This letterbook, covering the years 1876-1877, is divided into three parts. Pages 1-98 contain correspondence from January-May 1876, primarily in the hand of Charles Batchelor, writing as general manager of the Edison Electrical Pen and Duplicating Press Co. to the company's sales agents. Some of the correspondence refers to the removal of Edison and his associates from Newark to Menlo Park. On pages 101-131 can be found a three-page letter by Edison, dated October 26, 1876, discussing patent infringements against the electric pen, followed by other correspondence from 1877.

The third part of the volume begins on page 493 and runs in reverse order to page 284. It consists of tests and samples of Edison's duplicating ink in the form of spurious letters, doggerel, and numerous renditions of the Lord's Prayer. Most of the tests have been numbered and generally run about nine or ten pages, with the ink on each page becoming progressively fainter until the beginning of the next test. Most have been signed and many contain comments by Edison or Batchelor. Twenty-one pages of duplicating ink tests have been selected.

The book contains 505 numbered pages, of which 80 are missing. The volume is not indexed, although one of its index pages contains spurious letters and doodles signed by Charles P. Edison.