image: Wellcome Collection

The first International Exposition of Electricity, which took place in Paris from August to November 1881, highlighted the way the energy was rapidly expanding, such as with an electric-powered tramway and boat, a telephone, and a player piano. What amazed attendees even more were the nearly 2,500 electrical light bulbs, especially those of Thomas Edison and Hiram Maxim, the latter better known as the modern machine gun's inventor. The exhibition also pioneered the definitions of the standard electrical units volt, ohm, and ampere, all unanimously adopted at the 1893 World's Columbian Exposition.