Thomas Alva Edison

"Genius is 1% inspiration and 99% perspiration. Accordingly a genius is often merely a talented person who has done all of his or her homework." (Edison)

Thomas Alva Edison was born on February 11, 1847, in Milan, Ohio, as the seventh and last child of Samuel and Nancy Edison, a family of Dutch origin. He was one of these precocious youngsters who continuously asked the adults around him to explain how things worked and merely replying to their answers with a continuous “Why?” When at age seven he went to school, his unusually large head with its broad forehead combined with his questioning attitude resulted in his teacher calling him “addled”, a kind of scatter-brain. His mother, who had a much higher opinion of him, withdrew him from school after only three months and started home-schooling him. His parents also instilled in him an early love for books, including those of their local library, which he read with great gusto. Around the age of twelve he lost most of his hearing, which Edison himself attributed to being pulled up to a train car by his ears.

In 1854, when Edison was seven years old, his family moved to Port Huron, Michigan. Here the young boy showed his entrepreneurial skills by selling newspapers, candy and fruit on the trains passing through Port Huron. This income enabled him to set up his own laboratory in the basement of his home where he conducted his own experiments in chemistry and electricity. Obviously his mother did not particularly appreciate this development and he was forced to remove it to a baggage car at the local station.

One day, when the son of the local station master McKenzie wandered onto the railway tracks in front of an oncoming train, the young Edison managed to pull him away just in time. McKenzie was so grateful that he took Thomas under his wing and taught him the basics of telegraphy, including how to use Morse code. By the age of 15 he had learned enough to become employed as a telegraph operator at the local office. Following the end of the American Civil War in 1865 Edison started travelling through the Midwest as a telegrapher. During these years he studied the new technology and conducted many experiments.

He had become so intrigued by the Morse code system that he proposed in Morse code to his 16-year old girlfriend Mary Stillwell to marry him, which they did in 1871. He nicknamed their first two children “Dot” (Marion Estelle Edison, born 1873) and “Dash” (Thomas Alva Edison, Jr (born 1876) in an obvious reference to the Morse dots and dashes.

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Before Edison, silence and darkness

Although Edison invented and improved many telegraphic devices, like the automatic repeater and the carbon microphone, the invention that made him really famous was the phonograph (1877) – or gramophone in British English.


This device enabled the general public to hear recorded sounds of music which till then could only be enjoyed by attending live performances. Although the first version was a bit primitive, his continuous improvements soon made it a remarkable and widely used instrument. Although Edison initially saw the phonograph invention primarily limited to a business dictation machine, the later application of pre-recorded music makes him the great-grandfather of today’s iPod. He soon became known as “The Wizard of Menlo Park,” New Jersey, where he lived. There he also set up a fully fledged research facility, the first one in the world, thus creating a breeding ground for technological innovation and improvements resulting in many new inventions.


In 1878 he introduced the first incandescent light bulb that could be commercially produced. But Edison had enough practical experience to understand that a light bulb without a continuous supply of electricity would have little appeal to the public. So, a few years later he came up with the even more important invention: the electric distribution system. Combining this electricity distribution system with the mass-production of cheap light bulbs made it possible to light up streets and private homes on a large scale. In the early 1880s the first utility company opened using direct current (DC). Soon all kinds of electric light displays not only became showpieces during public events but they also became excellent marketing tools for the Edison products and services. DC however restricted the use of electricity to only those users within a short distance of the power station. To expand the system the much easier to transmit alternating current (AC), invented by Nikola Tesla (one of Edison’s assistants), would be more suitable. As there were already 121 Edison power stations in the United States delivering DC power in 1887 it comes as no surprise that Edison strongly objected to the alternative AC. Although this resulted in a lifelong feud between Tesla and Edison, ultimately AC took over from DC and today AC has been adopted as the main system for electricity generation and distribution.

In 1892 one of Edison's utility companies, the Edison General Electric Company, became the well-known General Electric Corporation.


Other Edison inventions worth mentioning are the dictaphone, a storage battery, the quadruplex telegraph, a roasting kiln for the cement industry, the motion picture projector and the kinetoscope – a peephole viewer which was installed in arcades so people could watch a short film for just one penny. During his life Edison registered close to 1100 patents. He had managed to convert many of them into practical applications. The man that “lit up the world”, as Life magazine called it, had also changed the world to modernity.
Edison died on October 18, 1931, in New Jersey.


From light bulb to vacuum tube

During one of his many experiments to improve and perfect his incandescent light bulb, Edison discovered in 1883 something unexpected. He had inserted a metal plate inside the bulb hoping that the plate would collect the soot given off by the burning filament. It didn’t, but to his surprise he noticed that the current travelled from the filament through the vacuum to the plate. Although not understanding its importance he called it the “Edison Effect” and he even filed a patent for it. What he had discovered was the diode, a one-way valve for electric current. From this Lee DeForest developed in 1906 the triode by inserting a grid between the metal plate and the filament, the first signal amplifier.


The older reader will remember these vacuum tubes in the bulky radio sets of yesteryear.

This early model of the FM radio, invented by Edwin Armstrong (1890-1954) had its vacuum tubes on top to solve the heat dissipation problem.


The vacuum tube has played a major role in the development of the early electronic computers. The famous ENIAC (1946) used 17,468 vacuum tubes. The first generation of computers (during the forties and fifties) used vacuum tubes for the storing of data and instructions, as well as for their controlling circuitry.

Tungsram, a Hungarian company founded in 1896, became a well-known manufacturer of vacuum tubes. In 1990 it was taken over by General Electric - one of Edison’s offspring utility companies had regained the offspring of the “Edison Effect”.

The vacuum tube’s demise came when the transistor was invented in 1949. Within ten years the vacuum tubes would virtually all become obsolete.

© Wobbe Vegter, 2007

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