After thoroughly enjoying the museum, we decided to take a side trip to Commonwealth Displays, a store that sells fireworks and cool model rocket stuff. After buying 300 feet of 200 lb tensile strength braided Kevlar line and other rocket building supplies, I notice a "Big Bang Cannon" along with metal tubes of "Bangsite" Bangsite is a trade name for calcium carbide. Calcium carbide reacts with water to make acetylene gas and lime. Acetylene burns with a bright hot flame and is now mainly used for welding. Calcium carbide once was regularly used in miner's lamps. A small water tank dripped water on the carbide. The acetylene generated was directed through a pinhole sized nozzle and burned for illumination. Lamps were also used for auto and bicycle headlamps and even home lighting.
In a Big Bang Cannon a small amount of Bangsite was dropped into water in a chamber at the end of the barrel. The acetylene formed was ignited by a push rod that rubbed against a lighter flint inside the gun barrel whereupon a satisfying "Bang!" was produced, sometimes with fire and smoke.
Anyway the two dozen tubes of bangsite had been sitting on their shelf for twenty years. "Was I willing to buy it, cheap?"
I now own two dozen tubes of Bangsite. My inner child is very pleased.