OPTICAL PHENOMENA. 



531 



Halo. 



45 in diameter, with segments of several others, displaying in parts the colours of the 

 rainbow. Besides these, there was another perfect ring of a pale white colour, which 

 went right round the sky, parallel with the horizon, and at a distance from it equal to the 

 sun's altitude ; and a horizontal band of white light appeared passing through the sun. 

 Where the band and the inner halo cut each other, there were two parhelia, and another 

 close to the horizon, directly under the sun, which formed the most brilliant part of the 

 spectacle, being exactly like the sun, slightly obscured by a thin cloud at his rising 



or setting. A drawing of this par 

 helion is given by Captain Parry, 

 who remarks upon having always ob 

 served such phenomena attended with 

 a little snow falling, or rather small 

 spicula? or fine crystals of ice. The 

 angular forms of the crystals deter 

 mine the rays of light in different 

 directions, and originate the conse 

 quent visual variety. We have vari 

 ous observations of parhelia seen in 

 different parts of Europe, which in 

 a less enlightened age excited con 

 sternation, and were regarded as por 

 tentous. Matthew Paris relates in 

 his history : " A wonderful sight 

 was seen in England A. D. 1233, 

 April 8, in the fifth year of the reign 

 of Henry III., and lasted from sun 

 rise till noon. At the same time on the 8th of April, about one o'clock, in the borders 

 of Herefordshire and Worcestershire, besides the true sun there appeared in the sky four 

 mock suns of a red colour ; also a certain large circle of the colour of crystal, about two 



