Sunday, January 3, 6715

Ctesibius (c. 285-222 BC) - Hydraulic Organ

Ctesibius or Ktesibios or Tesibius (fl. 285–222 BC) was a Greek or Egyptian inventor and mathematician in Alexandria, Ptolemaic Egypt. He wrote the first treatises on the science of compressed air and its uses in pumps (and even a cannon). This, in combination with his work on the elasticity of air On pneumatics, earned him the title of "father of pneumatics." None of his written work has survived, including his Memorabilia, a compilation of his research that was cited by Athenaeus.

Ctesibius was probably the first head of the Museum of Alexandria. Very little is known of his life but his inventions were well known. It is said (possibly by Diogenes Laertius) that his first career was as a barber. During his time as a barber, he invented a clever counterweight-adjustable mirror.

[Hydraulis and Bicinium (organ and trumpet)]

[England (b. c. 1290)- Organ Estampie No. 3 (Robertsbridge Codex, 1320)]

His other inventions include the hydraulis, a water organ that is considered the precursor of the modern pipe organ, and an improved water clock called a clepsydra. The clepsydra kept more accurate time than any clock invented until the Dutch physicist Christiaan Huygens detailed the use of a pendulum to regulate a clock in the 17th century. He described the one of the first force pumps for producing a jet of water, or for lifting water from wells, and examples have been found at various Roman sites, such as at Silchester in Britain. The principle of the siphon has also been attributed to him.

According to Diogenes Laertius, Ctesibius was miserably poor. Laertius details this by recounting the following concerning the philosopher Arcesilaus:

"when he had gone to visit Ctesibius who was ill, seeing him in great distress from want, he secretly slipped his purse under his pillow; and when Ctesibius found it, 'This,' said he, 'is the amusement of Arcesilaus.'"

Ctesibius's work is chronicled by Vitruvius, Athenaeus, and Philo of Byzantium who repeatedly mentions him, adding that the first mechanicians such as Ctesibius had the advantage of being under kings who loved fame and supported the arts. Proclus (the commentator on Euclid) and Hero of Alexandria (the last of the engineers of antiquity) also mention him.

The water organ or hydraulic organ (early types are sometimes called hydraulis or hydraulos or hydraulus or hydraula) is a type of automatic pipe organ blown by air, where the power source pushing the air is derived by water from a natural source (e.g. by a waterfall) or by a manual pump. Consequently, the water organ lacks a bellows, blower, or compressor. In addition to being the source of power to push air through the organ pipes, 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.

A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water (hýdrō in Greek) into air pressure to drive the pipes. Hence its name hydraulis, literally "water (driven) pipe (instrument)." The hydraulis was the world's first keyboard instrument, and was the predecessor of the church pipe organ. The ancient hydraulis was played by hand; 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”).

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 18 metres above the camera aeolis in the organ grotto. This drop provides sufficient wind to power the restored six-stop instrument.

Water organs were described in the numerous writings of the famous Ctesibius (3rd century BC), Philo of Byzantium (3rd century BC) and Hero of Alexandria (c. 62 AD). 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, as well as to produce the awe-inspiring sound emitted by Memnon's statue at Thebes. For the latter, solar heat was used to syphon water from one closed tank into another, thereby producing compressed air for sounding the pipes.

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.

[The first piece performed is Tielman Susato (c. 1500-1651) - Hupfauf]

[6832 Delphic Hymn / 6715 Ctesibius / 6700 Yoruba]