Day Two

Leaving the right kind of limestone in the stove (charged with charcoal) overnight seems to do the trick. It’s not converted completely to lime, but there’s enough lime been formed to produce an effective carbon dioxide filter. Lime's not very soluble in water; thank goodness. Now all I have to do is to build a rig that’ll show the viewer my carbon dioxide filter in action. My woodwork skills aren’t quite up to Jonathan’s standards, but at the end of three or four hours I’ve knocked together something that will work – using pop bottles and bits of PVC tubing – very Blue Peter. Most of the afternoon is spent ensuring that the system is airtight. Kathy had some time on her hands, so she kindly volunteered to help me. It’s amazing how long epoxy resin takes to harden when it’s watched!