[The following note describes all of the abandoned applications, Cases A-G.]
The originals of these seven applications, Cases A through G, for patents covering improvements in duplex telegraph apparatus were filed in April 1873. Case H, another application concerning duplex telegraphs (not present here), was filed on April 26, 1873. All eight applications were rejected in May 1873. Although some of these applications were subsequently amended, Cases A through G were eventually abandoned. Case H was amended in May 1873 and again in March 1875, and was issued as U.S. Patent 162,633 on April 27, 1875. Between 1876 and 1878 this patent became the subject of at least three suits involving the Western Union Telegraph Co. against Thomas A. Edison and George Harrington. (See the Quadruplex Case volumes in the Litigation Series.)
These certified copies of Cases A through G were obtained from the Patent Office on April 11, 1907 to be used as exhibits in Master's proceedings resulting from a suit brought in 1876 by George Harrington and Thomas Edison against the Atlantic and Pacific Telegraph Co. and Jay Gould in United States Circuit Court, Southern District of New York. On December 20, 1906 the Court ordered an accounting and appointed a Master to determine damages to be awarded to the Complainants for infringement of Edison telegraph patents. Hearings before the Master commenced in February 1907. The copies of the abandoned patent applications were introduced as Complainants' Accounting Exhibits numbers 67 through 73 on April 29, 1907. The first page of each application contains the inscription "C.A.Ex." written in ink and followed by the exhibit number. The applications are not reproduced in the printed record of the proceedings before the Master.
Courtesy of Thomas Edison National Historical Park.