Did you make sure that the outside of the cup wasn't wet? This often happens when filling a cup with water. Assuming it was dry, that sounds cool. And if, somehow, there ever was a fire in your house, you'd just have to chop into the wall and the fire would be extinguished.

Which makes me think: what if it's just a small fire and you don't need to empty the entire wall on it? The first idea that came to mind was that the wall could be divided up into sections, which would be wall-high but only a few feet long. Come to think of it, it would be best if the sections were only about a foot by a foot. And, if they were airtight, I don't see why you'd need to cycle in fresh water.

-eric "I'm all wet" sleator
Wed 13 Jun A.D. 2001