.s/A' WILLIAM SIEMENS, F.R.S. 373 



v. It occurred to me, therefore, that marine boilers might 

 be constructed on the same principle, by rolling a number of rings 

 in this fashion and placing them one behind the other, with these 

 copper rings inserted, and lx>lting the whole down. In that way 

 we should have at any rate a boiler-shell capable of resisting 

 jon ( .r ;;oo Ibs. pressure without the least risk of an explosion, 

 wlu-reas in riveting very heavy boiler plates of an inch in thick- 

 there is always some difficulty in treating the material. 



In the discussion of the Papers 



"ON THE MECHANICAL AND OTHER PROPERTIES 

 OF IRON AND MILD STEEL," by DANIEL ADAMSON, 

 C.E., Manchester ; and 



"ON CERTAIN MATTERS AFFECTING THE USE OF 

 STEEL," by M. ERNEST MARCHE, Paris, 



The PRESIDENT * (ME. C. W. SIEMENS) said he would proceed 

 to make a few observations upon the papers before them, com- 

 mencing with Mr. Adamson's, which he thought was one of great 

 practical merit. 



He agreed with Mr. Adamson both in his objection to short speci- 

 mens and in his reason for such objection, but regretted that he 

 had adopted a 10-inch specimen instead of the standard length of 

 8 inches ; for the 8-inch standard, or the length of 200 millimetres, 

 had found its way into very large practice. It had been adopted 

 first of all by the French Admiralty, and afterwards by the English 

 Admiralty and by Lloyds, and it was of very great importance to 

 have uniformity. There was, of course, no a priori objection to 

 Mr. Adamson's standard, but it would render comparison of his 

 results with those obtained by the Admiralty standard less easy, 



* Excerpt Journal of the Iron and Steel Institute, 1878, pp. 414-427 and 

 457-458. 



