NO. 17 



ULTRA-VIOLET INTENSITIES McALISTER 



more critical functions of the operating conditions and of the presence 

 of small amounts of foreign gases than are the intensities of the rest 



Fig. I.— Absolute intensities 250 mm from a 20 mm mid-section of the "high 



intensity " arc. 



of the spectrum. Hence in a commercial product one would expect 

 such a variation as is observed in comparing one arc with another. 



