From The Case of the Bigamous Spouse:

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“Can you,” she asked, “tell me the principle on which the telephone works, and how a voice can be transferred into electrical vibrations sent over a wire and then those vibrations again turned back into audible sounds so that the voice seems to come through the receiver?”

“Certainly,” Mason said. “You simply drop a dime in the slot indicated for such purpose.”

“Can you,” Della Street asked, “tell me why it is that it is noon in New York when it is only nine o’clock in Los Angeles?”

“Of course,” Mason said. “The people in New York get up three hours earlier.”