Daily camera., 1901-06-12
INFLUENCE WEATHER
Successful Attempts That Have
Been Recently Received.
Efforts of French Scientists to Pre-.
vent Nocturnal FrOsts by the Pros
ducttOn of Artiacinl Clouds
Producing Rain.

Involuntary influence exists with
out doubt; it is exercised, for in.
stance, by deforestation and by the
resulting alteration of conditions OF
soil, which modifies the flowing OF
streams and increases inundations;
and also by the development of in.
dustrial activity, as Russell has shown
IN the case of London fogs, which
augment considerably with Increased
consumption of coal. The consider.
able increase of the number of thun.
derstorms, which has doubled since
1870, leads us to believe that in this
case also there is an effect due, in
part, ut least, to industrial activity.
for it is difficult to attribute an in.
crease so considerable to the sole
action OF sun spots, says Cosmos, OF
Paris. An attempt has been made
to explain the increase in the mum.
Der of storms by the abundant pro.
duction of steam by industrial en-
sines. DR.. Trabert cannot accept
this explanation, for he calculates
that the quantity Of steam thus pro.
duccd in the whole of Germany would
scarcely represent an evaporation Of
O.0o25 millimeter OF water to the
square kilometef tli000 inch to the
square mile). But it is quite differ
ent with particles of dust scattered
in great abundance throughout the
air by the incomplete combustion OF
a quantity of coal equal to 200 kilo.
grams to the square kilometer G,lio
pounds To square mile). This con
siderable increase of atmospheric
dust should exercise an action on the
production of rain, When moist air
passes the state of saturation, con-
densation takes place on particles OF
dust. The mere there are Of these,
.ha mere drops are formed; thus,
tnr given quantity OF yapor CON
densed. the drops are necessarily
smaller. Now the tension Of satura-
tion on cou.eN surface increases
with the curvature Of the surface,
that is to say, with the smallncss
of the drops ~ ,Screase of the
quantity of dust in the air will there
fore tend to favor the Supersatara-
tion OF the any, ana consequently TO
Produce lhunaHfstashs and abundant
rains,
II is much more interesting, how
ever, to know whether we may vol
unfairly act upon the weather. To
this kind of action Eglong the at
tcmpts made successfully in France,
on a large scale, to prevent nocturnal
frosts by the Efaaeetiqn OF artificial
clouds. BHt when We come to the
artificial production ef rain, success
is much mere doubtful, as all at
tempts, so far. have proved. In the
production of any phenomenon il Is
always question of the equivalent
transformation of one kind Of en-
ergy into aEG;ho., aud we must in
guire whethet ihe necessary amount
Of energy is -, our disposal. Now
Trabert calculates that to bring to
quarter cubic milel of air at 10 per
cent. relatiyr pumshiy requires no
.es- than LOO kilogrammeters OF
work 10000 foot pounds). This
scarcely allow. As ~ think of the
possibility of artificial condensation.
Such thing weqh appear to be pos
Sible only II the conditions necessary
70 condensation aireat'y existed, and
If We had only 20 put latent forces
tnlo a"...on. Finally, to this Solun-
tary action on the Weather belongs
the uuih.51, used in the Austrian
Alps since the tiFae IF Emperor Jo-
scph H.. OF making numerous eNpio-
.ions to ward OIL q hailstorm,
process thai, .- ~ well known, has
been developed and systematized by
NJ. Steger at Wandisch-Feistritz, III
southern Styria. with great success.
uredoane tions Qtprnei- ,sofsi typyci