This notebook covers the period July-November 1880. The entries are by Charles L. Clarke. The book contains calculations, notes, and drawings relating to dynamos and steam engines for the jumbo dynamo. There are also tests of dynamos and motors, using meters with depositing plates to measure the current, and tests of the insulation for the electric railroad track. The label on the front cover is marked "C. L. Clarke." The book contains 284 numbered pages.
Blank pages: 222-257, 262-274, 277. Courtesy of Thomas Edison National Historical Park.