History, theory, and practice of the electric telegraph (1866)
Prescott, George B.(George Bartlett),1830-1894 · Boston, Ticknor and Fields · leaf 93
Fig. 32. 74 ELECTRIC TELEGRAPH APPARATUS. bar, called an armature, is attached to a brass lever sustained in ahorizontal position by two pivots. The soft iron armature isattached to one end of this lever, while the other end is armedwith a steel point, which is called a pen. Under the point of… … C?^ o Fig. 33. At the extremity of the circuit whence the despatch sets out isa battery, one of the poles of which communicates with theground, whilst the other pole may be put at pleasure into com-munication with the insulated wire, by which the two stations areconnected. If the circuit is closed…
Telegraph
Internet Archive · Medical Heritage Library · Public Domain Mark 1.0. Free to use for anything.
