Inside Out Library · ExploreHistory, theory, and practice of the electric telegraph (1866)Prescott, George B.(George Bartlett),1830-1894 · Boston, Ticknor and Fields · leaf 62Fig. 24.TelegraphInternet Archive · Medical Heritage Library · Public Domain Mark 1.0. Free to use for anything.More pictures from History, theory, and practice of the electric telegraphMore like this
