New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1905-09-20
THE =" PARAGRELE."
French Method of Protection
against the Hail.

After a long spell Of hot dry weather. from
which France has been suffering fresh cause
Of anxiety confronts the agriculturist here One
crop succeeds another. and SO. unlucklly does
one enemy take the place of the last All
through the year the utmost vigilance is re-
quired TO protect the young fruit trees and the
vines from the attacks Of an infinite variety of
noxious bugs from excess Of temperature from
death by drowning or from parching with
drouth. once set, the fruit is attacked by
caterpillars tnnumerable and. even worse HI
rats, against whose onslaughts many inventions
have been tried. The best would seem to be the
little bags Of wire gauze. which. while success
fully battling the live rarauders. yet admit
the air and sunshine to the fruit within. and
whole vineyards may be seen thus protected.
The expense on large estates is. of course, con-
siderable; it is, however richly compensated by
the improved condition Of the fruit.
But the enemy that follows in the wake of
long hot summer is more terrible than any Of
these and its attacks are harder to parry. 1t
is the hail. Already in the southeastern dis
tricts, that of Burgundy. fearful havoc has been
worked by three storms Of short duration.
which have destroyed the wine crops so care
fully tended till within sight of the vintage.
The heavy losses to proprietors aCcruing from
q fall of hail makes them eager to welcome
from this scourge. Any scheme of protection
is obviously out of the question. In a recent
storm the hailstones were so large that the
roofs of houses were crushed and old trees were
beaten to earth The district afterward pre-
sented a scene Of desoIation not to be described.
Three hundred acres of wheat were totally de-
stroyed by hail just before the recent harvest.
An ingenious Norman farmer has conceived
the idea of fighting the hail in its own element,
that is to say in the clouds while in the process
Of formation. Basng his experiments upon the
theory that hail is formed by sudden fall Of
temperature in the regions of the atmosphere
through which heavily charged cloud is travel
ling, he endeavored by means of the action of
electric currents. TO destroy this condition Of
high pressure and thus prevent the congelation
of the suddenly condensed vapor. Using the
tunnels of old locomotives the enterprising
agrcuIturist discharged into threatening clouds
enough guupOWder to cause a powerful detona-
ton and disturb the atmosphere as high as he
could attain with his Instruments At the same
time. in the Cote dor the Burgundy wine
country, NJ. VermoreI has been conducting sim
liar experiments. He has organized a carefully
planned system of defence against the common
enemy, using ring shaped projectile, dis
charged by a powerful cannon. called a para
grele" (han CONDUCTOR The projectile travels at
q high rate Of velocity when it first leaves the
cannon, diminishing as it rises at the height Of
800 yards it ceases TO exercise any appreCtable
action
To remedy this defect Dr. Vidal, Of Hyeres
has invented a charge which expIodes at high
altitude and thus materially extends the sphere
of influence of the "paragrele." He relies for
the results Of this explosion not alone on the
disturbance of the atmosphere produced by the
defamation, but on the gases which are difused
by the bursting of the bomb. With his latest
improved apparatus, Dr.. Vidal succeeded in
throwing 4 petard to the height Of 500 yards
which then explodes into thousands of frag-
ments
Throughout the present summer a long series
Of experiments with DR.. vidars 'paragrele." or
hail conductor, have been carried on, under the
auspices of one of the agricultural colleges
and as soon as the results warrant such a
course syndicates of protection will be formed
to organize the adoption of the method in every
district Of France. So far, some signal sue
cesses have been obtained. One large storm
area was observed arriving from the sea and
spreading across the Landes of the west coast
Thirteen posts of observation installed in the
district fired off a succession of petards. some
Of which reached an altitude of 700 meters
and in ten minutes the storm clouds were dis
persed In the neighborhood of Auch storm
burst on the same day and three discharges
were fired by the post stationed there. The
first produced no effect. the second dispersed
the storm centre. but the third effectually dis
posed of il. and no more hail fell.
COnparisOn Of the experiments carried on WIN
DR. VidaTs invention shows that three dis
charges are invariably sufficient TO disperse any
storm centre. It is in the direction OF increas-
ing the range in altitude that improvements OF
the apparatus wanted are being sought Tor
Recently a proposition was laid before the
Society of Aerial Navigation in Paris by an
inventor NJ Leloup who proposed to utllze
for this same purpose of dispensing storm clouds
kind Of kite which should carry explosives INTO
the very heart Of the storm.
The idea of producing disturbances in atrno-
spheric conditions is only new in connection
gardeners of certain districts Of France have
been wont to fire heavy discharges of gunpo"-
der on still autumnal nights when there IS a
menace Of white frost. ms mas oeeH -
successful that watchers are regularly appoint
ed on still evenings. when the frost, so danger
ans 10 delicate vegetables. may be expected, and
thew give the signal 10 whole district As
the gardeners employ no special apparatus, how
ever they cannot insure Ihe oeSiEFu 81 -
,,4+boyt repeatfne the explosions at frequent IN
te-I-als R1lt they manage TO save their crops
II the vine districts these frost signals are
I4scIarped automatically by means Of a fall
go roII7rqr Of mercury. which, graduated 10 q
or73a+ric scales fires off alarm cannon,
T-her the peasants rush TO the vineyards ana
1i.1+ bonfres that reduce the temperature.