A 



THE 



AMUAL OF SCIENTIFIC DISCOVERY. 



MECHANICS AND USEFUL AETS. 



THE SIEMENS FURNACE. 



THERE is a small collection of gas-furnace models exhibited at 

 Paris by Mr. Siemens, and now distinguished with the highest 

 prize of the international jury, namely, the " grand prix." It may 

 be said with justice that the Siemens furnace in this present Exhi- 

 bition holds much the same position which the Bessemer process 

 held in 1862, namely, that of the most important and most success- 

 ful metallurgic invention of the day. It is hardly less important; 

 than the Bessemer process, and, although its invention dates about 

 * as far back as Mr. Bessemer's patents, it has only lately attained 

 commercial success. In the space of the last five years che Sie- 

 mens furnace has not been very materially altered or improved, 

 but it has been largely introduced and its success established in 

 many different branches of industry. The first manufacturers in 

 England who availed themselves of the new furnace were the 

 glass-makers. For purposes of metallurgy, greater difficulties and 

 prejudices required to be surmounted. Some of the steel-makers 

 on the Continent led the way. Mr. Mayr, of Leoben, in Styria, 

 we understand to have been the first to introduce the new furnace 

 for crucible steel-making on a large scale. In this instance the 

 unfavorable position of the Styrian iron works, with regard to the 

 supply of mineral fuel, was the principal inducement to apply 

 gas in the steel-melting furnace. The gas is made, 'at Mr. Mayr's 

 works, from lignite, which cannot be directly applied for melting 

 steel, as the heat from it, when burnt on the grate, is not sufficient 

 to produce the high temperature required for this operation. Mr. 

 Mayr erected ten gas-furnaces, and they have proved a complete 

 and perfect success, enabling him to make crucible cast steel by 

 means of the cheap and very inferior lignite which exists in his 



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