OF ARTS AND SCIENCES. 109 



tents. In the 15,000 pounds of impure iron there are ordinarily 

 found about 230 pounds of silicon and 540 of carbon ; and as each 

 pound of carbon gives 8000 calories, and each pound of silicon 1 2,000 

 to 14,000, in connection with the air-blast's unlimited supply of 

 oxygen, the temperature of the already molten metal rapidly rises 

 under this enormous inflow of several million calories of heat. After 

 the blast has continued eighteen to twenty minutes, the temperature 

 of the contents is from 1800° to 2000° C, or higher than that of 

 melted platinum, taking the lowest estimate ; and now the " converter " 

 is again lowered, and about 1500 pounds more of melted iron added. 

 The temperature here perhaps falls slightly, but its effect may be 

 judged by any one who sees this second lot of iron poured in. Melted 

 iron by itself, every one knows, seems dazzlingly bright ; but as this 

 streams into the open mouth, the interior is so much brighter still, 

 that the stream is deep-brown by comparison, presenting a contrast 

 like that of dark coffee poured into a white cup. The contents are 

 now no longer iron, but liquid steel ready for pouring into the caldron ; 

 and, looking from in front into the inclined vessel, we see the almost 

 blindingly bright interior dripping with the drainage of the metal 

 running down its sides, so that the circular mouth, which is twenty-four 

 inches in diameter, presents the effect of a disk of molten metal of 

 that size, were it possible to maintain such a disk in a vertical position. 

 In addition, we have the actual stream of falling metal which continues 

 nearly a minute, and presents an area of some square feet. The 

 shower of scintillations from this liquid cataract of what seems at first 

 " sun-like " brilliancy, and the immense area whence such intense 

 heat and light are for a brief time radiated, make the spectacle a most 

 striking one. 



Platinum dipped in the steel as it pours from the lip melts away ; 

 and not to rely on this evidence, which might be alleged to be due to 

 an alloying rather than a true melting, I procured some platinum wire 

 which Mr. Preusser, the chemist of the works, stretched at my request 

 across the open mouth of the "converter" when in an erect position. 

 The platinum, here several yards above the metal, was melted by the 

 blast which came from it. 



Heat Comparisons. 



After many visits to the works, much trouble and repeated failures 

 due to the difficulties of working in such novel circumstances, I secured 

 a series of trustworthy measures, in May last, both of heat and light. 



