mrodoc
Well-known member
While reading a book on US cave exploration I came across a description of beach balls being used in narrow passages to modify or exclude draughts. Set me thinking that this technique might be used in caves to detect draughts by obstructing narrow sections. OR then suggested that airbags would be even better as they would expand to fit an irregularly shaped hole more snugly. The question is where could one obtain used airbags and has anybody seen a diagram of what the inflation point looks like. It would obviously need modification for pump or hose inflation? I have somewhere in a cave where the idea can be tested by the way.