xviii Proceedings. {^March 2'jtJi, igo6. 



and then dealt with recent cases which have come under his 

 notice. He has collected samples of plates of exploded boilers 

 from America, Austria, and Russia, and plates which have shewn 

 themselves brittle in the workshop. In one case the brittleness 

 is clearly due to an excess of phosphorus, but in all the other 

 cases there is no discernible cause, and the author suggested 

 that certain qualities of steel have the property of slowly deterio- 

 rating. Several of the fractured plates were exhibited, and 

 sections were prepared shewing the microscopic structure of 

 the different materials. The chemical compositions and the 

 mechanical tests were also given. 



At the end of the paper the author mentioned that he was 

 about to carry out experiments on 20 samples of steel which he 

 had collected, and asked for suggestions as to supplementary 

 tests which would discriminate between reliable and treacherous 

 steels. 



An interesting discussion followed the reading of the paper, 

 in which the President, Mr. E. F. Lange, Mr. M. Longridge, and 

 Mr. E. L. Rhead took part. 



Dr. W, E. HoYLE, F.R.S.E., communicated a paper entitled, 

 "Notes on a Captive Mole," by Lionel E. Adams, B.A., 

 which was postponed to the next meeting on April loth. 



General Meeting, April loth, 1906. 



Mr. Francis Nicholson, F.Z.S., Vice-President, in the Chair. 



The Lord Mayor of Manchester (J. H. Thewlis, Esq.), 

 was elected an ordinary member of the Society. 



