[LB062380], Letter from Thomas Alva Edison to Phoenix Glass Co, April 1st, 1896
https://edisondigital.rutgers.edu/document/LB062380
Transcription
April 1st 1896 The Phoenix Glass Company New Brighton Beaver County Penna. Dear Sirs:- I find that the glass plates used for photograph dry plates retard the X Rays very little. It would be a great aid to us experimenters if you would draw a few tubes and send by express of this kind of glass 3/4 of an inch in diameter and 1/16 of an inch wall. I am not sure that you make this quality of glass. I suppose its a good quality of window glass. Anything you can in regard to the above will be very much appreciated Yours truly- Thomas A Edison