By moonlight there is thus formed a semicircle of light on the grass, which continually moves before you; it is a halo on the grass-tips. I noticed this as a boy, and tried all sorts of experiments respecting it, but never met with any mention of it in books till quite lately, in Benvenuto Cellini's "Autobiography." He says, "There appeared a resplendent light over my head, which has displayed itself conspicuously to all I have thought proper to show it to, but those were very few. This shining light is to be seen in the morning over my shadow till two o'clock in the afternoon, and it appears to the greatest advantage when the grass is moist with dew; it is likewise visible in the evening at sunset. This phenomenon I took notice of in Paris, because the air is exceedingly clear in that climate, so that I could distinguish it there much plainer than in Italy, where mists are much more frequent; but I can still see it even here, and show it to others, though not to the same advantage as in France." Benvenuto thought this one of the most extraordinary things that had happened to him; and records it after a wonderful dream, as if it, too, were supernatural. It is, however, possible that some eyes are so constituted as not to be able to see this phenomenon in their own case; at least, I have sometimes tried in vain to get other people to see it. I should not have noticed it had I not been about at all hours with my gun as a boy. It is much more visible by moonlight, when the rabbits' white tails go dot, dot, lightly over the grass, and you are just as likely to shoot at their shadows as at their bodies. As the scythe of the mower mows a swathe before him, so the semicircle of light moves in front over the dew, and the grass appears another tint, as it does after a roller has passed.