22 INTRODUCTORY ADDRESS: 



In fa?t photomicrographs ( btained with it seemed to possess 

 almost equal quality to those from the lest foreign objectives. 

 Fig. 13 is a photomicrograph of a specimen of Steel - taken 

 with the above-mentioned foreign 2 mm. Apochromat, whilst Fig. 

 12 is a photomicrograph of the same section under exactly similar 

 conditions, taken with the Watson 2 mm. Apochromit. It will be 

 seen that tliere is veiy little to choose between the two photographs 

 from the point of view of resolution and flatness of fieli. There is 

 no doubt that English makers can, when required, produce Objectives 

 at least equal in quality to the best foreign makes. 



SECTION IV.— FERROUS METALLOGRAPHY. 



Several excellent Works have been published on the important sub- 

 ject of Metallography, including " Physical Metallurgy," by Dr. Walter 

 Rosenhain, F.R.S., which has proved of the highest service. N'o book, too, 

 on the subject has been of greater use in the past than that by Professor 

 Albert Sauveur, of Harvard University, " The Metallography of Iron 

 and Steel." Great advances have been made since the date of its 

 first publication, and in the second edition, 1916, it remains a 

 standard work of reference and a model for books on a special subject 

 • — excellent matter, well printed and illustrated. The chapters are 

 divided into Lessons, some twenty-four in all, commencing with 

 the Study of Pure Metals ; Pure Iron and Steel, up to High 

 Carbon Percentages ; the Effect of Impurities Upon Steel ; Close 

 Studies of Thermal Critical Change Points ; the Effect of Annealing, 

 Hardening and Tempering upon both ordinary and Special Alloy 

 Steels, are considered. The Metallography of Cast Iron also receives 

 attention. Various Apparatus for the Metallographic Laboratory, 

 including the study of the Microscope itself, and the Apparatus, 

 Illumination, Sources of Light, Condensers, and Photomicrographic 

 Cameras ; a description of the best Methods and Manipulations ; also 

 a most excellent nomenclature of the various Microscopic Constituents, 

 including Austenite, Cementite, Martensite, Ferrite, Osmondite, 

 Ferronite, Hardenite, Pearlite, Graphite, Troostite, Sorbite, Manganese 

 Sulphide, and Ferrous Sulphide. 



In words which deserve consideration by us all, so I quote them 

 in full. Professor Sauveur in his Introduction and Remarks upon 

 the Industrial Importance of Metallography, points out : 



"Invaluable information is given by chemistry without which both 

 the physicist and the metallurgist would be in utter darkness, but this 

 science throws little or no light upon the anatomy of living or inanimate 

 matter. Its very methods, which call for the destruction of the ])hysical 

 structure of matter, show how incapable it is to render assistance in 

 this, our great need. 



The parallel drawn here between metals and living matter is not 

 fantastic. It has been aptly made ly Osmond, who said rightly 

 that modern science was treating the industrial metal like a living 

 organism, and that we were led to studv its anatomy, that is, its jiliy- 

 sical and chemical constitution ; its biology, that is, the influence 



