Telegrams were first used in 1839 in Holland and were used elsewhere in the late 1800s.
cypher codes
they mostly used telegrams!
There were about 14 telegrams
Not in an historical context. Telegrams cost per word, so the fewer words, the less expensive the telegram. Telegrams are purely historical at this point; in the US they can no longer be sent.
typr writers, telegrams, radios
Central Bureau for Astronomical Telegrams was created in 1882.
There were no other forms of media available in the 1930s and 40s by which the governments could alert their nations about the war. Most families and businesses had radios. Television was not around then. Telegrams were sent too.
I have heard that term in several old movies and TV shows. Though I don't know much about it, I can say that the clerks almost always asked "straight wire" or "night service." I can also state that straight wires were delivered, in the movies anyway, within an hour.
Telegrams these days are different than telegrams "in the old days". You can still send telegrams all over the world, in a couple of hours if necessary. The big difference's is the way telegrams are send over the world. In earlier days telegrams where send by the telegraph-lines with Morse codes. At the other side of the line these codes where translated to words again and brought by messenger to the receiver. Today we don't use Morse codes anymore, but telegrams are still very important. You can use telegrams to congratulate someone, to send your deepest sympathy or wish someone much luck. Any occasion you can think of, a telegram will bring the message!
Japanese telegrams of "weather reports" were actually attack plans
They talked to each other, wrote letters, used the telephone, and sent telegrams.