1874.! Optical Phenomena of the Atmosphere. a7 
evil portent. M. W. de Fonvielle, in commenting on an 
appearance of very rare form of lunar halo, of which I had 
sent an account to ‘‘ Nature” (Jan. 26, 1871), makes the 
following remark :*—“‘ Il est presque inutile d’ajouter que 
Vapparition de ce halo a été suivie, comme d’ordinaire, d’une 
chate de neijes abondantes.” Of course this remark refers 
to the winter season. I am not aware, however, that any 
case is on record of a halo of go° appearing in the summer 
time. Other similar cases of equal prognostic value have 
since been observed. One of the most remarkable occurred 
during the autumn of 1871. 
This was a long horizontal band of light that proceeded 
ina straight line from the moon to a distance equal to the 
radius of an ordinary halo. At the point where this line 
would have intersected the halo there were two short bands 
of light passing through it vertically, so as to form a kind 
IGE. 
Parhelia. April, 1872. 
of cross laid horizontally in the sky. Another phenomenon, 
which, I imagine, has a kindred origin, was observed by me, 
near Liverpool, on the Sunday before Easter, 1872. On 
this occasion the cross was formed at the moon itself, and 
the bands were only two or three degrees in length, at right 
angles to each other. After these appearances I took 
particular note of the weather. In a day or two, very 
heavy rain set in, and continued for a long period. Students 
of Meteorology will long remember the summer of 1872, 
and it is remarkable that it should have begun with so 
many and such unusual optical phenomena. This fact, 
however, is particularly noteworthy—that after the great 
electrical disturbance set in, and till the termination of the 
storms, not a single instance of a well defined halo or any 
* Comptes Rendus, Fevrier 27, 1871. 
