Items

• [D8120ZAY], Letter from U.S. Signal Corps, William Babcock Hazen to Thomas Alva Edison, September 30th, 1881
  1881-09-30
• [D8120ZBB], Letter from U.S. Signal Corps, William Babcock Hazen to Thomas Alva Edison, October 12th, 1881
  1881-10-12
• [D8403ZES], Letter from U.S. Signal Corps, William Babcock Hazen to Thomas Alva Edison, July 14th, 1884
  1884-07-14
• [D8403ZFP], Letter from William Babcock Hazen, U.S. Signal Corps to Thomas Alva Edison, August 18th, 1884
  1884-08-18
• [D8403ZFY], Letter from U.S. Signal Corps, William Babcock Hazen to Thomas Alva Edison, August 25th, 1884
  1884-08-25