Search Results 2 items were found.

Keywords: Chapman, William H. (inventor)

  1. Item 12538
    Chapman electric neutralizing machine, Portland Company, ca. 1904
    Chapman electric neutralizing machine, Portland Company, ca. 1904
    Contributed by: Maine Historical Society
    Date: circa 1904
    Location: Portland
    Media: Ink on paper
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  2. Item 12544
    W.H.C. Automatic Voltage Regulators, Portland Company, ca. 1904
    W.H.C. Automatic Voltage Regulators, Portland Company, ca. 1904
    Contributed by: Maine Historical Society
    Date: circa 1904
    Location: Portland
    Media: Ink on paper, Photographic print
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