SIR WILLIAM SIEMENS, F.R.S. 65 



quite satisfactorily, and the result of a careful comparison has 

 shown a saving of 79 per cent, to have been effected over the old 

 furnace in heating the same quantity of metal. Mr. Atkinson 

 has also applied this principle of furnace for melting cast steel, 

 and has ohtaiued a still larger saving, although the new melting 

 furnace has not yet been rendered entirely satisfactory for the 

 workman. 



The regenerative furnace has also been applied to the purpose 

 of puddling iron ; and though the new puddling furnace has been 

 completed and worked only for a few days at the works of Messrs. 

 Rushton and Eckersley at Bolton, the writer is able to state that 

 it converts a charge of 480 Ibs. of pig metal into wrought iron 

 with an expenditure of only 160 Ibs. of common coal, as compared 

 with C cwt. required in the ordinary furnaces : the net yield of 

 wrought iron is higher than that of the ordinary puddling furnace, 

 and the quality of the iron produced seems also to be superior. It 

 is also worth mentioning that the chimney of this puddling furnace 

 may be watched for hours, and no trace of smoke be seen issuing 

 from it. Several other applications of this principle of furnace 

 are contemplated by the writer, which it would be premature to 

 enter upon on the present occasion. 



In the discussion of Hie Paper, 



MR. SIEMENS said he considered the durability of the brickwork 

 might be fully accounted for by the circumstance that, on attain- 

 ing the very high degree of temperature, the air had first to heat 

 the ends of the first wall of bricks that it met with to a very 

 intense degree, but the next wall to a less degree, and so on 

 gradually diminishing towards the chimney. It might be expected 

 at first that the cold air entering would have a tendency to crack 

 the hot bricks ; but it should be remembered that the air became 

 gradually heated as it advanced, coming in contact at first with a 

 comparatively cool wall, and afterwards by degrees with hotter 

 and hotter walls, taking up only 100 or 200 of temperature from 

 each successive wall, each one being only a little hotter than the 

 air on reaching it. There was consequently no sudden difference 

 of temperature at any point between the air and the brickwork 

 with which it came in contact, and ah 1 risk of sudden chilling and 

 VOL. i. r 



