When most people think of the electric light, they immediately recall Thomas Edison. However, the journey of electric lighting began long before him. In fact, the concept of an incandescent lamp was already being explored by others in the mid-19th century.
In 1845, a man named Henry Woodward from Cincinnati filed a patent for a device that used carbon filaments inside a vacuum-sealed bulb. Around the same time, Joseph Swan in the UK experimented with carbonized paper as a filament. Unfortunately, the technology at the time wasn’t advanced enough to create a long-lasting bulb. The poor vacuum pumps available back then allowed residual air to remain in the bulb, causing the filament to burn out quickly. These early lamps only lasted about one or two hours and were not practical for everyday use.
By 1878, improvements in vacuum pump technology allowed Swan to revisit his experiments. In January 1879, he successfully demonstrated his incandescent lamp in public, receiving positive feedback. Meanwhile, Edison, who had already begun working on electric lighting, focused on improving the lifespan of the bulbs. He believed that better vacuum levels and more durable materials would be key to success.
Edison tested over 6,000 different materials for the filament before finally settling on carbonized cotton thread. On October 21, 1879, he created a lamp with this filament, sealed it in a glass bulb, and pumped out the air. The result was a bright, stable light that lasted over 40 hours. This marked the birth of the first practical incandescent lamp, which Edison patented.
Not content with just one breakthrough, Edison continued searching for even better materials. In 1880, he developed a carbonized bamboo filament, which significantly extended the life of the bulb. Soon after, he established a factory in New Jersey to begin mass production, marking the world’s first commercial incandescent lamp. A year later, another factory was opened in Benville, near Newcastle, UK.
While Edison is often credited with inventing the electric light in the U.S., the British credit Joseph Swan. In 1978, the UK celebrated the centenary of electric lighting, while the U.S. held its own event a year later. The competition between these two inventors was intense, leading to several patent disputes. Eventually, they reached an agreement, forming the Edison-Swan Electric Company to produce incandescent lamps in the UK.
Later, in 1908, American inventor William David Coolidge made a major breakthrough by developing the modern tungsten incandescent lamp. Tungsten has a very high melting point, allowing it to withstand temperatures up to 3,000°C. The filament emits light through radiation, but as it heats up, some tungsten evaporates and deposits on the bulb’s inner surface, darkening it over time. To prevent this, bulbs are designed with a larger "belly" to spread the deposit over a wider area.
Despite its efficiency, the traditional incandescent lamp is far from ideal. Only about 2% of the energy it consumes is converted into light, with the rest lost as heat. Most incandescent bulbs last no longer than 1,000 hours. However, halogen lamps, which contain halogen gases like iodine or bromine, offer a longer lifespan. These lamps allow for a "self-regeneration" process where evaporated tungsten is redeposited onto the filament, extending its life.
Halogen lamps are commonly used in applications requiring focused light, such as desk or room lighting. They are smaller and more efficient than standard incandescent bulbs. In recent years, many countries have started phasing out incandescent lamps due to their inefficiency. For example, Australia introduced a plan in 2010 to ban incandescent bulbs in favor of energy-saving fluorescent lighting to reduce greenhouse gas emissions.
This move marks the beginning of the end for traditional incandescent lighting. As we look toward a more sustainable future, the era of the classic light bulb may soon be over. But its legacy will live on in the history of innovation and progress.
Folding Desk,Office Folding Table,Adjustable Removable Office Table,Foldable Office Computer Desk
Changzhou Offistyle Furniture Co., Ltd. , https://www.offistylefurniture.com