This sub-ledger covers the period June 1890-December 1896. It consists of cost accounts for the various experiments performed at the laboratory. The book contains 453 numbered pages and an index. The spine is stamped "Labor & Material Sub-Ledger. No. 6. Laboratory T. A. Edison, Orange, N.J." It is labeled "9A" and "June 1890 to Jany 1896."

Blank pages: 90-97, 104-225.

This book was microfilmed at a reduction ratio of 16:1.

Courtesy of Thomas Edison National Historical Park.