A travel monologue becomes a travelogue and a telegram sent by cable a cablegram.
From the en.wikipedia.org
The term cablegram is also sometimes used.
From the en.wikipedia.org
It is less likely to be leaked, and enables more personal contact than the formal cablegram, with its wide distribution and impersonal style.
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More examples
Cable: a telegram sent abroad
Telegraphy (from Greek: u03C4u1FC6u03BBu03B5 tu00EAle, "at a distance" and u03B3u03C1u03ACu03C6u03B5u03B9u03BD gru00E1phein, "to write") is the long-distance transmission of textual or symbolic (as opposed to verbal or audio) messages without the physical exchange of an object bearing the message. Thus semaphore is a method of telegraphy, whereas pigeon post is not.