Items

• [D9124AAQ], Letter from William Dennis Marks to Henry Wilson Spangler, University of Pennsylvania, May 7th, 1891
  1891-05-07
• [E1750AD], Letter from Thomas Alva Edison to University of Pennsylvania, Edgar Fahs Smith, June 16th, 1917
  1917-06-16
• [E1848AB], Letter from Thomas Alva Edison to University of Pennsylvania, Edgar Fahs Smith, January 10th, 1918
  1918-01-10
• [LB058666], Letter from Thomas Alva Edison to Eadweard Muybridge, University of Pennsylvania, February 21st, 1894
  1894-02-21
• [LB117098], Letter from Thomas Alva Edison to Edgar Fahs Smith, University of Pennsylvania, May 9th, 1917
  1917-05-09