MR. W. CROOKES ON THE SPECTRA OF ARGON. 251 
THE Two Spectra of Argon—(continued). 


Blue. Red. 

Wave-length. Intensity. Wave-length. Intensity. 


304:27 
299-82 
297-86 
294-27 
292-96 
283-02 
279-44 
273-45 
270°72 
269-30 
266-12 
265-26 
262-95 
257-12 
256-07 
248-49 
243-85 
224-66 

WN PWN ROWDY Ri HrEw 






119 lines in the ‘ Blue” Spectrum. 
80 lines in the ‘‘ Red” Spectrum. 
199 total lines. 
26 lines common to the two spectra. 
Nore.—-In the spectroscope the lies of argon appear almost equally fine, but of 
very different intensities. This difference of brightness is represented in the 
accompanying map by a variation in the thickness of the lines, faint lines being 
made narrow and strongly luminous lines being widened. In some cases two or 
three strong lines are too close together to enable their intensities to be represented 
in this way without overlapping. This is the case with lines 442°65 and 442°25, 
with lines 420710, 419°80, and 419°15, and with lines 415°95 and 415°65. In these 
cases I have indicated the centres of the strong lines by short projecting lines 
beneath. 
