Unfortunately, it was impossible to compare these (arc) spectra with the (spark) spectrum observed by Timma. 6 His observations covered the 3630-4400 A. region; aside from the fact that the methods of excitation used were different, his principal lines could not be looked for in the present arc spectrum with any hope of success because of interference by CZ and CN bands. However, the spark lines he mentioned as due to element 61 were observed in ...
