As of possible interest to some of your readers beg to report to you a phenomenon which I have observed here during the last ten days. It may be described as follows: every evening after sunset when twilight has completely died out of the western sky there is observable an illumination, starting due west and extending upwards to a height of about 40° above the horizon, fading away towards the top; in character it is much like the Milky Way, a little broader at its base, slightly less brilliant but more uniform. It extended this evening (August 10) from a point due west at 7.30 p.m., Gallegos mean solar time, upwards to a height of about 35° from the horizon, in the direction of the planet Jupiter, inclining towards the north at an angle with the horizon of about 60°. A curious fact I noticed in connection with this phenomenon was that it was best observed when the rays from it were allowed to fall on the periphery of the retina, as when the eyes were fixed on a point about 20° distant. It could be observed for about two and a half hours after sunset, gradually setting in the west. I presume this is the zodiacal light, but as I never noticed the same phenomenon in these latitudes (51° south) before, I thought it worth while mentioning the fact.