> I've seen this done at a smaller scale (biscuit tin size) in stinks
> lessons at skool, quite impressive. Another good one is to take a
> treacle tin and make a penny-sized hole in the base then put a largeish
> pinhole in the lid. Stand the lidded tin on a lab tripod and fill it
> through the lower hole with gas from e.g. a Bunsen burner. Remove the
> Bunsen and light the small escape of lighter-than-air gas at the pinhole
> in the lid.
> .
> wait.
> .
> wait a bit longer.
> .
> The gas burnt at the top will be replaced with air drawn into the hole
> in the bottom until eventually an explosive mixture is formed. At this
> point the tin goes *SPANG!* and blows the lid through the suspended
> ceiling tile above. Good fun, nearly as much fun as putting nitrogen
> tri-iodide on the chalkboard and the stinks-beak's lab-stool.
>