Britannia metal Britannia metal Britannia metal (also called britannium or Britannia ware) is a specific type of pewter alloy, favoured for its silvery appearance and smooth surface. The composition by weight is typically about 92% tin, 6% antimony, and 2% copper. Britannia metal is usually spun rather than cast, and melts at 255 degrees Celsius. Britannia metal was first produced in 1769 or 1770. James Vickers created it after purchasing the formula from a dying friend. It was originally known as "Vickers White Metal" when made under contract by the Sheffield manufacturers Ebenezer Hancock and Richard Jessop. In 1776 James Vickers took
Ceramic discharge metal-halide lamp discharge is contained in a ceramic tube, usually made of sintered alumina, similar to what has been used in the high pressure sodium lamp. During operation, the temperature of this ceramic tube can exceed 1200 kelvins. The ceramic tube is filled with mercury, argon and metal-halide salts (for example, sodium iodide). Because of the high wall temperature, the metal halide salts are partly vaporized. Inside the hot plasma, these salts are dissociated into metallic atoms and iodine. The metallic atoms are the main source of light in these lamps, creating a bluish light that is close to daylight with a