374 THE SCIENTIFIC PAPERS OF 



and this was the more to be regretted as, in his opinion, ^Ir. 

 Adamson's paper would be largely referred to hereafter regarding 

 the mechanical properties of steel. 



"With regard to weldings, he would observe that all the speci- 

 mens which Mr. Adamson had brought before them were very 

 beautiful indeed, and he had succeeded in welding up an angle- 

 iron ring in a very perfect manner ; but he (the President) 

 objected altogether to welded rings. Why not roll them at once 

 as they would roll a tire ? This had been done already to some 

 extent in England, and he thought it was a very excellent prac- 

 tice. The results which Mr. Adamson had placed before them 

 regarding corrosion were very interesting. This question of cor- 

 rosion, as they were aware, had occupied the attention of the 

 English Admiralty, and had been discussed on several occasions. 

 The results which Mr. Adamson now brought before the members 

 of the Institute made steel come out much better than they could 

 have hoped after the results that had been brought before them 

 by the Admiralty Committee ; and he must say he could not see 

 why a really pure metal like melted iron should corrode more than 

 an impure metal where different substances were at war one against 

 another. 



The reason why some specimens of mild steel had given such 

 unfavourable results was in his opinion (and he simply repeated 

 the opinion now) due to an excessive quantity of manganese. 

 Manganese was a highly oxidisable metal, and if eaten out of the 

 mixture, there remained only a sponge, which was easily de- 

 stroyed. Altogether he fully maintained the view he expressed 

 that manganese was only a cloak to hide imperfections in steel, 

 and when they wanted a really high-class metal, they should have 

 it as pure as possible, containing a little carbon in order to give 

 strength, but as little of other materials as they could possibly do 

 with. Manganese, no doubt, was a good metal for the maker. It 

 enabled him to push stuff through the rolls, whatever it might be 

 made of ; but now that they spoke of really high-class metal, he 

 thought manganese was one of its worst impurities. Mr. Adam- 

 son had also alluded to steel higher in carbon than the mild steel 

 which was now used for engineering purposes. He thoroughly 

 agreed with Mr. Adamson that it was absurd, in a bridge whore 

 they wanted any moderate extensibility and great strength, to 





