TRANSACTIONS OF SECTION G. 801 



trict bein^ known as the Black Country, on account of the wasteful manner in 

 which fuel was burnt. Of the many forms of furnace employed attention is mainly 

 drawn to those of the reverberatory class, and figures illustrating the old forms 

 used for melting, puddling, and re-heating iron and steel, and for the production 

 of glass, were given. 



The Rev. E.. Stirling was mentioned as having originated, in 1817, the idea of a 

 regenerative furnace when describing his regenerative caloric engine. He was 

 followed by Mr. J. Slater in 1837, and by Mr. R. Laming in 1847, the former two 

 employing solid coal and the latter gas made from coke. Mr. F. Siemens's in- 

 vention, in 1856, differed from the suggestions previously made in the novel 

 principle of heating both gas and air previous to combustion in the furnace, an 

 arrangement that had never before been adopted or even proposed. Another 

 feature introduced by the late Sir William and Mr. F. Siemens was the employ- 

 ment of a separate gas producer. 



A reference was next made to the calorific power of carbon and carbonic oxide 

 respectively, showing a loss of 30 per cent, by the employment of the latter, and 

 to the composition of gases made in a gas producer, from which the author deduced 

 the necessity for the use of gas regenerators in gas furnaces when economy and 

 maximum temperature are desired. 



The various types of the Siemens gas producers were next described and illustrated. 

 In the earlier forms the gas evolved by distillation of coal passes at once through 

 cooling tubes to the furnace ; in the later forms the gas passes through heated chan- 

 nels, and is thereby rendered more permanent than before. One of these arrange- 

 ments, moreover, may be modified, if desired, for the extraction of tar and ammonia 

 from the hydrocarbons, which are for that purpose treated separately from the 

 other gases leaving the gas producer. 



The old form of regenerative gas furnace was illustrated and described ; it was 

 so arranged that the flame came into intimate contact with the materials on the 

 bed of the heating chamber. 



Before proceeding to a description of Mr. F. Siemens's radiation furnace, the 

 method of making steel on the open hearth and glass-melting are described. The 

 furnace being at steel-melting temperature, pig iron and scrap steel are charged, 

 and, when melted, iron ore is added in small quantities until the metal boils, or, 

 hi other words, the ore reacts chemically upon the pig metal, some gases being 

 thereby liberated. Afterwards it is tested for carbon, and when in a fit condition 

 it is tapped, spiegel-eisen or heated fen-o-manganese being added in small pieces 

 while it is being run into the ladle. 



Sand, lime, and alkalies, well mixed and pulverised, are employed in various 

 proportions in the manufacture of glass. The ' batch,' as it is called, is melted in 

 pots or tanks, fresh batch being added as required ; a large proportion of gaseous 

 matter is contained in the batch, which is liberated from the metal when 'fining' 

 takes place, or when the metal is fused without contact of flame. 



The continuous method of making glass invented by Mr. F. Siemens was described 

 and illustrated. It allows of batch being charged and glass gathered simul- 

 taneously, the gathering being effected by means of floating vessels, containing two 

 compartments, in the first of which the glass raised from the lower part of the 

 mass becomes heated, and, increasing in density, sinks to the bottom and enters the 

 second, from which it is gathered. 



The author, having observed that more or less ' seedy boil ' (or gaseous blow- 

 holes) were found in glass gathered at difl'erent gathering holes in a semicircular 

 furnace, showed the plan of the furnace to Mr. F. Siemens, who at once inferred 

 that the * seedy boil ' was due to the flame striking the ' metal.' He made experi- 

 ments with a view to removing the defect, and eventually brought out his radia- 

 tion furnace, described by him at the Chester meeting of the Iron and Steel 

 Institute in 1884. 



Id this furnace the gas and air ports open at some distance above the materials 

 to be treated, so that the flame does not come into contact with them or with the 

 walls or roof of the furnace. In this way there is free development of the flame, 

 resulting in great economy of fuel, an increased life of the furnace, improvement of 



1886. ^ 3 P 



