432 THE SCIENTIFIC PAPERS OF 



structed of that material ; and amongst all the plates and angles 

 not one had been returned as defective in quality. Since then the 

 Admiralty had used steel for the construction of their boilers and 

 ship plates, almost to the exclusion of iron ; and although pro- 

 bably more than 10,000 tons had been used, he believed he was 

 correct in saying that no plate had been returned as being cracked 

 or unsatisfactory, except a very few from mere mechanical 

 blemishes. There had been no case of mild steel, properly made 

 and worked, giving way iu a mysterious and treacherous manner. 



The demon of cheapness, however, seemed to be abroad, and it 

 had settled especially upon steel. The works with which he was 

 more particularly connected had introduced two qualities of mild 

 steel : one which was to compete for price in the open market ; 

 and another, called "special metal," which was vouched for as 

 being in every way reliable. This metal was not only made of 

 more expensive material, but it received greater attention, and 

 was worked to a greater extent : crop ends were cut off more reso- 

 lutely than one could afford to do under all circumstances ; and 

 consequently it was rather more expensive to produce than ordi- 

 nary steel. But he was sorry to say there were many engineers 

 who, for the sake of 2 or 3 per ton, preferred the unguaranteed 

 material for the construction of their boilers ; others, however, 

 took only the special or guaranteed material. It appeared strange 

 to him that there should be such a tendency to get cheap steel for 

 the construction of boilers, &c. ; because, when a good iron boiler 

 was wanted, Yorkshire iron was used, costing from 22 to 40 a 

 ton ; whereas reliable steel plates could be obtained for 14 to 

 16 a ton. The special steel plates thus cost a great deal less 

 than what engineers were willing to pay for the best Yorkshire 

 plates ; but engineers would have the cheapest steel, at perhaps 

 11 to 13 a ton, and took their chance. He thought it was a 

 very dangerous policy, and one that naturally led to the dissatis- 

 faction of which they had heard. 



He might mention another form which steel now took, and 

 which had received his special attention : he referred to the pro- 

 duction of rivet-bars. For a long time engineers had continued 

 to use iron rivets for riveting steel plates together. He had 

 always considered this was like stitching a silk gown with a 

 cotton thread, making the stitching material a Aveaker thing than 



