Arc lamp Arc lamp An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as
Safety pin cover on the safety pin makes it less likely to hurt someone, a version was invented specially for use with babies' nappies, the nappy pin. This is larger and stronger than the typical safety pin. Modern nappy pins have the sliding cap to lock the pin. While the cover on the safety pin makes it less likely to hurt someone, a version was invented especially for use with babies' diapers, the diaper pin. This is larger and stronger than the typical safety pin. Modern diaper pins have either a sliding cap to lock the pin or a S shaped channel