Do you mean that telegrams are no longer available?
Anyway, before the Internet era, did telegraphs use letters?
Tempting Apple: Electronic communication over wires, optical fibre or radio uses binary coding (well, Morse was binary, or quatenary – dash, dot, gap, long gap), now like Manchester encoding that provides error correction and the ability to use an AC-coupled connection. The data would be ASCII, or now UTF-8 bytes, corresponding to letters. As used in email or the Web.
Telegrams are still in use. I'm not sure what technology is used to actually send the message – email, probably. In the UK in the 1970's it was common to send telegrams of congratulation at weddings, or to people who had no phone service. I assumed that the Post Office would make a long-distance phone call and an operator take dictation , but I may be totally wrong. The message arrived as strips of uppercase typewritten text pasted onto a card, later actually typed on a card.
Telegraphs used dots and dashes (Morse Code) to send messages via electronic "clicks." The same code could be used with a light source as well.
Telegraphs are still in use today: http://world.time.com/2013/07/14/reports…
I don't think there's any telegraphs in operation. The telephone made them obsolete. Now with e-mail, texts and every other communication device, we no longer need telegraphs.
Nope! They use numbers: But other than that it's still all just zeros and ones.
In information storage and retrieval Nothin' changes, eh! ("Dots and dashes" are not letters).
Then they used dots and dashes,
now they use ones and zeros,