ZOOLOGY A NO BOTANY, MICROSCOPY, ETC. 91 



axle made according to present-day requirements, and forged after 

 rolling. It is shown that poor mechanical properties accompanied the 

 coarse, handed structure. 



Microstructure of a Boiler Plate.* - - Matweieff indicates some 

 peculiarities in the structure of a boiler plate containing 06 p.c. 

 carbon, after fifteen years' service. Neumann lines probably indicated 

 that the material had been distorted when cold. The existence side by 

 side of large and small ferrite grains might be the result of cold-work 

 followed by annealing. 



Fluidity of Rails. + — Babochine has found that steel rails which, in 

 use, flow laterally to an undesirable extent, are commonly coarse in 

 structure and contain well-formed lamellar pearlite. Better wearing 

 qualities are accompanied by finer and more sorbitic structures. 



Cracked Boiler Plates. J — R. Baumann has examined thirty boiler 

 plates from various sources which had developed cracks. Peculiarities 

 of structure are described and illustrated with numerous photomicro- 

 graphs. 



Microstructure of Sintered Iron-bearing Materials. § — B. G. Klugh 

 gives photomicrographs of sections of flue-dust and similar materials 

 after they had been agglomerated by heating. In the description of 

 the microstructure, the relative porosity of 'the products of different 

 sintering processes is the chief point considered. When high tempera- 

 tures are used the nodules become entirely coated with a clear violet- 

 tinted glass of silicate of iron. 



& j 



Metals, Crystalline and Amorphous.! — \V. Rosenhain defends the 

 theory which explains certain properties of metals by the conception (if 

 an amorphous condition of the metal distinct from its normal crystal- 

 line condition. The theory consists of three propositions : — 1. That 

 mechanical disturbance of the surface of crystalline metal, as by polish- 

 ing, produces a thin surface film of amorphous metal. 2. That a 

 similar amorphous layer is formed within a metal crystal by the internal 

 rubbing which occurs on surfaces of slip during plastic deformation. 

 3. That the crystals of which a piece of metal is composed are sepa- 

 rated from each other by thin films of under-cooled liquid or amorphous 

 metal acting as an intercrystalline cement. The whole question is re- 

 viewed on broad lines. 



Micrometry as applied to Alloys.— C. H. Mathewsonf discusses the 

 application of the Microscope in the quantitative determination of the 



* Rev. Metallurgie, x. (1913) pp. 1271-3 (3 figs.). 



t Rev. Soc. Russ. Met., 1912, pp. 523-42, through Rev. Metallurgie, x. (1913) 

 Extraits, pp. 613-17 (10 figs.). 



t Stahl und Eisen, xxxiii. (1913) pp. 1554-61 (35 figs.). 



§ Bull. Amer. Inst. Min. Engineers, No. 77 (1913) pp. 813-28 (13 figs.). 



j| Engineering, xcvi. (1913) pp. 509-11, 537-9 (1 fig.). Paper read before British 

 Association, 1913. 



J Met. and Chem. Eng., xi. (1913) pp. 619-21. 



