Edison's Light Bulb (1879): Lighting the World with Electricity

Edison’s light bulb is the carbon-filament incandescent lamp developed by Thomas Edison and his team at Menlo Park, New Jersey, whose first long-lasting test took place on 22 October 1879. Edison did not invent electric light, and Joseph Swan in England reached a working carbon lamp at almost the same time. What made Edison’s lamp so important was that it was designed as one part of a complete system of power stations, wiring and meters that brought electric light into homes, offices and streets.

Background: light before the bulb

In the 1870s homes and streets in Europe and North America were lit by candles, oil and kerosene lamps, and coal gas. Gas lighting had spread through cities since the early nineteenth century, but it was smoky, hot, smelly and a fire risk, and it used up the oxygen in closed rooms.

Electric light already existed in another form. The arc lamp, in which a brilliant spark jumps between two carbon rods, had been shown by Humphry Davy in the early 1800s, and by the late 1870s arc lights powered by dynamos lit some streets, factories and public spaces. In 1878 Paul Jablochkoff’s “electric candles” lit the Avenue de l’Opéra in Paris. Arc lights were far too bright, noisy and power-hungry for a living room, however, and each lamp usually had to be wired in series with the others, so that one failure could darken the whole circuit. Inventors spoke of the problem of “subdividing” electric light into small, gentle units like gas jets.

The basic idea of incandescence, heating a thin conductor until it glows, was old. Warren de la Rue experimented with a platinum coil in a vacuum tube around 1840, and Frederick de Moleyns took out a British patent for an incandescent lamp in 1841. In the 1870s the Russian Alexander Lodygin and the Canadians Henry Woodward and Mathew Evans patented carbon lamps; Edison later bought the rights to the Woodward and Evans patent.

The most important rival was Joseph Wilson Swan (1828–1914), a chemist from Newcastle upon Tyne. Swan had experimented with carbonised paper filaments since the 1850s but was held back by poor vacuum pumps. After the mercury pump developed by Hermann Sprengel became available, Swan returned to the problem and demonstrated a carbon-filament lamp in Newcastle in December 1878 and again in early 1879. Historians Robert Friedel and Paul Israel counted more than twenty inventors who worked on incandescent lamps before Edison.

Edison’s research at Menlo Park

Edison took up electric lighting in September 1878, after visiting the arc-lighting works of William Wallace in Ansonia, Connecticut. He announced, with great confidence and long before he had a working lamp, that he would soon light whole districts of New York. On 15 October 1878 the Edison Electric Light Company was incorporated, backed by financiers including partners of the banking house of J. P. Morgan.

Edison’s laboratory was well suited to the task. It employed skilled machinists, the glassblower Ludwig Böhm and the Princeton-trained mathematician Francis Upton, while Charles Batchelor ran many experiments. Upton’s calculations helped establish the key insight: to supply many lamps in parallel from a central station without enormous and costly copper wires, each lamp needed a high electrical resistance and low current. That ruled out the thick, low-resistance carbon rods others had tried and called for a very thin filament.

The team first worked with platinum and other metals, which melted or failed. They improved vacuum pumps so that bulbs could be emptied of air to around one millionth of an atmosphere, preventing the filament from burning up. In autumn 1879 they returned to carbon, using very fine filaments.

The test of 22 October 1879

On 22 October 1879 a lamp with a filament of carbonised cotton sewing thread, sealed in a highly evacuated glass bulb, glowed steadily at Menlo Park. Laboratory notebooks indicate that it lasted roughly 13 to 14½ hours, depending on how the entries are read. It was not yet a commercial product, but it showed that a thin carbon filament in a good vacuum could survive for a useful time.

Experiments with carbonised cardboard soon produced longer-lasting lamps, often bent into the familiar horseshoe shape. Edison filed a patent application on 4 November 1879, and US Patent No. 223,898 for an electric lamp was granted on 27 January 1880.

On 21 December 1879 the New York Herald published a long article on the new lamp. Over the New Year period, Edison staged public demonstrations at Menlo Park, lighting the laboratory, nearby houses and street lamps. The Pennsylvania Railroad ran extra trains, and thousands of visitors came to see light without flame.

From lamp to lighting system

Edison’s team then had to make the lamp last longer and build everything else. In 1880 they discovered that carbonised bamboo made a far more durable filament, and Edison’s agents searched Asia and South America for the best fibres; a Japanese bamboo was chosen. A lamp factory opened at Menlo Park in 1880 and later moved to Harrison, New Jersey.

Just as important were the other parts of the system: large, efficient dynamos, screw-in lamp sockets, fuses, switches, insulated underground cables and meters to charge customers. In May 1880 the steamship Columbia became the first commercial installation of Edison lamps. In September 1882 Edison opened the Pearl Street Station in Lower Manhattan, the first central power station in the United States to sell electric light to paying customers.

Edison, Swan and the patent battles

In Britain, Swan’s lamps went into production in 1881. Sir William Armstrong’s house at Cragside in Northumberland was lit by Swan lamps, and in 1881 the Savoy Theatre in London became one of the first public buildings in the world lit entirely by electricity, using Swan lamps. Edison sued for infringement in Britain, but Swan’s prior work made the outcome uncertain, and in 1883 the two interests merged to form the Edison and Swan United Electric Light Company, known as “Ediswan”.

In the United States Edison’s company fought long court battles over the lamp patent. The courts eventually upheld Edison’s patent in the early 1890s, shortly before it expired. Meanwhile Edison’s commitment to direct current led to a bitter contest with George Westinghouse and Nikola Tesla’s alternating current, known as the War of the Currents.

Key people

• Thomas Alva Edison (1847–1931): American inventor and businessman who directed the Menlo Park research and promoted the complete lighting system.
• Joseph Wilson Swan (1828–1914): English chemist who developed a carbon-filament lamp independently and later partnered with Edison in Britain.
• Francis Upton (1852–1921): mathematician and physicist whose calculations guided the high-resistance design.
• Charles Batchelor (1845–1910): English-born chief experimental assistant who carried out much of the filament work.
• Ludwig Böhm: German glassblower who made the early bulbs at Menlo Park.

Consequences

Electric lighting spread slowly at first. In the 1880s it was expensive and limited to wealthy homes, theatres, hotels, ships and city centres. By around 1900 central stations operated in hundreds of towns, and in the early twentieth century electrification reached most urban homes in Western Europe and North America, though rural areas often waited until the 1930s or later.

The lamp itself kept improving. Tungsten filaments appeared around 1904–1906, William Coolidge at General Electric produced ductile tungsten wire in 1910, and Irving Langmuir introduced gas-filled lamps in 1913. These gave brighter, more efficient light than carbon. In the 2000s and 2010s many countries, including the members of the European Union, phased out ordinary incandescent bulbs in favour of more efficient fluorescent and LED lamps.

Myths and facts

Myth: Edison invented the light bulb. Fact: Many inventors made incandescent lamps before him, and Swan’s carbon lamp was developed in parallel. Edison’s achievement was a practical high-resistance lamp and the system that made it useful.

Myth: The first bulb burned for 40 hours. Fact: The notebook record for 22 October 1879 points to roughly 13 to 14½ hours; longer figures were added in later retellings.

Myth: Edison said he had “found 10,000 ways that won’t work”. Fact: Versions of this saying are widely attributed to him, but no reliable contemporary source records those exact words. His team did test thousands of materials, especially plant fibres, in the search for better filaments.

Timeline

• 1878, September: Edison begins intensive work on electric lighting after visiting William Wallace’s arc-lighting works.
• 1878, 15 October: The Edison Electric Light Company is incorporated in New York.
• 1878, December: Joseph Swan demonstrates a carbon-filament lamp in Newcastle upon Tyne.
• 1879, 22 October: A carbonised cotton-thread lamp glows for about half a day at Menlo Park.
• 1879, 4 November: Edison files his patent application for the carbon-filament lamp.
• 1879, 31 December: Public demonstrations at Menlo Park draw crowds of visitors.
• 1880, 27 January: US Patent No. 223,898 is granted.
• 1881: Swan lamps light the Savoy Theatre in London.
• 1882, 4 September: Edison’s Pearl Street Station begins supplying electricity in New York.
• 1883: Edison and Swan interests merge in Britain to form Ediswan.

Why it matters

The incandescent lamp of 1879 turned electricity from a scientific curiosity and an industrial tool into something every household wanted. Because Edison built a full system around it, the lamp helped create the electric utility industry, changed working hours and city life, and paved the way for the electrified world of the twentieth century.