ADDRESS. 47 



of undiscovered elements, and in the case of known elements to determine 

 many atomic weights which had not been fixed by any of the usual 

 methods. Several of these predictions have been verified in a remarkable 

 manner. A periodicity in the atomic weights of elements belonging to 

 the same class had been pointed out by Newlands about four years before 

 the publication of Mendelejeflf's memoir. 



In mechanical science the progress has not been less remarkable 

 than in other branches. Indeed to the improvements in mechanics we 

 owe no small part of our advance in practical civilization, and of the 

 increase of our national prosperity during the last fifty years. 



This immense development of mechanical science has been to a oreat 

 extent a consequence of the new processes which have been adopted in 

 the manufacture of iron, for the following data with reference to which I 

 am mainly indebted to Captain Douglas Galton and Mr. Stuart Rendel. 

 About 1830, Neilson introduced the Hot Blast in the smelting of iron. 

 At first a temperature of 600° or 700° Fahrenheit was obtained, but 

 Cowper subsequently ajjplied Siemens' regenerative furnace for heatino- 

 the blast, chiefly by means of fumes from the blast furnace, which were 

 formerly wasted ; and the temperature now practically in use is as much 

 as 1,400° or even more : the result is a very great economy of fuel and 

 an increase of the output. For instance, in 1830, a blast furnace with 

 the cold blast would probably produce 130 tons per week, whereas now, 

 600 tons a week are readily obtained. 



Bessemer, by his brilliant discovery, which he first brought before the 

 British Association at Cheltenham in 18-56, showed that Iron and Steel 

 could be produced by forcing currents of atmospheric air through fluid 

 pig metal, thus avoiding for the first time the intermediate process of 

 puddling iron, and converting it by cementation into steel. Similarly by 

 Siemens' regenerative furnace, the pig metal and iron ore is converted 

 directly into steel, especially mild steel for shipbuilding and boilers ; and 

 Whitworth, by his fluid compression of steel, is enabled to produce steel in 

 the highest condition of density and strength of which the metal is capable. 

 These changes, by which steel can be produced direct from the blast 

 furnace instead of by the more cumbersome processes formerly in use 

 have been followed by improvements in the manipulation of the metal. 



The inventions of Cort and others were known long before 1830, but 

 we were then still without the most powerful tool in the hands of the 

 practical metallurgist, viz., Nasmyth's steam-hammer. 



Steel can now be produced as cheaply as iron was formerly ; and its 

 substitution for iron as railway material and in shipbuilding, has resulted 

 in increased safety in railway travelling, as well as in economy, from its 

 vastly greater durability. Moreover, the enlarged use of iron and steel, 

 which has resulted from these improvements in its make, has led to the 

 adoption of mechanical means to supersede hand labor in almost every 

 branch of trade and agriculture, by which the power of production has 



