120 PROCEEDINGS OF THE SOCIETY. 



which had reached the surface of the specimen, and had thus been open 

 to the atmosphere when the specimen was heated ? He (the speaker) 

 was incidentally surprised to hear Mr. Rogers refer to a temperature of 

 250° C. as not being an " annealing temperature " ; since metal in that 

 over-strained and sensitive condition was known to be affected by 

 temperatures as low as 100° C, it was surprising to find that 250° C. 

 produced so small a result as that found by Mr. Rogers. 



The branch of metallography to which Mr. Rogers' paper formed a 

 ■contribution, was a very large and important one, destined, he believed, 

 to lead to the most important results. Some seven years ago, Professor 

 Ewing had initiated this work, at all events, so far as England was 

 concerned, and as the speaker had had the good fortune to be the first 

 of those who had been induced to take it up, he was particularly gratified 

 to find that the subject was now being pursued by an increasing number 

 of able workers, such as Mr. Rogers. 



Captain Howarth said he had listened to the two speakers with great 

 interest, but though he was not prepared to enter into the discussion, he 

 might mention that the inner tubes of guns were sometimes not quite 

 what they should be, and that they showed a tendency to crack — and any- 

 thing which would throw light on this subject would be of immense use. 



Mr. Rogers said it was hardly necessary on the present occasion to 

 argue out the points which had been mentioned, as it would be found 

 that he had intentionally used words in the paper which should avoid 

 controversy on this side issue, and his views on several points were very 

 similar to those held by Mr. Rosenhain. He thought, however, that it 

 was a question as to whether there was any orientation of crystallisation 

 in pearlite. As regards the opinion expressed that the beginning of a 

 fracture was probably of a different nature from the later stage, he 

 agreed that this was quite so, and the results of his investigations quite 

 bore out one of Mr. Rosenhain's ideas. 250° C. was, of course, in one 

 sense, an annealing temperature, but it was not one ordinarily used in 

 practice for steels of the nature of those he was dealing with. He 

 believed Mr. Rosenhain would have liked to go much further with his 

 remarks, and he could only regret that he had not done so. He could 

 hardly say that his experiments would at present show much as to the 

 cause of the cracks which, as Captain Howarth pointed out, were 

 observed in gun tubes, but they formed one method of gaining informa- 

 tion systematically upon the nature of breakdown, from which eventually 

 it might be possible to form conclusions as to the probable cause of 

 failure in any particular case. 



On the motion of the President, a vote of thanks was unanimously 

 accorded to Mr. Rogers for his paper, and to Mr. Rosenhain for the 

 remarks which he had made upon it. 



The Secretary announced that the following Fellows had been 

 nominated by the Council as the Ofiicers and Council of the Society for 



