Solar Phenomenon. 137 



Around the luminary, at a radial distance of perhaps twenty de- 

 grees, there was a dark halo of the usual defined character and ap- 

 pearance ; and circling this halo in various places, a rainbow was 

 visible. This rainbow was brightest in the eastern and western parts 

 of the halo, where it assumed that peculiar appearance which sea- 

 faring men call weather dogs, and which are of very frequent oc- 

 currence in the northern division of the Atlantic ocean. 



It was evident from the dull whitish light, that was diffused about 

 those portions of the circumference of the halo on which the pris- 

 matic colors were not perfectly defined, that, in some situations, an 

 observer might witness the singularly interesting spectacle of a cir- 

 cum-solar rainbow, in which the prismatic colors formed a complete 

 circle, concentric with the sun. 



In the course of the winter season, during changes of the weather 

 from frost to a thaw, I have frequently observed a small portion of a 

 vertical arch of the above description, although the sun was hardly 

 visible. Usually these occurrences have taken place when the sun 

 has been at the same elevation, as in the instance here described. 

 They have always happened when there was no rain. 



I am unable to say whether the appearances might not be cre- 

 ated by reflection from the brilliant surface of such a vast body of 

 ice, unincumbered by snow, as has been presented by Lake Ontario 

 during the last winter, as it is difficult to account for the formation 

 of a rainbow of so small a diameter on the usual principles, since 

 the sun at the time was forty degrees above the horizon. 



I have used the word rainbow in the above description, although 

 it is not a correct one, as there were no appearances of rain during 

 the presence of the phenomenon, although it is true there was a 

 slight mist or fog. 



Since writing the above, I have seen an almost complete circum- 

 solar rainbow, which appeared at Toronto, (U. C.) July, 1834, at 7 

 in the morning. 



Vol. XXX.— No. 1. 18 



