Poor Cloud for Rain Test At Halcombe

Chronicle (Levin), 2 April 1948, Page 4

Poor Cloud for Rain Test At Halcombe

A dry ice esperiment vliieh at least iroves tlnit tlie m:uiuf;ietu ro of artificiaJ ain is possil)le, even tliougli no grcuit [uantity was prodiu'ed, was condiK'te'l 'esterday nioi'ning over the Halcombe ii-ea by Atr. ILarold Anderson, of Halombe, and Mr. Paul Legg, of Feilding, lotli pilots of Middle Ilistricts Aero dub. -Tt was originaliy intended to weate rain over Mr. Anderson 's farni hist of the Mahino ltoatl, Imt when it ,vas diseovered that thero was no suitible cloud over that area the hundred ind seventy-odd pounds of ice were unloaded from a height of about ,'5500 t'eet above Halcombe. .Rain was produeed but not in a quantity that would do a great dcal of good to the land. The two men left Milson aerodrome in a Tiger Aloth at 9.20 vesterdav morxiing and .diseovered a cloud about 1000 feet alxoyo tho- Halcombe area. They feet aud while the pl'ane eircied Mr. Anden.ou unloaded a small quantity of eah'ium ehloride or purilied lime. As this is a very hygroseopic substance the moisture eondensed on to it and the eloud becaine den.^er, thus reducing the amount of ice that would have to be used. Next Mr. Anderson tipped out a sugar sack and a box full of broken. up dry ice, and the plaue flew above the cloud. From liere a circular rainbow, eontaining a mirage of the plaue in the centre, was seen. It tfaced exactly the course they had followed when unloading the ice and was paralleF to tho ground. From below the cloud the two men diseovered that streaks of rain had been produce d but only down 400 feet to a height of about 1800 feet aml no further. The cloud was denser and darker on the bottom. Although eonditious were against the experiment it certainly proved that artiticial rain can be. produced. If the drought eontinues more fliglits for the sarne purpose will probably "be earried out. The cost of the dry ice and the fiight is x\egligible to the saving that cah be made for the farnxeb Alr. Legg toki "The Times ' ' yesterday that this is probably tlxe lirst'-time. calcium ehloride lias been used in New Zealand. He and Mr. Anderson diseovered that tlxeoretically it should make the cloud denser but they did nor know, lxowr it would wox-k out ixx praetice. It has the effeet of supersaturating the eloud and redueingJdxQ. kad pf dry ice that lxas to be earried in the plane. Hoon after the failxire of this effort word was recexved that »a plaxxe froxxx Rongotai would come up to undertako a further experiment Tmt while certain of the. cloud formation suggested possibilities to those on the ground' observing no rain i'ell. A fresh' north-easteriy wlnd c.aused a broken cloud fornxatipu to move rather rapidly from the ranges which wete smothcred in. dense clouds attggestiv.e of rainfall in the high country.