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Stan’s Stuff

If the power fails –two beauties to help us through The Thermette and the Coolgardie Safe

How do you get your hands on these items? A Thermette is probably, possibly, at the back of your grandpa and/or grandma’s  shed. Go fossick. The Coolgardie Safe – you can knock one up in an hour or so. No special skills are required
 |  Stan Stewart  | 

There are some readers who lived in rural areas who will remember life before electricity.  I can still remember the excitement we had when with the flick of a switch, a 60watt electric bulb lit up our kitchen.

These days a hundred miracles later, I can’t think of anything that rivals that excitement. We have become blasé – nothing surprises us – we expect things to become easier, more spectacular, more transformative – yawn!

But what if the power failed? The electric suppliers are hinting that could be a possibility this winter. What then? Don’t panic.  Getting back to basics may not be such a bad thing.

It’s only in the last year that I heard about this wonderful Kiwi invention. And my guess is that most Kiwis will have never heard of the Aussie invention – the Coolgardie Safe.

Just suppose the power did go off for a long period. Well, these two inventions could help us survive and cope.

The Thermette: John Ashley Hart, invented and patented the thermette in 1929. Although he was an electrical engineer, he invented something which had no need of electrical power – all that was needed were a few twigs. It was first advertised as a ‘billy and fireplace all in one’ and marketed as a ‘Wonderful Xmas Present for Dad’.

As far as I can tell, this invention never crossed the ditch as it seems quite unknown in Australia. My guess is there were copyright problems. Perhaps Australia’s ever present bushfire danger meant that the ashes produced by the thermette could have been seen as a bush fire hazard.

The thermette looks like a super-sized vacuum flask. You didn’t sit the Thermette on a fire or fireplace. The fire was inside the flask. Set with bark, twigs, anything flammable at the base. inside the base, the fire flared up the interior of the thermette, often visible as flames coming out of the top of the device. The water (12 cups) was contained in a sleeve inside the flask in direct contact with the flames.

Thermette users extoll two great features of this flask. 1. You don’t need much fuel to fire it up. Twigs, bark, leaves will do it. Once lit and placed in the base, it’s away. 2. The water boils in minutes. No waiting forever as the billy swings forever over the fire.

During the second World War, John Hart waived the copyright so the thermette could be used by NZ troops in desert warfare. There it gained the name Benghazi Boiler. The thermette created confusion with the German high command. Not actually the thermette itself, but the marks it left on the ground. Inspecting trenches that had been vacated by kiwis, the Germans were puzzled by the round burnt patches in the kiwis’ trenches. It was speculated that the New Zealanders were working with some new kind of rocket.

The Coolgardie Safe: The blistering heat of the Coolgardie gold fields in Western Australia caused food items to spoil in hours. To cope with the effects of this climate around 1890, Arthur McCormick invented the Coolgardie Safe. McCormack observed how when a bottle was wrapped in a wet cloth, the contents of the bottle cooled. He was observing  the principle of heat transfer during the process of evaporation.

Based on this principle, he developed a safe with mesh walls which was draped with wet cloth. As the cloth dried, the items within the safe were cooled – not frozen, but chilled. Butter remained firm and meat would not spoil so quickly. The idea was taken up commercially and versions of the Coolgardie Safe were manufactured and sold all over Australia.

My Dad made his own. The design was simple. It was a box shape about 700mm square with no walls. Inside there were shelves and it had a door on the front. The box including the door, was covered with chicken wire. On top of the box, he placed a large baking tray. He filled this with water. He cut up wheat bags and draped them over the four sides of the structure with their tops in the baking tray which was full of water.

The bags sucked up the water and as a result the interior of the safe was cooled by evaporation. My job was to keep topping up the water tray. Don’t panic! If they do turn off the power, we can still survive.