This notebook covers the period July 1871-March 1872, with a few entries for 1874 and 1875. The majority of the notes and drawings are in Edison's hand and deal with the development of printing telegraphy. Some notes also describe experiments with chemicals for the electromotograph. Edison signed and dated most of the entries. The names of Joseph Murray and Samuel Edison frequently appear as witnesses. The front cover is labeled "Vol 6." The book contains 298 numbered pages.

Blank pages: 70-73, 76-151, 158-183, 186-235, 237-298.