Inside Out Library · ExploreTwentieth century manual of railway and commercial telegraphy (1905)Meyer, Frederic Louis, b. 1875 · Chicago, New York, Rand, McNally & Company · leaf 119Back Up, Train Parted. 116 THE TWENTIETH CENTUEYEngine Signals.TelegraphInternet Archive · Northeastern University Library · Public Domain Mark 1.0. Free to use for anything.More pictures from Twentieth century manual of railway and commercial telegraphyMore like this
