get your chimney swept!

[Skean Dhude]

A few years ago I read a SF book. They introduced some changes to become more self sufficient, basically re-introduced an old process. After a few months people became ill. They didn't think about the process because it was introduced too long ago and used chemicals already in use. The answer was the chemicals used in the process added toxins to the air and the new process exceeded at threshold. It was eventually solved by a historian reading an old book about the chemicals and recognised the symptoms. Everyone had forgotten about the side effects because their society had removed these chemical as much as possible hundreds of years ago.

Not everything can be considered common sense. Some things are taught by experience. If you have never had a real fire how would you know soot builds up? That is a learnt experience. It may be common sense to us but to others it isn't.