FLAME SPECTRA AT HIGH TEMPERATURES. 
1081 
The leading difference is owing to the composition of the metal being that of a 
highly manganiferous iron, containing much carbon and silicon. 
Here we have manganese oxidised from the first, but at a low temperature ; the 
silicon is also oxidised, and a slag is formed from the resulting materials. The 
combined carbon, the silicon, and the manganese, are oxidised together during the 
‘‘ boil,” when the temperature rapidly rises. The effect of this is to volatilise both 
manganese and iron, and the gas of the converter constituting a reducing atmosjDhere 
at a high temperature, carries the metals out of the converter, where they are burnt 
in air along with the carbonic oxide. Towards the close of the “ fining stage ” the 
manganese in the fume is reduced in quantity and the iron is increased, so that the 
lines of the one give place to those of the other metal. 
Suddenly the iron spectrum also becomes enfeebled, and the “ blow ” is stopped. 
Without doubt we have, at this point, a very rapid diminution of temperature, 
because the only combustible material left is iron, and its heat of combination is 
comparatively small. 
The Bessemer flame is not the result of combustible gases and vapours being mixed 
with oxygen and burning within the converter, and thus, in a state of combustion, 
issuing into the air; but on the contrary, it is a flame of carbonic oxide at an 
exceedingly high temperature burning outside the converter in a cold atmosphere. 
The Temperature of the Bessemer Metal and of the Flame. 
Various attempts were made by Watts to determine the temperature of the flame, 
and he concluded that, though it was above the melting-point of gold, it was below 
that of platinum. 
According to some recent measurements made by Le Chatelier (‘ Comptes Bendus,’ 
vol. 114, p. 670), the temperature in the Bessemer converter during the “boil” is 
1330° C., at the finish 1580°; while the steel in the ladle is at 1640° C. The scale of 
temperatures adopted was that of Violle, viz. ;—• 
Melting-point of gold. 1045° C. 
,, ,, palladium. . . . 1500° C. 
,, ,, platinum . . . . 1775° C. 
We have no measure of the temperature at the hottest period of the “ boil,” and 
unless the metal in the converter is cooled during the last minute of the blow, which 
my photographs clearly indicate, it is difficult to understand how its temperature 
could be raised by the addition of the cooler spiegel-eisen at tlie conclusion of the 
process of decarburization, and the still cooler ferro-manganese which is added while 
at only a red-heat. The rise of temperature at this period could be accounted for by 
the short “after-blow” of a few seconds, which is intended merely to mix the two 
MDCCCXCIV.—A. 6 Y 
