There was also: https://en.wikipedia.org/wiki/A_Pail_of_Air https://en.wikipedia.org/wiki/A_Pail_of_Air "they maintain a breathable atmosphere by periodically

There was also: https://en.wikipedia.org/wiki/A_Pail_of_Air https://en.wikipedia.org/wiki/A_Pail_of_Air "they maintain a breathable atmosphere by periodically retrieving pails of frozen oxygen to thaw over a fire"