.Y/A' WILLIAM 



F.R.S, 



447 



in the annealing furnace, and in order to bring the heat down to 

 the bottommost plate, a strong flame is applied to the uppermost, 

 and it is but natural that those plates are put in great danger. 

 The probability is that some of them will be overheated and that 

 will be heated all round at the edges, but will not be 

 uniformly heated. Such a process of annealing must be, at any 

 fraught with danger to the material produced. Now one 

 rord, my lord, with regard to the process used. It has been said 

 icre, that the plates last alluded to, those made at the Cumberland 

 Works, were undoubtedly made by the Siemens process. Now, no 

 doubt this statement has been received authentically, but was 

 there not perhaps some little mistake, inasmuch as those works 

 lave only lately put up one furnace according to my system, and I 

 was only told the other day by Mr. Snelus himself that it has not 

 yet been properly put to work. I do not, of course, wish to imply 

 that this could not have happened with steel manufactured by one 

 process or another. 



DR. SIEMENS. Might I be allowed to say one word in explana- 

 tion ? There is one observation which I made which has been 

 perhaps rather severely criticised. It concerns a matter of great 

 importance. I do not wish to say whether plates should be 

 punched only, and left, or whether it would be better to clean out 

 the holes. But what I say is, that in taking a strip of mild steel 

 (and I refer not to the somewhat harder steel used in ship building, 

 but to the milder steel used in boilers) and punching a line of 

 holes across a plate of this steel and subjecting it to tensile strain, 

 the total strain that piece of metal will bear would be fully equal, 

 or, in the case of first-class metal, about 10 per cent, superior, to 

 the normal strength of the material multiplied into the remaining 

 cross-section. I base that view, not upon mere theoretical grounds, 

 but upon many experiments, which I have made and seen tried, 

 and I should be very happy if Mr. Martell would give me an 

 opportunity of testing it with him. 



