The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

206 HISTORY OF THE ENGLIS-I TELEGRAPH.
with their respective, electrometers, and thence they 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
coilmplete. 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
neessary to be pressed down, in order to signal the letters and
numerals on the dial:
Letters.
For A, buttons 10 and 17. For M, buttons 9 and 12.
" B, " 10' 15. " N, " 11 " 14.
" D, " 12 " 17. " 0 " 13 " 16.. E, " 10 " 13. " P, " 15 " 18.
" F, " 12 " 15. " R, " 9 " 14.
" G, 4S 11 " 16.
" H,' 10 " 11. " T " 13 " 18.
" I, " 12 " 13. " T, " 9" 16.
" K, 14 " 15. W" ", " 11' 18.
" L, " 16 6 17. (Y, " 9 9" 18.
tNumerals.
For 1, buttons 7 and 10. For 6, buttons S and 9.
" 2, " 7 " 12. " 79, 7 " 8 11.
3,' 7 " 14. 8, 8 13.
i 4, "* 7 16. 9, " " 15.
66 5, 7 " 18. " 0, " 8 " 17.
The direction of the current, when the letter v is to be signalled, is this: pressing down the buttons, 9 and 16, at the
Paddington station, the fluid leaves the battery, o, along the
wire to the cross bar,; then to the hammer of the button,
16; then to the spring, 4; then along wire 4, to the electrometer, 4, and through it, deflecting the lower half of the needle
to the left; then along the extended wire, 4, to the dial, and
electrometer, 4, of the Slough station, deflecting the lower half
of that needle to the left; then to wire, 4, leaving the dial, to
key, 4; then to the cross-bar, L and L; and along the cross