This particular death ray may not have worked but check out this page- SOLAR DEATH RAY. Pretty cool.
SAN FRANCISCO – It wasn’t exactly the ancient siege of Syracuse, but rather a curious quest for scientific validation. According to sparse historical writings, the Greek mathematician Archimedes torched a fleet of invading Roman ships by reflecting the sun’s powerful rays with a mirrored device made of glass or bronze.
More than 2,000 years later, researchers from the Massachusetts Institute of Technology and the University of Arizona set out to recreate Archimedes’ fabled death ray Saturday in an experiment sponsored by the Discovery Channel program “MythBusters.” Their attempts to set fire to an 80-year-old fishing boat using their own versions of the device, however, failed to either prove or dispel the myth of the solar death ray Tests of Fabled Archimedes Death Ray Fail – Yahoo! News