TRANSACTIONS OF THE SECTIONS. 47 
rain. The direction thus known by observation, the angle of inclina- 
tion of the descending rain from the vertical is easily calculated. 
2. If the rain has fallen (in quantities g and g') in two of the verti- 
eal gauges as well as in h (in quantity H), then the direction of the 
rain, intermediate to the positions of the two receiving vertical gauges, 
may be easily calculated (by considering g and q! as sine and cosine ; 
the ratio between them being = cotangent of the angle by which the 
rain direction deviates from that of the gauge which receives most 
rain). This known, the quantity (Q) which would have been received, in 
a vertical funnel directly opposed to the rain, is also calculable, being 
=V@P+q"; and, finally, the angle of inclination from the vertical, 
H 
at which the rain descends, is calculable, its cotangent being = ai 
Observations with this instrument have been made satisfactorily for 
some months, and the author has found the angle of inclination of de- 
scending rain to vary from 0 to 6°, 13°, 17°, and in one case to 35°, 
without perceiving that these very unequal inclinations had any sensible 
effect on the relation of the quantities of rain received in the gauges 
which are placed at different elevations, 
On the Formation of Rain. By G. A. Rowertt. 
The author states his hypothesis, that vapour on rising carries with 
it its proportion of electricity according to its expanded surface, and on 
being condensed, becomes, if insulated, surcharged with electricity ; 
this buoys up the vapour by its lightness, and prevents ‘the for- 
mation of rain by its repulsive power, and, on its escape, the par- 
ticles of vapour attract each other and form rain. He then explains 
the phenomenon of rain, as follows :—That hills and mountains being 
more subject to rain than plains, is owing to their attracting the elec- 
tricity from the clouds or invisible vapour; that the rain accompany- 
are piled to a great height, and that any violent commotion in such 
_acloud would cause such heavy rains as follow flashes of lightning ; 
_that the successive Slashes of lightning JSrom the same cloud may be 
from vapour becoming more and more condensed, thus causing suc- 
€essive accumulations of electricity on the surface of the vapour, or 
Mulations; that the change in weight of the atmosphere previous to 
and during rain, is caused by the electricity passing from the cloud or 
invisible vapour to the earth, displacing the heavier air, and thus causing 
