"42 



THE POPULAR SCIENCE MONTHLY. 



ing furnace.* Nevertheless, they succeeded in producing in it 

 cast steel of excellent quality, of a variety of tempers, for which 

 they were awarded a gold medal at the French Exhibition of 18G7. 

 The success of the Messrs. Martin, together with the fact that 

 patents had been granted them for certain details of manipula- 

 tion, brought about a combination of the interests of the Messrs. 

 Siemens and Martin in the process, which has come to be known 

 as the " Siemens-Martin open-hearth process." The construction 

 of a small furnace for conducting this process is illustrated by 

 Figs. 55 and 50 the first being an elevation showing the " ingot 

 molds. " arranged in order upon a traveling carriage, k, by which 

 they are successively brought under the "tapping spout," b, to 



imiHwm'iwiiB'if i iiMMHii nmwi nn 



/rlillllilli'lll 

 ''r:a i aJfa fc f ! ' J n FTOT 





Fig. 55. Elevation of an Open-hearth Furnace. 



be filled. Fig. 5G is a vertical cross-section, taken through the 

 " charging door," a, and the " tapping spout/' b, of the same fur- 

 nace. Beneath the melting chamber will be seen the " regenera- 

 tive checker- work," C, C, whose function and operation are the 

 same as in the " pot melting furnace " already described. 



The earlier " open-hearth " furnaces were like that illustrated, 

 quite small, making but two or three tons of metal ; but at the 

 present time there are a number in operation of upward of twenty 

 tons capacity, equipped with much more perfect apparatus for 

 casting ingots than that shown in the engraving. 



To the Hon. Abram S. Hewitt is due the credit of introducing 

 the " Siemens-Martin " " pig and scrap " process into this country. 

 While serving as one of the United States commissioners to the 

 Paris Exposition of 18G7, he became favorably impressed with 

 the merits of the process, and sent Frederick J. Slade to Sireuil 



* In this connection we are reminded of a hunter, who, on his weary way home without 

 game after a hard day's tramp, thought he saw through the gathering mists of evening a 

 deer entangled in a thicket ; but, as he raised his gun, his companion suggested that it 

 might be a calf. " All right," said the hunter, " I'm going to aim so as to kill it if it's a 

 deer and miss it if it's a calf." A great many guns have been so aimed by hunters for 

 metallurgical "game," but it is quite safe to say that they oftener killed the "calf" than 

 the " deer." 



