03/08/1898 Andress, Fred R [supplied or conjectured] to Edison, Thomas Alva
(Ogden Ore Separating Plant) Production difficulties and adjustments; Ore milling and separation [Incomplete]
[CJ011]  Company Records Series -- New Jersey and Pennsylvania Concentrating Works -- Administrative and Financial Records: Correspondence (1898)
[CJ011AAT; TAEM 149:856]
Courtesy of Thomas Edison National Historical Park.