When his name is mentioned most think of radio wars (fighting with Marconi over the patent for the invention of radio) or the earlier Current Wars where he played a major part in the uptake of AC instead of DC (and getting revenge on Edison who had apparently "diddled him" whilst Tesla was in his employ) but there a multitude of lesser known works, stuff of science fiction: his papers were declared to be of national importance, all his effects were seized on the advice of presidential advisers and none other than J. Edgar Hoover who declared the case most secret because of the nature of Tesla's inventions and patents. Directed-energy weapon/peace ray/ death ray, call it what you will. He tried to prevent WWII and saw the "preventative possibilities in his new invention which embodied "death ray" characteristics". A system he said he had tried to sell...
Wow. Much talk of lightening balls and particle ray beam etc. Ideas that didn't necessarily go away with various reports of foo fighters during that war, or through the 80's but continue to this day. I digress, suffice to say he was most definitly one of the world's greatest inventors and a pioneer in his (electrical) field.
...to Great Britain for $30,000,000 on the basis of his presentation that the device would provide complete protection for the British Isles against any enemy approaching by sea or air, and would provide an offensive weapon to which there was no defense."
The oscillation option? As mentioned above Tesla is clearly thought of as an electrical genius but he was also responsible for a number of mechanical and other devices. One such was the Tesla Oscillator - his "Earthquake Machine". Apparently he once joked that he could split the Earth with one of these devices, and no-one ever knew if he was joking...!![credit to EclipseG - your page wouldn't load]