Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-08-17
BY THOMAS r. HENRY.

The United States Weather Bureau
is receiving scores of suggestions for
making rain.
The unprecedented drought evidently
has challenged the inventive genius of
the American people, but thus far,
Weather Bureau experts say, not q
single idea worth consideration has
been advanced.
Many of the rain-making schemes,
| in fact, go back to one of the moss
| primitive forms of human thinking
| initiative magic. The crude natural
philosophy held by savage tribes from
| time immemorial, probably even ante
| dating religion, is advanced over and
| over again. often cloaked in a pseudo
| scientific Technology. Some of sheSe
ideas are described as revelations Just
: received from the Lord"
Many Declare Lord Avenged.
| Sometimes specifically ingenious
| scientific suggestions are received. All
of these to date have contained 1aliacleS
| Immediately obvious to trained meteorol-
ogists. Many of the letters are religious
in tone, declaring the conviction OF tne
| writer's that the drought Is super
| natural vengence on wicked nation,
| which can be ended only by Supplica-
| ton. Others are from obvious para
noics. who insist that ways to end the
| drought have been confided to them
| bv the Lord. They will reveal their
| knowledge for a proper reward, sucr
as being made dictator OF the onlteo
| States. :.
MANY of these letters are written d.
| rectly TO President Hoover and sent 70
| the Weather Bureau from the Wnlte
| House. Some complain bitterly tnat
| Government agents have refused to lis
| ten to them. or are too ignorant and
| narrow minded to grasp the significance
| of suggestions. Actually every letter
sent to the Weather Bureau Is answered,
| however absurd the suggestion. mo-
where would an idea that gave the
| slightest promise of validity be well
| coined more eagerly, for the meteorolo.
| gists Themselves know OF no practical
| system of artificial rain-maKing, and
would try anything. not obviously I'M
possible or diSproved by experiment In
| the past, which offered a reasonable
| hope.
| Nearly all the scientific and pseudo
| scientific suggestions, according to Dr.
/ william j. Humphreys, who receives
many of the letters, are variations OF
well known ideas which DO not work.
| Nearly all rain-making schemes fall
] into familiar categorieS, such as cool
ing the upper atmosphere, sprinkling
| the atmosphere with dust particles, ef-
! fecting the condition of the atmosphere
with noise and shutting down radio sta
| tons and superpower plants. All these
! have been investigated thoroughly in
| the past.
| Cooling Suggestion Partly Logical.
The idea of cooling parts of the upper
| atmosphere, it was explained, has q
certain logic but is based on q naiscon-
ceptfon of the rain-making process. 1t
was tried in the earliest days Of bal
| looming more than a century ago. The
balloonist took up load of cracked ice
| and shoveled 1t upon a cloud. This
actually caused rain, for the ice fell
in the form Of water drops. But tn,
| rain was somewhat less than the
| amount of cracked ice which the bal
| looniSt had taken up with him.
| Now, of course. there are more eff
! fective cooling substances. The most
| frequent suggestion along this line is to
| sprinkle the clouds from airplaneS with
| liquid air. eActually. the meteorologists
say, this hardly could be done on a
| large enough scale to have any effect.
But If there was any result at all it
would be the opposite Of that expected.
| The scheme is based on the idea that
| the moisture from humid warm air il
| squeezed out by the contraction of the
volume of the air by cooling, and falls
as rain. This, however, Is only a super
! fetal explanation of the rain-makine
| mechanism. Artificial cooling of a
volume of air would tend to make it
fall to lower level where it would be
warmed again and could hold more
moisture.
Dust Suggestion Frequent.
Disappointing suggestions are fire.
quent. 1t is true, the meteorologists
| Say, that dust particles in the air are
| practically essential to the formation Of
| water dropletS, but there is always an
overSupply.
1t is not lack of dust, but lack of
| water which is responsible for drought
One man wrote in the other day sug-
| costing that aViatorS shovel powdered
cement on the clouds. The cement
would come down all right-most of il.
The result might be miniature cement
hailstOrm, if the suggestion was carried
out en- a sufficient scale.
Then there is the idea that lots of
noise will cause rain. This, DR.. Hum
phreys explains, has the weight of prec-
| edence behind it, Statistically, it can
be shown that most of the great battles
previous to the World War, where there
was intensive artillery firing. have
been followed-sooner or later, at least
by rain. But there is no physical
reason why noise should make rain, and
the meteorological statistics of the Ma
poleonic and Franco Prussian wars in
Europe and the Civil War in the United
States can be explained in q simpler
way.
Rain Followed Ancient Battles.
Dr. Humphreys points out that the
observation of rain following a battle
was made long before the days of ar
tillery 1t first was mentioned by
Plutarch. Some attributed 1t to the
unusual noise of men shouting and
screaming and the rattle of swords
against shields Others thought it was
due 10 the greater amount of moisture
absorbed in the air from the sweat Of
the soldiers and the blood of the
wounded. Others thought the gods
were weeping at the sight of men be-
having so scandalously.
But, 1t Is pointed out, In the days of
| open warfare no general would be likely
| to start an offensive in wet weather,
when streams were high, maneuvers
dtf1ciilt and baggage and artillery ike
ly to get stuck In the mud. He would
wait for favorable weather conditions
which would meaa that the air already