Items

• [D9102ABH], Letter from Sigmund Bergmann to Thomas Alva Edison, March 30th, 1891
  1891-03-30
• [D9111AAI], Letter from John Pelzer to John F Randolph, December 6th, 1891
  1891-12-06
• [NM025106], Technical Note, Arthur Edwin Kennelly, August 21st, 1890
  1890-08-21