The mention of electricity brought up new possibilities for future
discovery, some of them so amazing as to almost pass the bounds of
credibility. He said:
"Morse taught the world years ago to write at a distance by
electricity; the telephone enables us to talk at a distance by
electricity; and now scientists are agreed that there is no
theoretical reason why the well-known principles of light should not
be applied in the same way that the principles of sound have been
applied in the telephone, and thus allow us to see at a distance by
electricity. It is some ten years since the scientific papers of the
world were greatly exercised over a report that I had filed at the
Smithsonian Institution a sealed packet supposed to contain a method
of doing this very thing; that is, transmit the vision of persons and
things from one point on the earth to another. As a matter of fact,
there was no truth in the report, but it resulted in stirring up a
dozen scientific men of eminence to come out with statements to the
effect that they too had discovered various methods of seeing by
electricity. That shows what I know to be the case, that men are
working at this great problem in many laboratories, and I firmly
believe it will be solved one day.
"Of course, while the principle of seeing by electricity at a distance
is precisely that applied in the telephone, yet it will be very much
more difficult to construct such an apparatus, owing to the immensely
greater rapidity with which the vibrations of light take place when
compared with the vibrations of sound. It is merely a question,
however, of finding a diaphragm which will be sufficiently sensitive
to receive these vibrations and produce the corresponding electrical
variations."