Light Bulb Commercialization
Joseph Wilson Swan (1828–1914) was a British physicist and chemist. In 1850, he began working with carbonized paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device but the lack of a good vacuum and an adequate supply of electricity resulted in a short lifetime for the bulb and an inefficient source of light. By the mid-1870s better pumps became available, and Swan returned to his experiments.
With the help of Charles Stearn, an expert on vacuum pumps, in 1878 Swan developed a method of processing that avoided the early bulb blackening. This received a British Patent No 8 in 1880. On 18 December 1878 a lamp using a slender carbon rod was shown at a meeting of the Newcastle Chemical Society, and Swan gave a working demonstration at their meeting on 17 January 1879. It was also shown to 700 who attended a meeting of the Literary and Philosophical Society of Newcastle on 3 February 1879. These lamps used a carbon rod from an arc lamp rather than a slender filament. Thus they had low resistance and required very large conductors to supply the necessary current, so they were not commercially practical, although they did furnish a demonstration of the possibilities of incandescent lighting with relatively high vacuum, a carbon conductor, and platinum lead-in wires. Besides requiring too much current for a central station electric system to be practical, they had a very short lifetime. Swan turned his attention to producing a better carbon filament and the means of attaching its ends. He devised a method of treating cotton to produce ‘parchmentised thread’ and obtained British Patent 4933 in 1880. From this year he began installing light bulbs in homes and landmarks in England. His house was the first in the world to be lit by a lightbulb and so the first house in the world to be lit by Hydro Electric power. In the early 1880s he had started his company.
Thomas Edison began serious research into developing a practical incandescent lamp in 1878. Edison filed his first patent application for “Improvement In Electric Lights” on October 14, 1878 (U.S. Patent 0,214,636). After many experiments with platinum and other metal filaments, Edison returned to a carbon filament. The first successful test was on October 22, 1879, and lasted 13.5 hours. Edison continued to improve this design and by Nov 4, 1879, filed for a U.S. patent for an electric lamp using “a carbon filament or strip coiled and connected … to platina contact wires.” Although the patent described several ways of creating the carbon filament including using “cotton and linen thread, wood splints, papers coiled in various ways,” it was not until several months after the patent was granted that Edison and his team discovered that a carbonized bamboo filament could last over 1200 hours.
Hiram S. Maxim started a lightbulb company in 1878 to exploit his patents and those of William Sawyer. His United States Electric Lighting Company was the second company, after Edison, to sell practical incandescent electric lamps. They made their first commercial installation of incandescent lamps at the Mercantile Safe Deposit Company in New York City in the fall of 1880, about six months after the Edison incandescent lamps had been installed on the steamer Columbia. In October 1880, Maxim patented a method of coating carbon filaments with hydrocarbons to extend their life. Lewis Latimer, his employee at the time, developed an improved method of heat-treating them which reduced breakage and allowed them to be molded into novel shapes, such as the characteristic “M” shape of Maxim filaments. On January 17, 1882, Latimer received a patent for the “Process of Manufacturing Carbons,” an improved method for the production of light bulb filaments which was purchased by the United States Electric Light Company. Latimer patented other improvements such as a better way of attaching filaments to their wire supports.
In Britain, the Edison and Swan companies merged into the Edison and Swan United Electric Company (later known as Ediswan, which was ultimately incorporated into Thorn Lighting Ltd). Edison was initially against this combination, but after Swan sued him and won, Edison was eventually forced to cooperate, and the merger was made. Eventually, Edison acquired all of Swan’s interest in the company. Swan sold his United States patent rights to the Brush Electric Company in June 1882. Swan later wrote that Edison had a greater claim to the light than he did, in order to protect Edison’s patents from claims against them in the United States[citation needed]. In 1881, the Savoy Theatre became the first public building in the world to be lit entirely by electric lights.
In 1882, the first recorded set of miniature incandescent lamps for lighting a Christmas tree was installed. These did not become common in homes for many years.
The United States Patent Office gave a ruling October 8, 1883, that Edison’s patents were based on the prior art of William Sawyer and were invalid. Litigation continued for a number of years. Eventually on October 6, 1889, a judge ruled that Edison’s electric light improvement claim for “a filament of carbon of high resistance” was valid.
In the 1890s, the Austrian inventor Carl Auer von Welsbach worked on metal-filament mantles, first with platinum wire, and then osmium, and produced an operating version in 1898. In 1898 he patented the osmium lamp and started marketing it in 1902, the first commercial metal filament incandescent lamp.
In 1897, German physicist and chemist Walther Nernst developed the Nernst lamp, a form of incandescent lamp that used a ceramic globar and did not require enclosure in a vacuum or inert gas. Twice as efficient as carbon filament lamps, Nernst lamps were briefly popular until overtaken by lamps using metal filaments.
In 1903, Willis Whitnew invented a metal-coated carbon filament that would not blacken the inside of a light bulb.
On December 13, 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted a Hungarian patent (No. 34541) for a tungsten filament lamp, which lasted longer and gave a brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1905, so this type is often called Tungsram-bulbs in many European countries.
In 1906, the General Electric Company patented a method of making tungsten filaments for use in incandescent light bulbs. Sintered tungsten filaments were costly, but by 1910 William David Coolidge (1873–1975) had invented an improved method of making tungsten filaments. The tungsten filament outlasted all other types of filaments and Coolidge made the costs practical.
In 1913 Irving Langmuir found that filling a lamp with inert gas instead of a vacuum resulted in twice the luminous efficacy and reduction of bulb blackening. In 1924, Marvin Pipkin, an American chemist, patented a process for frosting the inside of lamp bulbs without weakening them, and in 1947 he patented a process for coating the inside of lamps with silica.
In 1930, Hungarian Imre Bródy filled lamps with krypton gas in lieu of argon. He used krypton and/or xenon filling of bulbs. Since the new gas was expensive, he developed a process with his colleagues to obtain krypton from air. Production of krypton filled lamps based on his invention started at Ajka in 1937, in a factory co-designed by Polányi and Hungarian-born physicist Egon Orowan.
By 1964, improvements in efficiency and production of incandescent lamps had reduced the cost of providing a given quantity of light by a factor of thirty, compared with the cost at introduction of Edison’s lighting system
Consumption of incandescent light bulbs grew rapidly in the United States. In 1885 an estimated 300,000 general lighting service lamps were sold, all with carbon filaments. When tungsten filament were introduced, there were about 50 million lamp sockets in the United States. In 1914 88.5 million lamps were used, (only 15% with carbon filaments), and by 1945 annual sales of lamps were 795 million (more than 5 lamps per person per year).