§ 62. A key is another form of contact, by means of which a long or short completion of circuit can be made by simply tapping on the knob. It is particularly useful when it is desired to transmit signals, either by ringing or otherwise. It consists, as may be seen at [Fig. 65], of a lever or arm of brass, pivoted at its centre, furnished with a spring which keeps the portion under the knob out of contact with the stud in the front of the base-board. As both the stud and the lever are connected to binding screws communicating with the battery and bell, etc., it is evident that on depressing the key the circuit with the bell will be completed for a longer or shorter period, varying with the duration of the depression. Hence, either by using preconcerted signals of short and long rings to signify certain common words, such as a long ring for No, and a short one for Yes, or by an adaptation of the ordinary Morse code, intelligible conversation can be kept up between house and stable, etc., etc., by means of a key and a bell. As Mr. Edwinson has given much time to the elucidation of this system of bell signalling, I cannot do better
than quote his instructions, as given in Amateur Work:—
"For this purpose preconcerted signals have been agreed upon or invented as required, and these have been found to be irksome and difficult to remember, because constructed without any reference to a definite plan. We may, however, reduce bell signals to a definite system, and use this system or code as a means to carry on conversation at a distance as intelligently as it can be done by a pair of telegraph instruments. In fact, the Morse telegraph code can be easily adopted for use with electric bells of the vibrating or trembling type, and its alphabet, as appended below, easily learnt. The letters of the alphabet are represented by long strokes and short strokes on the bell, as here shown.—
| A | – — |
| B | — – – – |
| C | — – — – |
| D | — – – |
| E | – |
| F | – – — – |
| G | — — – |
| H | – – – – |
| I | – – |
| J | – — — — |
| K | — – — |
| L | – — – – |
| M | — — |
| N | — – |
| O | — — — |
| P | – — — – |
| Q | — — – – – |
| R | – — – |
| S | – – – |
| T | — |
| U | – – — |
| V | – – – — |
| W | – — — |
| X | — – – — |
| Y | — – — — |
| Z | — — – – |
| Ch | — — — |
| Ä (æ) | – — – — |
| Ö (œ) | — — — – |
| Ü (ue) | – – — — |
| 1 | – — — — |
| 2 | – – — — — |
| 3 | – – – — — |
| 4 | – – – – — |
| 5 | – – – – – |
| 6 | — – – – – |
| 7 | — — – – – |
| 8 | — — — – – |
| 9 | — — — – |
| 0 | — — — — |
"It will be noticed that the strokes to represent a letter do not in any case exceed four, and that all the figures are represented by five strokes of varying length to each
figure. Stops, and other marks of punctuation, are represented by six strokes, which are in their combination representations of two or three letters respectively, as shown below:—
| Comma | (,) | by | A A A | or | – — – — – — |
| Full stop | (.) | " | I I I | " | – – – – – – |
| Interrogation | (?) | " | U D | " | – – — — – – |
| Hyphen | (-) | " | B A | " | — – – – – — |
| Apostrophe | (') | " | W G | " | – — — — — – |
| Inverted commas | (") | " | A F | " | – — – – — – |
| Parenthesis | ( ) | " | K K | " | — – — — – — |
| Semi-colon | (;) | " | K Ch | " | – — — — — — |
| Surprise | (!) | " | N Ch | " | — – — — — — |
| Colon | (:) | " | I Ch | " | – – — — — — |
"In sending signals to indicate stops, no regard must be had to the letters which they represent; these are only given as aids to memory, and are not to be represented separately on the bell. Bell signals must be given with a certain amount of regularity as to time; indeed, to carry on a conversation in this way it is necessary to be as punctilious in time as when playing a piece of music on a piano, if the signals are to be understood. The dots of the signal should therefore be represented in time by one, and the dashes by two, whilst the spaces between words and figures where a stop does not intervene should be represented by a pause equal to that taken by a person counting three, the space between a word and a stop being of the same duration. To make this more clear
I give an example. The mistress signals to her coachman:—
| G | E | T | T | H | E | ||
| — — – | – | — | — | – – – – | – | ||
| 2 2 1 | 1 | 2 | 3 | 2 | 1 1 1 1 | 1 | 3 |