what year did thomas edison invent the quadruplex telegraph
Within a year or two, Western Union and other telegraph companies were using diplex telegraphs on their busiest lines in major cities. In 1874, Thomas Edison invented the first quadruplex telegraph, which was capable of sending two messages simultaneously in each direction.ears later, quadruplex telegraphs were displaced by two new inventions, multiplex telegraphy capable of eight or more simultaneous transmissions, and the use of teletype machines, which did not require their operators to know Morse Code.