Notebook #56 N-79-07-25 (1879-1880)
This notebook covers the period July 1879-August 1880. The first part of the book contains entries by Edison, Charles Batchelor, John Kruesi, and Francis Upton and relates primarily to electric lighting. Included are drawings of lamp regulators and clamps; calculations and drawings of generators; notes, tables, and drawings of conductors; and calculations about electric power distribution. There is also a memorandum by Edison on the cost of telephone parts. The second part of the book contains memoranda by Kruesi concerning material to be ordered for the extension of the machine shop and material required for generators. There are also notes on the Porter steam engine and a map of Menlo Park containing a plan for the placement of electric lights. The book contains 284 numbered pages.
Blank pages: 32-33, 68-69, 72-83, 86-105, 132-135, 144-153, 162-165, 190-191, 200-201, 232-235, 252-253, 260-263, 266-279.
Missing page numbers: 118-120.