From this point the crossing of the bows was very striking, the buildings at Napier being, as it were, behind a blaze of coloured lights, as were also the objects fronting and hiding the Township of Meanee. The sun was now near setting, and further travelling along the road cut off the reflected sun, and ended observation.

Although I had not noticed such a thing before, nor even heard or read of such, I think it cannot be of infrequent occurrence. Given a very calm morning or evening, the sun bright, rain falling in the quarter opposite to the sun, and, lastly, a sheet of still water between the sun and the observer to reflect the rays from the sun—and it must appear.

A slight consideration of the subject will show that the distance of the centres of the two arcs will depend on the height of the sun above the horizon, and the consequent angular distance between the centre of the sun and that of his virtual image, the latter being apparently as much below the horizon as the sun is above it. Near the times of sunrise and sunset they will be very near each other, and more distant as the sun is higher in the heavens. When the sun is above 42° in height the vertex of the true bow will be below the horizon, and the nadir (and consequently the whole) of the false bow above it. The true bow will not be seen at all; the other will form a complete circle (all conditions being supposed favourable) in the heavens.

It is, however, evident that men may have eyes and not use them; hence only the general non-observance of such (shall I say?) common things. I have never heard of such a circular bow being seen, but hope that on some fine showery day in summer I may see it yet.

When, however, we consider that reflection is less perfect in proportion as rays strike the reflecting surface more directly, or at a greater angle, we must not expect in any circular bow from the reflected sun to see anything like the brilliancy of that described when the sun's rays fall very obliquely on the water. This also may be a reason why such phenomena have been hitherto overlooked.

Note.—Since writing the above I have seen Major-General Schaw's paper in the “Transactions,”^* in which a somewhat similar phenomenon is fully explained. As, however, confirmation by actual observation is always valuable, and the present instance differed in some details from that observed by Halley, who does not appear to have noticed the crossing of the ends of the two bows—also in his case there was a secondary bow as well as the two primaries—I think it worth recording. It will be observed that I saw no secondary bow;