•Flying Machines- his journals have sketches of machines that allow humans to 'fly'. He also drew sketches of helicopters (aerial screw) and parachutes
•Water Machines- He drew submarines, but refused to share it with the world because he thought they would be used for evil more than good. He studied properties of water in motion and density
•Other Machines- He drew machines that resemble the modern tank and machines that are now like the machine gun.
• He was fascinated with the human body and studied anatomy frequently. He could be considered the first medical examiner
