In the latter part of the second revolution, Thomas Alva Edison developed many devices that greatly influenced life around the world and is often credited with the creation of the first industrial research laboratory. In 1882, Edison switched on the world's first large-scale electrical supply network that provided 110 volts direct current to fifty-nine customers in lower Manhattan. Also toward the end of the second industrial revolution, Nikola Tesla made many contributions in the field of electricity and magnetism in the late 19th and early 20th centuries.
How many customers were supplied by Thomas Edison's electrical supply network?
fifty-nine