[LB062401], Letter from Thomas Alva Edison to Michael Idvorsky Pupin, April 2nd, 1896
https://edisondigital.rutgers.edu/document/LB062401
Transcription
April 2nd 1896. Prof M. I. Pupin Columbia College New York. Friend Pupin:- I am glad you like the Fluoroscope. If I Can only render stable certain Tubes which I have made, I will also send you one which I think will surprise you, and aid you in your scientific investigations which is out of my line. Yours truly Thomas A Edison