Fun with chemistry (5)

Explosions in the back garden has reminded me of experiments with sodium chlorate and sugar. In the nineteen-sixties sodium chlorate weedkiller was easy to obtain over the counter in Woolies - even ten-year-olds could buy it. After some experimentation I managed to prepare a small amount of an explosive mixture and constructed a small cannon from a glass vial (capacity a couple of tablespoons) with a push-on plastic lid. I put a small amount of the mixture in the tube and fashioned a fuse by packing a small piece of glass tubing (from my chemistry set) with the same mixture. I then made a hole in the plastic lid to accommodate the fuse and buried the whole lot in the garden so only the plastic cap and fuse were visible. I lit the fuse and retired a short distance. In due course there was a small explosion and the cap was blown off the vial and landed a couple of yards away. The vial was, amazingly, undamaged. Encouraged by this minor success I refilled the fuse and put somewhat more mixture in the vial. This time the effect was spectacular. The explosion blew quite a large amount of earth a couple of feet into the air, as if a small shell had landed, the glass vial was reduced to powder, and the plastic lid was nowhere to be seen. I was hunting around for materials to make a bigger and better bomb when there was a call from the house. Inside were mum, and dad, and the chap who lived in the house at the bottom of the garden - a couple of hundred yards away. He was spitting rivets. He had been asleep in a deckchair and my explosion had woken him. To add insult to injury my plastic lid had then landed on the lawn a couple of feet from him. After he left my parents wet themselves laughing (they were not very fond of this neighbour). Similar experiments were, however, forbidden.