Here's a miraculous Radio Police Automaton from the May, 1924 issue of Hugo Gernsback's Science and Invention. It will be useful for dispersing mobs, and for war. Note the built-in tear-gas tank. Also the "loud-speaker used to shout orders to the mob." Mr Gernsback notes, "They will be well-nigh irresistible."
There's something decidedly pre-Ewok about this design and the bold claims of irresistibility.
(via Wil Wheaton)