Editing Steam engine (section)

=== 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 (steam engine)|firebox]], furnace).  In the case of [[model steam engine|model or toy steam engines]] and a few full scale cases, the heat source can be an [[heating element|electric heating element]].