JF Ptak Science Books Quick Post
There is a wonderful, short paper by Lord Rayleigh in the August 21, 1873 issue of Nature on echoes, "Harmonic Echoes", echoes which have a life of their own, seemingly, after their initiation....echoes with 5 or 10 or more reverberations, echoes which seem to advance, or recede or both.
The mythological, beautiful nymph, Echo, a creature of Greek invention--or discovery--was much in love with her own voice and thus some of this interest in repetitive reverberations. Echo was interested in Narcissus, which means that between the two of them, there was more more than enough interest in them for anyone outside themselves, but neither could get enough of themselves. And with Echo there were others who couldn't get enough of her, though she denied herself to everyone. And so the tragedy. Pan wants her, the old lech, and is denied, and becomes enraged which leads to her tragedy of being torn to pieces. She is resurrected, a little bit, her voice surviving everything else, repeating the last words of others.
I've repeated below a story on the Rayleigh paper which in some respects is as interesting as the original.