Evans found that the 4686 series and the Pickering series can be obtained in a helium spectrum ... The lines of the new series have wave-lengths very close to the hydrogen lines of the Balmer series.

RECENTLY Prof. Fowler (Month. Not. Roy. Astr. Soc, December, 1912) has observed a number of new lines by passing a condensed discharge through mixtures of hydrogen and helium. Some of these lines ...