This notebook covers the period March-April and December 1881. Most of the entries are by Francis Jehl. The book contains notes and calculations relating to meter experiments and to tests of dynamos and wires. Included also is a summary by Edward L. Nichols of the meter experiments. The label on the front cover is marked "Francis Jehl." The book contains 278 numbered pages. The last few pages have been torn out of the book. Courtesy of Thomas Edison National Historical Park.