This subsidiary ledger covers the period March 1908-July 1916, although most of the entries are from 1908-1912. It consists of accounts, arranged alphabetically, for various experiments at the laboratory, along with accounts for Glenmont. Entries for experimental expense accounts include the project numbers assigned in laboratory record books N-01-03-15 and N-10-07-26. The totals for these accounts were posted monthly to General Ledger #9 under the heading, "Experimental Accounts." An alphabetical index to the account numbers in this ledger can be found in Experimental Expense Ledger (1912-1916). The front cover is labeled "Thomas A. Edison Laboratory  Work In Process Ledger  1908- 1912." The pages are unnumbered. Approximately 700 pages have been used.