48G PROFESSOE W. X. HARTLEY AXD MR. H. RAMAGE OX THE SPECTRA 
The Cause of the Continuous Spectrum^ which is a Marked Feature of the Flame 
from the “ Basic ” Process. 
It has already been stated in the description of the “blow” as observed at the 
North-Eastern Steel Company’s Works at Middlesbrough, that a flame is seen 
issuing from the mouth of the vessel from the first moment after the dispersion of 
the lime dust, a feature which is quite characteristic of the “basic” process. This 
flame is yellow and highly illuminating, but not to such an extent as to be visible 
on the slit plate of the instrument. It is evident, therefore, that some gas is 
evolved, the origin of which can only be the tarry matter used in the lining of the 
vessel. The smaller quantity of silicon in the iron is very quickly oxidised in this 
process. In the spectrum of the flame at this period it is observed that the continuous 
rays are generally stronger in the series of photographs taken at Middlesbrough 
than in those from Crewe and Dowlais, where the “ acid ” process was in use. This 
might be accounted for in part by the presence of larger quantities of the alkalies, 
which emit strong continuous flame spectra accomjDanied by lines, and partly by 
the presence of lime dust from the lime used in the “ basic ” process, which 
becomes incandescent in the flame. iVt this early period of the “ blow ” in the “ acid ” 
process only the lines of the alkali metals and of manganese appear, and they are very 
weak. The continuous spectrum cannot, however, be wholly attributed to the alkalies 
without further inquiry, for both iron and manganese or their compounds yield 
marked continuous spectra in the oxyhydrogen flame, which, however, is hotter than 
that of the flame of the converter at this stage. Moreover, in the “basic” as in the 
“acid” process, especially in the latter periods, this is caused by the flame of carbon 
monoxide. The visible spectra at Middlesbrough shortly after blowing has been 
started show the red and green l^ands of calcium oxide, and a minute later the hues 
of sodium. For instance, in the notes of our first series of photographs it is recorded 
that a flame was visible from the commencement, but it could not be seen ujDon the 
slit; there were showers of .sparks and flashes of red at intervals during the first 
three minutes. The bands of manganese, two red lines, and the yellow sodium lines 
were visi1)le. The manganese bands were mainly those in the violet. A subsequent 
examination of the photographs .showed a band in the green due to calcium oxide, 
the lines of potassium 4047'36 and 4044’29, as also the manganese lines ; hence one 
of the red lines belonged undoubtedly to calcium oxide, for this "would certainly be 
present along with the green calcium oxide Imnd ; the other red line is more likely to 
be that of lithium tlian potassium, owing to the former being so much the brighter, 
and lithium we know l)y eye observations is always conspicuous in these spectra a few 
minutes before the potassium line appears. Lastly, we have the sodium rays in the 
yellow. 
With i-eference to Plate 1 0, we have it recorded that the red and green hands of 
