Which is a unique or novel device, method, composition or process which involves an engineering and product development processes was done mostly in those early years before revolution and they brought about the world evolution and revolutions. Most Inventors were men and they came from the now most developed nations in the world. I am not sure whether there has never been an inventor from the least developed countries or the developed countries just stole the ideas of the “less privileged” countries. Have you ever heard of a black who is an inventor?