Maybe I'm just not picturing this right but this whole idea seems pretty inefficient. You have to build a fire to heat your rocks. You need to build or dig the equivalent of a solar still, in mud no less <img src="images/graemlins/confused.gif" alt="" />. And then use the hot rocks to boil water from the mud? It seems labor intensive for the return. Why not just strain the water from the mud through a sock, handkerchief, whatever, and then boil it to purify (or use the PA tablets that we all have) Like I said, maybe I missed something

Ed