18 REPORT— 1888. 



shell fell within this area, vomiting fire, and scattering its walls in 

 hundreds of pieces, with terrific violence, in all directions. Do not 

 suppose I am saying that similar effects cannot be obtained from a gun 

 where wire is not employed. They can be. But my point is, that they 

 can also be obtained by the aid of the insignificant thing which I am 

 holding up at this moment — this piece of steel ribbon, which looks more 

 suitable for the framework of an umbrella. 



I have already spoken to you, when considering steel as a mere alloy of 

 iron and carbon, as to the value of even a fraction of 1 per cent, of the 

 latter ; but we know that in actual practice steel almost always con- 

 tains other ingredients. One of the most prominent of these is manganese. 

 It had for years been used, in quantities varying from a fraction of 1 

 per cent, up to 2'5 per cent., with advantage as regards ductility, and 

 as regards its ability to withstand forging. A further increase was found 

 not to augment the advantage : a still further increase was foand to 

 diminish it : and here the manufacturer stopped, and, so far as I know, 

 the pure scientist stopped, on the very reasonable ground that the point 

 of increased benefit appeared to have been well ascertained, and that 

 there could be no advantage in pursuing an investigation which appeared 

 only to result in decadence. But this is another instance of how the 

 application of science reacts in the interests of pure science itself. One 

 of our steel manufacturers, Mr. Hadfield, determined to pursue this appa- 

 rently barren subject, and in doing so discovered this fact — that, while 

 with the addition of manganese in excess of the limit before stated, and 

 up to as much as 7 per cent., deterioration continued, after this latter 

 percentage was passed improvement again set in. 



Again, the effects of the addition of even the very smallest percent- 

 ages of aluminium upon the steel with which it may be alloyed are very 

 striking and very peculiar, giving to the steel alloy thus produced a 

 very much greater hardness, and enabling it to take a much brighter 

 and more silver-like polish. Further, the one-twentieth part of 1 per 

 cent, of aluminium, when added to molten wrpught iron, will reduce 

 the fusing-point of the whole mass some 500 degrees, and will render 

 it extremely fluid, and thus enable wrought iron (or what are commer- 

 cially known as ' Mitis ' — castings of the most intricate character) to be 

 produced. 



No one has worked more assiduously at the question of the effect of 

 the jDresence of minute quantities, even traces, of alloys with metals than 

 Professor Roberts-Austen, and he appears, by his experiments, to be 

 discovering a general law, governing the efiect produced by the mixture 

 of particular metals, so that, in future, it is to be hoped, when an alloy 

 is, for the first time, to be attempted, it will be possible to predict with 

 reasonable certainty what the result will be, instead of that result remain- 

 ing to be discovered by experiment. 



I have just, incidentally, mentioned aluminium. May I say that we 



