This tapper is actuated by the same current as the Morse printer, or other telegraphic recorder, so that when the signal is received and the metallic filings tube passes into the conductive condition and closes the relay circuit, this latter in turn closes the circuit of the Morse printer or other recorder, and at the same time, a current passes through the electromagnet of the tapper and the tube is tapped back.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
The tapper has to be so arranged that it is possible to receive and to record not only the dot but a dash on the Morse system.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
Edited by Bertha Feiring tapper.
"Resonance in Singing and Speaking"
Thomas Fillebrown