The polycarbonate gives a good greenhouse effect, but glass may be better. Maybe an emptied glass wine jug with its bottom cracked off would work. Harold and Richard gave the technique - though scoring the glass with a glasscutter beforehand and polishing edges with a flame afterwards might enhance the technique.
- CS>Distilled water Medwith, Robert
- CS>Distilled water Matthew McCann
- CS>Distilled water Matthew McCann