Journal of Electricity, September 1, 1920, page 219:

TALKING  TO  A  NATION  BY  WIRELESS

    "This is Hiram Percy Maxim speaking from the De Forest radio telephone station at the California Theater, with aerial from the Humboldt Savings Bank Building, San Francisco."
    This opening remark and the entire address which followed it were heard by owners--chiefly amateurs--of radio receiving sets all over the western United States. The address was delivered on July 3rd in connection with the programs planned by the California Theater, and the idea of having the theater's Sunday morning concerts "distributed" by radiophone.
    It is significant of the rapidly-growing interest in wireless that there are already some 300,000 amateur radio sets in the United States, the owners being organized into a flourishing body known as the American Radio Relay League, of which Mr. Maxim is president. Mr. Maxim said in part:
    "No one of the great multitude of human efforts being made at the present day can compare in far-reaching effect with radio communication.  *   *   *   At the great convention in San Francisco it was evident to the observer that assemblages of people have come to be of such vast proportions that no human voice is strong enough to be heard by all those present. Radio was called upon and a microphone installed and connected to amplifiers high up in the arena."
    Mr. Maxim went on to paint a picture of the extension of this idea, describing the possibility of radio sets and amplifiers located all over the country in such a way that millions of people could hear one speaker at the same time.
    "No one would be too remote to be able to listen. All he would need would be a radio receiving outfit, and we amateurs and professionals know how simple and inexpensive this would be. No code need be learned, for the spoken word would be the signal instead of the dot and dash.  *   *   *   This thing has a world of possibilities back of it. It points to the possibility of conventions being held at which the entire country may take part."
    The beginnings of these developments are already apparent in such plans as that mentioned above, by which the concerts held every Sunday morning at the California Theater would be transmitted to hearers with wireless receiving sets many miles away.