2. 1860, joseph swan, an Englishman, made a carbon filament electric lamp. For various technical reasons, he didn't get a patent until 1878, and made his house the first house with electric lights in Britain.
3. 1874, two electrical technicians in Canada applied for a patent for electric lamp: nitrogen was filled under the glass bulb to make the electrified carbon rod glow, but they didn't have enough financial resources to continue to improve this invention, so they sold the patent to Edison in 1875.
4. 1878, Edison began to study light bulbs, which was the beginning of a classic story in later generations. Keep trying, keep failing, keep standing up, this is the essence of this story. 1879, Edison's electric lamp was successfully developed, which can emit light continuously for 45 hours; 1880, Edison sent experts and assistants to test more than 6,000 kinds of materials, and finally found that carbon wires made of bamboo have the longest service life and can continuously emit light for more than 1000 hours. At this time Edison went to the US Patent Office to apply for a patent.