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CARBON FILAMENT LIGHT BULB, 1900's

There are no markings on this bulb.
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.
Thomas Edison (1847–1931) 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
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.
On December 13, 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted a Hungarian patent for a tungsten filament lamp in Budapest, 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.

A1311