This notebook covers the periods March 1887 and March 1901. All entries are by Edison. The first entry is undated and relates to battery experiments. It is followed by a set of notes and a drawing from 1887 pertaining to the development of an economical prime motor (probably his magnocaloric motor). In the course of making these notes, Edison recorded a discovery regarding magnetized iron. Following these entries are additional notes about battery experiments. The next dated entry is from March 1901 and concerns Edison\'s theoretical speculations on electricity and magnetism. There are also a series of hypotheses and some notes about thermoelectricity. The remainder of the book consists of miscellaneous notes, drawings, and calculations about thermoelectricity and batteries and some drawings that appear to be plans for an ore milling plant. The book contains 284 numbered pages.

Blank pages: 48-75, 78-97, 114-135, 168-175, 182-259, 266, 269-271, 276-277, 280-281.

Missing page numbers: 267-268.