A New Band System of Carbon Monoxide

Abstract

IN an attempt to photograph the so-called spurious bands associated with the third positive carbon bands, on a 21-ft. concave grating, my plates showed a band at λ3893.2 which was completely resolved under the dispersion. I could also see some bands at λλ3681.1, 4125.0, and 4380.3. Good plates of these bands were obtained in the first order of the grating. The band at λ3681.1 is completely mixed up with one of the spurious bands beginning at about λ3694, and those at λλ4125.0 and 4380.3 are to a more or less extent similarly mixed up with the Ångström bands at λλ4123 and 4393 respectively. On the other hand, the band at λ3893.2 is completely isolated. The fine structure analysis of this band was therefore easily achieved. It has been possible also to analyse the fine structure of the bands at λλ4125.0 and 4380.3, since the structure of the superimposed Ångström bands is definitely known. No attempt has yet been made to analyse the band at λ3681.1 as the structure of the spurious band superposing it is not known.