This notebook was used by Paul D. Payne during October 1920-August 1921 for notes on storage battery experiments. There are also a few additional entries from July and September 1922. Included are notes relating to battery applications and improvements, such as a miner\'s lamp, w-type audion, and hand flashlight. There are several references indicating that Payne was working under Edison\'s supervision. Two notes in Edison\'s hand have been inserted into the book. The front cover is marked \"P. D. Payne.\"" The book contains 143 numbered pages, some of which are blank, followed by 4 unnumbered pages."