6 Historical notes Telegraphy and Telephony •1837: Samuel Morse developed the electric telegraph (and some years later the well-known variable length
{"Image DocumentName": "Historical notes Telegraphy and Telephony", "Image ImageDescription": "1837: Samuel Morse developed the electric telegraph (and some years later the well-known variable length binary code) 1858: First transatlantic cable linking US and Europe. 1875: Emile Baudot developed a fixed length binary code (in which each letter was encoded using 5 bits) 1876: Alexander Graham Bell invented telephone. 1915: Long distance telephone transmission was made possible (mainly due to the invention of triode amplifier in 1906). The first transatlantic cable for telephone services became available in : Strowger developed the first (electromechanical) automatic switch. The first digital switch was developed in 1960.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}