436 SUMMARY OF CUKRENT llESEAKCHES RELATING TO 



between crossed nicols are not normal to the curved crystal. The author 

 considers the probability of a local rational atomic adjustment, which, 

 although the crystal has been distorted, causes it to remain in equilibrium. 



F. I. G. R. 



Progress Report of Research Sub -committee on Bearing Metals. 

 — (American Society of Mechanical Engineers, December, 1920). By 

 means of an 'instrument described as the micro-character, a tentative scale 

 of micro-hardness has been drawn up. Photo-micrographs of alloys, 

 ferrous and non-ferrous, are given, showing how the micro-hardness of 

 the constituents can be determined with great accuracy by this instru- 

 ment. F. I. G. R. 



" Slip-lines " and Twinning- in Electro-deposited Iron. — W. E. 

 Hughes (Iron and Steel Institute Meeting, May, ]'J21). Photomicro- 

 graphs of etched sections, deposited under various conditions, are shown 

 which exhibit peculiar lines or markings. It is suggested that these 

 lines may be " slip-lines " produced in the grains of which the deposit is 

 composed by the forces of contraction which act in it during its 

 formation. F. I. G. R. 



Solid Solution of Oxygen in Iron. — J. E. Stead (Iron and Steel 

 Institute Meeting, May, 1921). With the introduction of cupric 

 re-agents, evidence is accumulating that many solid solutions of iron 

 and every other element are electro-positive to pure iron. When iron 

 is heated in air or oxidizing gases, it appears that the surface layers 

 absorb oxygen which passes into solid solution, but when supersaturated 

 the oxide falls out of solution, forming separate globules of free oxide. 

 Photomicrographs accompany the paper. F. I. G. R. 



Rbntgen Spectrographic Investigations of Iron and Steel. — 

 A. Westg-hen (Iron and Steel Institute Meeting, May, 1921). This 

 most remarkable paper confirms, V»y means of a method analogous to 

 that used by the Braggs in their work on crystal structure, the cubic 

 habit of alpha and gamma iron, and also that beta iron contains crystals 

 oriented in the same way as alpha. Hence the beta-iron theory is 

 opened anew. In martensite, iron is in the alpha form, which is also 

 the case for high-speed steel of ordinary composition hardened at 

 1275° C. F. I. G. R. 



Cupric Etching Effects Produced by Phosphorus and Oxygen 

 in Iron.— J. H. Whiteley (Ii'on and Steel Institute Meeting, May, 

 1921). The author continues the work of Stead and others, and finds 

 that differences of less than • 02 p.c. in adjacent layers of otherwise pure 

 iron can be readily detected by means of cupric etching re-agents ; as 

 the difference is increased up to about 0'15 p.c. the contrast becomes 

 more marked. Attempts to produce an unequal distribution of oxygen 

 to which cupric methods could bo ap]iliod have failed. AVhen oxygen 

 is present, white resist-Hnes are formed only at the vveld-j unctions, but 

 these resist-lines are not found when unoxidized iron is welded in dry 



