Nikola Tesla (Nyarlathotep)

Many feel that the archtype of Nyarlathotep was Tesla. The fact that Lovecraft refers to him as a bit of a showman, and he either saw Tesla in person, or heard or read a firsthand report.

On Coast to Coast AM (21 Nov 2008) Ian Punnett interviewed a modern expert on Tesla. He's said to have worked with the Army Air Force to invent a death ray and other things:

During the middle two hours, Emmy-Award winning television producer and author Tim Swartz discussed the life, work, and 'lost journals' of inventor Nikola Tesla. Swartz said he first learned about Tesla while on assignment at Wright-Patterson Air Force Base in Ohio. A press liaison there told him the Air Force had been involved in research and development on various things from "that mad scientist, Tesla." Through FOIA docs Swartz discovered the U.S. government had been using notes confiscated from Tesla to build what the inventor referred to as a 'teleforce weapon' or death ray. Swartz spoke about Tesla's experiment in Colorado Springs, Colorado, where he reportedly received non-terrestrial radio transmissions. He theorized that Tesla may have been picking up EVPs (Electronic Voice Phenomena), some of which spoke verbally about global warming, Swartz noted. Swartz also touched on HAARP, which he said was based on Tesla's research into the wireless transmission of energy, as well as Tesla's concept of rotating electromagnetic fields, which he suggested may have resulted in the infamous Philadelphia Experiment and could one day lead to invisibility.

I'm constantly amazed at how "plugged-in" Lovecraft was just by reading the newspapers and corresponding with his eclectic friends. It's really unlikely that Lovecraft had any influence on this report, so that we have two independent trajectories of Tesla's eccentricity.

...that he had heard messages from places not on this planet. Into the lands of civilisation came Nyarlathotep, swarthy, slender, and sinister, always buying strange instruments of glass and metal and combining them into instruments yet stranger. He spoke much of the sciences of electricity and psychology and gave exhibitions of power which sent his spectators away speechless, yet which swelled his fame to exceeding magnitude.

... I remember when Nyarlathotep came to my city the great, the old, the terrible city of unnumbered crimes. My friend had told me of him, and of the impelling fascination and allurement of his revelations, and I burned with eagerness to explore his uttermost mysteries. My friend said they were horrible and impressive beyond my most fevered imaginings; and what was thrown on a screen in the darkened room prophesied things none but Nyarlathotep dared prophesy, and in the sputter of his sparks there was taken from men that which had never been taken before yet which showed only in the eyes. And I heard it hinted abroad that those who knew Nyarlathotep looked on sights which others saw not.