National Republican. (Washington City (D.C.)) 1872-1888, 1874-02-24
AMERICAN UNION ACADEMY.
INFLUENCE OF ARTILLERY FIRING IN
PRODUCING RAINFALL.

L
PRODUCING RAINFALL.
At . special meeting of the Union American
Academy of Science, Literature and Art, held
last evening in the chapel Of the Young Men,
Christian Association, Lincoln hall, DIR. A. G.
Mackey in the chair, and J. b. WIN secretary.
| Prof; Edward Powers, Of Chicago, delivered On
able address on the influence of tho firing Of ar
rst part Of his lecture presented facts, which he
had been at much pains to. collect from history,
from the log books Of the navy, from correspond
sources, in relation to the weather following bat
tiee These we're 50 arranged a. to make the evil
denee which they afforded cumulative. For ex-
that all great battles In which much artillery is
used are followed Immediately by rain The
not conclusive that the battles cause the rain.
But add to It the fact that the rain following
such battles 10 almost always very heavy, and the
rains that occur in the ordinary course Of nature
are light ones. Proceeding then to . considera-
ton Of the rains following other engagements
still further add to the probabilities that battles
cause ran and when 1t 10 also found that rain fol-
lows battles fought In time Of drought that it
and salutes f1red In the dry season on the Coro-
mandel coast In India and finally, that 1t follows
battles fought in country usually rainiess the
becomes almost . demonstration. ...
In endeavoring to account for the production Of
se tke theory Of E spy Who .oms re
large ares III Considers the eecs P su s1 not e
s Sas @ e. Of ~
currents always existing above US. He referS to
Maury9 Physicsl Geography Of the Sea for evil
aenSs going to show tha. ,nY:e are above thi, CON
tinent IVY great atmospheric CURRENTS the lower
one OF when nows fSon the sop'a- -. ward and
brings from the .dhs ocean the greater portion
o. .ne aauec SaEof that forms the rain that
1 hist ~ tn Omitted States and the upper one Of
r..ite direction. The conclusion Of heavy artii-
lery firing, he believes, rarines the air in the
lower and more humid Of these currents, and
current above. Thus the cold Of the upper cur
rent condenses the vapor Of the lower, and clouds
and rain are formed; This T. consistent with the
the humid current If the fire 10 large enough for
the heat to rise to It, but this method of producing
rain would be an exceedingly expensive and un-
The way in which heavy conclusions rarity the
rain bearing current. Mr.. Powers believes, Is by
por and setting free the latent heat Of this vapor
The reason why storm produced by battle
does not commence at the battlefield Is, accord
carried away by the current before It has had
time to mix with the cold air above. After the
storm 10 we'll under way, however, the upper cur
bsei to the bsttIe.neid, but also to 3 sres. dis
lance on each side. The force Of the latent heat
evolved from tho concerning vapOr VIII also aid
in widening the circle Of the storm. Its principal
motion, however, Will probably be along with the
vapor- bearing current - .-..- .....-
Prof NJ. r Maury, in his physical Geography
Of the Sea-" claims that the great atmospheric
current from the southwest Is . continuation Of
the southeast trade wind Of the Pacific ocean.
This wind reaches from the surface OF the ocean
to the height, 1t is supposed, Of three miles. It
moves over the ocean for more than two thousand
miles, and, with slight interruptions, 1t blows per-
petually. .
At the Equator 1t rises and, as claimed by
Maury, passes over tho northeast trade wind,
then, coming nearer the ocean, It becomes the at
mospheric current above mentioned. The amount
of vapor which 1t takes up from the and pre-
cipitates rain on land and sea in the northern
hemisphere is exceedingly great. Mr.. Powers
places these facts alongside Of the facts devel-
0ped by his Investigations in relation to the occur
Of rains after battles and argues that there
is always an abundance Of aqueous vapor above
u.s. whichever may be the condition Of the air 1t
the earth's surface. In q time Of drought, the
vapor-bearing currents are uninterrupted as they
dow the country, and the vapor Is carried oh
to form rain in the northern Atlantic and snow In
the Polar regions. But need not allow 1t to %
20 to waste. When the influences which nature
has provided to cause disturbances in those cur
rents fail to act, can produce the required dis
in them by the firing of artillery, and 30
bring rain in Sny quantities desired.