200 CAUSE OF THE CORONA. 



being often foggy, with a bright sun sometimes 

 shining at the height of the day, some extraordinary 

 coronse were observed from the mast-head. These 

 occurred opposite to the sun, the centre of all the 

 circles being in a line drawn from the sun through 

 the eye of the observer. On one occasion four 

 coloured luminous circles were observed. The ex- 

 terior one might be twenty degrees in diameter. It 

 exhibited all the colours of the spectrum. The next, 

 a little within it, was of a whitish-gray colour ; the 

 third was only four or five degrees in diameter, and 

 though it exhibited the colours of the spectrum, 

 these colours were not very brilliant. The fourth 

 was extremely beautiful and brilliant. The interior 

 colour was yellow, then orange, red, violet, &c. 

 The colours of the whole three coronse were, I think, 

 in the same order, but of this I am not very certain. 

 Indeed, on reflection, I suspect that the second circle 

 must have been in the reverse order of the first ; 

 the first and the fourth being the same. The third 

 was not coloured. In the midst of these beautiful 

 coronse I observed my own shadow, the head sur- 

 rounded by a glory. All the coronse were evidently 

 produced by the fog ; my shadow was impressed 011 

 the surface of the sea." 



The cause of these phenomena is " the reflection 

 of the sun's rays, decomposed by different refractions 

 in minute globules of water, of which the mist, 

 wherein the coronse occur, in a great measure appears 

 to consist." 



