X-ray experimentation

Starting in 1894, Tesla began investigating what he referred to as radiant energy of "invisible" kinds after he had noticed damaged film in his laboratory in previous experiments (later identified as "Roentgen rays" or "X-Rays"). His early experiments were with Crookes tubes, a cold cathode electrical discharge tube. Soon after, much of Tesla's early research—hundreds of invention models, plans, notes, laboratory data, tools, photographs, valued at $50,000—was lost in the 5th Avenue laboratory fire of March 1895. Tesla is quoted by The New York Times as saying, "I am in too much grief to talk. What can I say?" Tesla may have inadvertently captured an X-ray image (predating Wilhelm Röntgen's December 1895 announcement of the discovery of x-rays by a few weeks) when he tried to photograph Mark Twain illuminated by a Geissler tube, an earlier type of gas discharge tube. The only thing captured in the image was the metal locking screw on the camera lens.:134

In March 1896, after hearing of Wilhelm Röntgen's discovery of X-ray and X-ray imaging (radiography), Tesla proceeded to do his own experiments in X-ray imaging, developing a high energy single terminal vacuum tubeof his own design that had no target electrode and that worked from the output of the Tesla Coil (the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation). In his research, Tesla devised several experimental setups to produce X-rays. Tesla held that, with his circuits, the "instrument will ... enable one to generate Roentgen rays of much greater power than obtainable with ordinary apparatus."