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Crime Machines. Members of the New York Electrical Society watched Dr. A. P. Link of New York University attach an electrically-amplified stethoscope, developed by the Bell Telephone laboratories, to the chests of three young men, in turn. The third one had previously been sent from the room with instructions that one of them commit a "crime" (steal $10 from an overcoat upstairs). The stethoscope amplified the suspects' heartbeats 100,000 times, making them sound like pounded tom-toms. The "innocent" hearts beat steadily during questioning. The "guilty" speeded up, syncopated, despite its owner's efforts to stay calm. Another device spotted the culprit by flashing upon a screen a light which danced brightly when, during "guilty excitement," the electrical resistance of his skin was lowered.