These letters, which cover the period August 1877-September 1878, relate to Thomas E. Cornish, an electrical supply dealer who became the first president of the Bell Telephone Co. of Philadelphia. They pertain to the organization of the Bell Telephone Co., competition with Western Union, and various technical improvements of the Bell telephone. The correspondents include Gardiner G. Hubbard and Thomas A. Watson, officials of the Bell Telephone Co., and Henry Bentley, president of the Philadelphia Local Telegraph Co.