In 1881 a light bulb cost a dollar — about $23 in today’s money, which for some workers was a day’s pay. Compared with the tungsten-filament bulb invented in 1907, Thomas Edison’s carbon-filament bulb used four times more power, which also was not cheap.

How much did a light bulb cost in 1879? It had cost $40,000 (about $850,000 in today’s money) and taken 1,200 experiments, but was ready at last for a public debut. On New Year’s Eve, 3,000 people visited the lab in Menlo Park to witness 40 electric light bulbs glowing merrily.

One hour of light (referred to as the quantity of light shed by a 100 watt bulb in one hour) cost 3200 times as much in 1800 in England than it does today, amounting to 130 euros back then (or a little more than 150 dollars). In 1900, it still cost 4 euros (close to 5 dollars).

Tesla didn’t invent the light bulb but when Westinghouse won the bid to illuminate the 1893 Chicago World’s Fair they couldn’t use Edison’s patented design so Tesla made a new bulb base with a pair of nipples on it that you twisted into place rather than Edison’s screw design.

Edison, the iconic inventor of the light bulb, the phonograph and the moving picture and Tesla, whose inventions have enabled modern-day power and mass communication systems, waged a ‘War of Currents’ in the 1880s over whose electrical system would power the world.

Nikola Tesla wanted to create the way to supply power without stringing wires. He almost accomplished his goal when his experiment led him to creation of the Tesla coil. It was the first system that could wirelessly transmit electricity.

Genius inventors and industrialists – with Thomas Edison on one side, facing George Westinghouse and Nikola Tesla on the other – battled to lead the technological revolution that has powered humankind ever since. The success at the fair, essentially, declared the winner.

Edison is revered as a great inventor and businessman, while Tesla has, in many cases, been compared to more of the mad scientist type.

Tesla died a broke humanitarian. “Tesla did what he did for the betterment of humanity, to help people have a better quality of life,” said Alcorn. “He never seemed to be interested in monetary gain, although a possible downside of that was he never seemed to have enough money to do what he needed to do.”

Born during a lightning storm in 1856, Nikola Tesla went on to invent the Tesla coil and alternating current machinery. His estimated IQ scores range from 160 to 310 by different measures.