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.
Definition of tread. 1  1a (1) : the part of a wheel or tire that makes contact with a road or rail (2) : the pattern of ridges or grooves made or cut in the face of a tireb : the part of a shoe or boot sole that touches the ground; also : the pattern on the bottom of a sole. 2  2a : the upper horizontal part of a stepb : the width of such a tread.