radiotelegraph vs radiotelephone

radiotelegraph

verb

  • To communicate or transmit by wireless telegraphy. 

noun

  • wireless telegraphy 

radiotelephone

verb

  • To communicate via such a device 

noun

  • a device that allows two-way communication via radio 

How often have the words radiotelegraph and radiotelephone occurred in a corpus of books? (source: Google Ngram Viewer )