The "Sky-Coloured Clouds" or Twilight Glows

THERE can, I think, be no doubt that the numerous descriptions which have appeared of the recent twilight phenomena relate to essentially the same phenomenon as the "sky-coloured clouds", or, as the late O. Jesse called them, the "luminous night-clouds". On June 30 and July 1, which seem to have been the principal dates, I was unfavourably situated for observing the phenomenon, but I may point out that I directed attention to it in your issue of June 11, p. 127.