FLAME SPECTRA AT HTCH TEMPERATURES. 
1085 
The weight of the silica and the manganese oxide— 
Sp. Ht. kilo, heat-units. 
= 438,679 grms. X 0T9 = 83-3. 
The total kilo, heat-units developed by combustion in the converter amount to 
1,558,197, and the specific heat of the iron and the products of combustion, with also 
the nitrogen in the air, amounts to 1071'8 kilo, heat-units, and the pyrometrical 
effect is 
1558197 
1071-8^ 
or 1454° C. 
The temperature attained, according to the foregoing calculations, amounts to 
1454° C. above that of the molten cast iron. This, however, is the theoretical value ; 
we must allow for the specific heats of the gases, the metal, and the slag being 
greater at the elevated temperatures than at the temperatures at which the numbers 
representing specific heats were determined. 
The specific heat of the converter must be considerable, but it must be remembered 
that it is already heated to the temperature of the molten metal. 
But even if we allow that 50 per cent, of the heat is absorbed or conveyed away, 
then we should have the temperature 727° C. above that of the molten pig iron, and 
thus with grey iron at 1220° C. the metal may acquire a temperature of more than 
1947° C., which is above the melting point of platinum. 
Judging by the number of lines and bands belonging to iron and manganese which 
have been photographed in the spectrum of the Bessemer flame, the temperature 
must nearly approach that of the oxyhydrogen flame, even if it does not exceed it in 
certain cases at the highest temperature of the “ boil." At Dowlais, for instance, 
where the metal, which is very rich in silicon, carbon, and manganese, is just tapped 
from a hot-blast furnace and conveyed by rail in ladle to the converters, it is 
probably hotter at the commencement of the “blow” than if cold pig iron had been 
merely melted in a cupola. 
The parallel columns below show the numbei’ of lines observed in the spectra of the 
respective substances under different conditions :— 
Bessemer flame. 
CO spectrum, 8 lines and edges of bands. Ex¬ 
posure If to 3 minutes 
Mn spectrum, 73 lines and edges of bands. 
Exposure | to 3 minutes. 
Fe spectrum, 92 lines. Exposure f to 3 
minutes. 
Carbon monoxide burnt tuith oxygen. 
CO spectrum, 16 lines and edges of bands. 
Exposirre 60 minutes. 
Oxyhydrogen bloiv-pipe flame. 
Mn spectrum, pure metal, 103 lines and edges 
of bands. 
Fe spectrum, 92 lines. Exposure from 15 to 
30 minutes. 
The temperature is to be judged by the iron lines, because there is a smaller 
