The Barker lever is a

pneumatic Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air. Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases. A centrally located and ele ...

system which multiplies the force of a finger on the key of a tracker

pipe organ The pipe organ is a musical instrument that produces sound by driving pressurized air (called ''wind'') through the organ pipes selected from a keyboard. Because each pipe produces a single pitch, the pipes are provided in sets called ''ranks' ...

. It employs the wind pressure of the organ to inflate small

bellows A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtigh ...

called "pneumatics" to overcome the resistance of the pallets (

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

) in the organ's wind-chest . This

lever A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is ...

allowed for the development of larger, more powerful organs still responsive to the human hand. These larger organs first flourished in France, e.g., the organ produced by Cavaillé-Coll at St. Sulpice. The first Barker lever was built in the Cavaillé-Coll organ of the

Basilica of Saint-Denis The Basilica of Saint-Denis (french: Basilique royale de Saint-Denis, links=no, now formally known as the ) is a large former medieval abbey church and present cathedral in the commune of Saint-Denis, a northern suburb of Paris. The building ...

. This "contrivance" was named after Charles Spackman Barker (1804-79), engineer and organ-builder. A similar lever was developed by David Hamilton in 1835, and there has been debate whether Barker stole the design.

Bibliography

* George Laing Miller: "The Recent Revolution in Organ Building", 1913, chapter III *{{cite episode , title=Of Organs and Engines , series=The Engines of Our Ingenuity , series-link=The Engines of Our Ingenuity , credits=John H. Lienhard , network=NPR , station=KUHF-FM Houston , airdate=2005 , number=1973 , transcript=No 1973: Of Organs and Engines (transcript) , transcript-url=http://www.uh.edu/engines/epi1973.htm Compares Barker-lever to similar devices in the

Corliss steam engine A Corliss steam engine (or Corliss engine) is a steam engine, fitted with rotary valves and with variable valve timing patented in 1849, invented by and named after the American engineer George Henry Corliss of Providence, Rhode Island. Engines f ...

. He cites the Grove's article below and other good web sources, e.g. Bridgeman-Sutton. * David Bridgeman-Sutton
"Barker-lever"
This is based on the following two print sources, Hinton suggesting Barker's copying & Thistlethwaite noting the differences in design. * John William Hinton: The Story of the Electric Organ. London: Simpkin, Marshall, Hamilton, Kent & Co., 1909. * Nicholas Thistlethwaite: The Making of the Victorian Organ. Cambridge Musical Texts and Monographs. Cambridge: Cambridge University Press, 1990. Pp. 352–354. * P. Williams: "Organ." The New Grove Dictionary of Music & Musicians. (Stanley Sadie, ed.), vol. 13, New York: Macmillan, 1995, pp. 710–779. * Hans Dieter Meyer: ''Buchholz und Haupt, oder: Wie der Barkerhebel nach Deutschland kam''. In: Ars organi 52 (2004). ISSN 0004-2919 * Duncan Mathews, ''Charles Barker's Wondrous Machines''. In: Organ builder 5 (2008), 17-20.

External links

Organs (music)