It is common knowledge that Bell invented the telephone. (Although as many times as I got called during this last election I'm not so sure it was a good idea.) But it was a time when great advances were being made in such devices. There were other inventors such as Meucci in Europe and Oki in Japan who were doing the same thing.
What is less known is that Bell was an inventor in many areas, rather like Edison or Tesla, he worked in many areas: sonar, ultra sound, iron lung, electric heating, and many more.
Perhaps as outstanding was his subsequent creation of The Bell Telephone Company. He had the ability to make the fundamental invention and then to capitalize on it to create a giant company where there had been nothing before, rather like Bill Gates was able to do in our time.
This is a major biography, it contains original research and understanding into his life combined with an excellent writing style that brings his life to life.