Spectrograms of χ Cygni have been obtained with the Mills Spectrograph of the Lick Observatory. For the purpose of spectrophotometry, the intensity spots have been given to all the plates using the Mills sensitometer. These spectrograms have been traced by the photo-electric microphotometer at the Yerkes Observatory, and equivalent widths of nearly 215 atomic and molecular lines have been derived.

The curve of growth was constructed by two methods. One is to make use of the observed values of the transition probabilities. The other is to make use of the theoretical values assuming LS coupling. Although Wright has used both values for constructing a single curve of growth, we have used them separately.