I thought it was common knowledge that Bell ripped the idea off from Gray.

Bell's patent application was less a description of how the phone worked, more a 'wouldn't it be nice if we had a telephone' description.

Gray's patent application, filed the same day I believe, had the workings of the mic involved.

Then, in the margins of Bell's application, appeared a tiny sketch that was an exact copy of Gray's description - same microphone, same mechanism...same head. The smoking gun's been smoking for years.

It was covered rather well in one episode of a series called 'Inventions that Changed The World' by the BBC presented by Jeremy Clarkson - must have been 5 years ago.

Maybe this book will bring all the facts and evidence together well, but smoking gun is already well known.