Hydraulis
A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water (Ancient Greek: ὕδωρ hýdōr) into air pressure to drive the pipes (Ancient Greek: αυλός aulos). Hence its name hydraulis, literally "water (driven) pipe (instrument)." It is attributed to the Hellenistic scientist Ctesibius of Alexandria, an engineer of the 3rd century BC. See more about the Hydraulis and its further development in pipe organ. The hydraulis was the world's first keyboard instrument and was, in fact, the predecessor of the modern church organ. Unlike the instrument of the Renaissance period, which is the main subject of the article on the pipe organ, the ancient hydraulis was played by hand, not automatically by the water-flow; the keys were balanced and could be played with a light touch, as is clear from the reference in a Latin poem by Claudian (late 4th century), who uses this very phrase (magna levi detrudens murmura tactu . . . intonet, “let him thunder forth as he presses out mighty roarings with a light touch”) (Paneg. Manlio Theodoro, 320–22). See organ (music) for more details and external links.
Read more about this topic: Water Organ