The dated entries in this notebook cover the period September-October 1880, but the book was probably begun earlier in the year. Most of the entries are by Francis Upton. There are also a few entries by Edison and probably by William J. Hammer. The material by Upton includes calculations about the cost of a central station; calculations about the conductors needed for the first New York central station (another member of the staff, probably Hammer, assisted Upton in gathering the statistics); and calculations concerning the location of the New York central station. The material by Edison includes calculations and drawings relating to tubes for conductors, along with calculations about the conductors needed for the New York central station. The label on the front cover is marked "Upton" and "Estimates Conductors." The book contains 284 numbered pages.

Blank pages: 174-175, 270-281.

Missing page numbers: 107-108, 223-226.