+ E # - 
e = 
326 Proceedings of the British Association. 
phenomenon, and that the rings were the effect of the double re- 
fraction of the minute crystals. A few experiments, however, 
overturned this hypothesis, and I was soon satisfied, by a little 
further investigation, that the phenomena arose wholly from the 
polarization of the transmitted light by refraction, the splendid 
colors being entirely those of thin plates, which were sometimes 
arranged so as to have the appearance of concentric rings. ‘The 
structure by which these effects was produced, was compared by 
the author to a heap of very deep watch glasses laid one above 
another. When the thin films were arranged longitudinally, and 
were inclined to the general surface of the plate, so as to trans- 
mit the rays obliquely, the light was still polarized, but only in 
one plane, viz. a plane perpendicular to the plane of incidence. 
When a drop of water or oit was introduced between the films, 
the phenomena of polarization as well as of color, instantly dis- 
appeared. : ; 
Prof. Phillips communicated new experimental researches on 
rain. He had endeavored, by a new train of researches on the 
quantities of rain received on horizontal. surfaces, at different 
heights above the ground, and by a contemporaneous series of 
experiments on the direction and angle of inclination of the de- 
scending lines of rain drops, and by contemporaneous registration 
of wind, temperature and moisture, to furnish additional data of 
importance in the theory of rain. In the second part of his com 
munication he described a new rain-gauge, for the purpose of de- 
termining the direction in which rain comes, and the angle of in- 
clination at which it descends. For this object, a compound 
gauge is constructed, having five equal receiving funnels and 
tubes; one with a vertical tube and horizontal aperture, the other 
four with tubes recurved, so as to present the openings of the fun- 
nels in four vertical planes, directed to four quarters of the ho- 
rizon. ; 
Excessive rain.—Prof. Forbes remarked that some doubt had 
been expressed concerning the remarkable fall of rain at Genoa 
(not Geneva,) stated in his report of the previous year, Viz. 30 
inches in 24 hours, Oct. 25, 1822. He now adduced satisfactory 
proof of its truth. He then noticed some other remarkable fails 
of rain. Flaugergues, the eminent meteorologist of Viviers, ob- 
tained, on the 6th of September, 1801, 143 English inches of rain 
in eighteen hours. On the 20th of May, 1827, there fell at Ge 
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