I remember seeing a few years ago the mythbusters. Funny, but many times lame. In this particular episode, they tried to reconstruct the parabolic mirror of Archimedes. The first mistake they did, is that this is not a myth, but history. The other mistake is that they failed to make it and "busted" the "myth". Eric Jacqmain, from Indiana, US, managed to re-construct a smaller version of this "weapon". He glued 5800 small mirror pieces on a parabolic surface, and with this simple construction he managed to burn wood, melt iron, vaporize aluminum and melt stone and concrete. Imagine what this thing could do on a tar-covered wooden ship with the powerful sun of Greece.