we get
The observed value for the factor outside the bracket in the formula (4) is
The agreement between the theoretical and observed values is inside the uncertainty due to experimental errors in the constants entering in the expression for the theoretical value. We shall in [§3] return to consider the possible importance of the agreement in question.
It may be remarked that the fact, that it has not been possible to observe more than
lines of the Balmer series in experiments with vacuum tubes, while
