Convection

Convection, in Physics, a process of altering the distribution of heat in a system by actual conveyance. A body may impart some of its heat to another by giving heat to the air particles in its immediate neighbourhood, these particles then carrying the heat to the other; such a process is termed convection, and is of much importance in nature. By convection the upper layers of water in a kettle that is being heated from below are themselves heated. Similarly an electrical body may lose its electricity by touching and electrifying neighbouring particles of air, which then carry off the electricity elsewhere. This process is observable in the Brush discharge (q.v.).