For many years, Tesla tried to perfect a device that could project your thoughts onto the wall, an invention he called the "thought camera." As he explained in a newspaper interview late in his life, "In 1893, while engaged in certain investigations, I became convinced that a definite image formed in thought, must ... produce a corresponding image on the retina, which might be read by a suitable apparatus."108 His diagram of this device was like a movie projector, with the operator staring into the machine that projected his thoughts on the wall. Being able to project your thoughts like a movie, you have to admit, would be both incredibly cool, and incredibly disturbing.