A lute  (/ljuːt/)[1] is any plucked string instrument with a neck (either fretted or unfretted) and a deep round back enclosing a hollow cavity, usually with a sound hole or opening in the body. More specifically, the term "lute" can refer to an instrument from the family of European lutes. The term also refers generally to any string instrument having the strings running in a plane parallel to the sound table (in the Hornbostel–Sachs system). The strings are attached to pegs or posts at the end of the neck, which have some type of turning mechanism to enable the player to tighten the tension on the string or loosen the tension before playing (which respectively raise or lower the pitch of a string), so that each string is tuned to a specific pitch (or note). The lute is plucked or strummed with one hand while the other hand "frets" (presses down) the strings on the neck's fingerboard. By pressing the strings on different places of the fingerboard, the player can shorten or lengthen the part of the string that is vibrating, thus producing higher or lower pitches (notes).
The European lute and the modern Near-Eastern oud descend from a common ancestor via diverging evolutionary paths. The lute is used in a great variety of instrumental music from the Medieval to the late Baroque eras and was the most important instrument for secular music in the Renaissance.[2] During the Baroque music era, the lute was used as one of the instruments which played the basso continuo accompaniment parts. It is also an accompanying instrument in vocal works. The lute player either improvises ("realizes") a chordal accompaniment based on the figured bass part, or plays a written-out accompaniment (both music notation and tabulature ("tab") are used for lute). As a small instrument, the lute produces a relatively quiet sound. The player of a lute is called a lutenist, lutanist or lutist, and a maker of lutes (or any similar string instrument, or violin family instruments) is referred to as a luthier.
Etymology
The words lute and oud possibly derive from Arabic al-ʿoud (العود- literally means "the wood"). It may refer to the wooden plectrum traditionally used for playing the oud, to the thin strips of wood used for the back, or to the wooden soundboard that distinguished it from similar instruments with skin-faced bodies.[3] Henry George Farmer considers the similitude between al-ʿūd and al-ʿawda ("the return" – of bliss).[4]
Many theories have been proposed for the origin of the Arabic name. A music scholar by the name of Eckhard Neubauer suggested that oud may be an Arabic borrowing from the Persian word rōd or rūd, which meant string.[5][6] Another researcher, archaeomusicologist Richard J. Dumbrill, suggests that rud came from the Sanskrit rudrī (रुद्री, meaning "string instrument") and transferred to Arabic  and European languages by way of a Semitic language.[7] However, another theory according to Semitic language scholars, is that the Arabic ʿoud is derived from Syriac ʿoud-a, meaning "wooden stick" and "burning wood"—cognate to Biblical Hebrew 'ūḏ, referring to a stick used to stir logs in a fire.[8][9]
Construction

Soundboard
Lutes are made almost entirely of wood. The soundboard is a teardrop-shaped thin flat plate of resonant wood (typically spruce). In all lutes the soundboard has a single (sometimes triple) decorated sound hole under the strings called the rose. The sound hole is not open, but rather covered with a grille in the form of an intertwining vine or a decorative knot, carved directly out of the wood of the soundboard.
The geometry of the lute soundboard is relatively complex, involving a system of barring that places braces perpendicular to the strings at specific lengths along the overall length of the belly, the ends of which are angled to abut the ribs on either side for structural reasons. Robert Lundberg, in his book Historical Lute Construction, suggests ancient builders placed bars according to whole-number ratios of the scale length and belly length. He further suggests the inward bend of the soundboard (the "belly scoop") is a deliberate adaptation by ancient builders to afford the lutenist's right hand more space between the strings and soundboard.
Soundboard thickness varies, but generally hovers between 1.5 and 2mm (0.06–0.08in). Some luthiers tune the belly as they build, removing mass and adapting bracing to produce desirable sonic results. The lute belly is almost never finished, but in some cases the luthier may size the top with a very thin coat of shellac or glair to help keep it clean. The belly joins directly to the rib, without a lining glued to the sides, and a cap and counter cap are glued to the inside and outside of the bottom end of the bowl to provide rigidity and increased gluing surface.
After joining the top to the sides, a half-binding is usually installed around the edge of the soundboard. The half-binding is approximately half the thickness of the soundboard and is usually made of a contrasting color wood. The rebate for the half-binding must be extremely precise to avoid compromising structural integrity.
Back
The back or the shell is assembled from thin strips of hardwood (maple, cherry, ebony, rosewood, gran, wood and/or other tonewoods) called ribs, joined (with glue) edge to edge to form a deep rounded body for the instrument. There are braces inside on the soundboard to give it strength.[10]
Neck
The neck is made of light wood, with a veneer of hardwood (usually ebony) to provide durability for the fretboard beneath the strings. Unlike most modern stringed instruments, the lute's fretboard is mounted flush with the top. The pegbox for lutes before the Baroque era was angled back from the neck at almost 90° (see image), presumably to help hold the low-tension strings firmly against the nut which, traditionally, is not glued in place but is held in place by string pressure only. The tuning pegs are simple pegs of hardwood, somewhat tapered, that are held in place by friction in holes drilled through the pegbox.
As with other instruments that use friction pegs, the wood for the pegs is crucial. As the wood suffers dimensional changes through age and loss of humidity, it must retain a reasonably circular cross-section to function properly—as there are no gears or other mechanical aids for tuning the instrument. Often pegs were made from suitable fruitwoods such as European pearwood, or equally dimensionally stable analogues. Matheson, c. 1720, said, "If a lute-player has lived eighty years, he has surely spent sixty years tuning."
Bridge
The bridge, sometimes made of a fruitwood, is attached to the soundboard typically between a fifth and a seventh of the belly length. It does not have a separate saddle but has holes bored into it to which the strings attach directly. The bridge is made so that it tapers in height and length, with the small end holding the trebles and the higher and wider end carrying the basses. Bridges are often colored black with carbon black in a binder, often shellac and often have inscribed decoration. The scrolls or other decoration on the ends of lute bridges are integral to the bridge, and are not added afterwards as on some Renaissance guitars (cf Joachim Tielke's guitars).
Frets
The frets are made of loops of gut tied around the neck. They fray with use, and must be replaced from time to time. A few additional partial frets of wood are usually glued to the body of the instrument, to allow stopping the highest-pitched courses up to a full octave higher than the open string, though these are considered anachronistic by some (though John Dowland and Thomas Robinson describe the practice of gluing wooden frets onto the soundboard). Given the choice between nylon and gut, many luthiers prefer to use gut, as it conforms more readily to the sharp angle at the edge of the fingerboard.
Strings
Strings were historically made of animal gut, usually from the small intestine of sheep (sometimes in combination with metal) and are still made of gut or a synthetic substitute, with metal windings on the lower-pitched strings. Modern manufacturers make both gut and nylon strings, and both are in common use. Gut is more authentic for playing period pieces, though unfortunately it is also more susceptible to irregularity and pitch instability due to changes in humidity. Nylon offers greater tuning stability, but is seen as anachronistic by purists, as its timbre differs from the sound of earlier gut strings. Such concerns are moot when more recent compositions for the lute are performed.
Of note are the catlines used as basses on historical instruments. Catlines are several gut strings wound together and soaked in heavy metal solutions to increase the string mass. Catlines can be quite large in diameter compared to wound nylon strings of the same pitch. They produce a bass that differs somewhat in timbre from nylon basses.
The lute's strings are arranged in courses, of two strings each, though the highest-pitched course usually consists of only a single string, called the chanterelle. In later Baroque lutes two upper courses are single. The courses are numbered sequentially, counting from the highest pitched, so that the chanterelle is the first course, the next pair of strings is the second course, etc. Thus an 8-course Renaissance lute usually has 15 strings, and a 13-course Baroque lute has 24.
The courses are tuned in unison for high and intermediate pitches, but for lower pitches one of the two strings is tuned an octave higher (the course where this split starts changed over the history of the lute). The two strings of a course are virtually always stopped and plucked together, as if a single string—but in rare cases, a piece requires that the two strings of a course be stopped or plucked separately. The tuning of a lute is a complicated issue, described in a section of its own below. The lute's design makes it extremely light for its size.
History and evolution of the lute

First lutes

Curt Sachs defined the word lute in the terminology section of The History of Musical Instruments as "composed of a body, and of a neck which serves both as a handle and as a means of stretching the strings beyond the body."[11] His definition focused on body and neck characteristics and not on the way the strings were sounded, so the fiddle counted as a "bowed lute".[11] Sachs also distinguished between the "long-necked lute" and the short-necked variety.[11] The short necked variety contained most of our modern instruments, "lutes, guitars, hurdy-gurdies and the entire family of viols and violins."[11]
The long lutes were the more ancient lutes; the "Arabic tanbūr...faithfully preserved the outer appearance of the ancient lutes of Babylonia and egypt."[12] He further categorized long lutes with a "pierced lute" and "long neck lute."[11]  The pierced lute had a neck made from a stick that pierced the body (as in the ancient Egyptian long-neck lutes, and the modern African gunbrī).[13] The long lute had an attached nick, and included the sitar, tanbur and tar (dutār 2 strings, setār 3 strings, čatār 4 strings, pančtār 5 strings).[11][12]
Sachs' book dates from 1941, and the archaeological evidence available to him placed the early lutes at about 2000 B.C.[14] Discoveries since then have pushed the existence of the lute back to c. 3100 B.C.[15]
Musicologist Richard Dumbrill today uses the word lute more categorically to discuss instruments that existed millennia before the term "lute" was coined.[16] Dumbrill documented more than 3000 years of iconographic evidence for the lutes in Mesopotamia, in his book The Archaeomusicology of the Ancient Near East. According to Dumbrill, the lute family included instruments in Mesopotamia prior to 3000BC.[15] He points to a cylinder seal as evidence; dating from c. 3100BC  or earlier (now in the possession of the British Museum) the seal depicts on one side what is thought to be a woman playing a stick "lute".[15][17] Like Sachs, Dumbrill saw length as distinguishing lutes, dividing the Mesopotamian lutes into a long variety and a short.[18] His book does not cover the shorter instruments that became the European lute, beyond showing examples of shorter lutes in the ancient world. He focuses on the longer lutes of Mesopotamia,  various types of necked chordophones that developed throughout ancient world: Greek, Egyptian (in the Middle Kingdom), Iranian (Elamite and others), Hittite, Roman, Bulgar, Turkic, Indian, Chinese, Armenian/Cilician cultures. He names among the long lutes, the pandura and the tanbur[19]
The line of short-necked lutes was further developed to the east of Mesopotamia, in Bactria and Gandhara, into a short, almond-shaped lute.[3][20][21] Curt Sachs talked about the depictions of Gandharan lutes in art, where they are presented in a mix of "Northwest Indian art" under "a strong Greek influences."[22] The short-necked lutes in these Gandhara artworks were "the venerable ancestor of the Islamic, the Sino-Japanese and the European lute families."[22] He described the Gandhara lutes as having a "pear-shaped body tapering towards the short neck, a frontal stringholder, lateral pegs, and either four or five strings."[22]
Persian barbat, Arab oud

Bactria and Gandhara became part of the Sasanian Empire (224–651). Under the Sasanians, a short almond shaped lute from Bactria came to be called the barbat or barbud, which was developed into the later Islamic world's oud or ud.[23] When the Moors conquered Andalusia in 711, they brought their ud or quitra along, into a country that had already known a lute tradition under the Romans, the pandura.
During the 8th and 9th centuries, many musicians and artists from across the Islamic world flocked to Iberia.[24]  Among them was Abu l-Hasan 'Ali Ibn Nafi' (789–857),[25][26] a prominent musician who had trained under Ishaq al-Mawsili (d. 850) in Baghdad and was exiled to Andalusia before 833 AD. He taught and has been credited with adding a fifth string to his oud[23] and with establishing one of the first schools of music in Córdoba.[27]
By the 11th century, Muslim Iberia had become a center for the manufacture of instruments. These goods spread gradually to Provence, influencing French troubadours and trouvères and eventually reaching the rest of Europe. While Europe developed the lute, the oud remained a central part of Arab music, and broader Ottoman music as well, undergoing a range of transformations.[28]
Although the major entry of the short lute was in western Europe, leading to a variety of lute styles, the short lute entered Europe in the East as well; as early as the sixth century, the Bulgars brought the short-necked variety of the instrument called Komuz to the Balkans.
Beside the introduction of the lute to Spain (Andalusia) by the Moors,  another important point of transfer of the lute from Arabian to European culture was Sicily, where it was brought either by Byzantine or later by Muslim musicians.[29] There were singer-lutenists at the court in Palermo following the Norman conquest of the island from the Muslims, and the lute is depicted extensively in the ceiling paintings in the Palermo's royal Cappella Palatina, dedicated by the Norman King Roger II of Sicily in 1140.[29] His Hohenstaufen grandson Frederick II, Holy Roman Emperor (1194–1250) continued integrating Muslims into his court,  including Moorish musicians.[30] By the fourteenth century, lutes had disseminated throughout Italy and, probably because of the cultural influence of the Hohenstaufen kings and emperor, based in Palermo, the lute had also made significant inroads into the German-speaking lands.
From Middle Ages to Baroque

Medieval lutes were 4- or 5-course instruments, plucked using a quill as a plectrum. There were several sizes, and by the end of the Renaissance, seven different sizes (up to the great octave bass) are documented. Song accompaniment was probably the lute's primary function in the Middle Ages, but very little music securely attributable to the lute survives from the era before 1500. Medieval and early-Renaissance song accompaniments were probably mostly improvised, hence the lack of written records.
In the last few decades of the fifteenth century, to play Renaissance polyphony on a single instrument, lutenists gradually abandoned the quill in favor of plucking the instrument with the fingertips. The number of courses grew to six and beyond. The lute was the premier solo instrument of the sixteenth century, but continued to accompany singers as well.
In about the year 1500 many Iberian lutenists adopted vihuela de mano, a viol-shaped instrument tuned like the lute, but both instruments continued in coexistence. This instrument also found its way to parts of Italy that were under Spanish domination (especially Sicily and the papal states under the Borgia pope Alexander VI who brought many Catalan musicians to Italy), where it was known as the viola da mano.
By the end of the Renaissance the number of courses had grown to ten, and during the Baroque era the number continued to grow until it reached 14 (and occasionally as many as 19). These instruments, with up to 26–35 strings, required innovations in the structure of the lute. At the end of the lute's evolution the archlute, theorbo and torban had long extensions attached to the main tuning head to provide a greater resonating length for the bass strings, and since human fingers are not long enough to stop strings across a neck wide enough to hold 14 courses, the bass strings were placed outside the fretboard, and were played open, i.e., without pressing them against the fingerboard with the left hand.
Over the course of the Baroque era the lute was increasingly relegated to the continuo accompaniment, and was eventually superseded in that role by keyboard instruments. The lute almost fell out of use after 1800. Some sorts of lute were still used for some time in Germany, Sweden, Ukraine.
Gallery

Ancient Greek (Tanagra) terracotta statuette depicting a player of the pandura, second century BC
 A stele from Augusta Emerita for a Roman boy, with pandurium, 2nd Century A.D; Museo Arqueologico, Merida, Spain.[31]
Christian and Muslim playing lute, miniature from Cantigas de Santa Maria by king Alfonso X. 13th century.
Angel Playing Lute by Vittore Carpaccio (from Presentation of Jesus in the Temple 1510)
Frans Hals: Buffoon playing a lute, 1623.
A reconstruction of a 6 course early renaissance lute built by Jo Dusepo.

Lute in the modern world
The lute enjoyed a revival with the awakening of interest in historical music around 1900 and throughout the century. That revival was further boosted by the early music movement in the twentieth century. Important pioneers in lute revival were Julian Bream, Hans Neemann, Walter Gerwig, Suzanne Bloch and Diana Poulton. Lute performances are now not uncommon; there are many professional lutenists, especially in Europe where the most employment is found, and new compositions for the instrument are being produced by composers.

During the early days of the early music movement, many lutes were constructed by available luthiers, whose specialty was often classical guitars. Such lutes were heavily built with construction similar to classical guitars, with fan bracing, heavy tops, fixed frets, and lined sides, all of which are anachronistic to historical lutes. As lutherie scholarship increased, makers began constructing instruments based on historical models, which have proven lighter and more responsive instruments.
Lutes built at present are invariably replicas or near copies of those surviving historical instruments that are in museums or private collections. Many are custom-built, but there is a growing number of luthiers who build lutes for general sale, and there is a fairly strong, if small, second-hand  market. Due to this fairly limited market, lutes are generally more expensive than mass-produced modern instruments: factory-made guitars and violins, for example, can be purchased more cheaply than low-end lutes, but at the highest level of modern instruments, guitars and violins tend to command higher prices than lutes.
Unlike in the past there are many types of lutes encountered today: 5-course medieval lutes, renaissance lutes of 6 to 10 courses in many pitches for solo and ensemble performance of Renaissance works, the archlute of Baroque works, 11-course lutes in d-minor tuning for 17th-century French, German and Czech music, 13/14-course d-minor tuned German Baroque Lutes for later High Baroque and Classical music, theorbo for basso continuo parts in Baroque ensembles, gallichons/mandoras, bandoras, orpharions and others.
Lutenistic practice has reached considerable heights in recent years, thanks to a growing number of world-class lutenists: Rolf Lislevand, Hopkinson Smith, Paul O'Dette, Christopher Wilke, Andreas Martin, Robert Barto, Eduardo Egüez, Edin Karamazov, Nigel North, Christopher Wilson, Luca Pianca, Yasunori Imamura, Anthony Bailes, Peter Croton, Xavier Diaz-Latorre. Singer-songwriter Sting has also played lute and archlute, in and out of his collaborations with Edin Karamazov, and Jan Akkerman released two albums of lute music in the 1970s while he was a guitarist in the Dutch rock band Focus. Lutenist/Composer Jozef van Wissem composed the soundtrack to the Jim Jarmusch film Only Lovers Left Alive.
Lutes of several regional types are also common in Greece: laouto, and outi.
Repertoire

Lutes were in widespread use in Europe at least since the 13th century, and documents mention numerous early performers and composers. However, the earliest surviving lute music dates from the late 15th century. Lute music flourished during the 16th and 17th centuries: numerous composers published collections of their music, and modern scholars have uncovered a vast number of manuscripts from the era—however, much of the music is still lost. In the second half of the 17th century lutes, vihuelas and similar instruments started losing popularity, and almost no music had been written for the instrument after 1750. The interest in lute music was revived only in the second half of the 20th century.
Improvisation (making up music on the spot) was, apparently, an important aspect of lute performance, so much of the repertoire was probably never written down. Furthermore, it was only around 1500 that lute players began to transition from plectrum to plucking. That change facilitated complex polyphony, which required that they develop notation. In the next hundred years, three schools of tablature notation gradually developed: Italian (also used in Spain), German, and French. Only the last survived into the late 17th century. The earliest known tablatures are for a six-stringed instrument, though evidence of earlier four- and five-stringed lutes exists.[32] Tablature notation depends on the actual instrument the music is written for. To read it, a musician must know the instrument's tuning, number of strings, etc.
Renaissance and Baroque forms of lute music are similar to keyboard music of the periods. Intabulations of vocal works were very common, as well as various dances, some of which disappeared during the 17th century, such as the piva and the saltarello. The advent of polyphony brought about fantasias: complex, intricate pieces with much use of imitative counterpoint. The improvisatory element, present to some degree in most lute pieces, is particularly evident in the early ricercares (not imitative as their later namesakes, but completely free), as well as in numerous preludial forms: preludes, tastar de corde ("testing the strings"), etc. During the 17th century keyboard and lute music went hand in hand, and by 1700 lutenists were writing suites of dances quite akin to those of keyboard composers. The lute was also used throughout its history as an ensemble instrument—most frequently in songs for voice and lute, which were particularly popular in Italy (see frottola) and England.
The earliest surviving lute music is Italian, from a late 15th-century manuscript. The early 16th century saw Petrucci's publications of lute music by Francesco Spinacino (fl. 1507) and Joan Ambrosio Dalza (fl. 1508); together with the so-called Capirola Lutebook, these represent the earliest stage of written lute music in Italy. The leader of the next generation of Italian lutenists, Francesco Canova da Milano (1497–1543), is now acknowledged as one of the most famous lute composers in history. The bigger part of his output consists of pieces called fantasias or ricercares, in which he makes extensive use of imitation and sequence, expanding the scope of lute polyphony. In the early 17th century Johannes Hieronymus Kapsberger (c. 1580–1651) and Alessandro Piccinini (1566–1638) revolutionized the instrument's technique and Kapsberger, possibly, influenced the keyboard music of Frescobaldi.
French written lute music began, as far as we know, with Pierre Attaingnant's (c. 1494 – c. 1551) prints, which comprised preludes, dances and intabulations. Particularly important was the Italian composer Albert de Rippe (1500–1551), who worked in France and composed polyphonic fantasias of considerable complexity. His work was published posthumously by his pupil, Guillaume de Morlaye (born c. 1510), who, however, did not pick up the complex polyphony of de Rippe. French lute music declined during the second part of the 16th century; however, various changes to the instrument (the increase of diapason strings, new tunings, etc.) prompted an important change in style that led, during the early Baroque, to the celebrated style brisé: broken, arpeggiated textures that influenced Johann Jakob Froberger's suites. The French Baroque school is exemplified by composers such as Ennemond Gaultier (1575–1651), Denis Gaultier (1597/1603–1672), François Dufaut (before 1604–before 1672) and many others. The last stage of French lute music is exemplified by Robert de Visée (c. 1655–1732/3), whose suites exploit the instrument's possibilities to the fullest.
The history of German written lute music started with Arnolt Schlick (c. 1460–after 1521), who, in 1513, published a collection of pieces that included 14 voice and lute songs, and three solo lute pieces, alongside organ works. He was not the first important German lutenist, because contemporaries credited Conrad Paumann (c. 1410–1473) with the invention of German lute tablature, though this claim remains unproven, and no lute works by Paumann survive. After Schlick, a string of composers developed German lute music: Hans Judenkünig (c. 1445/50–1526), the Neusidler family (particularly Hans Neusidler (c. 1508/09–1563)) and others. During the second half of the 16th century, German tablature and German repertoire were gradually replaced by Italian and French tablature and international repertoire, respectively, and the Thirty Years War (1618–48) effectively stopped publications for half a century. German lute music was revived much later by composers such as Esaias Reusner (fl. 1670), however, a distinctly German style came only after 1700 in the works of Silvius Leopold Weiss (1686–1750), one of the greatest lute composers, some of whose works were transcribed for keyboard by none other than Johann Sebastian Bach (1685–1750), who composed a few pieces for the lute himself (though it is unclear whether they were really intended for the lute, rather than another plucked string instrument or the lautenwerk).
Of other European countries, particularly important are England and Spain. English written lute music only began around 1540, however, the country produced numerous lutenists, of which John Dowland (1563–1626) is perhaps the most famous. His influence spread very far: variations on his themes were written by keyboard composers in Germany decades after his death. Dowland's predecessors and colleagues, such as Anthony Holborne (c. 1545–1602) and Daniel Bacheler (1572–1619), were less known. Spanish composers wrote mostly for the vihuela; their main genres were polyphonic fantasias and differencias (variations). Luys Milan (c.1500–after 1560) and Luys de Narváez (fl. 1526–49) were particularly important for their contributions to the development of lute polyphony in Spain. Finally, perhaps the most influential European lute composer was the Hungarian Bálint Bakfark (c. 1526/30–1576), whose contrapuntal fantasias were much more difficult and tighter than those of his Western European contemporaries.

20th century revival and composers
The revival of lute-playing in the 20th century has its roots in the pioneering work of Arnold Dolmetsch (1858–1940); whose research into early music and instruments started the movement for authenticity.[33]  The revival of the lute gave composers an opportunity to create new works for it.
One of the first such composers was Johann Nepomuk David in Germany. Composer Vladimir Vavilov was a pioneer of the lute revival in the USSR, he was also the author of numerous musical hoaxes. Sandor Kallos and Toyohiko Satoh applied modernist idiom to the lute, Elena Kats-Chernin, Jozef van Wissem and Alexandre Danilevsky minimalist and post-minimalist idiom, Roman Turovsky-Savchuk, Paulo Galvão, Robert MacKillop historicist idiom, and Ronn McFarlane New Age. This active movement by early music specialists has inspired composers in different fields; for example, in 1980, Akira Ifukube, a classical and film composer best known for the Godzilla's theme, wrote the Fantasia for Baroque Lute with the historical tablature notation, rather than the modern staff one.[34]
Tuning conventions

Lutes were made in a large variety of sizes, with varying numbers of strings/courses, and with no permanent standard for tuning. However, the following seems to have been generally true of the Renaissance lute.
A 6-course Renaissance tenor lute would be tuned to the same intervals as a tenor viol, with intervals of a perfect fourth between all the courses except the third and fourth, which differed only by a major third. The tenor lute was usually tuned nominally "in G" (there was no pitch standard before the 20th century), named after the pitch of the highest course, yielding the pattern (G'G) (Cc) (FF) (AA) (dd) (g) from the lowest course to the highest. (Much renaissance lute music can be played on a guitar by tuning the guitar's third string down by a half tone.)
For lutes with more than six courses the extra courses would be added on the low end. Because of the large number of strings, lutes have very wide necks, and it is difficult to stop strings beyond the sixth course, so additional courses were usually tuned to pitches useful as bass notes rather than continuing the regular pattern of fourths, and these lower courses are most often played without stopping. Thus an 8-course tenor Renaissance lute would be tuned to (D'D) (F'F) (G'G) (Cc) (FF) (AA) (dd) (g), and a 10-course to (C'C) (D'D) (E♭'E♭) (F'F) (G'G) (Cc) (FF) (AA) (dd) (g).
However, none of these patterns were de rigueur, and a modern lutenist occasionally retunes one or more courses between pieces. Manuscripts bear instructions for the player, e.g., 7e chœur en fa = "seventh course in fa" (= F in the standard C scale).
The first part of the seventeenth century was a period of considerable diversity in the tuning of the lute, particularly in France. However, by around 1670 the scheme known today as the "Baroque" or "D minor" tuning became the norm, at least in France and in northern and central Europe. In this case the first six courses outline a d-minor triad, and an additional five to seven courses are tuned generally scalewise below them. Thus the 13-course lute played by composer Sylvius Leopold Weiss would have been tuned (A″A') (B″B') (C'C) (D'D) (E'E) (F'F) (G'G) (A'A') (DD) (FF) (AA) (d) (f), or with sharps or flats on the lower 7 courses appropriate to the key of the piece.[35]
Modern lutenists tune to a variety of pitch standards, ranging from A = 392 to 470Hz, depending on the type of instrument they are playing, the repertory, the pitch of other instruments in an ensemble and other performing expediencies. No attempt at a universal pitch standard existed during the period of the lute's historical popularity. The standards varied over time and from place to place.
See also
Instruments

European Lutes:
String instruments
Angélique
Archlute
Cobza
Gallichon
Kobza
Mandore
Mandora
Swedish lute
Tablature
Torban
Theorbo
Vihuela
Early music
Medieval music
Renaissance music
Baroque music
Classical music
Turkish music
Greek music
Cretan music
African Lutes:
Gonje
Xalam
Asian Lutes:
Barbat
Biwa
Dombra
Dotar
Dramnyen
Komuz
Kutiyapi
Oud
Pipa
Qinqin
Rubab
Sapeh
Setar
Sitar
Tanbur
Tar
Veena
Yueqin
Stringed instrument tunings
Composers of lute music
Category:Composers for lute
List of composers for lute
Lute players
Robert Barto
Timothy Burris
Johann Georg Hamann
Lutz Kirchhof
Rolf Lislevand
Nigel North
Paul O'Dette
Ben Salfield
Hopkinson Smith
Jozef van Wissem
Eduardo Eguez

Lute makers
Cezar Mateus
Stephen Murphy
David Rubio
Andrew Rutherford
Antonio Stradivari
Joachim Tielke
Notes

The Lute in Europe by Andreas Schlegel, published by  (2006). ISBN978-3-9523232-0-5
A History of the Lute from Antiquity to the Renaissance by Douglas Alton Smith, published by the  (2002). ISBN0-9714071-0-X ISBN978-0-9714071-0-7

The Lute in Britain: A History of the Instrument and its Music by Matthew Spring, published by Oxford University Press (2001).
Historical Lute Construction by Robert Lundberg, published by the Guild of American Luthiers (2002).
La musique de luth en France au XVIe siècle by Jean-Michel Vaccaro (1981).
Articles in  (1968–), The Lute (1958–), and other journals published by the various national lute societies.
Eckhard Neubauer, "Der Bau der Laute und ihre Besaitung nach arabischen, persischen und türkischen Quellen des 9. bis 15. Jahrhunderts", Zeitschrift für Geschichte der arabisch-islamischen Wissenschaften, vol. 8 (1993): 279–378.
 Viol and Lute Makers of Venice 1490 - 1640" by Stefano Pio, published by Venice Research (2012) ISBN978-88-907252-0-3
 Violin and Lute Makers of Venice 1630 - 1760 " by Stefano Pio, published by Venice Research (2004) ISBN978-88-907252-2-7
"Il Liuto" by Davide Rebuffa, published by L'Epos, Palermo (2012). ISBN978-88-830237-7-4

Societies
 (America)
 (Belgium)
 (France)
 (Germany)
 (Japan)
 (Japan, Founded by Toyohiko Satoh)
 (the Netherlands)
 (UK)
Online music and other useful resources
 collection of many useful links: luthiers/lute makers, lute players, tablatures, etc. (in English and Hungarian)
 Watch Tommie Andersson play the theorbo, 7-course & 10-course lutes.

 The website for the great Hamburg lute maker Joachim Tielke
 Facsimiles/Scans (Dowland, etc.) and pdfs - by Alain Veylit
 7000+ lute solo and ensemble pieces by 300+ composers in midi, PDF, TAB, and Fronimo formats
 Categorized view on youtube videos of over 250 lute composers
 Modern (post 1815) and Contemporary Lute Music. A list of modern lute music written after 1815
 in Cambridge Digital Library. One of the most important collections of manuscript music in Cambridge University Library is the group of nine lute manuscripts copied by Mathew Holmes in the early years of the seventeenth century.
 The most important collection of modern Urtext music editions for lute.
Photos of historic instruments
Photos of historic lutes at the  in Paris
– search-phrase: Mot-clé(s): luth
– search-phrase: Instrument fabriqué: luth
– search-phrase: Instrument de musique, ville ou pays: luth

Articles and resources
 by Jo Van Herck (Belgian Lute Academy)
Original: ; Luthinerie / Geluit  and

 from Lute Society of America


An automated pool cleaner is a vacuum cleaner intended to collect debris and sediment from swimming pools with minimal human intervention. Popularly dubbed a ''creepy-crawly'' or "Kreepy Krauly" in South Africa,[1] it is one of several types of swimming pool vacuum cleaners. Other major types are battery-powered or manually powered wands effective only for very small pools, kiddie or wading pools and small spas and hot tubs, and battery-powered, handheld/extended reach pool and spa vacuums. The latter are powered by rechargeable batteries and can be hand held attached to a telescopic pole used for extended reach. These are used for small to medium-sized pools, larger spas, and to spot clean larger pools.[2] The name ''creepy-crawly'' derives from the vacuum's webbed-nozzle crawling creepily through the underwater mist as well as for its creepy suction noise. ''Creepy crawly'' originally referred to strange creatures that crawl on the bottom of the ocean, as the webbed nozzle of the vacuum slightly resembles an octopus in both appearance and suction ability.
History
Evolution
Swimming pool cleaners evolved from two areas of science: development of the water filter and early cistern cleaners.
The forerunner of today's pool cleaners were cistern cleaners. A cistern (Middle English cisterne, from the Latin cisterna, from cista, box, from Greek kistê, basket) is a waterproof receptacle for holding liquids, usually water. Often cisterns were and still are built to catch and store rainwater. The great palaces of antiquity had both lavish pools and cisterns. They were prevalent in early America as well. United States Patent and Trademark Office makes reference to a cistern cleaner patent filed (though never issued) as early as 1798. Before swimming pools were affordable and fashionable, many swam in their larger cisterns.
In 1883 John E. Pattison of New Orleans filed an application for a "Cistern and Tank Cleaner " and the first discovered patent was issued the following year.[3]  It swept and scraped the bottom of a cistern or tank, and through a combination of suction and manipulation of the water pressure was able to separate and remove sediment without removing the water. Over the next 20 years his invention was improved on numerous occasions. Many pool cleaner patents issued in the modern era refer to some of the cistern cleaners as predecessors of their invention.
Early models
The first swimming pool cleaner was invented in 1912 by Pittsburgh, Pennsylvania local citizen John M. Davison. On November 26, 1912, he submitted a patent application to the United States Patent and Trademark Office entitled "Cleaning Apparatus For Swimming Pools And The Like," patent number 1,056,779 that was issued on March 25, 1913.[4]
The first suction-side pool cleaner was invented by Roy B. Everson of Chicago in 1937, which he entitled "Swimming Pool Cleaner".[5]
Nineteen years later, the first suction-side pool cleaner was the work of Joseph Eistrup of San Mateo, California, who called his invention simply "Pool Cleaner".[6]
Two years later, the first truly automatic, aptly named "Automatic Swimming Pool Cleaner" was created by Andrew L. Pansini of Greenbrae, California, founder of the industry icon Jandy Corporation. Patent Number 3,032,044 was touted by Pansini as "an automatic swimming pool cleaner", which is effective to remove the scum, dirt and other accumulations from both the bottom and side walls of a pool to disperse foreign matter in the, water for removal therefrom by normal pump-filter system of the pool.[7]
The first robotic pool cleaner that used electricity was the work of Robert B. Myers of Boca Raton, Florida in 1967, who filed a patent.[8]
The third and last of the generally accepted pool cleaner technologies, the pressure-side cleaner, was invented by Melvyn L. Henkin of Tarzana, California in 1972. His "Automatic Swimming Pool Cleaner[9], United States Patent Number 3,822,754 utilized three wheels to allow the machine "to travel underwater along a random path on the pool vessel surface for dislodging debris therefrom". The design is probably familiar to pool owners as the Polaris Pool Cleaner.[10]
Independently from his American counterparts Ferdinand Chauvier invented the Kreepy Krauly in South Africa in 1974 in Springs.[11]
Types
There are three main types of automated or automatic swimming pool cleaners, classified by the drive mechanism and source of power used:
Suction-side
In this type, water pumped out of the pool via its skimmer or drains is used for locomotion and debris suction and returned after being filtered via pool return or outlet valves. This is the least expensive and most popular type. It traces a random course. This type of cleaner is usually attached via a 1.5 inch hose to a vacuum plate in the skimmer, or to a dedicated extraction or "vac" line on the side of the pool. The suction action of the pool's pump provides motive force to  the machine to randomly traverse the floor and walls of the pool, extracting dirt and debris in its path. The first automatic pool cleaner was a suction cleaner.
These are the least expensive and most widely used pool cleaners with purchase costs ranging in the $100–$300 price range. They are powered solely by the main pump of the pool and utilize the pool's filter system to remove dirt and debris from the water. These machines effectively diminish the suction of the main pump - using them will increase the electricity costs and require the main pump and filter system to be serviced more frequently. There is minimal maintenance and part replacement costs on these devices over time.
Pressure-side
In this design, pool water inflow is further pressurized using a secondary "booster" pump on most but not all models. This high-pressure water is used for locomotion and debris suction, employing the venturi effect. It traces a random course. The requirement of a booster pump makes this type the highest in  electricity use of the three types of pool cleaners.
The pressure causes turbulence in the water, distributing some debris on the floor and walls of the pool, some of which is re-floated to the pool surface and then sucked into the main filter through the skimmer inlets. A portion of the dirt and debris is caught in an attached filter bag. The purchase cost of this type of cleaner range from a minimum of $200 to about $700 plus the costs of the booster pump, usually over $200. Some more sophisticated models can cost over $1,000.
Both suction-side and pressure-side cleaners are dependent on the pool's main pump and filter system to remove contaminants from the pool water, so cannot remove particles smaller than the pore size of the pool's existing filter element. Such elements can be made of sand, diatomaceous earth, zeolite or other natural or synthetic materials. That particle size ranges from under 5µm for diatomaceous filters to well in excess of 50µm for sand filters. Disadvantages of these types of pool cleaners are the additional electricity use, and filtration limitation by the pore size of the main filter element, as well as the time and effort needed to attach the device to the ports that connect to the main pump and filter, and the increased burden of maintenance time and expense on the pool's mechanics.
Electric robotic
These cleaners are independent from the pool's main filter and pump system and are powered by a separate electricity source, usually in the form of a set-down transformer that is kept at least 10 feet (3.0m) from the water in the pool, often on the pool deck. They have two internal motors: one to suck in water through a self-contained filter bag and then return the filtered water at a high rate of speed back into the pool water. The second is a drive motor that is connected to tractor-like rubber or synthetic tracks and "brushes" connected by rubber or plastic bands via a metal shaft. The brushes, resembling paint rollers, are located on the front and back of the machine and help remove contaminating particles from the pool's floor, walls (and in some designs even the pool steps) depending on size and configuration. They also direct the particles into the internal filter bag.
An internal microchip is pre-programmed to turn on and off and reverse the direction of the drive motors. The chip will cause the machine to change direction when it reaches a wall or the water surface after climbing the pool walls.
These machines may also be directed by sensors located in the bump bars which, on contact with objects such as a wall, cause a reverse in direction, with a small offset allowing it to move one machine's width over on each crossing of the pool. The delay timer is an important feature for many pools, as many switch off a number of circulation pumps during the night to allow suspended particles to settle on the bottom of the pool; after a couple of hours the pool cleaner begins its cleaning cycle. This cleaning cycle is set up to complete before the pumps are turned back on. Though not necessary for adequate pool cleaning, this feature saves energy and improves cleaning efficiency.
In order to move forward and backward and negotiate walls and steps electric robotic cleaners rely on three natural principles, traction and movement caused by the drive motor and tracks, buoyancy created by the large areas inside the machine that fills with air, and the force resulting from the high pressure of water being emitted from the top of the machine that pushes it against the floor and walls. Some electric robotic machines use brushes made out of polyvinyl alcohol (PVA) Polyvinyl alcohol that has an adherence quality that allows the unit to almost cling to the walls, steps and floors. They also are resistant to dirt and oil improving lifespan over rubber or other synthetic materials.
The combination of these three natural principles along with an internal mercury switch that tells the microchip that the unit has gone from a horizontal to vertical position as it climbs a wall allows it to change direction from ascending to descending the wall at pre-programmed intervals based on the average height of a pool walls. Some machines have delayed timers that cause the robot to remain at the water line, where more dirt accumulates, for momentarily resulting in a scrubbing action, much like the wheels of a powerful automobile spinning or peeling out.
The major benefits of these machines are efficiency in time, energy, and cleaning ability as well as low maintenance requirements and costs. The major disadvantage is purchase cost which can range from $500 for floor-cleaning-only machines to over $2,000 for the most sophisticated residential units.
Commercial versions
According to P.K. Data of Duluth, a Georgia consulting and market research firm that has been retained for many years by the pool and spa industry's internal trade organization, The Association of Pool & Spa Professionals (APSP) there are approximately 14,000,000 residential pools and spas in the United States and over 400,000 commercial or public pools. As a result, this has created a market for larger, more powerful commercial pool cleaners. All commercial pool cleaners are electric robotic and can range in price from a little over $1,000 to upwards of $15,000 or more. They closely resemble residential models but in addition to their addition size they are made with heavy duty components and often more sophisticated computer guidance and on and off systems.
Controlling legislation
There have been attempts for nearly 100 years to mandate the use of pool cleaners, primarily addressed to public pools. Currently the Center for Disease Control and Prevention located in the Greater Atlanta, Georgia metropolitan area on a grant provided by the National Swimming Pool Foundation (NSPF) is about to publish the first uniform Model Aquatic Health Code (MAHC). Included is a section on pool filtration proposed regulations directed to the nation's 3200+ state and local agencies that enforce laws and ordinances relating to the operation of swimming pools and spas.
Historical perspective
The proposed MAHC is not the first attempt to propose a uniform aquatic health code. The credit for that goes to the American Public Health Association(APHA) which 100 years ago recognized the dangers of improperly maintained aquatic facilities and formed a committee in 1918 that, for the next 66 years, issued eleven so-called "Swimming Pools and Other Public Bathing Places Standards For Design, Construction, Equipment And Operation" recommended ordinances and regulations. But for a variety of reasons none of these recommendations were adopted, at least not formally or completely adopted.
Uniform Aquatic Health Code
The APHA has tried to develop a uniform aquatic health code, or what it referred to for years as referenced above, and published short reports annually from 1920 through 1925 that it simply referred to as "Report of the Committee On Bathing Places". and finally in 1926 [12] published in its journal its first comprehensive report it called "Standards for Design, Construction, Equipment and Operation" for "Swimming Pools and Other Public Bathing Places". Twelve others were published through 1981. However, its lack of authority to enforce them is implied by the changing description of what was limited to their recommendations or suggestions and the expressed purposes in issuing them.
Reports
In 1957, it referred to its report as "Recommended Practice for Design, Equipment and Operation of Swimming Pools and Other Public Bathing Places".[13]
In the most comprehensive one since 1926 and until it stopped issuing them in 1981 it referred in 1964 to its report as "Suggested Ordinance and Regulations Covering Public Swimming Pools" and in 1970 one for "Private Swimming Pools". Its last report in 1981 was called "Public Swimming Pools: Recommended Regulations for Design and Construction, Operation and Maintenance". In 1926 appears the committee believed its standards would be adopted by the empowered jurisdictions, although who they were never mentioned in the report.
In 1964 the boldest move of all took place as it presented its recommendations in the form of proposed ordinances and regulations and in the Forward concluded: "State and local governments who desire to enact this Suggested Ordinance and Regulations Covering Public Swimming Pools a useful resource".
New York City Meeting, 1912
In 1912, coincidentally the same year when the United States Patent and Trademark Office issued the first patent for a swimming pool cleaner, the Sanitary Engineering Section of the American Public Health Association (APHA) convened in New York City to lay the groundwork for the first recommended pool and spa regulations. As reported in the American Journal of Public Health in April 1912 a meeting was held in Havana the previous December and at the New York meeting among the subjects that the committee was to be studying was "Hygiene of swimming pools".[14]
Six years later a committee on swimming pools was appointed at the APHA's annual meeting in Chicago and in 1920 a similar committee was appointed at the meeting in Washington, D.C. In 1921 and periodically over the next seven decades until the work of the APHA on this subject matter went through a series of divisions and consolidations, diverted elsewhere its committees and joint committees with other health-orientated public and quasi-public organizations issued proposed ordinances and regulations in the form of unenforceable recommendations. Despite their intended and published goals, none became law, uniform, much less national.[15]
None of the proposed Standards included more than a passing reference of the need to properly clean a pool. A few, but curiously not all of these recommended ordinances and regulations, related to the use of a vacuum, although the first that included any specificity in 1923 at least required a certain level of clarity. The 1921 report, barely a few pages in length, made this reference to the need to clean the pool.
Pool cleaning is done by completely emptying the pool an average of twice weekly and scrubbing with stiff brushes and soap. Hose flushing follows the scrubbing. After the flushing outlet is opened, the well turned on and clean water allowed to water over the floor of the drains, etc...

The 1923 report of the American Journal of Public Health, Sanitary Engineering Section American Public Health Association read before the Sanitary Engineering Section of the American Public Health Association at the Fifty-second Annual Meeting at Boston, Massachusetts, October 8, 1923. slightly longer, but still very brief stated:
Section 3. Clearness: At all times when the pool is in use the water shall be sufficiently clear to permit a black disk six inches in diameter on a white filed, placed on the bottom of the pool at the deepest point, to be clearly visible from both sides of the pool when the water is quiet.

It further stated:
No swimming pool shall be opened to the use of bathers on any day until all visible dirt (not stains) on the bottom of the pool and any visible scum or floating matter on the surface has been removed. Scum and floating matters may be infectious material and should always be removed as soon as possible after they are observed.

Therefore, in 1921 it was recognized that infectious material, namely pathogens collect in the pool and should be removed.
It was not until 1926 twelve years after the organization recognized the need to address swimming pool "hygiene" and eight years after the committee was organized that the first true report was issued and later published in the Journal of the American Public Health Association. Of all of its reports from 1920 through 1981 the first major report by the APHA the 1926 one, written in narrative form as were the succeeding nine ones though 1957 the committee included the detailed provisions relating to pool cleaning, vacuuming and vacuums:
E. Suction Cleaner: In the opinion of the committee the only satisfactory method of removing the dirt, hair, etc., settling on the bottom of a pool is by means of a suction cleaner. As such cleaners are commonly operated by the circulation pumps; they may be classed as an adjunct to the recirculation system. When a suction cleaner is to be operated by the recirculation pump, a gate with graduated stem or other registering device should be provided for throttling the flow from the pool outlet to permit the pump to operate at maximum efficiency when the suction cleaner is in use. Fixed pipe connections for attachment of suction cleaner to pump suction should be of ample size to reduce friction to a minimum and the cleaner and all removable connections should be designed to provide a maximum velocity at the suction nozzle.
XXVI Cleaning Pool
A. Visible dirt on the bottom of a swimming pool shall not be permitted to remain more than 24 hours.
B. Any visible scum or floating material on the surface of a pool shat be removed within 24 hours by flushing or other effective means

The 1964 report included the following language:
A vacuum-cleaning system shall be provided. When an integral part of the recirculation system, sufficient connections shall be located in the walls of the swimming pool, at least eight inches below the water line and "Visible dirt on the bottom of the swimming pool shall be removed every 24 hours or more frequently as required. Visible scum or floating matter on the swimming pool surface shall be removed within 24 hours by flushing or other effective means.

The CDC was founded (in 1946), followed by the Cabinet-level Department of Health, Education and Welfare (in 1953), now the Department of Health, and Human Services and its 11 operating divisions, the National Health Service Corps (in 1977) and along the way a variety of private and non-profit aquatic organizations such as the National Spa and Pool Association (in 1956), now the Association of Pool and Spa Professionals the National Swimming Pool Foundation (in 1965).
Presently a variety, but not by a long shot the majority, of states and jurisdictions that have codified the requirement of inclusion of an independent vacuum cleaner including the two states with the highest number and concentration of both residential and public pools:
California: 2010 Title 24, Part 2, Vol. 2 California Building Code. Section 3140B, Cleaning Systems:
A vacuum cleaning system shall be available which is capable of removing sediment from all parts of the pool floor. A cleaning system using potable water shall be provided with an approved backflow protection device as required by the California Department of Public Health under Sections 7601 to 7605.—[16]

Florida:
Florida Department of Health section 64E-9.007 Recirculation and Treatment System Requirements
(12) Cleaning system– A portable or plumbed in vacuum cleaning system shall be provided. All vacuum pumps shall be equipped with hair and lint strainers. Recirculation or separate vacuum pumps shall not be used for vacuuming purposes when in excess of 3 horsepower. When the system is plumbed in, the vacuum fittings shall be located to allow cleaning the pool with a 50 foot maximum length of hose. Vacuum fittings shall be mounted no more than 15 inches below the water level, flush with the pool walls, and shall be provided with a spring loaded safety cover which shall be in place at all times. Bag type cleaners which operate as ejectors on potable water supply pressure must be protected by a vacuum breaker. Cleaning devices shall not be used while the pool is open to bathers.—[17]

Call to action
In 2005 the CDC in response to a growing concern and feared epidemic with the pathogen Cryptosporidium the Center for Disease Control Center for Disease Control, much like the American Public Health Association did in 1912 convened many of the country's foremost medical and other scientific experts to study the concern for aquatic health. As a result, in 2007 they began their quest, again much like the APHC for a uniform aquatic health code.
Each health and safety segment has been assigned to a committee to study it and draft a proposed module open for public comment before being adopted and then recommended to the nation's 3200+ state and local health agencies that enact ordinances and regulations for swimming pools and spa and other aquatic facilities, inspect and monitor them and then enforce the regulations. Since the focus of the MAHC was to respond to the threat of Cryptosporidium the Technical Committee of Recirculation Systems and Filtration is a major focus. The University of North Carolina Charlotte Associate Professor James Amburgey is the Chairperson of the Center For Disease Control, Model Aquatic Health Code Technical Committee on Recirculation Systems and Filtration.
Amburgey has conducted many tests to evaluation existing swimming pool filters and his conclusions have been they are extremely ineffective in most cases to help remove Cryptosporidium.[18] He is reported to be working with several manufacturers of swimming pool and spa vacuum cleaners to develop a filter bag that will result in exponential advancements in the current filter bags, cleaners and vacuums on the market.
See also
Domestic robot
Hot tub
Robotic vacuum cleaner
Swimming pool
Water purification

Further reading
United States Swimming Market, 2005, Pool and spa marketing reference directory. Markham, Canada: Hubbard Marketing & Publishing Limited; March 2005:19-21.
United States Bureau of the Census. Statistical abstract of the United State, 1995. 115th ed. Washington, DC: US
Yoder J, Blackburn B, Levy DA, Craun GF, Calderon RL Surveillance for waterbome-disease outbreaks associated with recreational water—United States, Beach MJ. 2001-2002. Surveillance Summaries, October 22, 2004.
Progress of the U.S. Model Aquatic Health Code Project World Conference on Drowning Prevention May 13, 2011 Da Nang, Vietnam
William R. Peterson, PH.D. and Renee E. Berman A New Method For Removing and Inactivating Water-borne Patho-gens Utilizing Saline Treated Materials Coating Systems Laboratories, Inc.
Making Waves in the Aquatics Industry 2005 International Symposium on Household Water Management, Model Health Code.
New Code Aims at Standards for Nation's Pools
Delaunay A. Gargala, G, Li X, Favennec, L, Ballet JJ, Quantitative Flow Cytometric Evaluation of Maximal Cryptosporid-ium parvum Oocyst Infectivity in a Neonate Mouse Model Applied and Environmental Microbiology -Volume 66, Issue 10, p.4315.
Huw. V. Smith, Rosely, A. B. Nicols, Anthony M. Grimason, Cryptosporidium excystation and invasion: getting to the guts of the matter Trends in Parasitology volume 21, Issue3, March 2002, pp.133–142.
Okhuysen PC, Chappell CL, Crabb JH, Sterling CR, Dupont HL Virulence of three distinct Cryptosporidium parvum iso-lates for healthy adult's Journal of Infectious Diseases, Volume 180, Issue 4, pp.1275–128
Capet C. Kapel N, Huneau JF, Magne D, Laikuen R, Tricottet V, Benhamou Y, Tome D, Gobert JG Cryptosporidium par-vum Infection in Suckling Rats: Impairment of Mucosal Permeability and Na+-Glucose Cotransport' Experimental Para-sitology. Volume 91, Issue 2, February 1999, pp.119–125, Water Quality Criteria, 1972"
A report of the Committee on Water Quality Criteria Environmental Studies Board, National Academy of Sciences National Academy of Engineering, Washington, D.C., 1972-EPA-United States Environmental Protection Agency. United States Environmental Protection Agency Guide, 2 Swimming Pool Architects and Building Branch at the Department for Education (DFE).
Gordon Nichols, Rachel Chalmers, lain Lake, Will Sopwith, Martyn Regan, Paul Hunter, Pippa Grenfell, Flo Harrison, Chris Lane, Cryptosporidiosis. A report on the surveillance and epidemiology of Cryptosporidium and epidemiology of Cryptosporidium infection in England and Wales
Jennifer L. Clancy, Karl G. Linden, Randi M. McCuin ‘‘Cryptosporidium Occurrence in Wastewaters and Control Using UV Disinfection International Ultra-Violet Association- Volume 6, Issue 3
In Search of Crypto's Achilles Heel University of Georgia Research Magazine, University of Georgia Research Magazine
Guidelines for Safe Recreational Water Environments Volume 2 Swimming Polls and Similar Environments World Health Organization
Franz J. Maier A System for Fluoridating Individual Water Supplies American Journal of Public Health, Volume 48, Issue 6, June 1958
Fiona L. Henriquez, Thomas A. Richards, Fiona Roberts, Rima McLeod and Craig W. Roberts The unusual mitochondrial compartment of Cryptosporidium parvum -X. Trends in Parasitology, Volume 21, Issue 2, February 2005
James E. Amburgey, Kimberly J. Walsh, Roy R. Fielding and Michael J. Arrowood Removal of Cryptosporidium and polystyrene microspheres from swimming pool water with sand, cartridge, and pre-coat filters Journal of Water and Health, Volume 10, Issue 1, pp. 31–42
Paul A. Rochelle, Steve J. Upton, Beth A Montelone and Keith Woods The response of Cryptosporidium parvum to UV light, Trends in Parasitology, Volume 21, Issue 2, February 2005, pp. 80–87
James E. Amburgey and J. Brian Anderson Disposable swim diaper retention of Cryptosporidium-sized particles on human subjects in a recreational water setting Journal of Water and Health, Volume 9, Issue 4, September 2011, pp. 653–658
James E. Amburgey Removal of Cryptosporidium-Sized Polystyrene Microspheres from Swimming Pool Water with a Sand Filter with and without Added Perlite Filter Media Journal of Environmental Engineering, Volume 137, Issue 12, December 1, 2011, pp. 1205–1208
J. Lepage P. Rouvroy D, Vandepitte, J ‘‘Cryptosporidium spp., a frequent cause of diarrhea in Central Africa Bogaerts  Journal of Clinical Microbiology, Volume 20, Issue 5, November 1984, pp.874–876
Thulin JD, Kuhlenschmidt MS, Rolsma MD, Current WL, Gelberg HB An intestinal xenograft model for Cryptosporidium parvum infection. Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois Urbana 61801, Infection and Immunity, Volume 62, Issue 1, January 1994, pp.329–331
Neutralization of cryptosporidium parvum sporozoites by immunoglobulin and non-immunoglobulin components in serum-Hill, BD. Dawson AM, Blewett, DA, Research in Veterinary Science, Volume 54, Issue 3, May 1993, pp.356–360
Moredun Research Institute, Edinburgh Characterization of cyclophosphamide-rat model of cryptosporidiosis. Rehg JE, Hancock ML, Woodmansee DB.'Infection and Immunity Volume 55, Issue 11, November 1987, pp.2669–2674, Comparative Medicine Division, St. Jude Children's Research Hospital, Memphis Tennessee 38101
James E. Amburgey, Kimberly J. Walsh, Roy R. Fielding and Michael J. Arrowood Removal of Cryptosporidium and polystyrene microspheres from swimming pool water with sand, cartridge, and precoat filters, IWA Publishing 2012
B T Croll, C R Hayes, C J Wright, S Williams and D. Rowlands Optimisation of pool water filtration for Cryptosporidium oocyst removal and new research Swansea University, Wales, Biofilm- A Nasty that's in your Pool! Professional Pool Operators of America, 2012
Michael Unger The Role of the Schmutzdecke in Pathogen Removal in Slow Sand and Riverbank Filtration Presenta-tions/unger_schmutzdecke.pdf, University of New Hampshire
Equipment for Swimming Pools, Spas, Hot Tubs and Other Recreational Water Facilities. National Sanitation Foundation International Standard
Kuan Mu Yao, Mohammad T. Habibian, and Charles R. O'Melia Water and Waste Water Filtration: Concepts and Applications. Environmental Science & Technology, Volume 5, Issue 11, November 1971
Gautam Chalasani, Weimin Sun A Report on Backwashing of Sand Filter medium Experiment Filter-Backwashing.pdf, Michigan State University College of Engineering Student-developed filter in Honduras is cause for a party. Anne Ju.
Zerihun Alemayehu Filtration Addis Ababa Institute of Technology/Department of Engineering. Pool Filters-Sand Pool Filters

When was the first automated pool cleaner developed?


''The New York Times'' Fiction Best Sellers of 2018This is a list of adult fiction books that topped The New York Times Fiction Best Seller list in 2018, in the Combined Print & E-Book Fiction category.[1]

See also
The New York Times Non-Fiction Best Sellers of 2018

The New York Times Fiction Best Sellers of 2018