\M' WILLIAM SIEMENS, F.R.S. 2ig 



capable of managing steel furnaces), the result has been most 

 beneficial, in affording me an opportunity of working out the 

 details of processes for producing cast-steel from scrap-iron of 

 tn-dinary quality and also directly from the ore, and in proving 

 these results to others. 



I shall now proceed to describe the construction and working ot 

 the regenerative gas furnaces (similar to those at Birmingham) 

 wlurh are now at work, or in course of erection, in this country 

 and abroad for the production of cast-steel, both by the old method 

 of fusion in pots, and by the new system of making cast-steel on a 

 large scale and on an open furnace bed, from scrap-iron and from 

 the ore. 



The regenerative gas furnace consists of two essential parts : 



The gas producer, in which the coal or other fuel used is con- 

 verted into a combustible gas ; and 



The furnace, with its " regenerators " or chambers for storing 

 the waste heat of the flame, and giving it up to the in-coming air 

 and gas. 



Any combustible gas might be burned in the regenerative 

 furnace ; I have used ordinary lighting gas very successfully on a 

 small laboratory scale, but it is far too costly to be employed in 

 larger furnaces, and the only gas generally available is that gene- 

 rated by the complete volatilisation of coal, wood, or other fuel, 

 with admission of air in a special " gas producer." Any descrip* 

 tion of carbonaceous matter may be worked in a suitable gas 

 producer, and will afford gas sufficiently good for the supply of 

 even those furnaces in which the highest heat is required. Coal 

 is the fuel chiefly used for gas furnaces in England ; small coke 

 has been employed in some cases, as in gas-works, where it is to 

 be had at a cheap rate ; wood is used in France, Bohemia, and 

 Spain ; sawdust in Sweden, furnishing gas for welding and other 

 high-heat furnaces ; lignite in various parts of Germany ; and peat 

 in Italy and elsewhere ; this last being applicable with the greatest 

 relative advantage. 



Plate 38 represents a gas producer suitable for burning non- 

 caking slack. 



In form it is a rectangular fire-brick chamber, one side of 

 which, B, is inclined at an angle of from 45 to 60, and is pro- 

 vided with a grate, C, at its foot. The fuel is filled in at the top 



