Having shown the several parts of Mr. Wheatstone’s plan, we will proceed to describe the arrangement of two termini, as prepared for transmitting intelligence. [Figure 61] represents the arrangement of one station, which we may suppose to be Paddington. [Figure 62] represents the plan of the other station, which we will suppose to be Slough. The distance between these two places is eighteen miles.

In [figure 61], it will be seen, that a wire is soldered to the end of each of the springs 6, 1, 2, 3, 4 and 5, and are respectively connected with the five wires of the dial, and the common communicating wire, number 6, which does not pass through the dial, nor is connected with any of the galvanometers. On the right hand side of the dial, the wires are extended until they are shown as broken. From this point to the opposite one, [figure 62], where the wires appear also as interrupted, we may suppose 18 miles to intervene. The wires here proceed to the dial of the Slough station, making their proper connections with their respective galvanometers, and from thence are continued and soldered to their springs of the key arrangement, with the exception of wire, number 6, which passes direct to the key, 6, without going through the dial case. In both figures, is represented the battery, O, consisting of six cups. The wire from one pole of the battery is connected with the N metallic plate, the other wire with the P metallic plate. While none of the buttons are pressed down, the battery is not in action, and it will also be observed that the circuits are all complete. The action of the keys, then, is this, by a single operation to break the circuit formed with the cross bar, L, L, and, at the same time, bring into the circuit, the battery, O.

The following numbers, representing the buttons, are those necessary to be pressed down, in order to signal the letters and numerals on the dial:

Letters.
For A,buttons 10and 17.For M,buttons 9and 12.
B, 10 15. N, 11 14.
D, 12 17. O, 13 16.
E, 10 13. P, 15 18.
F, 12 15. R, 9 14.
G, 14 17. S, 11 16.
H, 10 11. T, 13 18.
I, 12 13. V, 9 16.
K, 14 15. W, 11 18.
L, 16 17. Y, 9 18.

Numerals.
For 1,buttons 7and 10.For 6,buttons 8and 9.
2, 7 12. 7, 8 11.
3, 7 14. 8, 8 13.
4, 7 16. 9, 8 15.
5, 7 18. 0, 8 17.

Fig. 61.
PADDINGTON.