38 Optical Phenomena of the Atmosphere. [January, 
cognate optical appearance was seen; and equally remark- 
able was the absence during the same time of the cirrus 
and cirro-cumulus forms of cloud. It would appear that 
the amount of electricity diffused through the atmosphere 
had some influence on the congelation of vapour, or that 
the forms of cloud in question are in some way dependent 
on an electrical condition, or a relation of the upper to the 
lower stratum of vapour. During this season the electric 
cumulus, of various forms and shapes, was the prevailing 
cloud form. 
Professor Poey, in his recently published remarks on 
cloud classification, points out that, during the most 
pronounced rain seasons, the two kinds of ‘“ pallium,”’— 
viz., the high ice-pallium and the low mist-pallium—are 
separated by a neutral region of the atmosphere, and that 
the pallio-cirrus is then in a state of negative electrical 
excitement, in common with the air at the surface of the 
ground; while the pallio-cumulus and the rain that issues 
from it are in positive electrical excitement; and that 
electrical discharges continually take place between the two 
concomitantly with the pouring down of wnelectrified rain 
from the lower stratum upon the earth. 
These results are singular and interesting, though it is to 
be regretted, perhaps, that Prof. Poey has not given some 
details of the means by which they were obtained. It has 
seemed strange to me that the invention of atmospheric 
electrometers and electroscopes, in combination with the 
Captive balloon, has not been put to some praétical 
use in the prediction of weather. By placing several of 
these instruments at various altitudes, and synchronously 
noting their indications, further important results may 
perhaps be obtained. 
On referring to Buchan’s “‘ Handy Book of Meteorology,” 
I find acase of a halo intersected by twelve rectilinear bands 
of light proceeding from the sun. No remark is made on 
the origin of the bands; but experiment seems to show that 
we must attribute these to reflection, and look for the cause 
in the configuration of the terminating facets of the 
suspended crystals. This theory is corroborated by the fact 
that these bands of light are achromatic, which would not 
be the case if they were caused by refraction. 
A halo broken in its outline, and caused by well-defined 
bands of linear cirrus, is, I believe, a more certain sign of 
rain than a continuous circle. Another form that I have 
noticed before bad weather is a fleecy and irregular circle, 
wider in some parts than in others ; it is of a very evanescent 
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