SEND HER DOWN HUGHIE

Cue (NZERS), Issue 17, 15 February 1945, Page 11

SEND HER DOWN HUGHIE

A DROUGHT faces the farmer. The spring rains have been insufficient. The summer sun and blustering nor’ westers have scorched the land. The farmer derives little sympathy from his town cousin. True, there are restrictions in the town on the. use of hoses, but it is excellent weather for tennis, bowls, and swimming. The farmer drives home through the : parched land, bemoaning the cruel fates 1 that conspire against him. He resolves to think about irrigation. Why, he asks, cannot the scientists produce rain when it is required? ' Well, why can’t they? Or can anyone produce rain at will? ♦ ♦ ♦ ' Droughts are a special curse of several districts in New Zealand. North Otago is • one of them. The - district possesses excellent mixed farm-landalmost anything thrives on its rich, limestone soil. But— -and it is a very big "but” to the North Otago —droughts are much too common and prolonged. , ' • In recent years, many a farmer in the district has , considered irrigationuntil the drought broke. Several have made good use of this artificial means *of bringing the necessary moisture to the parched land. Many again have tried in the past other ways of overcoming the drought by. trying to make it rain.. Many years ago, explosives were used in the district to induce the heavens to disgorge their valuable moisture — it Was j n vain. During one bad drought, special church services were held and Prayers for rain offered. But again the natural . cycle of ’ events had to take

place before rain came to break the drought. Nothing controlled the weather for the farmer. The seasons were either too dry, too wet, or wind, hail,'or frost destroyed the crops. Byrd’s expedition to the South Pole, the introduction of Summertime, and, more recently, the great battles of this war, have all come in for their share of blame. But Nature goes on in her own, sweet way. ' From time immemorial man has tried to produce rain at will. So far, he has had no more success than the early experimenters in; New Zealand. At first, he turned to magic to help him out Even to-day, age-old practices are if vogue. In Estonia, for example, there is a recognised recipe, which consists of imitating lightning, thunder and rain. For this comedy, three men climb a tree. One strikes fire-brands together to simulate lightning! a second beats a drum or strikes a metal pot to resemble thunder; and the third merely sprinkles water on the ground, no doubt in the nope that the skies will take heed of the hint. Somehow the skies remain adamant to auto-suggestion. This practice of sprinkling, splashing, or drenching as a charm for inducing rainfall is not confined to Estonia. Sumatra, Serbia, Macedonia, Russia and Africa know it, too. Usually, it consists of processions of women and girls around the village and at each house they are suitably sprinkled or, drenched with water. As droughts usually take place in summer, this practice may have its uses even if it does not produce ’rain. There are some people, however, who prefer their own. magic for making

rain—by mimicking aquatic birds or animals, such as ducks and frogs. Another favourite has always been the religious ceremony. Some make a sympathetic appeal, but others . try to annoy the spirits so that in their rage they will send down large quantities of the much-wanted rain. In many countries, appropriate talismans are hung for the rain god’s benefit. Praying for rain is common among people of varying religions.

It was thought by some that battles produced rain, either. through the carnage or the fire of canons. Wars have been started for many strange reasons — a pickled ear in a glass bottle, for one. But it is doubtful if even the most callous statesman would commence a war to break a mere.drought. The production of rain as a result of good men and true pouring out their sweat and’ blood on the battlefield does not seem likely. But the idea that the noise and concussion of cannon could bring about a much wanted downpour caught on in many places. In the United States of America there were many advocates for such a plan to control the rainfall. So clamorous were they that, in 1891,, Congress sanctioned the expenditure of 9,000 dollars for rain making experiments. The touching off of large quantities of dynamite and th# creation of much expensive noise were productive of any results. Drought is a constant worry for the Australian farmer, and, consequently, the Commonwealth has not been without

its experiments in rain-making.a "scientific” way of bringing rain was to .cave those uneasy bed-mates, zinc ant sulphuric acid, in large containers out-?f-doors. The resultant hydrogen wa, expected to waft upwards, disturb th? clouds, cause precipitation, and bring rain to the stricken land below. This was tried without success in 1903. Another means put forward has been the spraying ot the sky with dust, on whic i convenient base the water vapour might condense. Sprinkling the clouds with electrified sand, spraying the atmosphere from an aeroplane with a mixture of salt and fine sand, and a vast project to cool the free air have been other suggestions for the professional rain-maker. But what a task confronts man when; he attempts to control the atmosphere and produce rain at will! He has to compete with the mighty forces of Nature and cope with billions of tons of air. ' ■ Rain is produced in’ three main ways —the thunderstorm type, the orographic and the cyclonic. . In the orographic type, an air stream is deflected upwards over a large region on account of barriers of hills and mountains, the ascension leading to,rain under favourable temperature and moisture conditions. New Zealanders are used to hearing about cyclones, anti-cyclones, and depressions in the Tasman Sea, for they form the basis of weather reports, and forecasts. In the field of a depression or a cyclone, there is a convergence of two different kinds of air-streams. As a result there is a gradual, sloping ascent of moist or warm air over cold and dry air. In India, in a monsoon depression travelling over; the country, moist air from monsoon sources ascends over the less moist, original land air and gives copious, widespread and steady precipitation. In all three types of ram there is a large scale ascent of air. ' Going into figures, one can see plain y the futility of man’s experiments m producing rain. The man who tries 0 make rain by cooling, the atmosphere is set a tremendous problem. If h e ea . with a column of air one mile high an one mile square with a temperature 0 , say, 25 degrees Centigrade an

humidity of 90 per cent, he would have to lower its temperature to 23.2 degrees merely to saturate it. To separate the moisture as rain, the temperature would have to be' dropped still lower, —say to 21 degrees. This could release the water, causing a rainfall of approximately oneseventh of an inch over the square mile. The quantity of water so precipitated would be 333,000 cubic feet. To cool one cubic mile of air by four degrees Centigrade, 1,000,000 lb. of liquid oxygen would be required. . But apart altogether from the colossal task revealed by the above figures, the method is wrong in principle

In actual fact, Nature, in order to produce an inch, of rainfall over a square

mile, raises several millions of tons of air through a height of a mile or more. Every day, 16,000,000 tons of water vapour are evaporated per second. This is equivalent to one-tenth of the waterlayer over the whole surface of the earth each day. A thunderstorm which would produce rain over about 10 miles square, deals with 232,320,060 cubic feet of water and in its production entails energy of more than 36,000,000. horse-power for a week for the evaporation or condensation of the quantity of water involved.

It can be seen what a problem confronts man when he toys with a scheme to control the weather and produce rain as required.