Coal breaker Coal breaker A coal breaker is a coal processing plant which breaks coal into various useful sizes. Coal breakers also remove impurities from the coal (typically slate) and deposit them into a culm dump. The coal breaker is a forerunner of the modern coal preparation plant. Generally speaking, a coal tipple was typically used at a bituminous coal mine, where removing impurities was important but sorting by size was only a secondary, minor concern. Coal breakers were always used (with or without a tipple) at anthracite mines. While tipples were used around the world, coal breakers were used primarily in
Carbon button lamp a lecture to the Institution of Electrical Engineers, in which he described the carbon button lamp in detail. He also described several variants of the lamp, one of which uses a ruby drop in place of the carbon button. Carbon button lamp The carbon button lamp is a single-electrode incandescent lamp invented by Nikola Tesla. A carbon button lamp contains a small carbon sphere positioned in the center of an evacuated glass bulb. This type of lamp must be driven by high-frequency alternating current, and depends on an electric arc or perhaps a vacuum arc to produce high current around