430 



NATURE 



[September i, 1898 



Hughes' induction balance was made evident, the source of 

 current being three Leclanche cells, and the interrupter being of 

 the scraping contact type actuated lay clockwork. 



Among other experiments was shown one to prove that in 

 certain cases the parts into which a rapidly alternating electric 

 current is divided may be greater than the whole (see Phil. Mag., 

 vol. xxii. p. 496, 1886). The divided circuit was formed from 

 the three wires with which, side by side, a large flat coil is 

 wound. One branch is formed by two of these wires connected 

 in series, the other (in parallel with the first), by the third wire. 

 Steady currents would traverse all three wires in the same 

 direction. But the rapidly periodic currents from the interrupter 

 distribute themselves so as to make the self-induction, and con- 

 sequently the magnetic field, a minimum ; and this is effected 

 by the assumption of opposite values in the two branches, the 

 ratio of currents being as 2 : - i. On the same scale the total 

 or main current is + i . It was shown by means of the telep hone 

 and flame that the current in one branch was about the same 

 (arithmetically) as in the main, and that the current in the other 

 branch was much greater. 



THE STOCKHOLM MEETING OF THE IRON 

 AND STEEL INSTITUTE. 



THE autumn meeting of the Iron and Steel Institute, held at 

 Stockholm on August 26 and 27, under the presidency of 

 Mr. E. P. Martin, of Dowlais, was a most successful one. An 

 influential reception committee, including the Governor General 

 of Stockholm and all the leading men in the iron industry, 

 entertained the members with lavish hospitality. The King of 

 Sweden invited the members to supper at his Palace, and 

 attended the meeting in person. 



The meetings were held at the House of Lords, a fine building 

 erected in 1648, and were largely attended. Addresses of 

 welcome were given, and the President announced that Prof. 

 AV. C. Roberts-Austen, C.B., F.R.S., had been unanimously 

 chosen to succeed him as President. 



No less than eleven papers were on the programme. The 

 first paper read was by Mr. R. Akerman, Director General 

 of the Board of Trade, on the development of the Swedish 

 iron industry. He traced the history of the industry from 

 the earliest times, and showed the influence exerted by the 

 chemists Scheele and Berzelius on metallurgy. The Swedish 

 production last year comprised 538,197 tons of pig iron, 189,632 

 ions of wrought iron, 107,679 tons of Bessemer ingots, and 

 165,836 tons of open-hearth ingots. 



Prof. G. Nordenstrom read a paper describing the character- 

 istic features of Swedish iron ore mining. He began with an 

 account of the geology of the country, and then discussed the 

 geographical distribution of the iron ores, their mode of occur- 

 rence, composition, mining and production. The total 

 production last year was 2,086,119 tons. Much of the paper 

 was devoted to the use of magnetic instruments in exploring for 

 iron ore, a subject previously treated by Mr. B. H. Brough in a 

 tpaper read before the Institute in 1887. 



Mr. C. P. Sandberg's paper on the danger of using too hard 

 ■.rails, contained the results of experience on the Swedish rail- 

 ways. He considered that it is preferable to adopt a heavier 

 weight of rail of moderate hardness, rather than to try to remedy 

 'the deficiency in weight of rails originally used by now resorting 

 \.o a dangerous hardness of rail of the same section. 



Mr. A. Greiner, director of Cockerill's works at Seraing, 

 communicated, as a supplement to the paper he read in May, 

 the results of experiments by Mr. A. Witz with a simplex 

 motor, using blast furnace gas. The results were highly 

 satisfactory, showing that the working of the 200 horse-power 

 engine is very econoinical and as regular as that of a steam 

 engine. The dust in the gas is in no way injurious to its 

 continuous operation. 



Mr. H. Lundbohm, of the Geological Survey of Sweden, 

 described the iron ore deposits of Kiirunavaara and Luossavaara, 

 the largest deposits in Swedish Lapland. The ore occurs in 

 bed-like masses in porphyry. It is very rich, and the author 

 estimates that there is above the level of the lake at Kiirunavaara 

 215,000,000 tons, and at Luossavaara 18,000,000. The situation 

 of the beds within the Arctic circle at 67° 50' north lat. renders 

 them inaccessible. A railway, now in course of construction, from 

 the Gulf of Bothnia to Ofoten, will give access to these deposits 

 and furnish a most important source of iron ore supply. 



Mr. J. E. Stead supplemented the important paper on the 



NO. 1505, VOL. 58] 



crystalline structure of iron by presenting further facts bearing 

 upon the brittleness produced in soft steel by annealing. The 

 most important point established is that phosphorus must not 

 exceed o'oS per cent. 



The paper on the micro-chemistry of cementation, read by 

 Prof J. O. Arnold, was of special interest as giving a detailed 

 description of the effect of cementation on the brands of iron 

 sent by Sweden to England. 



Mr. G. R. Johnson, of Embreville, Tennessee, contributed a 

 paper on the action of metalloids on cast iron. He insisted that 

 foundrymen in buying iron should require analysis as well as 

 fracture, for it is impossible to judge of the composition of an 

 iron merely by looking at it. 



Prof. W. C. Roberts-Austen discussed the action of the pro- 

 jectile and of the explosives on the tubes of steel guns, showing 

 the interesting results obtained by an examination of the bores 

 of corroded guns by the aid of micro-photography. An interest- 

 ing discussion followed the reading of the paper, a noteworthy 

 contribution being supplied by Mr. Nordenfeldt. 



The two other papeis on the list were taken as read. Baron 

 H. Jliptner applied the data as to the thermal relations of iron 

 carbon alloys contained in Prof. Roberts- Austen's fourth Report 

 to the Alloys Research Committee of the Institution of Me- 

 chanical Engineers, to correcting the conclusions expressed in 

 his paper on the solution theory of iron and steel read last May. 

 And Prof. E. D. Campbell, of the University of Michigan, 

 described some further experiments made by him on the diffusion 

 of sulphides through steel. 



The usual votes of thanks were given, and the meeting 

 terminated. 



An elaborate programme of excursions was arranged. Various 

 works in Stockholm were visited. Before the meeting a limited 

 number of members visited the remarkable iron mines of the 

 Arctic Circle, and after the meeting there were two excursions 

 occupying several days : one to the ironworks of Domnarfvel, 

 Hofors, Sandviken, and the mines of Grangesberg, Falun, and 

 Dannemora ; and the other to the ironworks of Lax4, Degerfors, 

 Bofors, Uddeholm and Storfors, and to the Persberg iron mine. 

 All the arrangements were most satisfactory, and great credit 

 is due to the Hon. Secretary of the Reception Committee, Mr. 

 J. C. Kjellberg. and to Mr. Brough, the Secretary of the 

 Institute. 



THE OLD BEDS OF THE AMU-DARIA. 

 "PHE Russian Geographical Society has just issued a new 

 ■'■ volume which contains an important contribution to the 

 much debated question as to the old beds of the Amu-daria. It 

 is written by the mining engineer, A. M. Konshin, and con- 

 tains a geological map showing the extension of the Pliocene 

 and modern Caspian deposits, as well as of the Loess and the 

 fluviatile deposits in the Transcaspian region, and a number of 

 drawings of dunes and barkhans (of aeolic origin), and small 

 plans of the Uzboi and the Ungus (supposed old beds of the 

 Amu).^ 



When the Transcaspian region was first opened to scientific 

 exploration it was generally believed that the ravine which runs 

 from Lake Aral to the Caspian Sea, the Uzboi, as well as the 

 Ungus and the Kelif Uzboi, represent old beds of the Amu, 

 which, continually shifting its bed towards the right, ran 

 successively at the foot of the Kopet dagh, then across the 

 Karakum desert, and finally, after having taken to its present 

 bed, sent a branch towards the Caspian Sea along what is now 

 known as the Uzboi. This hypothesis has still a fervent 

 adherent in Baron Kaulbars. A further exploration of this 

 region, which was made in 1883, proved, however, that the 

 Uzboi has not the characters of an old river bed, and that 

 in Post-Pliocene times the Caspian Sea sent a broad gulf 

 eastwards, into what is now the Karakum desert. The Ungus, 

 which crosses this desert, is also not an old bed but an escarp- 

 ment by which the Pliocene clays of the Karakum Plateau fall 

 towards the lower- lying Post- Pliocene Karakum Sands. Con- 

 sequently, two hypotheses are now in presence. One of them, 

 supported by M. Konshin, is that a gulf of the Caspian stretched 

 as far eastwards as the longitude of Merv, sending in its western 

 part a branch northwards, along the Uzboi, as far as the 



1 " Contribution to the Question relative to the Old Course of the Amu- 

 daria." 256 pp. with several maps and drawings. St. Petersburg, 1897. 

 {Memoirs of the Russian Geographical Society, General Geography, vol. 

 xxiii. part i). Russian. 



