The telephonic work of Spanish pioneer electrician Enrique Bonnet

The authors summarize the results of their research to bring to light and put into an international context the activities of this little-known, Cádiz-based inventor and entrepreneur who seems to have built Bell-type telephones as early as 1876, introducing his own commercial version in January 1878. In June 1878 he also had Hughes-type microphones for sale, and one year later he had combined them with his telephones in a set that included all the necessary elements to make and receive calls. Details of these instruments are given, taken from the descriptions written by Bonnet himself in an 1882 patent, and by one of his superiors in the State Telegraphs in a book published in 1884. Some considerations on the diffusion of his apparatus are also included.