American inventor of the phonograph.
Autograph Letter Signed, Thomas Edison, in pencil, two pages, octavo, undated. To Fagan.
“Call Patterson’s attention to the fact that if 90 grams of Lithia is right for say an A4 it is not right for any other size as we have found out at Lab. There is an unknown relation between the Lithia, the amount of solution & capacity of the cell-a single tube cell gives best results with 2 grams of Lithia but this would be 240 grams to an A4 & this is fatal altho OK for a single tube.”
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