IV.—The Fulcher Bands of Hydrogen

Abstract

SummaryThe Fulcher Bands of Hydrogen have recently been arranged by Richardson. An examination of Richardson's arrangement in the light of recent accurate measurements of the hydrogen spectrum by Gale, Monk, and Lee, while strongly confirming Richardson's allocation of the Q branches, has failed to yield confirmation of the remaining branches which he gives.The present paper gives a number of combination relations which have been found to hold between the lines of the Fulcher Bands. These indicate that there are three main branches in each band, designated the R', Q, and P' branches, the Q branch being identical with that of Richardson. The R' and P' branches have a common initial level differing from that of the Q branch, while all three branches have a common final level. The arrangement yields term differences consistent throughout the bands.As far as these term differences have been investigated, they have been found to be in agreement with the new mechanics.The present investigation was suggested to me by Prof. H. Stanley Allen of St Andrews, and my warmest thanks are due to him for constant encouragement and helpful criticisms and suggestions.