Waging War on the Weather

Sun (Auckland), Volume IV, Issue 986, 31 May 1930, Page 20

Waging War on the Weather

rato hi OR the first time in hisI tory man has succeeded iU making rain - The feat I IruKiM kas keen accomplished 1 in the last few months at a naval aircraft station. Curiously enough, the object sought in the experiments was quite different, namely, the removal of fog. The rain-making was incidental. Fog is the greatest eifemy of aviators. If it were practicable to sweep a landing field clear of fog and to keep it clear as long as the fog lasted, many lives would be saved. That is exactly what the experimenters are trying to find means for doing. Science has already been successful in some degree, and there is little question that the problem will

be satisfactorily solved very soon. A fog is a cloud resting upon the surface of the earth; it may be 300 ft. or 2,500 ft. high. A cloud is fog floating in the sky. In both cases the cloud consists of droplets of moisture condensed upon particles of dust suspended in the atmosphere. To clear a landing field of fog, electricity is used to drive the particles of moisture together, so that, forming sizable drops, they will fall to the ground by gravity. By this means the fog is washed out of the air. The apparatus employed consists of water tanks, an airplane engine fitted with a propeller and a 75,000-volt transformer, the whole affair being mounted on a truck. Connected to the tanks and mounted in front of the propeller is a steel ring perforated with small holes. The water, charged in the tanks to a high voltage is blown by the propeller outward through the holes in the ring, which acts as an atomiser, and is dispersed in the form of a fine mist. The mist is so fine that it evaporates almost instantly, leaving an electrical charge in the foggy atmosphere. The electrical charge causes the fog droplets to run together, forming big drops that fall to the earth. Thus, locally, the fog is swept out k and removed. Up to now, the experimenters have not succeeded in clearing an area the size of a landing field by this means, but they are sure that, with improved apparatus, they soon can. On a number of occasions, even when there was no fog but when the air was humid, scientists have, by the means described, caused rain to’fal’; in itself a most remarkable and wholly unprecedented achievement. It is their belief that when the method and apparatus have been perfected it will be practicable, under suitable conditions, to produce rainfall over a large area. Man will never be able to control the elements, but he is getting remarkable results in fighting them. A small yet important instance is that of protecting airplanes against ice. At high altitudes moisture sometimes freezes on the wings ot a plane, forming a.coat of ice so thick and heavy as to deform the wings, thus disabling the machine. But this trouble is now being

avoided by extending electric heaters through the wings. When it comes to showers of ice from the sky, the problem of defence cannot be said to have found any satisfactory solution yet. Such showers, unfortunately frequent and often disastrous in their effects, are called hail; and since very early times men have been trying to fight them. The methods of defence adopted have been, and still are, quaint and curious. In the Middle Ages church bells were rung and prayers were said to ward off hail. Later on, discharges of artillery were directed against threatening clouds in the summer time, which is the hail seagon. A century or more ago tall poles tipped with iron spikes were numerously erected on housetops, in vineyards and elsewhere for the same purpose, th idea being seemingly derived from the lightning rod. In Europe there were more than a million of these : “paragreles”—hail-preventers—as tbev i were called. | The newest device in use in Europe I is the “hail cannon,” a mortar fitted i with a huge funnel of sheet iron | pointed skyward. It is fired with i blank cartridges, which throw aloft i whirling rings of smoke and gas with ■' a whistling sound. These are sup* ; posed in some way to interfere with the formation of hail. I Another idea is to send up a num her of captive balloons bearing iron points to draw electricity from the clouds. Copper wires woven into the retaining cables are expected to conduct the electricity to the earth, and the clouds, thus deprived of their dangerous charge, cannot deliver hail, j In the vine-growing regions of i Southern Europe hail is frightfully de- | structive. | Where lightning is concerned, man j kas established a fairly effective de- | fence. It will be noticed that few light- | ning rods are to be seen in cities and i toy ns nowadays. That is because tin I roofs and metal drainpipes afford a | much better protection. They will ; carry off a great amount of electricity, 1 being even more efficient when wet ; j with rain, whereas a rod, though it | caD seize and conduct into the ground ] a thunderbolt of moderate size, may

not be a„.. to handle a very big one. In such a case the lightning may jump off and do damage.

Thanks to tin roofs and drainpipes the average urban resident’s chance of being struck by lightning is only one-fifth as great as that of the average person in a rural district. To provide rods for any house in a diy block is no longer deemed worthwhileNevertheless thousands of person? are killed by lightning each year, while destruction of property by lighrning bolts amounts to thousands pounds.

Can man figlit the hurricane? Abool r utely not. What can his puny effort? avail against so monstrous an elemental force, a mass of air, perhaps 10 miles in diameter and whirling on its axis at. a rate of 100 miles an hour? But he has found means o defence. Strong buildings wifi sue- ; eessfullv resist hurricanes and, i*»" : much as most of the damage it doe? is by throwing the sea up over the land, safety is best sought by taking ; refuge on high ground. Warnings ol The approach of such a storm are usually issued days in advance. Weather control indoors has bee- 1 carried so far that nowadays mai. T j office buildings, theatres and even lac- | tories are artificially cooled in summer By the aid of ingenious mechanical ap i paratus they are supplied with that has been cleansed of dust and dirt i by passing through filters and cooled by fans blowing through a curtain ot water spray. , When frost threatens fruit orchards there are now effective meins where- : with to fight it. The latest development is a machine which blows heated I air over the trees from a huge shaped pipe, elevated high above tM ground. The pipe slowly rotate: i o pierated by a gasoline engine, ab' the air, taken in at the ground levelis warmed by an oil heater. To produce rain by artificial me* l - 5 has been a human ambition since historic times. Among many sav **' tribes, the principal business of primitive priest, or witch doctor, is make rain. When rain is wanted it * his job to fetch it by magics’. supposed to be a secret of his profersion. Within the last few years there j have been interesting experiments i tain-making, the object being sou* 11 ; ; in one case by scatetring electrines i sand from airplanes. The belief that cannonading cause* rain and may therefore be employ as a cure for drought is an examP ol a modern idea founded on an a ; cient superstition. Ancients deliev that malevolent beings inhahkeo storm clouds and could be ‘ ,: rn * , by a hostile demonstration on 1 ; part of mankind. The belief that gu fire will bring rain is one of the wo* common popular fallacies. During v et summer of 1910. in England, t» i farmers of the southern counties a s * ■ the Admiralty to postpone target prs t-ce until they got their crops # vc sted, which were lieing ruined heavy rains. The rains in and France during the World * '-ere popularly ascribed to However, statistics prove that : -ainfall during those particular y J was no heavier than in times of P**