Twain_in_Tesla’s_Lab: Mark Twain (penname of Samuel Langhorne Clemens) in the lab of Nikola Tesla, spring of 1894. Taken in the spring of 1894, and originally published as part of an article by T.C. Martin called “Tesla’s Oscillator and Other Inventions” that appeared in the Century Magazine (April 1895). Picture is in the public domain.