Yesterday I cited this 1910 article on telegraphers, focusing on the neurological implications of music and Morse occupying the same brain section.
The words are also interesting.
Telegraphers are usually nervous, high-strung men, and some develop eccentricities that cause them to be considered cranky.
High-strung is literal enough. It might have originated in the violin section of an orchestra, but the usage of the term pretty clearly follows the popularity of telegraphs and telephones:
(The later rise in the 1990s appears to be news articles about cocaine, especially in Wall Street.)
In mechanics, any part of a shaft that departs from the central axis is eccentric. Clear metaphor. Cranks are the most obvious eccentrics, and cams are also common.
I’ve reprinted and re-used the Foy telegraph too often, but it’s just too perfect in this case.
Crank and cam powering a telegraph:
We associate Morse himself with keys and sounders, not cranks. But the very first Morse invention was a paper tape system. The sending end was like a music box, with a pre-pegged surface pulled through a contactor by a crank:
So the active end of his first demonstration was cranked. The key replaced the music box quickly. His first patent was for a key sender and paper tape receiver. The sounder came much later after operators realized they were decoding from the sound of the pen hitting the paper, so they didn’t need the reels and tapes.
As always in genes and language and technology, the first invention contains all possible variations, and the practical versions branch off by simplifying one part or another.