This notebook covers the period December 1887-November 1889. All entries are by Edison. The book contains drawings and several long notes relating to filament experiments. There are also phonograph drawings; notes on battery solutions; and notes, drawings, and cost calculations regarding ore milling and hydroelectric power production at Niagara Falls. On the inside back cover is a list of points to include in an electric railway caveat. The pages are unnumbered. Approximately 120 pages have been used.
[NA015AAA], Technical Note, Thomas Alva Edison, December 10th, 1887 1887-12-10
[NA015AAB], Technical Note, Thomas Alva Edison, September 9th, 1888 1888-09-09
[NA015AAC], Technical Note, Thomas Alva Edison, May 18th, 1889 1889-05-18
[NA015AAD], Technical Note, Thomas Alva Edison, November 6th, 1889 1889-11-06