"Personnel at the Fourth Naval District believe that the questions surrounding the so-called "Philadelphia Experiment" arise from quite routine research which occurred during World War II at the Philadelphia Naval Shipyard. Until recently, it was believed that the foundation for the apocryphal stories arose from degaussing experiments which have the effect of making a ship undetectable or "invisible" to magnetic mines. Another likely genesis of the bizarre stories about levitation, teleportation and effects on human crew members might be attributed to experiments with the generating plant of a destroyer, the USS Timmerman. In the 1950's this ship was part of an experiment to test the effects of a small, high-frequency generator providing l,000 hz instead of the standard 400hz. The higher frequency generator produced corona discharges, and other well known phenomena associated with high frequency generators. None of the crew suffered effects from the experiment."