These documents cover the period February 1877-May 1878. They relate to the organization of the Bell Telephone Co., competition between rival telephone inventors, and observations regarding Edison's carbon telephone. The correspondents include inventors Alexander Graham Bell, Amos E. Dolbear, and Elisha Gray; Gardiner G. Hubbard, president of the Bell Telephone Co. and Bell's father-in-law; Percival D. Richards, Bell's neighbor and friend; Thomas A. Watson, chief electrician and superintendent of the Bell company; and George L. Bradley, Thomas B. A. David, and Hilborne L. Roosevelt, businessmen associated with the Bell system. Also included is a draft patent specification, probably from April 1878, for an improvement in the carbon telephone.