Telegrams were faster than letters, and were usually delivered the same day, sometimes even late at night. Letters, especially from afar, sometimes took several days to deliver. Furthermore, telegrams usually conveyed a sense of importance or urgency, since they cost much more to send than a letter.

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.

Central Bureau for Astronomical Telegrams was created in 1882.

Telegrams were first used in 1839 in Holland and were used elsewhere in the late 1800s.