This notebook has no dated entries but was probably used in 1880. All of the entries are by Francis Upton, with the exception of one entry by Edison, and relate to calculations for a central station system. Most of the entries are block-by-block calculations of the copper needed for the Pearl Street district. There are also a series of notes and calculations relating to the economy of the central distribution system and to the cost of a system of 10,000 lamps as compared to the cost of gas. The label on the front cover is marked "Hammer" and "N.Y. Cen. Station." The book contains 284 numbered pages.

Blank pages: 1, 138-284.