440 



NATURE 



[OCTOBFR 6, 1910 



IHE iUrUMN MEETING OF THE lRO.\ AND 

 STEEL INSTITUTE. 



WHEN Buxton was selected as the locality for the 

 autumn meeting of the Iron and Steel Institute 

 doubts were freely expressed as to the suitability of the 

 choice. These doubts proved to be groundless, for the 

 attendance of members was larger than usual, and visits 

 to the Midland Railway works at Derby, the London and 

 North-Western works at Crewe, and to the Staveley Iron 

 Works afforded opportunities for instruction, while the 

 beautiful weather conditions caused the Duke of Devon- 

 shire's rtarden-party at Chatsworth, and other excursions 

 in Derbyshire, to be very successful and enjoyable func- 

 tions. 



From a scientific point of view, the paper which 

 attracted the most attention was that on the theory of 

 hardening carbon steels, bv C. A. Edwards, of Man- 

 chester. .-Xs is well known, metallurgists Uave long been 

 divided into two camps, the " carbonists " and the 

 " allotropists," and at times much heat has been intro- 

 duced into the discussions which have taken place. The 

 position advocated by Mr. Edwards is to an extent an 

 intermediate one, as "it is based on the assumption of the 

 existence of three allotropic forms of iron, known as o, 

 e, and 7 respectivelv. At the same time, the absolute 

 necessitv of carbon for true hardening is maintained. 

 .■\fter a clear explanation of the elementary facts con- 

 nected with the phase rule in its application to alloys in 

 general, and particularly to the iron carbon series, the 

 author concludes that tlie hardness of carbon steel is due 

 to the retention, by quenching, of the solid solution of 

 carbon, or carbide of iron, in 7 iron, and that the ^-iron 

 theory, as applied to the explanation of the increased 

 hardness of steel, is untenable. The solid solution of 

 carbon or carbide in 7 iron decomposes with slow r.-ites 

 of cooling, and some force must be applied to prevent 

 inversion taking place. The force is mechanical, and is 

 caused by the contraction of the outer shell. There is no 

 constitutional difference between austenite and martensite, 

 the apparent difference being due to the twinning of the 

 7 solid solution as a result of the mechanical pressure. 



In the discussion which followed the reading of this 

 paper. Prof. .Arnold warmly congratulated the author on 

 his contribution, but contended that more facts were re- 

 quired before generalisations were accepted, and pointed 

 out that the cooling curves as given by himself, and con- 

 firmed at Charlottenburg, did not agree with those pub- 

 lished bv Dr. Carpenter. The latter stated that the 

 difference was not one of observation, but of methods of 

 recording and of interpretation. Prof. Turner asked for 

 evidence of twinning, and suggested that twinning in 

 crvstalline rocks or" in the brasses was the result of 

 annealing after pressure, but that in the hardening of 

 steels there was no such annealing. 



Two papers which also led to an interesting discussion 

 were taken together, and dealt, inter alia, with the 

 changes on the length of cast-iron bars when cooling in 

 a sand mould. These papers were entitled " The influence 

 of Silicon on the Properties of Pure Cast Iron," by A. 

 Hague and Prof. T. Turner, and " Manganese in Cast 

 Iron, and the Volume Changes during Cooling." bv 

 H. I. Coe. It was pointed out that in Prof. Turner's 

 original papers on silicon in cast iron, published in 18S5, 

 the materials used were relatively impure, and though the 

 results have been confirmed bv very extended practical 

 application, it was thought well to start with the purest 

 available materials and to observe the temperature and 

 contraction changes and the microstructure, which had 

 not been examined in the earlier tests. White iron, when 

 free from elements other than carbon, shows only two 

 slight arrests in the rate of contraction, and these corre- 

 sDond with the eutertic and the pearlite points respectively. 

 On adding silicon or manganese, the iron, though still 

 white, expands during and immediately after solidification. 

 With more silicon the carbon is thrown out of solution, 

 and a marked additional exoansion occurs. Though much 

 manganese tends to make iron white, about o-i^ per cent, 

 of manganese, in presence of silicon, produces more 

 secondary graphite, and thus lowers the combined carbon. 

 In the manganese series of white iron the expansions form 



a regular curve with the percentages of manganese, and 

 minima are found corresponding with the existence of four 

 definite carbides. In the grey-iron series the expansions 

 were relatively large, and the pearlite point disappeared 

 suddenly with about 3-5 per cent, of manganese. 



In the discussion references were made to the great 

 detail involved in such an inquiry, and to the need of 

 further work and generalisation. In a paper by S. Hilpert 

 and E. Colver-Glauert, sulphurous acid was recommended 

 as an etching agent for metallographic work. The acid is 

 used as a saturated solution of sulphurous acid in water. 

 It should be free from sulphuric acid, and should be 

 diluted with water to about 3 or 4 per cent, of such acid. 

 The time taken is said to vary from seven seconds to one 

 minute. S. Hilpert, of Berlin, submitted a useful note 

 on the preparation of magnetic oxides of iron from 

 aqueous solutions, and stated that the production of FejO^ 

 from aqueous solution is only possible through the pre- 

 cipitated FeO dissolving in the ammoniacal residue. The 

 true magnetic oxide is Fe^O, in the form of ferric ferrate, 

 and the magnetic properties of FCjOj have their source 

 in the acid properties of Fe^Oj. 



The remaining papers of a varied programme dealt with 

 briquetting iron ores, electric pow'er and electric steel 

 refining, the Hanyang iron works in China, the produc- 

 tion of rolled H beams, and experiments on fatigue in 

 metals. 



THE GEOLOGICAL CONGRESS AT 

 STOCKHOLM. 

 'T'HE eleventh International Geological Congress in 

 Stockholm from August 17-25 has been generally 

 pronounced by the members to have been one of the 

 most successful yet held. There was an attendance of 

 about 900, including representatives of all European 

 countries except Portugal, of Australia, China, and Japan, 

 and a distinguished contingent from America. The 

 excursions at this congress have been unusually various 

 and instructive, and they were heartily enjoyed, thanks 

 to their skilful organisation and management. Eiefore 

 the meeting there were excursions to Spitsbergen, Lap- 

 land, and central Sweden ; during it to the -Archaean areas 

 and glacial deposits around Stockholm and Upsala, and 

 to the classical Silurian sections at Gothland ; and after 

 it to the chief iron fields and areas of geological interest 

 in southern Sweden. The library of guide-books issued 

 for the excursions forms an invaluable summary of the field 

 geology of Sweden. The Swedes as a people are charac- 

 ter ised by the thoroughness of their work and the charm of 

 their manners ; the foreign visitors return impressed by the 

 excellence of .Swedish contributions to geology and with 

 pleasant memories of the hospitable reception from all 

 classes, from the gracious courtesy with which the King 

 and Queen received us in the palace to the smiling 

 welcome of the peasants in the field. 



So much w^ork was done at the congress that no 

 adequate account of it can be given in a short notice. 

 Five sections and various commissions and committees 

 met simultaneously.' The discussions were sometimes not 

 influential, for they often followed the reading of several 

 disconnected papers, and many of the speeches were rather 

 further contributions to the subject-matter than discussions 

 of the papers that had been submitted. 



The first formal meeting of the congress was held on 

 August 18, when the honorary president, H.R.H. Prince 

 Gustave .^dolphe, welcomed the congress in a graceful 

 speech, referring to the dependence of mining on geology 

 and the increasing importance of science now that it_ is 

 devoting more attention to practical questions. The King 

 of Sweden then declared the congress open. Prof, de 

 Geer was installed as president, and gave a lecture on 

 "The Geochronology of the last 12,000 Years." He re- 

 marked the complete ifailure of previous attempts to measure 

 geological time in years, and described his determination 

 of the length of post-glacial time in the Stockholm dis- 

 trict. He noticed there that the marine post-glacial clays 



1 For notes on some of th" meetings the wr 

 Hobbs, Prof. Cole, and Dr. J. W. Ev.ins. 



indebted 10 Prof. 



NO. 2136, VOL. 84] 



