Mental Telegraphy (extract)

Mark Twain, 1891

The aberrations which gave Leverrier the idea that there must be a planet of such and such mass and such and such orbit hidden from sight out yonder in the remote abysses of space were not new; they had been noticed by astronomers for generations.

Then why should it happen to occur to three people, widely separated - Leverrier, Mrs. Somerville, and Adams - to suddenly go to worrying about those aberrations all at the same time, and set themselves to work to find out what caused them, and to measure and weigh an invisible planet, and calculate its orbit, and hunt it down and catch it? - a strange project which nobody but they had ever thought of before.

If one astronomer had invented that odd and happy project fifty years before, don't you think he would have telegraphed it to several others without knowing it?