482 Transactions. — Miscellaneous. 



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 w^ater between the sun and the observer 

 to reflect the rays from the sun — and it imist appear. 



A slight consideration of the subject will show that the 

 distance of tbe 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 line 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, con- 

 firmation 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 ; 



* Trans. N.Z. Inst., vol. xxv., p. 450. 



