Fig. 13.
I have now done with Hero of Alexandria, but, before passing to another period, I cannot resist showing you an invention of his which although not an automaton is too interesting in the light of modern civilization to omit. This ([Fig. 14]) is Hero’s automatic penny-in-the-slot machine for giving a drink in exchange for a coin. If a “coin of five drachmas” be dropped into the slot it falls on a little plate at the end of a lever thereby opening a valve and allowing the liquid to escape through the nozzle.
Fig. 14.
It is more than probable that Hero was not himself the inventor of all the devices he describes, it is possible that many are due to Ctesibius whose pupil he was, and it is clear, from his own writings, that he was acquainted with the writings of Philo and of Archimedes. He was, however, the first to describe these inventions, and therefore it is only fair, in the absence of other evidence, to give him the credit.
