Figure 71 represents a top view of that part of the instrument at the _receiving_ station, by which the signals are recorded. The seven wires on the left of the figure are a continuation of those wires, marked ̈1, ̈2, ̈3, ̈4, ̈5, ̈6, and 8, in figure 70. The first six pass through a wooden support, _b_ and _b_, and terminate upon the edge of the platinum rings, _a_, _a_, _a_, _a_, _a_ and _a_, forming a metallic contact. The six platinum rings surround a wooden insulating cylinder, _t_, which revolves upon axes in the standards, _h_ and _i_. The rings are _broad_ where they come in contact with the wooden roller, and are bevelled to an _edge_ where they come in contact with the six wires. Y represents a compound battery, with one pole of which, wire 8, from the needle arrangement, figure 70, is connected, and from the other pole the wire proceeds to the electro magnet, Z, Z; it then passes on and is brought in connection with the metallic cylinder, _d_, at the point, _g_. The cylinder, _d_, revolves upon axes, and is supported in the standards, _k_ and _l_. To the cylinder is attached a barrel, _n_, upon which is wound a cord, supporting the weight, _e_, by which the cylinder is made to revolve. C′, C′, represents a prepared fabric, such as calico, (impregnated with hydriodate of potass and muriate of lime,) and is placed between the platinum rings, _a, a, a, a, a, a_, and the metallic cylinder, _d_; _o_ is a cog wheel upon the end of the axis of the cylinder, _d_, and is connected with other machinery, omitted here, but shown in figure 72, which is a side elevation of part of figure 71: _o_ is the cog wheel, (figure 72,) on the arbor of the cylinder, _d_. B and B, are the two sides of the frame containing the clock work, and is secured to the platform, R: _d_ is a part only of the metallic cylinder, upon which is seen a portion of the prepared fabric, K. The cog wheel, _o_, drives the pinion, A, on the shaft of the fly vane, G. M is an end view of the electro magnet, (represented by Z, Z, in figure 71,) of which N and P are the two ends of the wire composing the helix. D is its armature, constructed so as to move upon an axis represented by two small circles. To the armature are connected, and capable of moving with it, two arms, E and I, which project, so as to come in contact with the pallet, _a_, of the fly, G. F is a spiral spring, one end of which is fastened to the armature, D, and the other passes through a vertical hole in the screw, S, in the bar, T, by which the armature is held up in the position now seen, when not attracted by the electro magnet. Now, if the wires, N and P, connected with battery, Y, (figure 71,) have their circuit closed, the current passing through the helix of the magnet, M, brings down the armature, D, in the direction of the arrow, which raises the arm, I, against which the pallet, _a_, of the fly vane, is resting, and releases the fly. It then