"My main purpose in life is to make money so that I can afford to carry on more experiments."

"I have not failed. I've just found 10,000 ways that won't work."

"My mind is a receptacle for everything useful. I don't care a rap for anything else."

"I am not a spiritualist, but I am a firm believer in the fact that we can communicate with the beyond. I believe that we can build a machine that will allow us to hear the voices of the dead."

"My principal business is to be a failure. I fail in a great many things. Every time I fail, I learn something. That is the way I succeed."