314 THE SCIENTIFIC PAPERS OF 



can produce such enormous changes in the behaviour of steel, how 

 important it must be to give to steel the nature which we desire 

 for structural purposes. Now, if you take a plate and throw it 

 down in a wet court-yard, and then punch it and use it for the 

 manufacture of a boiler, there can be very little satisfaction in the 

 result obtained from the material. Yery likely in the same plate, 

 if you could cut out pieces, you would find very different qualities, 

 and some of these qualities would be valuable in one place and 

 would be destructive to the plate in another. It may be laid 

 down as a general rule, that a higher material and a higher pro- 

 cess require higher intelligence to deal with them. If you ride a 

 common cart-horse you may go to sleep on him, but if you ride a 

 fine spirited horse all your wits must be about you, or else you 

 may be landed in a ditch. So with steel, you have to understand 

 first of all what quality of steel you have to produce, how much 

 carbon, and how much manganese should be mixed with the 

 material, and how little sulphur and phosphorus you can put up 

 with. Until you have done that, you do not know what you are 

 speaking of. It is a material belonging to a group varying 

 between the hardness of the diamond and the toughness of copper ; 

 and it is also of the highest importance that the manufacture 

 throughout, and the construction throughout, should be carried 

 on with superior intelligence. Now, should we shrink from using 

 a material, because intelligence is required in working and using 

 it ? Surely that would be a very poor compliment to this age of 

 progress. We should have no difficulty in finding what are the 

 conditions necessary to produce steel of such and such a quality, 

 and should see to it that we obtain this quality and obtain it 

 always. With regard to the question of obtaining it always, I 

 maintain that we have a greater power in our hands than with 

 regard to iron ; iron, as we know, is produced in small quantities ; 

 the puddler produces sometimes a ball which is rather young, and 

 at other times produces it overheated ; and this material is piled 

 again, put through the rollers, and in the end we get a sort of 

 average between the qualities of the different balls. In making 

 steel we formerly dealt with it in small quantities also by melting 

 it in pots, but Mr. Bessemer has shown us how to deal with it in 

 large quantities in his converter. I have had considerable ex- 

 perience in dealing with it in large quantities in the open hearth 



