.s7A' U'lI.I.lA.M \//-;. !/A. Y.V. I'.R.S. 449 



ol)t iiint'il jus regards thecorrosion of their ships. I would attribute tint 

 result also in some measure to their continuing to use iron rivets 

 in the construction of steel hulls. The discussion already alluded to 

 lit nut the most variable results regarding corrosion. In one 

 case steel seemed to corrode much more quickly than iron. In other 

 cases, in experiments continued over years, steel showed decidedly less 

 corrosion than iron. But one thing is certain, that when different 

 rials are brought into contact with one another, and with sea- 

 water, rapid corrosion of one or the other will ensue, and I could 

 not too strongly urge the desirability of using in naval construc- 

 tion one material only, be it iron or be it steel. As I have men- 

 tioned the process with which I am most intimately connected, I 

 wish it to be understood that I have no desire whatever to set that 

 process before any other. I do not think that users of steel should 

 inquire too much into the process involved. We had yesterday 

 brought before us facts regarding certain materials that had been 

 used, which speak for themselves ; and plates, different parts of 

 which give different analyses, are evidently materials that ought 

 never to be employed. It is in the users' power to ascertain 

 whether the material they propose to use, and which is supposed 

 to be homogeneous, is so or not. I was reproached for not having 

 gone into the causes of the failure of the material employed in the 

 construction of the LivadicCs boilers, but the facts speak for them- 

 selves. Metal that is brought into the ship-yard ought to be 

 above all things homogeneous. I mentioned yesterday a circum- 

 stance which gave rise to great difference of opinion. I said that 

 good mild steel should not lose strength in being punched, but 

 should rather gain strength. My lord, I have since then looked 

 up such experimental facts as I happened to have at my office in 

 support of that view. I have here a report which was made by 

 an assistant to Mr. Ilendel, who wished to see what the effect of 

 punching was, and those experiments were made in consequence 

 of observations I made at the Institution of Civil Engineers. The 

 result of the experiments, which are very accurate and perfect, is 

 as follows : In a strip which broke with 30f tons to the square 

 inch, when one hole was punched the strength diminished to 

 30 tons to the square inch ; when two holes were punched side by 

 side the strength increased per square inch to 31'G5 tons ; and 

 when three holes were punched the strength was increased to 



VOL. I. GO 



