or Cholamandalu. This coast extends in a long line on the western side of the bay of Bengal, from Point Calymere to the mouths of the Krishna river, being about 350 miles in length. Along the whole extent of this coast there is not a good harbour, though there are several flourishing towns; and, with the excep- Coronas may be produced by placing a lighted candle in the midst of steam in cold weather; also, if glass windows be breathed upon, and the flame of a candle be placed some feet from it, while the spectator is also at the distance of some feet from another part of a window, the flame will be surrounded with a coloured halo; and if a candle be placed behind a glass receiver, when air is admitted into the vacuum within it, at a certain degree of density, the vapour with which it is loaded will form a coloured halo round the flame. This was observed by Otto Guericke. In December 1758, M. Muschenbroeck observed, that when the glass windows of his room were covered with a thin plate of ice on the inside, the moon appearing through it was surrounded with a large and variously coloured halo; and, opening the window, he found that it arose entirely from that thin plate of ice, for none was seen except through it.

Similar in some respects to the halo, was the remarkable appearance which M. Bouguer describes, as observed by himself and his companions on the top of Mount Pichinchia, in the Cordilleras. When the sun was just rising behind them, so as to appear white, each of them saw his own shadow projected upon it, and no other. The distance was such, that all the parts of the shadow were easily distinguishable, as the arms, the legs, and the head; but what surprised them most was, that the head was adorned with a kind of glory, consisting of three or four small concentric crowns, of a very lively colour, each exhibiting all the varieties of the primary rainbow, and having the circle of red upon the outside. The intervals between these circles continued equal, though the diameters of all of them were constantly changing. The last was very faint; and at a considerable distance was another great white circle which surrounded the whole. As nearly as M. Bouguer could compute, the diameter of the first of these circles was about $5\frac{1}{2}$ degrees, that of the second $11$, that of the third $17$, and so on; but the diameter of the white circle was about $76$ degrees. This phenomenon never appeared but in a cloud consisting of frozen particles, and never in drops of rain like the rainbow. When the sun was not in the horizon, only part of the white circle was visible, as M. Bouguer frequently observed afterwards.

Similar also to this curious appearance was one observed by a gentleman in Scotland. This individual observed a rainbow round his shadow in the mist, when he stood upon an eminence above it. In this situation the whole country seemed, as it were, buried under a vast deluge, and nothing but the tops of distant hills appeared here and there rising above the flood; so that one could not think of diving down into it without a kind of horror. In those upper regions the air, he says, is at that time very pure and agreeable to breathe in. At another time he observed a double range of colours round his shadow in these circumstances. The colours of the outermost range were broad and very distinct, and everywhere about two feet distant from the shadow. Then there was a darkish interval, and after that another narrower range of colours, closely surrounding the shadow, which was very much contracted. This person was of opinion that these ranges of colours are caused by the inflection of the rays of light, the same that occasioned the ring of light which surrounds the shadows of all bodies, observed by M. Maraldi and others. But the prodigious variety with which these appearances are exhibited seems to show that many of them do not result from the general laws of reflection, refraction, or inflection, belonging to transparent substances of a large mass; but depend upon the alternate reflection and transmission of the different kinds of rays, peculiar to substances reduced to the form