The dated entries in this notebook cover the period November-December 1880, but the book was probably begun earlier in the year. All of the entries are by William J. Hammer. Most of the material relates to the gathering of statistics for the Pearl Street district. Included are statistics that were copied from block survey books of the district and from answers to questions asked by the surveyors. There are also tables of tests relating to the second lot of one hundred lamps sent from the lamp factory to the laboratory for testing, a table of the first lot, notes and drawings of lamp experiments, and a drawing of a Brush arc light. The label on the front cover is marked "Electric Lamps Statistics &c &c Figuring," and "Wm. J. Hammer." The book contains 284 numbered pages and has been used in both directions.

Blank pages: 1-2, 9, 50-53, 90-91, 112-117, 120-123, 128-237, 240-245, 248-255, 270-271, 274-277, 282-283.

Missing page numbers: 3-8, 11-12, 21-22, 261-266.