Before revision: Preliminary research 150px|Nicéphore Niépce The Niépce brothers were living in Nice when they began their project to create an engine based on the newly defined principle of hot air expanding during an explosion .
After revision: Preliminary research 150px|Nicéphore Niépce The Niépce brothers were living in Nice when they conceived of a project to create an engine based on the newly defined principle of hot air expanding during an explosion .