[LB062352A], Letter from Thomas Alva Edison to John Sophronus McKay, March 27th, 1896
https://edisondigital.rutgers.edu/document/LB062352A
Transcription
Mar 27 96 John S. McKay Esq- The Packer Collegiate Institute Brooklyn. N. Y. Dear Sir :- In reply to your favor of the 21st inst, I beg to state that I have given up trying to make powerful tubes separated from the pumps. I am getting up a portable pump which will be illustrated in electrical papers then one can get reliability and powerful results Yours truly Thos. A. Edison R[andolph].