Until 1939, control over these products was dominated by the Phoebus Cartel.
Until 1939, control over these products was dominated by the Phoebus Cartel. An early use of these products was on the SS Columbia. A vacuum pump developed by Hermann Sprengel was a crucial step in the development of this invention. Due to its durability, cellulose replaced thread as a key component in Joseph Swan's version of this invention. By the 1920s, these devices were "frosted" with hydrofluoric acid before being sold to consumers. This invention was more practical than an earlier carbon-arc invention that had to be installed in series and had an open flame. A key improvement to these devices was the development of a tungsten component. For 10 points, name this invention, subject to hundreds of filament experiments by Thomas Edison.
Until 1939, control over these products was dominated by the Phoebus Cartel.
incandescent lightbulb [or incandescent lamp or incandescent light globe]