For a good book has this quality, that it is not merely a petrifaction of its author, but that once it has been tossed behind, like Deucalion's little stone, it acquires a separate and vivid life of its own.
Before I put a sketch on paper, the whole idea is worked out mentally. In my mind I change the construction, make improvements, and even operate the device. Without ever having drawn a sketch I can give the measurements of all parts to workmen, and when completed all these parts will fit, just as certainly as though I had made the actual drawings. It is immaterial to me whether I run my machine in my mind or test it in my shop. The inventions I have conceived in this way have always worked. In thirty years there has not been a single exception. My first electric motor, the vacuum wireless light, my turbine engine and many other devices have all been developed in exactly this way.
My method is different. I do not rush into actual work. When I get a new idea, I start at once building it up in my imagination, and make improvements and operate the device in my mind. When I have gone so far as to embody everything in my invention, every possible improvement I can think of, and when I see no fault anywhere, I put into concrete form the final product of my brain.
It's not my story anymore: whenever I speak about the past now, I feel as if I were talking about something that has nothing to do with me. All that remains in the present are the voice, the presence, and the importance of fulfilling my mission. I don't regret difficulties I experienced; I think they helped me to become the person I am today, I feel the way a warrior must feel after years of training; he doesn't remember the details of everything he learned, but he knows how to strike when the time is right.