Elise gave a few hand signals to her detail.
In this manner the signals are read by ear.
In Squier and Crehore's " Synchronograph " system " sine waves of current, instead of sharp " makes and breaks," or sharp reversals, are employed for transmitting signals, the waves being produced by an alternating-current dynamo, and regulated by means of a perforated paper ribbon, as in the Wheatstone automatic system.
The signals must therefore be sent at regular intervals, and to ensure this being done correctly a telephone or time-tapper is provided at each keyboard to warn the operator of the correct moment to depress his keys.
For working long submarine cables the apparatus ordinarily employed on land lines cannot be used, as the retarding effect of the electrostatic capacity of the cable is so marked that signals fail to be recorded except at a very slow speed of working.
