Thomas Edison is one of the most famous and successful inventors of all time. During his lifetime, he patented 1,093 of his inventions. While Edison developed the first phonograph and early motion picture equipment, he may be best-known for inventing the light bulb. But did Edison actually invent it? In reality, he refined an idea that was already decades old and made it commercially successful.

The arc lamp 

The first working, electric lamp was demonstrated in 1809 by Humphrey Davy, an English scientist and inventor. Davy connected two wires to a battery and attached a charcoal strip between the other ends of the wires. The charged carbon glowed, creating the first arc lamp. 

Davy's lamp produced an extremely bright light similar to a welding torch, and lacked a constant power source, making it impractical for most uses. In the decades that followed, there were numerous attempts to create a commercially viable arc lamp, all of which failed. In the 1870s, however, inventor Charles Francis Brush developed an arc lamp with a longer operating life and a generator that served as a viable power source. The Brush lamp soon became widely adopted throughout the United States for street lighting, as well as in large commercial and public buildings.

The evolution of the light bulb 

The extremely bright light of the arc lamp limited its applicability, so inventors looked for new ways to create a light source that was practical for homes and offices. One promising area was a technique known as incandescence. It was known to science that if you passed electric current through certain materials, they would heat up and glow. Unfortunately, the materials (filaments) tested would quickly burn or melt. To create a practical incandescent bulb, this problem needed to be solved.

Since oxygen is necessary for combustion, inventors soon realized that enclosing the filament in a glass container and pumping the air out would prevent the filament from burning. In 1841, Frederick de Moleyns, a British inventor, was granted a patent for an incandescent lamp using this vacuum method. Later, British inventor Joseph Swan improved and patented incandescent bulbs using vacuum tubes and various filaments. None of these efforts proved commercially viable, however. 

Source:www.archives.gov

Thomas Edison was born in Ohio in 1847. Growing up in Michigan, he became interested in chemistry and electronics, and spent much of his time experimenting in a laboratory that was set up in his family's home. Edison's early inventions involved mostly telegraphic devices, but it was the development of the phonograph in 1877 that gave him wide recognition. It was around this time that Edison also built his famous research laboratory in Menlo Park, New Jersey.

In 1878, Edison entered the race to make a practical light bulb. Over the next two years, he and his team experimented with a wide variety of theories and materials hoping to create an efficient incandescent lamp. They developed an improved pumping method to create an oxygen-free bulb and settled on a carbonized cotton thread filament that would last more than 40 hours before burning out. Edison was granted U.S. Patent #223898 for his light bulb in January 1880. Edison later developed a bulb with a bamboo filament that would last up to 1,500 hours.

While Edison built on work done by others before him, his innovations helped to revolutionize the world by creating the first practical lamp that could be easily manufactured and used in every home or business.