Working principle of <a href="https://en.wikipedia.org/wiki/Nicolas_L%C3%A9onard_Sadi_Carnot" class="extiw" title="en:Nicolas Léonard Sadi Carnot">Carnot's</a> heat engine.
Eric Gaba (<a href="//commons.wikimedia.org/wiki/User:Sting" title="User:Sting">Sting</a> - <a href="https://fr.wikipedia.org/wiki/User:Sting" class="extiw" title="fr:User:Sting">fr:Sting</a>)
Own work<br>Based upon <a href="https://en.wikibooks.org/wiki/fr:Image:Moteurthermo.png" class="extiw" title="b:fr:Image:Moteurthermo.png">Wikibooks:Image:Moteurthermo.png</a>