Figure 51 represents a side view of the apparatus, used at the _receiving_ station: _a, a_ is a side view of the multiplier, composed of 30,000 feet of wire, (almost 5½ miles,) upon a table, B: _n, s_ is the magnetic bar, weighing 30 pounds, from which rises a vertical stem, _o_, upon which is a rod at right angles, supporting a mirror, H, on one end, and at the other a metallic ball, I, as a counteracting weight to that of the mirror. The magnetic bar is suspended by a small wire, fastened to the vertical stem, and at the top is wound round the spiral of the screw, _i_, which turns in the standards, _h′_ and _h_, upon the platform, A, and which is secured to the ceiling. In the standards, _h′_, there is cut a female screw, of the same gradation as that upon which the wire is wound. By this means, the magnetic bar may be raised or let down, by turning the screw, without taking the bar from its central position in the multiplier: _g_ is a screw for fastening the spiral shaft, when properly adjusted. P and N are the two ends of the wire of the multiplier. G is a stand for supporting the spy-glass, D, and also the case, E, into which slides the scale, F. The mirror, H, is at right angles with the magnetic bar, and presents its face to the spy-glass, D, as also to the scale at E. It is so adjusted, that the reflection of the scale at E, from the mirror, may be distinctly seen by the spy-glass. If the magnetic bar turns either to the right or left, the mirror must move with it, and if a person is observing it through the spy-glass, the scale will appear to move at the same time, thereby presenting to the eye of the observer another part of the scale than that seen when the bar is not deflected. The figures on the scale will show in what direction the bar has turned, and thus render it distinct to the observer, the only apparent object of the mirror, spy-glass and scale. For the purpose of generating the galvanic fluid, they use the magneto electric machine. Their plan, being unwieldy and difficult to operate, is omitted, and in its stead, we introduce that form of it, invented by Dr. Page, which has already been described in figures 45, 46 and 47. There is also required for the purpose of making the desired deflections of the magnetic bar, a commutator, or pole changer, such as we have described in figures 48, 49 and 50. Figure 51 represents that portion of the apparatus at the _receiving_ station. The magneto electric machine, and the pole changer, properly connected, are the instruments of the _transmitting_ station. Two wires, or one wire and the ground, form the circuit between these two stations. The machine is put in operation by turning the crank, and the person sending the intelligence is stationed at the commutator, and directs the current through the extended wires to the multiplier of the receiving station, so as to deflect the bar to the right or left, in any succession he may choose, or suspend its action for any length of time.