This volume covers the period October 1878-March 1880. It contains weekly statements of expenditures. The statements relate primarily to experimental projects, including the electric light, the dynamo, and the direct converter. Each set of statements is glued or pinned to a page in the book. At the beginning of the book is a record of the visitors to the Menlo Park laboratory from December 1879 through February 1880. There are 318 numbered pages. Numerous pages have been torn out of the book.
Page 45 was published as Doc. 1562 in The Papers of Thomas A. Edison, Vol. 4.
Blank pages: 2-9, 18-177, 202-213, 216-227, 232-237, 240.
Missing page numbers: 11-14, 197-198, 229-230.