Although X-rays were invented by Wilhelm Röntgen on Nov. 8, 1895, Nikola Tesla had also been experimenting with what he called “shadowgraphs.”
In the fall of 1894, Tesla became intrigued by damage to photographic plates during experiments to study radiant power on phosphorescent bodies. His early investigations were deterred, however, by a fire in his lab.
Even so, it’s likely that Tesla took the first X-ray photograph in the United States. While trying to photograph his friend Mark Twain, he captured only the metal screws of the camera lens.
When Röntgen unveiled his invention, Tesla realized he’d been working on something quite similar. He sent Röntgen his own “shadowgraph” images. Röntgen wrote back: “These pictures are very interesting. If only you would be so kind as to disclose the manner in which you obtained them.”