By: Patrick J. Kiger

6 Key Inventions by Thomas Edison

Edison's genius was improving on others' technologies and making them more practical for the general public.

Thomas Edison

Bettmann Archive/Getty Images

Published: March 06, 2020

Last Updated: February 07, 2025

Thomas Edison applied for his first patent in 1868, when he was just 21 years old. The famous inventor’s first brainchild was for a device that recorded legislative votes. That was just the start of a career in which he would obtain 1,093 U.S. patents, in addition to another 500 to 600 applications that he either didn’t finish or were rejected. But Edison’s greatest invention may have been developing a new process for coming up with inventions.

“When Edison raised enormous capital, built a laboratory in Menlo Park, N.J., and hired a staff of several dozen, each with distinct talents, he pioneered what became the modern corporate research and development process,” explains Ernest Freeberg, a historian at the University of Tennessee, Knoxville and author of The Age of Edison: Electric Light and the Invention of Modern America.

“He considered it an invention factory, one that would produce surprising new products at a regular rate.”

Thomas Edison

Thomas Edison's most famous invention, the lightbulb, paved the way for modern life.

In many cases, Edison’s genius was taking a new technology that someone else had pioneered and developing a superior way of doing the same thing. “An invention not only has to work fairly well, but it has to be something that the market wants and can afford to buy. Edison understood that as well as anyone in his day,” says Freeberg.

Below are some of Edison’s most significant inventions.

1.

Automatic Telegraph

While Samuel Morse’s invention of the telegraph in the 1830s and 1840s made it possible for the first time to communicate over long distances, the device had its drawbacks. An operator had to listen to incoming dots and dashes in Morse code, which slowed messages to a speed of 25 to 40 words per minute. A British system for automatically printing code in ink on paper only achieved 120 words tops.

Between 1870 and 1874, Edison developed a vastly superior system, in which a telegraph receiver utilized a metal stylus to mark chemically-treated paper, which then could be run through a typewriter-like device. It was capable of recording up to 1,000 words a minute, which made it possible to send long messages quickly.

Thomas Edison

Thomas Edison pictured operating a telegraph machine.

Science History Images/Alamy Photo

2.

Carbon Telephone Transmitter

It was Alexander Graham Bell who patented the telephone in 1876. But Edison, with his knack for building upon others’ innovations, found a way to improve Bell’s transmitter, which was limited in how far apart phones could be by weak electrical current. Edison got the idea of using a battery to provide current on the phone line and to control its strength by using carbon to vary the resistance.

To do that, he designed a transmitter in which a small piece of lampblack (a black carbon made from soot) was placed behind the diaphragm. When someone spoke into the phone, the sound waves moved the diaphragm, and the pressure on the lampblack changed. Edison later replaced the lampblack with granules made from coal—a basic design that was used until the 1980s.

Edison's Lamp-black Carbon Telephone Transmitter

Cross-section of Edison’s lamp-black button telephone transmitter.

Universal History Archive/Getty Images

3.

The Light Bulb

Thomas Edison, perhaps the most famous inventor in American history, created many of his numerous innovations, from the phonograph and the movie camera to the alkaline storage battery, during the Second Industrial Revolution. But perhaps his most influential breakthrough was his invention and marketing of the first incandescent light bulb that was long-lasting and practical for wide use.

Edison came up with the idea of putting a carbonized bamboo filament inside a vacuum bulb, and then heating it to produce light. He kept tinkering with his creation and eventually improved his bulbs so much that they could last for 1,200 hours. Edison’s “electric lamp,” for which he obtained a patent in January 1880, illuminated homes and businesses across the nation, and helped create an indoor culture that defined its days by the clock rather than by sunrise and sundown.

Ask History: Who Really Invented the Light Bulb

Thomas Edison wasn’t the only inventor to lay claim to the light bulb, so whose bright idea was it? Ask History finds out.

4.

Phonograph

While developing his telephone transmitter, Edison got the idea of creating a machine that could record and play back telephone messages. That notion led him to imagine being able to record not just voices, but music and other sounds, by using sound to vibrate a diaphragm and push a stylus that made indentations on a cylinder covered with wax paper that was being turned by a crank.

In late 1877, he got a machinist to build the device, using tin foil instead of wax, and Edison recorded the nursery rhyme “Mary Had a Little Lamb.” The following year, he was granted a patent for the design, which also included a lighter needle to find the groves and transmit vibrations to a second diaphragm, which recreated the person’s voice.

Edison’s phonograph created a sensation and helped enhance his reputation as a great inventor. Eventually, he began to market and sell the machines and cylinder records, reverting again to using wax. But by the early 1900s, the Victor Talking Machine Company’s phonographs that played discs surpassed Edison’s cylinder phonographs in popularity. Even though cylinders produced better-quality sound, the early discs had a big advantage in that they could fit four minutes of music, compared to the two minutes that could fit on a cylinder.

Edison's Phonograph

Thomas Edison and his phonograph

Bettmann Archive/Getty Images

5.

Movie Camera and Viewer

In the late 1880s, Edison supervised his lab’s development of a technology “that does for the eye what the phonograph does for the ear.” Most of the work on the Kinetograph, an early movie camera, and the Kinetoscope, a single-person peephole movie viewer, was actually performed by Edison’s employee William Kennedy-Laurie Dickson.

Movies became a big industry and Edison’s camera and viewer were quickly replaced by innovations such as the Lumière Cinématographe, a combination camera, printer and projector that allowed audiences to watch a film together. But Edison adjusted and his company became a thriving early movie studio, churning out scores of silent films between the 1890s and 1918 when it shut down production.

Edison's Kinetograph

A Kinetograph camera, 1912. 

Hulton Archive/Getty Images

6.

Alkaline Storage Battery

When the automobile was developed in the late 1800s, electric vehicles were more popular than those equipped with gasoline-burning internal combustion engines. But early electric cars had a big drawback—the batteries they used were heavy and tended to leak acid, which corroded the cars’ interiors.

Edison decided to take on the challenge of inventing a lighter, more dependable and more powerful battery. After conducting extensive research and the embarrassing flop of an early design, Edison came up with a reliable alkaline battery, and in 1910 began production of it. His work, however, was soon overshadowed by Henry Ford’s development of the inexpensive Model T car that ran on an internal combustion engine. Nevertheless, Edison’s storage battery was used in mining lamps, trains and submarines and turned into the most successful product of Edison’s later career.

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About the author

Patrick J. Kiger has written for GQ, the Los Angeles Times, National Geographic, PBS NewsHour and Military History Quarterly. He's the co-author (with Martin J. Smith) of Poplorica: A Popular History of the Fads, Mavericks, Inventions, and Lore that Shaped Modern America.

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Citation Information

Article title
6 Key Inventions by Thomas Edison
Website Name
History
Date Accessed
March 21, 2025
Publisher
A&E Television Networks
Last Updated
February 07, 2025
Original Published Date
March 06, 2020

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