The law makes no special mandate. In 1789, Justice James Wilson was sworn in by the mayor of Philadelphia, Pennsylvania, where the court first sat. Thurgood Marshall, the nation's first African-American justice, took the Constitutional Oath in 1967 from Associate Justice Hugo Black, an Alabaman.
ballast - A device required by electric-discharge light sources such as fluorescent or HID lamps to regulate voltage and current supplied to the lamp during start and throughout operation.
ballast factor (BF) - The ratio of the light output of a fluorescent lamp or lamps operated on a ballast to the light output of the lamp(s) operated on a standard (reference) ballast. Ballast factor depends on both the ballast and the lamp type; a single ballast can have several ballast factors depending on lamp type. compact fluorescent lamp (CFL) - A family of single-ended fluorescent-discharge light sources with small-diameter [16-millimeter (5/8-inch) or less] tubes.