Solar Halos and Mock Suns. 411 



the one on the right and the other on the left side of the true 

 sun. 



23^4ini. Mock sun C had disappeared. 



23^ 44°'. Mock sun B disappeared. 



23^ 45'^. From the part of the halo A where the mock 

 sun C had appeared, there proceeded outwards an arc of a 

 circle, D, which was apparently a segment of a circle whose 

 diameter was about 90°. There were 30° of this arc visible. 



23^ 46"". Another segment of a circle, E, of seemingly the 

 same diameter as D, cut the circle A at 12° on either side the 

 base. D had disappeared. 



23^^ 55^. E had vanished, and the circle A was indistinct ; 

 much linear cirri now appearing. 



13doiiiom Circle A again brilliant, and the upper half 

 of another circle, G, fig. 3, appeared, of 46° radius, which 

 had the sun for its centre; it was colourless and 1° in breadth. 

 There was about 140° of this circle visible. Clouds much 

 thinner, the sky being now clear, with the exception of a very 

 thin uniform haze. 



0^ 15°^. Mock sun B again just visible, and another, H, 

 at the apex of the circle A, colourless. 



Qh 20™. The phaenomenon had vanished excepting the 

 circle A. 



0^ 35°^. A indistinct. From this time until 1 o'clock no 

 change, the halo being feeble for a time, and then brightening 

 up again. 



1*". A curious feature now showed itself; within the circle 

 A an ellipse, I, fig. 4, was formed, and immediately became 

 brilliant; its horizontal diameter (measured in the centre of 

 the ellipse) was 20° and its vertical diameter 30° ; within this 

 ellipse the sky was much brighter than that without; its lower 

 edge blended with the solar burr; at its apex was a mock 

 sun, K, and also the mock sun H again formed. 



jh 5m^ 'pijg appearance had changed ; mock sun K and 

 the ellipse I gone; but a segment of a circle, L, fig. 5, of 

 about 140° in diameter, rose from the sun S,- and cut the 

 circle A at its summit, and extended towards the north-west j 

 90° in length of this segment was plainly visible. Where it 

 cut the circle A at H was a mock sun ; also two other mock 

 suns, M and N, were formed in the circle A at the distance of 

 8° on either side the vertex of this circle. All colourless. 

 Sky becoming loaded with colourless cirri, but were less abun- 

 dant near the phaenomenon. Prospect, foggy; wind, west; 

 temperature in shade, 43° ; Franklin's hygrometer, 95 ; baro- 

 meter, 30*15 inches. 



I*' 9°^. Another portion of a circle, O, fig. 6, of like dimen- 



