55 
Robert Mallet, Esq., read an account ofa remarkable lunar 
halo on the night between the 10th and 11th instant :— 
«¢ At 12 o'clock, night, between the 10th and 11th Febru- 
ary, 1854, looking from a southern window of my house 
(Delville, Glasnevin), I observed the nearly round disc of the 
moon, then thirteen days old, riding high in an almost clear 
heaven, and surrounded by a very large and perfectly circular 
halo. ‘The size of the circle was such as to convey an idea of 
great grandeur, almost of awe, and the great comparative 
diminution of the apparent magnitude of the moon’s disc 
within it, which really seemed as though it could be covered 
by a shilling, was equally striking. 
‘The annexed dia- 
gram is intended to repre- 
sent the general appear- 
ance of the halo. 
‘7 had no means of 
directly measuring the an- 
gle subtended by the inner 
edge of the ring, which, 
however, was so large as 
to be with difficulty kept 
within the field of vision § 
with the eye fixed. 
“The inner edge of ™™ 
the halo was well defined, and slightly tinted with prismatic 
red, passing outwards into orange and yellow, and the whole 
becoming evanescent into white vapoury mist or light cloud. 
The prevailing colour of the mass of the ring was that of white 
bright moon-illuminated cloud. The width of the distin- 
guishable annulus (which was almost uniform all round) was 
from one-eighth to one-seventh of the internal diameter. To- 
wards the lower part, the shading off into vapour assumed a 
streaky appearance, like scirrus cloud, and below the ring were 
larger surfaces of very light fleecy scirrus and cumulo stratus, 
