Items

• [D0707ABH], Letter from Heller and Merz Co to Thomas Alva Edison, December 19th, 1907
  1907-12-19
• [D0707ABK], Letter from Heller and Merz Co to Thomas Alva Edison, December 28th, 1907
  1907-12-28
• [D0807ABU], Letter from Heller and Merz Co to Thomas Alva Edison, September 15th, 1908
  1908-09-15
• [E1518ABR], Letter from Heller and Merz Co to William Henry Meadowcroft, January 26th, 1915
  1915-01-26
• [E1518BBF], Letter from Heller and Merz Co to Thomas Alva Edison, February 22nd, 1915
  1915-02-22