Who Actually Invented the Light Bulb?

Who invented the telephone? How about the airplane? The lightbulb? If you paid attention in high school history class, you’ll probably know the standard answers: Alexander Graham Bell, The Wright Brothers, and Thomas Edison. But if you’ve been watching our channels long enough, you’ll also know that when it comes to the big inventions that have most shaped our modern world, things are never so simple. And the story of the invention of the lightbulb is no different. While perhaps the most famous creation attributed to inventor extraordinaire Thomas Edison, the incandescent light bulb was actually in development for nearly a century before Edison finally perfected it and brought it to the masses. This is the story of the dozens of inventors who struggled to harness the power of electricity to banish the darkness of night and bring about a technological and social revolution.

To create a practical electric light, one first needs a reliable source of electricity, and this would not become available until 1800 when Italian scientist Alessandro Volta created the Voltaic Pile – the ancestor of the modern electric battery. Two years later, English scientist Sir Humphrey Davy used a massive battery composed of 2,000 electrochemical cells to pass a current across two carbon rods, generating an extremely bright arc. He next passed this current through a thin strip of platinum, which due to its high electrical resistance and high melting point, glowed white-hot. Over the following half-century, several inventors would develop and patent similar filament-based incandescent lamps, further refining the idea by encasing the filament in a glass bulb and pumping out the air to prevent the filament from oxidizing and burning up. These pioneers included Scottish author James Lindsay in 1835, Belgian Lithographer Marcellin Jobard in 1838, British scientists Warren la Rue and Frederick de Moleyns in 1840, and French magician Jean Robert-Houdin in 1851. However, none of these early light bulbs proved commercially viable. For one thing, most of them used platinum filaments which were prohibitively expensive, while the pump technology of the time prevented a hard enough vacuum from being drawn, causing the filaments to last only a few hours before burning up. Furthermore, giant banks of batteries were not a practical source of electricity for everyday use. Thus, even if long-lasting light bulbs could be developed, their large-scale adoption would have to await the introduction of practical electrical generators turned by water or steam power.

But when such technology finally became widely available, the first electric lights to see practical use were not incandescent bulbs but rather arc lamps, based on Humphry Davy’s 1802 experiments with carbon rods. Davy’s original design, which used fixed rods, was impractical as the heat of the arc steadily vaporized the ends of the rods, widening the gap between them to widen and eventually causing the arc to go out. This problem was solved in the 1840s by English inventors Thomas Wright and William Straite, who developed clockwork mechanisms to maintain the gap between the rods. Later, in 1875, Russian engineer Pavel Yablochkov invented an even simpler lamp called the Yablochkov candle, which used two parallel carbon rods separated by a block of plaster of Paris. Once an arc was struck, the rods would be steadily consumed from top to bottom, the constant gap between them eliminating the need for an adjustment mechanism.

In 1846, the Opera theatre in Paris became the first public building to be lit by electricity, using arc lamps powered by giant banks of zinc-carbon batteries. Soon, more efficient steam-powered generators became available and other facilities were fitted with electric lights, including lighthouses, train stations, factories, and large street intersections and public squares. The first arc lamps in the United States were installed in the Wanamaker department store in Philadelphia in 1878, while the first in the United Kingdom were installed in front of the Bank of England in London in 1881. But while arc lamps were fine for lighting large open spaces, their light was far too harsh for ordinary household use. Thankfully, by this time, research on incandescent lamps was beginning to show promise.

One of the first practical incandescent lamp designs was patented in 1872 by Russian inventor Alexander Lodygin. Lodygin’s bulb did not use a traditional filament but a pair of carbon rods, arranged so that current would pass to the second rod once the first burned out. To get around the limitations of vacuum pumps, Lodygin instead filled the bulb with inert Nitrogen, an arrangement that would later become standard – albeit with different gases. Lodygin was later among the first to patent a light bulb using a tungsten filament – another now-standard design feature – but unfortunately at the time tungsten was prohibitively expensive to work with, and none of Lodygin’s designs saw commercial production.

The same year as Lodygin, Canadian medical student Henry Woodward and hotel keeper Mathew Evans patented a similar light bulb design, consisting of carbon rods mounted in a nitrogen-filled glass tubes. Their invention was inspired by an incident in 1873 when the pair were experimenting with a high-voltage induction coil when a part of their apparatus began to spark, creating a bright light that lit up the room. As Woodward later recalled:

“[I thought], if one could only confine that in a globe of some sort, what an invention we would have! It would revolutionize the world!”

Shortly after patenting their bulb design, Woodward and Evans demonstrated their invention to a group of financiers at the Morrison Brass Foundry in Toronto:

“There were four or five of us sitting around a large table,” Woodward closed the switch and gradually we saw the carbon become first red and gradually lighter and lighter in colour until it beamed forth in beautiful light. This was the most exciting moment of my experience.”

Unfortunately, the investors were not impressed, and Woodward and Evans were widely mocked as eccentrics and crackpots for pursuing such a “useless” invention. After several years of fruitlessly seeking funding to improve and commercialize their light bulb, the pair eventually gave up, and in 1879 sold their patent to Thomas Edison for $5,000 (about $160,000 today).

Meanwhile, across the Atlantic, a British physicist and chemist named Joseph Swan was having much better luck commercializing his own light bulb design. Swan began his research in the 1850s, developing a bulb with a filament made of carbonized paper. Unfortunately, vacuum pump technology prevented Swan’s bulb from achieving practical longevity, and he abandoned his research. In 1865, however, German chemist Hermann Sprengel invented the Sprengel Pump, which used falling mercury to achieve lower pressures than previously possible, spurring Swan to return to his experiments. On January 17, 1979, Swan successfully demonstrated a new bulb design at a meeting of the Newcastle Chemical Society. But while the bulb, which used a carbon rod from an arc lamp instead of a filament, was the most advanced of its time, it was still a flawed design. The carbon rod offered very low resistance and thus required a very large current to make it glow, making the bulb very inefficient. The bulb also only lasted 40 hours, and grew progressively dimmer as it burned as carbon evaporating from the rod was deposited on the inside surface of the lamp. But Swan was undeterred, and in 1880 patented a specially-treated carbonized thread filament which drew far less current and eliminated the blackening problem. In February 1879, Swan installed the first incandescent streetlights on Mosley Street in Newcastle Upon Tyne. In 1880, his own house in Gateshead became the first in history to be lit by incandescent lamps, while in 1881 the Savoy Theatre in London became the first public building to be so illuminated. That same year, the technology was used at sea for the first time, with the SS City of Richmond being the first civilian vessel and HMS Inflexible the first military vessel to use electric lamps.

Around the same time, American inventors William Sawyer and Albion Man discovered that looping the light bulb filament helped it last longer, and patented a bulb incorporating this improvement. However, the filament support in their design prevented the filament from expanding and contracting as it heated and cooled, making the bulb prone to cracking. Despite this, the Swayer-Man patent was to play a key role in the ensuing legal fight over who was the true inventor of the practical light bulb.

And now, at last, we get to the man you have all been waiting for: the ‘Wizard of Menlo Park’ himself, Thomas Alva Edison. Edison’s involvement in the light bulb story began in 1878, when he was trying to sell America on the idea of large-scale electrification. Unfortunately, while all sorts of useful electric devices had been invented by this time – from electric motors to electric stoves – outside of arc lamps there was no real practical form of electrical illumination, meaning the home lighting market was dominated by gas lamps. In response, Edison publicly stated that he could create a safer, cheaper, and more reliable electric light to replace gas lights in only six weeks. Amazingly, such was Edison’s clout at this time that this announcement caused gas company stocks to plummet. After raising funds from investors, Edison assembled a group of researchers he nicknamed his “muckers” at his laboratory in Menlo Park, New Jersey, and set to work.

In December 1879, Edison and his team demonstrated a practical light bulb using a thin platinum filament, which drew a much lower current than Joseph Swan’s designs. However, the bulb lasted only 14 hours, and, as noted, platinum was too expensive for a commercially-viable bulb. So, after patenting his design as Improvement in Electric Lights on 14 October 1878, Edison and his “Muckers” embarked upon a marathon hunt for a lightbulb filament that would be durable, long-lasting, and economical to manufacture. Much has been written about Edison’s technical abilities compared to his contemporaries, especially rival Serbian inventor Nikola Tesla. But what Edison might have lacked in theoretical knowledge, he more than made up for with the realization that large-scale technical problems require large-scale solutions – an ethos that predicted today’s era of “big science” and industrial research laboratories and inspired his famous motto “Genius is 1% inspiration and 99% perspiration.” Between 1878 and 1880, Edison and his team at Menlo Park tested over 6,000 different filament materials, including cotton, linen, cedar, baywood, boxwood, and hickory. Edison even wrote botanists from around the world to obtain samples of exotic plants to test. At first, carbonized cotton seemed to hold the most promise, glowing for nearly 500 hours straight. Ultimately, however, Edison and his team hit upon carbonized bamboo, which allowed for bulb lives of up to 1200 hours. Of the entire research and development, process, Edison later wrote:

“The electric light has caused me the greatest amount of study and has required the most elaborate experiments,” he wrote. “I was never myself discouraged, or inclined to be hopeless of success. I cannot say the same for all my associates.”

In 1880, Edison formed the Edison Illuminating Company to manufacture and market his new light bulbs. However, before he could patent his new developments, over in England Joseph Swan used them to improve his own light bulb designs. Infuriated, Edison sued Swan for copyright infringement. Unfortunately for Edison, the courts not only ruled in favour of Swan, but also ruled that Edison’s work was based on the prior art of William Sawyer and Albion Man – remember them? – who, along with Hiram Maxim, inventor of the first modern machine gun, formed the United States Electric Lighting Company in 1878. Edison’s 1880 patents were thus nullified. In response, Edison joined forces with Joseph Swan to create the Edison and Swan United Electric Company or “Ediswan”, which soon became one of the world’s largest manufacturers of lightbulbs. Finally, after nearly a decade of litigation, in 1889 the court reversed its decision, and Edison’s 1880 patent claim for “a filament of carbon of high resistance” was ruled as valid.

Over the following decades, Ediswan and its rivals would introduce dozens of key improvements to the basic light bulb design. The familiar one inch screw base and socket was patented by Edison in 1881 and introduced commercially in 1909 in General Electric’s “Mazda” brand lamps. This design would soon become an industry standard worldwide; indeed, before the widespread adoption of standard electrical plug outlets in the 1910s, early electrical appliances plugged directly into light bulb sockets. Edison also introduced new ways of heat treating carbon filaments to make them last longer, as well as methods of improving the vacuum in the bulb. A major problem which plagued lightbulb manufacturers during this era was air and moisture becoming absorbed into the glass during the manufacturing process, causing bulbs to split and burn out when switched on – a problem not even the most powerful vacuum pump could solve. In 1893, however, Italian inventor Arturo Malignani discovered that if red phosphorus was introduced into the bulb, it acted as a “getter”, bonding with any remaining water and oxygen and preventing them from damaging the bulb or filament. In 1898 Edison purchased this patent, allowing him to increase the average life of his bulbs from 500 to 800 hours.

Thus, Edison did not “invent” the lightbulb in the traditional sense; rather, he simply perfected the technology to the point where it became economically viable and then helped popularize it. As Robert Friedel, professor of history at University of Maryland College Park explains:

“He carefully identified all of the key qualifications for a successful rival to the alternatives … reliability, longevity, economy and aesthetics. He deliberately set out to create an electric light that would check all these boxes — this is something no one else succeeded in doing.”

But Edison did far more than just create a practical light bulb; he also created the entire electrical generating and distribution system without which the light bulb would be nothing but a curiosity.

In September 1882, Edison opened the Pearl Street Generating Station in lower Manhattan, the first commercial power plant of its kind. Prior to this, any home or business that wanted electric lighting needed to install its own dedicated generator. Edison’s genius idea was imagining a larger commercial electric grid, which would not only make distribution more efficient, but also drive sales of electrical appliances like the light bulb. By the end of the century, the incandescent electric bulb had almost entirely replaced the gas lamp – just as Edison had intended. As Thomas P. Hughes writes in his book Technology at the Turning Point:

“The lamp was a small component in his system of electric lighting, and no more critical to its effective functioning than the Edison Jumbo generator, the Edison main and feeder, and the parallel-distribution system. Other inventors with generators and incandescent lamps, and with comparable ingenuity and excellence, have long been forgotten because their creators did not preside over their introduction in a system of lighting.”

The early 20th century brought further improvements to lightbulb design, including the replacement of carbon filaments with metal one. While Alexander Lodygin first patented the tungsten filament in the 1870s, it would be another 30 years before manufacturing technology made this material economical to work with. In the meantime, manufacturers experimented with various other metals, including osmium and tantalum.

The first successful metal filament lamp using osmium was developed in 1898 by Austrian inventor Carl Auer von Welsbach and sold under various brand names including “Osmi” and “Auer-Os.” However the osmium was so expensive that the bulbs were not sold but rather rented, with the consumer trading in the bulbs for partial credit when they burned out. Due to this flaw and competition from other, cheaper bulbs, osmium bulbs were discontinued in 1905. In 1902, German firm Siemens introduced tantalum filament lamps which were not only brighter and longer-lasting than carbon filament lamps, but cheaper than osmium lamps. The filament also had the useful property of welding itself back together again if it broke, though this gradually reduced the filament’s resistance and thus its brightness.

In the end, however, tungsten proved to be the superior material, with the first tungsten-filament bulbs being introduced in 1904 by the Hungarian company Tungsram. In 1913, Tungsram introduced another key innovation: replacing the vacuum with an inert gas like argon. This allowed the filament to glow brighter with less current and slowed its evaporation, increasing efficiency and bulb lifespan. Other innovations included the ductile tungsten filament, patented in 1906 by William Coolidge at General Electric; the coiled tungsten filament, first mass produced by Japanese firm Haunetsusha – today better known as Toshiba – in 1936; and the frosted bulb, developed by Marvin Pipkin in 1925.

These innovations, along with the ongoing electrification of cities around the world, caused sales of lightbulbs to skyrocket. Between 1914 and 1945, lightbulb consumption in the United States alone grew from 88.5 million to 795 million – more than 5 lamps per person per year. The longevity of lightbulbs also reached truly impressive heights; one light bulb at Fire Station #6 in Livermore, California has been burning almost continuously since it was first installed in 1901, earning it a place in the Guinness Book of World Records. In fact, lightbulb lifespans became so good that they began cutting into manufacturers’ bottom line, as the market became saturated and people stopped buying new bulbs.

In response, in 1924 a group of lightbulb manufacturers based in Geneva formed the Phoebus Cartel, which limited the maximum lifespans of its members’ bulbs to 1000 hours partially in order to maintain steady sales. This was one of the first deliberate applications of the now-common tactic of planned obsolescence.

Over the course of the 20th Century, inventors would come up with a wide variety of new and improved electric light sources, from mercury and sodium vapour lamps to halogen bulbs, neon lights, fluorescent lamps, and finally light emitting diodes or LEDs. But, with the possible exception of LEDs, none of these innovations has had as outsized an impact on our modern world as the original incandescent lightbulb, which finally brought cheap, reliable electric lighting into businesses and homes and allowed commerce and leisure to carry on 24/7. But as with so many key technological developments, this illumination revolution was not the product of a single, inspired “lightbulb moment”, but rather many.

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