Engineering (technical drawings, etc.)
Technical drawings with a lot of mechanical devices. Steam engines, turbines,...
Technology (parts of engines, etc.)
Steam engines, turbines, pumps, motors, details as valves, propellers etc....
The Energy (forms of energy, etc.)
Considerations about the origin and the meaning of the energy and the matter...
Polytechnic (regulation, accuracy, etc.)
Considerations about measurement and regulation of technical processes. ...