.v/A' WILLIAM SIEMENS, F.R.S. 137 



power to be employed to give motion to a dynamo-electrical 

 machine, a very powerful electrical current will be the result, 

 which may be carried to a great distance, through a large metallic 

 conductor, and then be made to impart motion to electro- 

 magnetic engines, to ignite the carbon points of electric lamps, or 

 to effect the separation of metals from their combinations. A 

 copper rod 3 in. in diameter would be capable of transmitting 

 1,000 horse-power at a distance of say 30 miles, an amount suffi- 

 cii'iit to supply one quarter of a million candle-power, which would 

 suffice to illuminate a moderately sized town. 



The use of electrical power has sometimes been suggested as a 

 substitute for steam power, but it should be borne in mind that so 

 long as the electric power depends upon a galvanic battery, it must 

 be much more costly than steam power, inasmuch as the com- 

 bustible consumed in the battery is zinc, a substance necessarily 

 much more expensive than coal ; but this question assumes a 

 totally different aspect if in the production of the electric current 

 a natural force is used which could not otherwise be rendered 

 available. 



The force of the wind is another source of natural power 

 representing fuel according to the general definition above given, 

 which, though large in its aggregate amount, is seldom used, 

 except in navigation, owing to its proverbial uncertainty. On 

 this account we may dismiss it from serious consideration until 

 our stores of mineral wealth are well-nigh exhausted, by which 

 time our descendants may have discovered means of storing and 

 utilising it in a manner entirely beyond our present conceptions. 



PROCESSES. Having thus dwelt too long, I fear, for your 

 patience upon the subject of fuel, I now approach the question 

 as to the processes by which we can best accomplish our purpose 

 of converting the crude iron ore into such materials as leave our 

 smelting works and forges. 



The subject of blast furnace economy has already been so fully 

 discussed by you, during the term of office of your past President, 

 Mr. I. Lowthian Bell, M.P., F.R.S., who has done so much him- 

 self to throw light upon the complicated chemical reactions which 

 occur in the blast furnace, that I may be permitted, on the present 

 occasion, to pass over this question, and to call your attention 

 more particularly to those processes by which iron is made to 



