In the late 1890s, Tesla's work moved in several directions at once. He helped bring the power of Niagara Falls to a distant city, demonstrated the first remote-controlled vessel, and developed ideas for wireless communication that would later fuel a long dispute over who invented radio.

Niagara Falls

For years, engineers had dreamed of harnessing Niagara Falls, one of the greatest sources of water power in North America. An international commission considered many proposals, including compressed air and DC. The decision went to AC. In 1893 Westinghouse won the contract to build generators for the new Adams Power Plant, using Tesla's polyphase system. On 16 November 1896, power began flowing over lines to the city of Buffalo, about twenty-six miles away. It was one of the first large-scale demonstrations that AC could transmit useful power over long distances, and it helped settle the war of the currents. Tesla's name was on the patents, and he was celebrated at a banquet in Buffalo. Many engineers contributed to the project, but it fulfilled the vision he had sketched in Budapest.

The remote-controlled boat

In 1898, at an electrical exhibition at Madison Square Garden, Tesla demonstrated a small boat that he steered and controlled from across the room, using radio signals. Audiences were baffled; some thought he was using mind control or hiding a trained monkey inside. Tesla patented the system, which he called a “teleautomaton,” the same year. He imagined fleets of such machines doing dangerous work and even fighting wars, so that, he hoped, war might become a contest of machines rather than men. The demonstration is now seen as a pioneering step toward remote control, robotics and drones.

The radio question

Who invented radio? The question has no single answer, and Tesla is part of the story. In the 1890s, many people worked on sending signals by electromagnetic waves, building on the theory of James Clerk Maxwell and the experiments of Heinrich Hertz. Tesla developed tuned circuits for transmitting and receiving and filed important patents in 1897, granted in 1900. Others, including Oliver Lodge in Britain and Jagadish Chandra Bose in India, made key contributions.

The Italian inventor Guglielmo Marconi built the most practical commercial system. On 12 December 1901, Marconi reported receiving a wireless signal, the letter S in Morse code, sent across the Atlantic from Cornwall to Newfoundland. He became famous and shared the Nobel Prize in Physics in 1909. In 1904 the US Patent Office, which had earlier rejected some of Marconi's claims, reversed course and granted him a patent for radio. Tesla was bitter, believing Marconi had used his patents.

In 1943, months after Tesla's death, the US Supreme Court ruled in a long-running patent case between the Marconi company and the US government. It invalidated key claims of Marconi's patent, finding that earlier work, including Tesla's, Lodge's and that of an American named John Stone Stone, had anticipated them. The ruling is often described as declaring Tesla the inventor of radio. That goes too far. The court decided a patent dispute; it did not name a single inventor. Radio, like many technologies, had several inventors, and Tesla was an important one.

Sixty cycles

One quiet legacy of this period still shapes daily life in North America. AC systems can run at different frequencies, the number of times the current reverses each second. Early systems used many different frequencies. Westinghouse eventually standardized on 60 cycles per second, and Tesla is often credited with favoring that choice because it suited his motors. Today the electric grid in the United States and Canada runs at 60 hertz, while much of the rest of the world uses 50. The hum of an old transformer is, in a sense, an echo of decisions made in the 1890s.

Debt and ambition

By the late 1890s Tesla's expenses were enormous, and his income from the Westinghouse sale was dwindling. He sought investors among the wealthy, including John Jacob Astor, who funded some of his work. His ambitions were growing too. He was no longer satisfied with motors and lamps. He wanted to send messages, and then power itself, through the Earth without wires.

Worked example: credit in invention

The radio dispute shows why credit for inventions is complicated. Consider the different kinds of contribution.

• Theory. Maxwell predicted electromagnetic waves mathematically in the 1860s.
• Proof. Hertz produced and detected them in the laboratory in the late 1880s.
• Key components. Tesla, Lodge and others developed tuning and detection methods.
• A working system. Marconi combined components into a practical system and built a business that sent messages across oceans.
• Legal ownership. Patent offices and courts decided who owned which claims, sometimes reversing themselves.

Each kind of contribution matters, and the public often remembers only one name. The Tesla legend sometimes swings too far the other way, crediting him with everything and treating Marconi as a thief. A fairer view recognizes that major inventions are usually built by many hands, that Tesla's contribution was real and important, and that Marconi's achievement in making radio work commercially was real too.