This notebook covers the period October-December 1880. The entries are by Francis Upton. There is also one entry by Edison near the end of the book. The book contains notes, calculations, and a few drawings relating to lamp tests and to the wiring of the lamp factory. There are also notes and calculations regarding central stations, including estimates of costs and horsepower to be sold. In addition, there are notes, calculations, and a few drawings of isolated plants for the Vanderbilt home and for a building on 5th Avenue (probably the Edison Electric Light Co. headquarters). The label on the front cover is marked "Upton" and "Calculations." The book contains 290 numbered pages.

Blank pages: 276-283, 286-287.