thumb|Musicians with [[Cornu (horn)|cornua and a water organ, detail from the Zliten mosaic, 2nd century CE]]

The water organ or hydraulic organ ( Wiktionary:hydro-| + aulos| /

On the water organ, since the 15th century, the water is also used as a source of power to drive a mechanism similar to that of the barrel organ, which has a pinned barrel that contains a specific song to be played. The hydraulis in ancient Greek is often imagined as an automatic organ, but there is no source evidence for it.

Hydraulis

thumb|upright|Fragments of a hydraulis, [[Archaeological Museum of Dion, Greece]]

A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water () into air pressure to drive the pipes (). Hence its name hydraulis, literally "water (driven) pipe (instrument)". It is attributed to the Hellenistic scientist Ctesibius of Alexandria, an engineer of the The hydraulis was the world's earliest keyboard instrument, and was the predecessor of the modern pipe organ. The ancient hydraulis was operated by pressing keys on the manual; the hydraulis' keys were well-balanced, and could be played with a light touch, as is clear from the Latin poem by Claudian who uses that exact phrase to describe playing the keyboard:

:{|

|-

| magna levi detrudens murmura tactu ... intonet

|  

| “let him thunder forth as he presses out mighty roarings with a light touch”

|}

Mechanics

Typically, water is supplied from some height above the instrument through a pipe, and air is introduced into the water stream by aspiration (using the Bernoulli effect) into the main pipe from a side-pipe holding its top above the water source. Both water and air arrive together in the camera aeolis (wind chamber). Here, water and air separate and the compressed air is driven into a wind-trunk on top of the camera aeolis, to blow the organ pipes. Two perforated ‘splash plates’ or ‘diaphragms’ prevent water spray from getting into the organ pipes.

The water, having been separated from the air, leaves the camera aeolis at the same rate as it enters. It then drives a water wheel, which in turn drives the musical cylinder and the movements attached. To start the organ, the tap above the entry pipe is turned on and, given a continuous flow of water, the organ plays until the tap is closed again.

Many water organs had simple water-pressure regulating devices. At the Palazzo del Quirinale, the water flows from a hilltop spring (once abundant, now only sufficient to play the organ for about 30 minutes at a time), coursing through the palace itself into a stabilizing ‘room’ some above the camera aeolis in the organ grotto. This drop provides sufficient power to maintain air pressure to the restored six-stop instrument.

Among Renaissance writers on the water organ, Salomon de Caus is particularly informative. His book of 1615 includes a short treatise on making water organs, advice on tuning and registration, and many fine engravings showing the instruments, their mechanisms and scenes in which they were used. It also includes an example of suitable music for water organ, the madrigal Chi farà fed' al cielo by Alessandro Striggio, arranged by Peter Philips.

History

thumb|left|upright|A modern reconstruction of the wind organ and wind wheel of Heron of Alexandria

Water organs were described in the numerous writings of the famous Ctesibius Philo of Byzantium and Hero of Alexandria Like the water clocks (clepsydra) of Plato's time, they were not regarded as playthings, but might have had a particular significance in Greek philosophy, which made use of models and simulacra of this type. Hydraulically blown organ pipes were used to imitate birdsong, and musicologists Susi Jeans and Arthur W.J.G. Ord-Hume have suggested that it was used to create the sounds of the Vocal Memnon. For the latter, solar heat was used to syphon water from one closed tank into another, thereby producing compressed air for sounding the pipes. The Talmud mentions the instrument as having been played in the Jerusalem Temple.

thumb|upright|Reconstruction of hydraulic organ

After its invention by the Greeks, the hydraulis continued to be used through antiquity in the Roman world. Characteristics of the hydraulis have been inferred from mosaics, paintings, literary references, and partial remains. In 1931, the remains of a hydraulis were discovered in Hungary, with an inscription dating it to 228 AD. The leather and wood of the instrument had decomposed, but the surviving metal parts made it possible to reconstruct a working replica now in the Aquincum Museum in Budapest. The exact mechanism of wind production is debated, and almost nothing is known about the music played on the hydraulis, but the tone of the pipes can be studied.

In the Middle Ages, Eastern Roman (Byzantine) Empire, Medieval Europe and Muslim world further developed these instruments. Among the illuminated manuscripts of the British Museum there are many miniatures representing interesting varieties of the portable organ of the Middle Ages used in European churches. The Pippin's organ of 757 was a hydraulic organ sent as a gift to the Carolingian empire by the Byzantine emperor Constantine V. A long-distance hydraulic organ that could be heard from sixty miles away was described in Arabic texts and attributed to an ancient Greek figure called Muristus; this individual's identity is unknown, but is sometimes suggested to be an Arabized version of the name Ctesibius. The lower part of the organ, with the air-pressing system, was missing.

In 1995, a reconstruction project started, and by 1999 a working replica of hydraulis was made based on the archaeological finding and on ancient descriptions. The remains of the ancient hydraulis are exhibited at the Archaeological Museum of Dion.

See also

  • Calliope
  • Hydraulophone
  • Muristus
  • Organ (music)
  • Trompe

Notes

References

Further reading

  • Hydraulis video (click "The Ancient Hydraulis" in the second paragraph to watch)
  • A Bach piece being played on a hydraulophone pipe organ (video) Dead link