http://www.nuc.berkeley.edu/dept/Courses/E-24/E-24Projects/Krumme1.pdfThe friendship of the two men is well-documented, albeit slightly unusual. Tesla was a tall, slender man with peculiar habits, an oft-forgotten engineer and inventor; Twain, a man with a booming literary voice, was one of the best-known and best-loved of American authors. Yet despite these differences, the two forged a strong and enduring friendship, meeting often at The Player’s Club in Manhattan or in Tesla’s laboratory. It was there that the friends exchanged stories, laughs, and an occasional show of the ‘lightning’ so esteemed by Mr. Twain. . . .
When Tesla arrived in New York one June day in 1884, his mind was focused on matters apart from those of the literary ilk. He went to work for Thomas Edison, and it was not until 1888, more than four years later, that the stories of Tesla and Twain once again intersected. Twain first became aware of Tesla’s brilliance in November of that year, when he remarked upon the inventor’s newly publicized AC polyphase system. The author was awestruck by the sheer genius of the machine, and wrote in his Notebook: “I have just seen the drawings & description of an electrical machine lately patented by a Mr. Tesla, & sold to the Westinghouse Company, which will revolutionize the whole electric business of the world. It is the most valuable patent since the telephone.” . . .
Yet another excitement awaited Tesla’s visitors at the laboratory. Tesla had been perfecting a mechanical oscillator, a sort of engine that would produce alternating current of a high frequency. The inventor had noticed an interesting effect of the machine: it produced significant vibrations. Tesla wondered if these vibrations might have therapeutic or health benefits, and one day when Mark Twain was at his lab the author asked if he might experience these vibrations himself.
As the story goes, Mr. Twain stood on a platform of the machine while Tesla set the oscillator into operation. Twain was enjoying himself greatly and exclaimed: “This gives you vigour and vitality.” After some time Tesla warned the writer that he should come down, but Twain was having fun and he refused. Tesla again insisted, but Twain stayed on the machine for several minutes more until, suddenly, he exclaimed: “Quick, Tesla. Where is it?” Tesla directed his friend to the restroom. Twain had experienced first hand what had been known to the laboratory workers for some time: the laxative effect of the machine’s vibrations.