123 years ago today, Nikola Tesla gave the first public demonstration of transmission by radio waves - wireless power transfer. In the news of the day, the lecture hall was described as "thronged" and "literally packed" with over 5000 attendees. It's easy to see why. He was a showman: "His last experiment was to make the current pass in waves of light across the bench and then through his body, illuminating two glass tubes he held in his hands." The text of the associated lecture is available online.