This notebook covers the period September 1887-October 1889. All entries are by Edison. The book contains drawings and occasional calculations relating to the electric railway, dynamos, and 3- and 4-wire electrical distribution systems. In addition, there are drawings and patent caveats for the phonograph, typewriter, and spiral kinetoscope. There is also a list of cost calculations for an ore milling system.The book contains 245 numbered pages and has been used in both directions. Two loose pages have been inserted into the book.

The notebook pages appear in the following order: 1-149, 245-154; loose items.

Blank pages: 8-9, 16-19, 112-115, 126-133, 138-141, 144-145, 150-153, 156-159.