"a radiophone system would be very popular in a country town, as everybody can hear what everybody else is saying simply by properly tuning their receiving apparatus," said professor power, laughing.
"these lines illustrate radiophone messages going through the air in all directions." he said, holding up the drawing he had made. "the problem is to make them selective, that is, to prevent tom, dick, and harry who has a receiving set from listening in on any conversation that sounds interesting."
"like love talk," i suggested.
"yes." he said, smiling. "lovers ought to learn a code if they intend using the radiophone to exchange 'sweet nothings.' "
"don't they use a code of their own now?" i asked.
"yes," he replied, "but it is one that is universally understood."