This is the last known photograph of Nikola Tesla. On 7 January 1943, the man who helped bring electricity into every home in the world died alone in a small hotel room in New York, with almost nothing to his name. In the 1880s, Tesla’s inventions for alternating current, above all his AC motor, were licensed by Westinghouse, made him rich and famous, and helped make possible the kind of electrical system that still powers the world today. But a few years later, when Westinghouse ran into financial trouble, Tesla agreed to give up the royalty deal that might have made him a fortune, and he poured much of what he had left into his next idea, and his next idea was enormous... He wanted to send messages, and even electricity itself, through the earth without wires. In 1901 he persuaded the most powerful banker in America, J.P. Morgan, to give him $150,000 to build a giant tower at Wardenclyffe, on Long Island. Morgan thought he was paying for wireless communication but Tesla’s real plan was to prove he could transmit power. When he asked for more money to make the tower bigger, Morgan refused. The project collapsed, and in 1917 the tower was blown up and sold for scrap to pay Tesla’s debts. Ever since, one line has followed the story, supposedly Morgan’s reason for walking away: “If anyone can draw on the power, where do we put the meter?” Tesla never recovered... he moved from one New York hotel to another, leaving unpaid bills behind him, and spent his last days in parks feeding pigeons, even nursing injured ones back to health in his room. His life ended in solitude: a maid at the Hotel New Yorker found him dead in Room 3327. He was 86. Within days, the federal government ordered his belongings and papers to be seized, even though he was an American citizen, and an engineer was brought in to examine them. Whatever else Tesla left behind, the world has been arguing about it ever since...