1050 
PROFESSOR W. N. HARTLEY ON 
flashes out occasionally. The temperature is evidently low, not much above that of 
cast iron. Sparks of graphite and of iron are ejected, but these come from the 
burning of spray caused by the eruption of air from the molten metal within the 
converter. After seven minutes the spectrum of sodium is constant, at ten minutes 
the spectrum of lithium becomes visible. Neither the hydrogen lines nor those of 
])otassium were as a rule visible. Two violet lines of potassium appear in all the 
photographs. During the “ boil ” the sparks are few and small, because the metal 
being much hotter and more liquid there is less spray. The flame is large and it 
burns with a steady roar. At Crewe, it generally possessed the greenish-yellow 
colour of the vapour of manganese, and maintained this colour until about three 
seconds before the termination of the process. Sometimes, however, the mouth of 
the converter showed, during the progress of the “boil,” the amethyst-coloured flame 
for a foot or two, extending from its edge, and there was a further tinge of the same 
tint beyond the yellowish-green, and quite at the outside of the tip of the bright 
flame. The duration of the “ blow ” varied from fifteen to twenty-one minutes. The 
metal used was haematite pig-iron, and the steel made was intended for boiler plates 
and also for small tyres and wheels. In certain cases particulars are given, but this 
is not a matter of consequence in considering the spectra observed. In all, twelve 
plates were exposed, some of which were so entirely satisfactory as to render any 
further work at Crewe unnecessary, there being ample material for some months of 
study. 
S'pectra of the Bessemer Flame photographed at Crewe in January, 1893, loith a 
detailed account in each case of the period of the “ hloio" the plates used, and 
the duration of each expos'o.re. 
Plate 1. 
The first exposure lasted three minutes. (Edwards’ isochromatic instantaneous 
plate.) 
A second exposure was made of another part of the plate, and a different “ blow.” 
“ Blow ” started at. 
First appearance of Na line. 
,, ,, red and green bands. 
Exposure commenced. 
Continued till end of “ blow ” . . . . 
Duration of exposure. 
A third exposure. 
“Blow ” commenced at. 
First appearance of sodium line at 
„ ,, red and greeii bands 
Exposure began. 
End of “blow” . .. 
Duration of exposui'e. 
1.34 p.M. 
1.41 „ 
1.45 „ 
1.46 „ 
1.554 „ 
94 minutes. 
3.38 P.M. 
3.45 
3.48 
3.51 
3.574 
? > 
64 minutes. 
