I should have gotton that.
When I was a kid we would take a tin can with a lid that pressed on, a coffee can would work. A hole would be punched in the can with a nail, I think near the bottom. Then a small piece of carbide would be dropped in the can and someone would spit on it.
You could see it bubble and sizzle. The cover would quickly be jammed on. After about a minute one kid would crawl up to the can and strike a wooden match and stick the flame by the touch hole. A loud PFFUUMMP sound would occur and the cover would fly in the air. This was our version of a carbide canon.
Shortly after that black powder was invented and firecrackers came on the scene, ending our carbide canon activities.
No one was hurt or killed in the performance of this boyhood fun. However, I do have to ask people nowdays to speak into my good ear.