What Did Edison Invent?
Telegraph, Vote Recorder, Phonograph, Carbon Microphone, Kinetograph & Kinetoscope
Fluoroscope, Alkaline Storage Battery, Light Bulb, Electric Power Distribution

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Thomas Edison Was Born in 1847
Early Years
1863 Automatic Telegraph Repeater Edison's first invention at 16. It sent telegraph signals between unmanned stations, allowing almost anyone to easily and precisely translate code at his own speed and convenience. Edison never patented this invention.
1869 Electric Vote Recorder Edison's first patent. Permitted a "yes" or "no" vote via one of two switches. Washington congressmen were not interested in the device and the invention was a failure (U. S. Patent 90,646).
1875 Quadruplex Telegraph A telegraph system which was capable of sending two messages simultaneously in each direction on the same wire (US Patent 209,241).
1877 Phonograph The invention which first gained edison fame. The phonograph, record player, or gramophone is a device that was mostly commonly used from the late 1870s through the 1980s for playing sound recordings. Thomas Alva Edison conceived the principle of recording and reproducing sound as a byproduct of his efforts to "play back" recorded telegraph messages and to automate speech sounds for transmission by telephone. Edison's early phonographs recorded onto a tinfoil sheet phonograph cylinder using an up-down ("hill-and-dale") motion of the stylus. The tinfoil sheet was wrapped around a grooved cylinder, and the sound was recorded as indentations into the foil. Edison's early patents show that he also considered the idea that sound could be recorded as a spiral onto a disc, but Edison concentrated his efforts on cylinders, since the groove on the outside of a rotating cylinder provides a constant velocity to the stylus in the groove, which Edison considered more "scientifically correct". (US Patent 200,521).
Menlo Park Inventions
1877 Carbon Microphone Edison invented and developed the carbon microphone used in all telephones along with the Bell receiver until the 1980s. After protracted patent litigation, in 1892 a federal court ruled that Edison—and not Emile Berliner—was the inventor of the carbon microphone. The carbon microphone was also used in radio broadcasting and public address work through the 1920s. The carbon microphone, also known as a carbon button microphone (or sometimes just a button microphone) or a carbon transmitter, is a sound-to-electrical signal transducer consisting of two metal plates separated by granules of carbon. One plate faces outward and acts as a diaphragm. When sound waves strike this plate, the pressure on the granules changes, which in turn changes the electrical resistance between the plates. (Higher pressure lowers the resistance as the granules are pushed closer together.) A direct current is passed from one plate to the other, and the changing resistance results in a changing current, which can be passed through a telephone system, or used in other ways in electronics systems to change the sound into an electrical signal. (U.S. Patent 0,474,230).
1879 Incandescent Light Bulb Improvement After many experiments with platinum and other metal filaments, Edison returned to a carbon filament. The first successful test was on October 22, 1879; it lasted 40 hours. Edison continued to improve this design and by November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using "a carbon filament or strip coiled and connected to platina contact wires". Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours.
1880 Electric Power Distribution Edison patented a system for electricity distribution in 1880 (U.S patent 239,147), which was essential to capitalize on the invention of the electric lamp. On December 17, 1880, Edison founded the Edison Illuminating Company. The company established the first investor-owned electric utility in 1882 on Pearl Street Station, New York City. It was on September 4, 1882, that Edison switched on his Pearl Street generating station's electrical power distribution system, which provided 110 volts direct current (DC) to 59 customers in lower Manhattan. Earlier in the year, in January 1882 he had switched on the first steam generating power station at Holborn Viaduct in London. The DC supply system provided electricity supplies to street lamps and several private dwellings within a short distance of the station. On January 19, 1883, the first standardized incandescent electric lighting system employing overhead wires began service in Roselle, New Jersey. In the late 1880s, George Westinghouse and Thomas Edison became adversaries due to Edison's promotion of direct current (DC) for electric power distribution over alternating current (AC) advocated by Westinghouse and Nikola Tesla which prevailed in the end - what is called the "War of Currents".
After Menlo Park and Last Years
1885 Wireless Telegraph A telegraphy system of radio communication between ships (which later he sold to Marconi). The patent, however, was not based on the transmission and reception of electromagnetic waves. Instead it used induction transmission by the use of a vibrator magnet (U.S. patent 465,971)
1891 Kinetograph & Kinetoscope Motion picture camera and viewing apparatus. Many researchers in the late 19th century realized that films as they are known today were a practical possibility, but the first to design a fully successful apparatus was W. K. L. Dickson, working under the direction of Thomas Alva Edison. His fully developed camera, called the Kinetograph, was patented in 1891 (U.S. Patent 589,168) and took a series of instantaneous photographs on standard Eastman Kodak photographic emulsion coated on to a transparent celluloid strip 35 mm wide. The results of this work were first shown in public in 1893, using the viewing apparatus also designed by Dickson (1891), and called the Kinetoscope (U.S patent 493,426).
1896 Fluoroscope The beginning of fluoroscopy can be traced back to 8 November 1895 when Wilhelm Röntgen noticed a barium platinocyanide screen fluorescing as a result of being exposed to what he would later call x-rays. Within months of this discovery, the first fluoroscopes were created. Early fluoroscopes were simply cardboard funnels, open at narrow end for the eyes of the observer, while the wide end was closed with a thin cardboard piece that had been coated on the inside with a layer of fluorescent metal salt. The fluoroscopic image obtained in this way is rather faint. Thomas Edison quickly discovered that calcium tungstate screens produced brighter images and is credited with designing and producing the first commercially available fluoroscope. In its infancy, many incorrectly predicted that the moving images from fluoroscopy would completely replace the still x-ray radiographs, but the superior diagnostic quality of the earlier radiographs prevented this from occurring. In 1903, Edison abandoned his work on fluoroscopes, saying "Don't talk to me about X-rays, I am afraid of them." Rontgen discovered x-rays, but Edison invented the first practical fluoroscope.
1904 Alkaline Storage Battery Improvement U.S. patent 879,612
Thomas Edison Died in 1931

Scientists & Inventors
Ampère André-Marie
Baird John
Bell Alexander
Carver George
Cavendish Henry
Darwin Charles
Eastman George
Edison Thomas 1
Edison Thomas 2
Einstein Albert
Electric Motor
Faraday Michael
Fitzroy Robert
Foucault Léon
Franklin Benjamin
Fuel Cell
Galileo Galilei 1
Galileo Galilei 2
Gutenberg Johannes
Hertz Heinrich
Joule, James Prescott
Leonardo da Vinci
Leeuwenhoek Antonie
Marconi Guglielmo
Mendel Gregor
Miller-Urey Experiment
Millikan Robert
Morse Samuel
Newton Isaac
Ohm Georg
Pavlov & Skinner
Pitch Drop Experiment
Radio Inventions
Spectrum of Light
Tesla Nikola
Torricelli Evangelista
Tycho Brahe
Volta Alessandro
Whitney Eli
Wright Brothers
Young Thomas
Zuse Konrad
Ampère André-Marie

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Last updated: February 2018
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