Philo Farnsworth Transmits Electronic Television Image

Twenty-one-year-old Philo Farnsworth used his image dissector tube to transmit a single horizontal line painted on a glass slide from one room to another at his San Francisco laboratory on Green Street. The fully electronic system scanned images without any mechanical moving parts, unlike competing designs by Baird and others. Farnsworth had conceived the idea at age fourteen while plowing a potato field in Idaho, envisioning electron beams scanning an image line by line. Eight months later he demonstrated the device to investors, transmitting a dollar sign.