Hero's miraculous altar. Illustration showing details of a steam-driven mechanical apparatus for opening the doors of a temple. Designed by Hero of Alexandria, the device appears in Pneumatics (around 62 AD) along with other machines that work through air, steam or water pressure. Hero (10-70 AD) was a Greek engineer and geometer in Alexandria, Roman Egypt, known for his mechanical ingenuity throughout the ancient world. This is one example of the devices he created for temples to instill faith by deceiving believers with 'magical acts of the gods'. Pneumatics was translated and published for the first time by Giovanni Battista Aleotti in 1589, whilst incorporating ideas of his own.