The Sunday herald and weekly national intelligencer., 1891-07-05

1t has long been sought to devise some
means whereby the blessings of rainfall
might b somewhatequally enjoyed; that is to
say where rainfall might be blessing and not
a disaster, and there might not be disaster
from lack thereof. Many schemes, more or
less rational, have been devised. Among
them was that of Professor Espy In 1889
Espy suggested plan for compelling nature
TO unloose the pent-up volume of moisture
suspended aloft. He proposed to build great
fires to heat the air. upon the theory that warm
air 'rsing to height where, owing 10 a
diminished pressure, 1t would expand, was by
the expansion, cooled, thereby condensing
and eventually precpitating its vapor.''
The acknowledgements in 1864, proposed
to consider Espys theory, and put it to test,
but Mr.. H. G. Russell, the Government
Astronomer at New South Wales, demon
strated that it would require 9 ,OOO, 900 tons of
coal to be burned daily in order to ncreas e by 60
per cent. the rainfall at Sydney, where the
average humidity is 73, for it would be neces-
sary to raise column of air to a height of
!,SuU feet over surface ten miles by 1000 feet
II has also been suggested to build fires along
1he margins of rivers; but il we have the river
water may be brought more cheaply to where
1t Is desired by bitches and canals.
Another suggestion was to erect a tall
chimney over pool of water, and build fires
at the edge OF the water, which will have their
draught over the water up the chimney, and
thus carry moisture into the air. There is no
doubt that this will form clouds of vapor in
the AIR; but 1t is not equally certain that the
vapor will be condensed to rain drops and come
down where it is wanted
Many years ago, Mr.. Edward Powers pub
lished book entitled sWar and the Weather.
"nich purports to be, and probably is, a
collection of statistics, tending to show that
every great battle, even in regions where
Ihere was prevailing drought has been fol-
lowed by copious falls of rain.
indeed there seems to be little reason to
doubt that rainfall may be induced by con-
oussion. The theory that rainfall can be pro
auced by conclusion caused by explosions is
as Old as the hills. Even in the time of old
P!utarch, 10 quote literally, it was ''a matter
OF current observation that extraordinary
rams pretty generally fall after great battles',
Napoiean is said to have believed from his own
observations, that rain usually followed heavy
Cannonadlng and he took advantage of this
theory in ordering the maneuvres of his
troops. European scientists of later date
VINO entertained the same theory pointed with
trlumph, as vindication of their idea, to the
unusually wet season which prevailed through
out france during the Franco-Prussian war.
IL Is within the knowledge of those who
were engaged in the construction of the Union
faclhc Road, notably of Senator Stanford,
That, in building that road, stretch of country
was passed through where it never or hardly
eyer ranea; and 1t having been necessary to
Dlasf, II commenced to rain soon after the blast
ing operations began, and it rained while they
continued. 1t is said not to have rained there
since. The idea of Mr.. Powers who by the way,
is CIVIL engineer of note was to resort to can
nonading; but it was found that an expert
ment OF the kind could, perhaps, scarcely he
carried out for less than $4,000 to $50, ,OO0
Inc ldea OF producing rainfall by concus-
SION with the incident advantages to the
word OF rain where it was needed and such
proper distribution OF the rainfall that there
might not be floods and torrents made a
strong impression upon the mind of ex-Sena-
tor Charles b. Farweli, of Illinois. Consider
ing the question of expense, however, It oc-
cured TO him that great saving might be eff
iected and that probably increased efficiency of
sipns 0peratton would result by causing the explo
nons 10 take place above the earth's surface,
IN The region of the clouds, by setting off
high explosives from balloons.
IL is preferable to produce explosions some
What above the surface of the earth for two
reasons First, to reduce the danger to the
operators and the surroundings to a minimum:
and secondly, by closer proximity of explosion
10 the clouds; that is, to an apparent stratum
or strata of moisture, Or If there be no
apparent clouds, still at situation Where the
conclusion VIII be most widespread by not
being lmpeded by Irregularities or obstacles
on tic surface, to extend the area of concus-
Sion. and make less extensive or fewer num-
Der of explosions necessary.
IL may be objected by many that in order to
get the precipitation of moisture-that is rain
fall, there must first be the stratum of moist
nreln the air TO be condensed; but it would
seem that the immediate reply to this is that
there is always moisture in the air even in the
most arid regions, or no being could live and
perhaps conclusion creates something in the
nature OF q vortex. From a mere mechanical
standpoint II would seem that such stirring
up OF the atmosphere must result in aggrega-
ZION ana precipitation OF any heavier body like
water, held IN suspension, particularly by the
tendency OF such body as water to condensa-
uol' collection, or agglomeration, like quick
silver Another reason why it is best to have
Inc explosion above the earth's surface, is be-
cause there is more likely to be moisture pres
ent In large quantities somewhat above than
immediately at the earth's surface since moist
ure-for example, steam-is specifically lighter
than the mixture of nitrogen and oxygen
which constitutes air. The segregated moist
ure then, in the form of yapor, whether visible
or not ~ being generally invisible, for it is
only visible when condensation exists or has
begun J, rises and tends to remain above the
surface of the earth. In addition to declared
observations of rainfall succeeding battles
from conclusion of the air from cannonading
ltis within the observation of every one that
during shower a heavy clap of thunder ia
always succeeded by an Immediately increased
fall OF rain, even If this be but for short time
Impressed with the desirability of testing
the question of producing rainfall by concus-
sion, senator Farwell got an appropriation
lrom Congress, at first of $4,000, and then of
$4,000 which was accredited to the Depart
d Of 4 IG