[masraum]

Originally Posted by stevej37

The old, old, type that my G'ma used for canning were dangerous because they didn't yet have the pressure relief valves that they do today.

I remember her saying that those were dangerous if not watched closely.
She never used it for anything other than canning.

No pressure relief valve? How did those work, heat them for a bit and then turn the heat off? Because I can't imagine manually relieving the pressure of a hot cooker.