Franklin was a fellow-student of engineering. He helped his friends the Montgolfiers in their ballooning experiments, and worked with Fulton on naval steam-power, trying also to get his submarine commissioned. Berthollet, Fourcroy and Chaptal helped him put technical strategies in place. Monge (who originally taught him) and he had a close and friendly professional relationship, founding the École Polytechnique together — Carnot the technocrat, Monge the great teacher; Fourier was another colleague. Hegel visited him in exile, while he helped the Humboldts revolutionise Prussian technical and scientific education.