[LB063145], Letter from Thomas Alva Edison to Samuel Insull, May 2nd, 1898
https://edisondigital.rutgers.edu/document/LB063145
Transcription
May 2/98 My Dear Insull Yours of April 29 received. The phrase “Central Station” was coined I think by myself or some of the boys at the Laboratory at Menlo Park in the days when guessing was a substitute for mathematics Yours Edison