Tom Swift and His Photo Telephone

"Tom, I don't believe it can be done!""But, Dad, I'm sure it can!"Tom Swift looked over at his father, who was seated in an easy chair in the library. The elderly gentleman-his hair was quite white now-slowly shook his head, as he murmured again: "It can't be done, Tom! It can't be done! I admit that you've made a lot of wonderful things-things I never dreamed of-but this is too much. To transmit pictures over a telephone wire, so that persons cannot only see to whom they are talking, as well as hear them-well, to be frank with you, Tom, I should be sorry to see you waste your time trying to invent such a thing.