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TELEGRAPH
The idea appeared in Samuel Morse's mind when he listen a conversation about electromagnetism. -
TELEGRAPH: Morse code
The telegraph used Morse code, a really simple code that used dots and dashes. It could easily be implement in the technology of that time, closing briefly for a dot and keeping longer for a line. -
TELEGRAPH: 1st demostartion
Morse did the first public demostration sending a message from Washintong to a railway in Baltimore. The first sentence sent was "What hath God wrought?" -
MULTIPLEXING
It allowed people to send several messages using the same cable. Also a submarine cable made possible the communication between Europe and America. (1866) -
FIXED TELEPHONE: Meucci
In 2002, Meucci was recognized as the first one to transmitted the human voice across a distance using an electronical device in 1860. -
FIXED TELEPHONE: Alexander Bell
Alexander Graham Bell obtained the telephone patent after winning in the court. Is thanks to him that the telephone was industrialy produced, popularised and improved. -
MOBILE PHONE
The first handheld cellular mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing 2 kilograms. -
MOBILE PHONE: 1st Prototype
It weighed 1.1 kg and measured 22.86 cm long, 12.7 cm deep, and 4.44 cm wide. It offered a talk time of about 20 minutes and took 10 hours to recharge. The only problem was the difficult to hold something of that weight and size to an ear for more than 20 minutes. -
TELEPHONE: Past and Actuality
This is a curious picture where we can see a man speking with a mobile telephone near a telephone box.
