section_path: Components and accessories of steam engines/Heat source
section_name: Heat source
paragraph_text: Heat source
  
  The heat required for boiling the water and raising the temperature of the steam can be derived from various sources, most commonly from burning combustible materials with an appropriate supply of air in a closed space (e.g., combustion chamber, firebox, furnace). In the case of model or toy steam engines and a few full scale cases, the heat source can be an electric heating element.