282 
GREENLAND VOYAGE. 
the axis of the globules, immediately around the 
centre of the circles, undergo a slight refraction 
from the circmnstance of being out of the cen¬ 
tre, and thus exhibit the prismatic colours ? 
But, admitting the explanations now offered 
to be agreeable to the laws of dioptrics, it will 
not, I believe, be possible to account for the 
formation of the second and third corona;, by 
any probable combination of reflections and re¬ 
fractions by globular particles. Hence, it is 
not improbable, that the* snowy spicuke ob¬ 
served in both the instances here recorded, may 
have had a share in the production of the pheno¬ 
mena. And this idea, I perceive, is supported by 
the opinion of M. Bouguer, who observed anthe- 
lia and corona;, somewhat similar, on the top of 
IN'Iount Pichinca, one of the Cordilleras, at the 
time of sun-rising. His description, which only 
recently fell under my observation, is given in the 
“ Histoire de l’Academie B,oyale des Sciences” of 
France, for the year 1744. Among many judi¬ 
cious and correct observations on the subject, he 
remarks, that “ Le phenomene outre cela ne se 
trace que sur les nuages, et meme sur ceux dont 
les particules sont glacees, et non pas sur les gout- 
tes de pluie, comme l’arc-en-ciel.” 
The figure of the observer in the centre of the 
anthelion, witnessed by M. Bouguer, was impressed 
on the edge of a cloud:—in all the cases that have 
