We shall, in the first place, consider the transmitting arrangements and, incidentally, the nature of the effect or wave transmitted; in the second place, the receiving appliances; and, finally, discuss the problem of the isolation or secrecy of the intelligence conveyed between any two places.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
The signalling key is really a very important part of the transmitting arrangement, because whatever may be the improvements in receiving instruments, it is not possible to receive faster than we can send.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
The next element of importance in the transmitting arrangement is the spark gap.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming