A 13th century French mason who is known to have worked on several cathedrals from France to Hungary from the records he left in stone. However, he is more famous for his notebook he constructed for his students.

His notebook is a focus on geometric principals in relation to the world around us. People of his time often believed that geometry was the key to becoming a better person; as geometry itself was related to the divine notion of celestial spheres guiding the heavens.

The notebook contained several sketching tips, ideas in managing loads, a few mechanical principals, a saw powered by an overshoot waterwheel, and even a perpetual motion machine.

His notebook can still be seen in the National Library of France.