In 1933, Jehovah’s Witnesses began to employ another innovative method of preaching. A transportable transcription machine with an amplifier and loudspeaker was used to broadcast 33 1/3-rpm recordings of Brother Rutherford’s radio lectures, in halls, parks, and other public places. Sound cars and sound boats also were used to let the Kingdom message ring out.

A sound boat broadcasting on the River Thames, in London, England (above)