This notebook dates from April 1886. The few entries are by Edison and concern the speed of the earth around the sun and the design of quadruplex and phonoplex telegraphs. The first page contains the notation: "Present By T. A. Edison Apr 3rd 1886 Ft. Myers." There are 286 numbered pages.

Blank pages: 2-3, 18-286.

Courtesy of Thomas Edison National Historical Park.