Both pneumatics and hydraulics are applications of fluid power. The system was thus entirely electromechanical, without hydraulics, pneumatics or electronics. The device used pneumatics and hydraulics for movement and silicone based skin. Most are powered by either hydraulics or possibly pneumatics. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Advanced use of Lego pneumatics has been made in various Lego Mindstorms creations. In the early 1980s Atlas Copco was the world leader in rock drilling and pneumatics. There is also a materials lab along with electrical/electronic and pneumatics labs. Alternative methods of motive power include magnetic levitation, horse-drawn, cable, gravity, pneumatics and gas turbine. Aerodynamic sources include fans, pneumatics, and combustion. Also, a train can be powered by horses, cables, gravity, pneumatics and gas turbines. He described the construction of such automata in his treatise on pneumatics. This design places an exceeding demand upon precision engineering due to the lack of pneumatics. Walking braces controlled by pneumatics are also used. His subsequent experimental work focused on chemistry and pneumatics.