ABSTRACT
Although sound broadcasting and television are forms of communication, it has long been the convention to reserve this term for transmissions of a non-entertainment character, such as commercial or military intelligence or weather reports. These may be in the form of telephony or telegraphy and may be sent broadcast, or transmitted by radio link from point to point or over line conductors. Aviation communication is of course a branch of this work, but because of its specialist nature has been dealt with in a separate chapter.
