OldEric says :-) I would be 12 or 13 when I got this brilliant idea for fishing, to catch the elusive trout in the larger becks and small rivers. I had read about the salmon poachers who used to make carbide bombs, throw them in the rivers and when they exploded the shock waves of the explosion stunned the fish, they came to the surface and all that had to be done was to lift the fish out of the water. Simple.
I found out all that I needed to do was get a screw top bottle, get a piece of carbide and put it in the bottle, light it, put some damp rag or cotton wool in the bottle and put the screw top on. The smouldering carbide mixing with water vapour causes a gas to develop and as the gas increases, the pressure in the bottle increases to the point where the bottle explodes and the dirty deed is done.
I had the bottle, I had the cotton wool, the trouble was the carbide. None of the ironmongers of the time who stocked carbide would sell it to me. They were more than conversant with the trick. In the old days before batteries carbide was easy to procure. The principle was used for lighting and the gas emissions were controlled by ventilation. Carbide burning gave off a very intense white light. Many people bought carbide before the advent of batteries. In my days as a boy only those who had nefarious activities in mind generally wanted carbide.
It was the same with fire works. During WW2 fireworks were prohibited and I decided to build my own, I had got some formulae and I tried all the chemists in Penrith with my list of ingredients. But they were on the ball too, some would smile and say no, others would just say "get out".