The Pneumatics of Hero of Alexandria

the statues of Vulcan and Daedalus, the wooden dove of Archytas, and the eagle and the fly, which Peter Ramus reports. Of this he wrote similarly two books and called them The Automata, or Of Self-Moving Machines, placed in the vernacular language with much diligence and happiness, and illustrated with beautiful figures by our Most Reverend Abbot Baldi. The third teaches us, by way of spirit or enclosed air, how to make organs play, as Ctesibius did, or to imitate the voices of various birds, the hisses of serpents, and the sounds of trumpets. With such reasons or similar ones, it can be believed that the statue of Memnon or of Sesostris was fabricated, which, as Pausanias reports, every day at the appearing of the sun sent out a certain harmonic clamor. And the silver oars that were operated in the boat of Cleopatra, Queen of Egypt, which, being hollow inside, every time they struck the water, returned a most sweet sound, by respect of the air or spirit that, driven and agitated by the water, broke while passing through certain narrow holes, made by art. It teaches similarly how to make various vessels of admirable effects, concerning which the ancients were very curious; whence one reads that a Python of Agrigentum had in his private house three hundred vessels artfully made. What more? Vitruvius wished that vessels should be made, observing a certain determined proportion of size between them, and placed in theaters with their mouths turned downward, so that, receiving the voices of the actors, they returned a certain sound grateful to the ears. Besides these, it teaches how to perform many other effects, part useful and part marvelous, from which one can extract the way to make all the most artificial fountains and, mixing nature with art, to represent gushings, sprinklings, gurgles, drippings, boilings, murmurs, foams, tremors, the music of falling waters, and other many delightful charms and strange eccentricities. Of this, Hero wrote the present treatise, called by him Pneumatic, which is as much as to say "Spiritual" referring to pneumatic/air-based mechanics; the study of which, as he himself affirms, is common both to the natural philosopher and to the mechanic. For the mechanic puts on almost the habit of the natural philosopher when he considers the qualities of matter, the mover, motion, rest, place, the vacuum, and all the other similar circumstances that can in