S/fi WILLIAM SIEMENS, F.R.S. 83 



1 11 the early form of the regenerative heating furnace, which 

 has been in continuous work during the lost three years for heating 

 Icirs of steel at Messrs. Marriott and Atkinson's Steel Works, 

 Sheffield, and also at the Broughton Copper Works, Manchester, 

 there is a single fireplace containing a ridge of fuel fed from the 

 top ; and two heating chambers, in which the bars of metal to be 

 licatrd are laid, with a regenerator at the end of each chamber, by 

 which the waste heat passing off from the furnace is intercepted 

 on its way to the chimney, and transferred to the air entering the 

 furnace. Each regenerator is composed of a mass of open fire- 

 bricks, exposing a large surface for the absorption of heat, through 

 which the products of combustion are made to pass from the 

 furnace, and are thus gradually deprived of nearly all their heat 

 previous to escaping into the chimney : the end of the regenerator 

 nearest the furnace becomes gradually heated to nearly the tempera- 

 ture of the furnace itself, while the other end next the chimney 

 remains comparatively cool. The direction of the draught being now 

 reversed by means of a valve, the air entering the furnace is made 

 to pass through the heated regenerator in the contrary direction, 

 encountering first the cooler portions of the brickwork, and ac- 

 quiring successive additions of heat in passing through the re- 

 generator, until it issues into the first chamber of the furnace at a 

 very high temperature, and traversing the ridge of fuel produces 

 a flame which fills the second heating chamber ; whence the 

 products of combustion passing through the second cold regenera- 

 tor deposit their heat successively in the inverse manner, reaching 

 the chimney comparatively cool. By thus alternating the current 

 through the two regenerators, a high degree of temperature is 

 maintained constantly in the furnace. This arrangement of fur- 

 nace is evidently applicable only in exceptional cases where two 

 chambers are to be heated alternately, nor does it admit of being 

 carried out upon a large scale. 



In heating a single chamber the expedient was resorted to of 

 providing two fireplaces to be traversed in succession by the 

 heated air, with the heating chamber placed between, as in the 

 furnace shown in the drawings accompanying the previous paper 

 (Proceedings Inst. M.E., 1857, Plate 118). Here the difficulty 

 arose that the air, the oxygen of which was already combined with 

 carbon (forming carbonic acid) in traversing the first fireplace, 



o 2 



