- ° J atf/t o ° of Arts, papers).—CWvr Lecturesamo men who have been two years employed in the quicksilver Alloys the Society 1884-1901.—Heycock Nevulle. Various papers Transactions of the Royal SoScZ, am Journal of the Chemical Society, 1890 to the present time.- mines. The average output of mercury is 10 per cent, on Osmond, Le Chatelier Charpy, and Others. Bull, soc d the ore extracted, and, according to official returns, 75 per l encouragement pour l Industrie nationale, Paris (various paper cent, of the value of the output is clear profit. In 1898 there 1880 to present year especially last ten years).-Roberts-Austei were 1906 men and 417 lads employed in the mines. The L 0DStltUt alUa r. des1900, ««« Report of the Physical; V Congress, Paris, vol. n^talliques i. Gauthie• amount of ore extracted was 19,945 tons, from which 1595 tons of quicksilver were drawn, being 46,211 flasks weigh-
