AMERICAN INDUSTRIES SINCE COLUMBUS. 737 



Fig. 51. Vertical Cross-section of a Siemens Furnace for melting Steel in Fots. 



on the left having been removed to show the flues. The dis- 

 tinguishing peculiarity of the " Siemens furnace " is the method 

 of utilizing the escaping heated products of combustion for 

 heating the incoming gas and air. This is accomplished by 

 what are called the " regenerative chambers," which are situated 

 to the right and left of, and at a lower level than, the " melting 

 holes." As will be seen in Fig. 51, there are four of these cham- 

 bers, the two smaller being for gas, and the two larger for air. 



Air enters the flue at the lower part of the left-hand chamber, 

 and, passing upward, it absorbs whatever heat may be in the 

 reticulated mass of fire-brick with which the chamber is filled, 

 and, on reaching its top, it turns to the right in the direction 

 of the arrow, and, just previous to entering the " melting hole," 

 it encounters and combines with the incoming gas, which also 

 has been highly heated by contact with the bricks in the " gas 

 chamber." The result is the ignition of the gas immediately at 

 the entrance to the " melting hole " ; intense combustion ensues, 

 the ignited gas expanding and completely enveloping the "pots," 

 and the highly heated products of this combustion leave the 

 " melting hole " on the side opposite to that at which they en- 

 tered, and on their way to the chimney they pass through each 

 of the right-hand chambers of the furnace, and in their passage 

 raise the bricks therein to a high temperature. 



After the furnace has worked for a proper time in the way 



vol. xxxix. 5 3 



