P ALGERIA complemented bystuccoand wooddecoration. pound, the dowed [12]. monuments with several Tlemcen They arethe inlaid glazedpottery called decorationwith ofthisheritage,isthepolychrome the ornamentation that established to the Andalusian monumentsofGranadainSpain[11]. compared often been of thefourteenthcenturies,have from thethirteenthtomiddle in theartoffaiencemosaic[7-10]. Tlemcen’s mainmonuments,whichspan theperiod who excelled (1248/1269-1465) the Marinids andmostparticularly dites) (1235-1556), (1040-1147moravids CE), the (1121/1147-1269),Almohads (Abdelwa- the Zayyanids royal cityremainsbut,atthesametime,stressingneed topreservethem. monuments in of thegreat heritage architectural the valuable Tlemcen, highlighting architecture attests to a thrivingart production [4]. Marcais [5, 6] documented the Arab proximity to Spain andMorocco explains thepresenceof numerous vestigeswhose of Islamicartin monuments that stillhousesmajor representative places Its Algeria. the city of Tlemcen, locatedinthe northwestern part of Algeria, remainsone of the few with theFrench[2,3].Inthiscontext, and theOttomansconcluded the Spanish the the Romans, the Phoenicians, occupants;theyincluded by itssuccessive Arabs, vehicle forinterpretationincontemporarydesign. preservation. Furthermore,this approach may enable architecturalheritageto act as a starts approach to architectural heritage documentation and with its acknowledgment, [1]. to theculturalidentityofapeople essential inherently dimensions, A sustainable * Correspondingauthor:[email protected] The Marinidsinparticular,reign overthecity, their quarter-century-long during en- The cityof Tlemcen owesitsIslamicheritagetosuccessivedynasties: the Al- built heritage architectural diversiied and rich of land a is Africa, North in Algeria, visual and aesthetic symbolic, powerful, inluential, carries heritage Architectural 1. Introduction Kheira TabetKheira Aoul* Mohamed Boudiaf,USTO-MB, Oran, Algeria Département d’Architecture,UniversitédesSciencesetdela Technologie d’Oran Meriem Benkhedda Keywords: Emirates University,United Arab Emirates Al Ain, Department of Architectural Engineering,College ofEngineering,United Arab AND RESULTING AMBIENCES IN A MARINIDMOSQUE, OLYCHROME CERAMICS, ARTISTIC DIAGNOSIS Sidi Al-Halwi ambience,ceramic,color, Marinidheritage 3 Mosque andtheentirecityof mosaic of faience (also referredto as El-Mansourah Sidi Boumediene Sidi zellij . One keyfeature, ). The zellij com- is 27

CONSERVATION SCIENCE IN CULTURAL HERITAGE Indeed, in architecture, everyone remarks on the colorful aspect of Islamic art. Blair and Bloom [13] state that the use of color deliberately destabilizes a static geometrical design by introducing a new dynamic in architecture, while Renan [11] compared the wall decorations to colorful vertical carpets (Figure 1). Islamic religious buildings are characteristically devoid of furniture. Ultimately, their surface treatment and the impor- tance given to the choice of material coatings (ceramic for example) becomes of prime importance.

Figure 1. Wall decoration with faience mosaics inside the Madrasa of Sidi Boumediene, Tlemcen, Algeria. Source: Authors.

The colors enhance the character of the building, contributing to its image and its spatial ambience, allowing appropriation of the space and modifying the atmosphere of the place. According to Léger [14], color can totally change the atmosphere of a place by creating a new space. The simple act of coloring a wall has the power to adorn it, make it stand back, advance, or even destroy it. The mural decorations in polychrome ceramics, moreover, provide a high aesthetic quality to architectural monuments. Several specialists of Muslim Art consider these mural decorations as full-ledged works of art [10, 15-17]. Colored decorative motifs allow an expression of patterns. It gives them a particular appearance and depth, and therefore perfection [18]. Accordingly, the colors in this Marinid ornamentation enhance the building character, contributing to its image and its spatial ambience. On walls, the play of geometry combined with colors makes these panels a work of abstract art, as Islamic art is devoid of igurative forms. According to Barnet’s guide [1λ], non-objective art, unlike igurative art, depends on representa- tive forms. It relies entirely on the emotional signiicance of color, form, texture, size and spatial relationships. In this regard, the polychromatic compositions of the ceramic mural decorations in the Marinid Sidi Boumediene εosque and their resulting ambience, offer a fertile ield of investigation, which has yet to reveal all its intrinsic spatial and aesthetical value. M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

28 hr plcrm crmc wr etniey sd ws eetd o ti speciic this for selected was used, extensively were ceramics polychrome where

dynasty; totheMarinid architectural heritagebelonging ramics inoneworkofrepresentative Goethe’s treatise of colors [21] develops relationship between these dimensions using color contrastsbased on Itten’s work [20]. the saturationlevel(purityorvividnessofcolor)[22,23],andattempttobringout Itten) analyzethethreedimensionsofcolor:tint(color),value(brightness),and of abrighttoneagainstdarkground”[19]. The lawsofcolorcontrast(establishedby proximity,tones ineachother’s toexpressthethoughtbehindabrow, bytheradiance complementary colors,theirmixtureandoppositions,themysteriousvibrationsof the deines guide Barnet’s artistic colorconceptthroughVan Gogh’s studyofhis own artworkasthe“marriageof in analysis color The [21]. colors of treatise Goethe’s and analysis fromBarnet’s guide[19];thelawsofcolorcontrastestablishedbyItten[20]; this purpose,theanalysisreliesonacombinationofapproachesincludingcolor ment ofthesecolorshasontheambiancecreatedinspaceisalsoaddressed.For how they are placed in the composition alongside other colors. The effect the arrange This focusesontheeffects ofcolorswhenjuxtaposed,astheirappearancedependson colors employedineachpolychromecomponent. of the and comparison the material,itslimitations,description volves examining By whomandforwhom? and whywastheworkmade? where also in- The analysis when, contextν cultural and historical its in studied work the placing irstly,in consists in Barnet’sartistic studyof an artwork,asdeveloped guide [19]. The Barnetanalysis of Muslim eral specialists Art [10,15-17]. is basedontheaestheticand The approach analysis of the mosaic of faience panels and loors, considered as works of art by sev color andtheirresultingambience. it asanartworkandsecondly,and analyze of theceramics’the composition toanalyze panels faïence of mosaic the of colors the document and inventory to irst objectivesν canus carried out,usingin-situobservationsandphotographicsurveys. Finally,were [4]. investigations εonuments ield Historical of Service then-formed the Danjoy,Edouard and Duthoit by Edmond surveys wereundertaken 1872, by followed from Starting explorers. scientiic and engineers military by drawn and identiied irst investigated. were period of The monuments were and theirsurroundings Tlemcen as thoseby are basedonthreesetsofinformation.First,travelers’such considered, taleswere warm-cold, by analogy with natural phenomena and the environment (sky, sun, ire etc.). The relatively well-preserved architectural ensemble of architectural ensemble The relativelywell-preserved 3.1. SidiBoumedieneMosque; casestudy The aim of this study is therefore to investigate the unexplored role ofcolorce- the unexplored The aimofthisstudyisthereforetoinvestigate 2. Objectiveofstudyandresearchmethodology 3. Thepolychromeceramics inthe The second objective aims to analyze color composition and its resulting ambience. The secondobjectiveaimstoanalyze color composition and itsresulting ambience. artistic an of consists used, colors the of inventory the beyond objective, irst The The integrity of the information and the authenticity of the colors explored hereby,explored of thecolors the authenticity and The integrityoftheinformation 2 [5, 24]. Second, surveys the and constructiondrawingsdating colonial from Sidi Boumediene Sidi al-Hasan ibn Muhammad al-Wazzanal-Hasan ibnMuhammad al-Fasi εosque in Tlemcen, Algeria. The study has two speciic two has study The Algeria. Tlemcen, in εosque 1 the effects of colors, such as in distant-close, Sidi Boumediene , better known as , betterknown Sidi Boumediene Mosque Mosque, Leo Afri- - - 29

CONSERVATION SCIENCE IN CULTURAL HERITAGE study. An additional reason for this selection resides in the spiritual value bestowed upon this building by worshipers and visitors alike. The Sidi Boumediene Mosque compound, located in the neighborhood of El Eub- bad within the city of Tlemcen, was built in honor of Abu Choaïb Madyane (Boume- diene) El Andaloussi. Boumediene was a teacher, writer, poet and an eminent refer- ence of Suism in Algeria and the εaghreb. The architectural ensemble includes the Sidi Boumediene Mosque, built in 1339 by the Marinid Sultan, Abu Hassan Ali. It also includes the tomb of Sidi Boumediene himself, a Madrasa (religious school) built in 1347, and a small palace [7]. Sidi Boumediene Mosque stands out as a landmark and an attraction in the city of Tlemcen. It is the lavish ornamentation, composed mainly of lat ceramic decorations that make this building stand out as a remarkable heritage legacy [11]. The mosaic of faience, in general, covers the base of the walls, the loors of the courtyards, the porches and doorframes, as well as the upper part of the minarets. The artistic use of color is superimposed on the ceramic tile work with geometric and loral arabesque forms. Color creates speciic ambiences while highlighting architectural components, exposing spatial richness and a distinctive prowess in its construction [24]. The visual attractiveness of the colored ceramics, the geometry of the patterns, and the fractals in this important heritage have been broadly recognized in Sidi Boumedi- ene Mosque’s architectural heritage. However, little has been done in terms of studying the design and arrangement of the colors and their resulting ambience. This shortcom- ing reinforces the main objective of this research, which is to explore the polychromy.

3.2. Color and materials in the ceramics of Sidi Boumediene Mosque

In Sidi Boumediene Mosque, the dominant pigments used, as described and clas- siied by εarçais [5], are as followsμ – White: half-matt, slightly greenish, very small cracks. – Manganese brown: generally used very thickly, so as to form an almost black tone. – Yellow: an iron yellow, rather impure and produces a spotted yellow. – Copper green: has an intrinsic value and a very variable tone. In the same con- text, it can appear as very dark and very deep, or very clear, leaning towards celadon or turquoise colors. – Cobalt blue: quite rare. It does not seem to have been used in Tlemcen before the second half of the sixteenth century; it is clear and almost pure. The mosaics of faience are the heirs to the Byzantine mosaics, which were made of colored glass paste and smalts. The Marinid mosaics of faience are made from multi- colored tiles on stanniferous enamel. They form an assembly of varnished pieces with different tones, cut according to a template and recessed into each other.

3.3. Description of the polychromatic elements of Sidi Boumediene Mosque

The chromatic analysis of the colored component elements of Sidi Boumediene Mosque follows the visual encounter that a visitor may have in gradually discovering the site. In exploring the site, viewing both at a distance and close-up, induces different perceptual experiences. Hence, the mosque has been sequentially explored, starting from external elements such as the porch and its details, to the stairs leading to the M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

30 Boumediene Mosque.Source: Authors. access porch ofSidi Figure 2.Monumental that givesaccesstoanintrovert interior. Prophet, orsimplyapoem. marks thethreshold of theporch ornamentation The subtle of the verses, oraHadith Qur’anic art, itiscommon toincorporate Muslim decorative In mostcases,the It is dedicated to Sultan Abu al-Hassan and surmounts the loral decoration (Figure 4). coatings. the porch. announces band, inblackonawhitebackground, An epigraphic 4). ocher white, yellowandbrown geometric The intradosofthearchcarriesregular plates and green bands, above ive radiating rosettes around eight-sided stars (Figure a green-tonedceramicnet(Figure3). mosaic iron. in yellow and using fourtones:white,brown,green tiles is framedby This ensemble repeated regularly palms, double interlacing with decor loral in are They are intheformofarabesques. framework, theimpoststhatsupportitandspandrels border around the hanger. The second is circular formed by two spandrels. large The inishes a of this by formed keystone, the is irst The parts. two into frame the divides mosaics, ultimatelyprovidethearcadeentrancewithamajesticbase(Figure2). en-meter highhorseshoearchthat encloses it. Eleven steps covered withcolorful rate component. paving. its colored as asepa- is addressed perspectives, from all The minaret,visible entrance. Once inside the compound, the focus is then centeredonthe courtyard and

The friezethat crowns theportalisdecoratedwith inlaidbricks of brown enamel On the front porch, a triple festoon of brick, enameled with agreennettingpattern, On thefrontporch,atriplefestoonofbrick,enameled 1) by asev- adorned consists ofaporch to themosque entrance The monumental jafr or“scienceofletters”isapoem devotedtothegloryofGod.In pattern. Source: Authors. pattern. of bricks green netting inlaid with an enameled festoon with atriple 3. Thefrontporch Figure 31

CONSERVATION SCIENCE IN CULTURAL HERITAGE a b Figure 4. Distant view (a) and close-up view (b) of the epigraphic inscription detail in cursive composed of arabesques. Source: Authors.

2) The square courtyard of the mosque, delimited by the arch of the prayer hall in front of the main entrance, has an onyx basin for ablutions at its center (Figure 5). This courtyard is covered with simpler mosaics than the more ornate porch.

Figure 5. The courtyard of Sidi Boumediene Mosque, with polychrome mosaic of faience. Source: Authors.

3) Similar to the porch and the doorframe, the minaret located at the northwest cor- ner of the mosque, is richly decorated with polychrome mosaic (Figure 6). M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

32 architectural elements. features usedinthedifferentthat arecarriedthrough,identifythecolored brightness value comparedtotheothertones. in termsofhue,saturation and The coloranalysis is notveryvaried. vivid effectThe resulting liesinthepurityofeachcolorandits Figure 7.Chromaticsurveyoffaience mosaics (France), theεédiathèquedel’architectureetdupatrimoine(Paris));Figure(b): Authors. de laculture by ©Ministère (authorized 1872 by Duthoit (a): watercolor rosettes. Source:Figure decor of ofthemosquewithageometricandpolychrome Figure 6.Thetoppartoftheminaret a The tonalrangeof the ceramicsthatcoverarchitectonicelementsof the mosque bience and theresultingam- elements 4. Chromaticcomposition of thearchitectural

used inthearchitecturalelements. b 33

CONSERVATION SCIENCE IN CULTURAL HERITAGE The shape and size of the colored spots in Figure 7 differ from one element to an- other. The purest hues are located on the outer fringe of the circle and become less pure, or less saturated, as they move further away from the circumference. Hence, the green and the ocher-yellow are both pure colors and similar in brightness. When the colors used are compared with each other, they form different contrasts. As Indicated in Table 1, the encounter with colored sets can be appreciated in two ways. From a distance one can contemplate the colorful ornamentation and obtain a general overview with an optical mixture of colors, resulting in a speciic atmosphere (Figure 8). Up close, the intricate designs and the variety of their colors can be appreci- ated differently [26].

Figure 8. The décor in rich polychrome ceramic of the porch contrasts with the surrounding white and sober walls. Source: Authors.

Both inside and outside the building, the choice of decorated elements appears an intentional and deliberate act. Generally, they are representative and allegorical ele- ments with complex scenery and can be contemplated from afar. The colorful appear- ance attracts the attention because of the foreshortening effect of the colors. These various elements modulate the perception of the polychrome mosaic composition, ac- cording to an optical forward or withdrawal movement.

4.1 The porch and its components

The access to the mosque is the subject of a particular staging and is enhanced by the magical work of colors (Figure 2, Figure 3). This richly colored frontage serves as an announcement and a preamble to the monument. Its colored appearance contrasts with the white background of the adjacent walls (Figure 8, Figure 10) which captures

M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque and relects the light.

34 leaves andstems( namentation. is The one elementinthe cursive calligraphy composition of intertwined of theor- universe masses, thevisitormovestographic and physical vision overall These architecturaldetailsaredescribedandfurtheranalyzedbelow. volume. a light thewallsscintillateandvibratesuggesting play ofshadowandlight,making Similarly,catches thelight. of thesmallmosaicpieces theirregularity This createsa colorfulness. warmth and of brilliance, qualities with adornment fers thepolychrome which gleaminthesunandthus the brick color.highlight This interplayof colors con- spots ocher-yellow the by enhanced are walls the instance, effects.For lickering with appearance whenplacednexttoothers. most relativeelementinart and astutelyobserveshowsomecolorsappeartoshift in of warmhues[28].Notedcolortheorist,Josef Albers [29],explainsthatcoloristhe picture reinforces therepeatedcolorsandtheirafter-images.It synthesizes anoverall to accentuate thedifferencessimilarities [27]. byeliminating This colorcombination eye:thehumaneyetends different tonescreateanopticalmixtureintheobserver’s tonalities andfusedtogetherby the brain. From a distance, the colored spots with side, provideapointillismeffect. (green, ocher-yellow,the coloredspotsofporch side-by- white), placed and black thus suggesting a strong invitation to ind out more about the object itself. Furthermore, effectcauses aperceptual oftheobject,and only anapproximation ofrelief,allowing (Figure5,Figure9) In thisregard,thewarm/coldcontrastaboveaneutralbackground of thedifferentcan bebestevaluatedthroughananalysis typesofchromaticcontrasts. achromatic environment[27]. from the colorcombinations The resultingimpression in contrast with the clear colorsof the the epigraphic frieze,the dark toneis reserved for the calligraphy. The latter emerges them standout. This visualphenomenonsuggestsingenuityandsynchronization. either continuityandcomplementeachother, or they create a contrast, which makes create forms loral colors, to way similar a in [18], Paccard to calligraphy.According colored (green and ocher) loral patterns mingle, intertwine and contrast with the black decor ismadeupof a successionof spirals inscribedintangentcircles(Figure4). The

tion betweenthedarkform, thought of as positive,andthewhitenegative”[20, p clear/obscure isneededtodevelop notonlyasenseof but also aconnec- proportions, and recedingcolors).“The (contrast betweenadvancing from thewhitebackground out stand to seem brown, dark in decor, loral the and calligraphy The effect. pattern setup iscomposedofarabesquesonawhitebackground. green colorof the foliage, whichbecomesa key element inthe composition. This entire white contrast (clear/obscure contrast) highlights the calligraphy. It also highlights the The viewing distance transforms the perception one has of the building. From the one hasofthebuilding. The viewingdistancetransformstheperception 4.1.1. Thecalligraphyabovetheporchdecoration gate. monumental entire the into it details the how see helps view general The the walls provide contrast andtheinbrightness the clear/obscure Likewise, This optical phenomenon is notthatof phenomenon This optical in an particularly objects andcreatesanimation, Color highlightsthearchitectural Similarly, the colorsusedareverydarkbrown,white,greenandocher-yellow. On In this loral composition, the color contrast is greatly pronounced. It creates a raised tawriq ) in a set of curves and counter curves. This iligree foliage iligree This curves. counter and curves of set a in ) tawriq camaieu patterns (loral decoration). The black and , where colors arecloserintheir , where 35

CONSERVATION SCIENCE IN CULTURAL HERITAGE 40]. For painters, white and black are the strongest means of expression for light and darkness. From the point of view of their effects, white and black relect the ultimate opposition or contrast [20].

4.1.2. Polychrome decoration of the arch: keystone, impost and spandrels

In the lower arrangement that adorns the keystone and the impost of the arch, the colors of the leaves are set in yellow, green, black and white. The color contrast (hue, temperature and brightness) is visibly accentuated. The dark brown loral decor stands out from its white background. It creates a counterbalance effect (Figure 9).

a b Figure 9. Distant view: Figure (a), and close-up view: Figure (b) of the loral decoration: mosaic tile work with a combination of leaves and stems interwoven into a set of curves and counter-curves. Source: Authors.

The black on white makes the shape smaller, while the tone-on-tone of the color with its background makes it appear ininite [27]. In addition, color is never perceived alone, but always according to its setting. “A color that appears dark in one palette, for instance, may be judged lighter in another context, while a hue that appears bright in one palette, may appear less saturated among other colors” [30, p. 7]. The black graphic design of leaves is accentuated, because clear colors appear brighter on a dark background and darker on a lighter one. The green and ocher-yellow tones, in proximity to the black leaves (thus creating a dark background), appear larger and radiate outwards. However, they appear duller close to the white leaves, therefore creating a compensation effect. The intrados and spandrels are an ensemble of stylized motives. They are under- lined by a series of green strips, within which geometric and loral motives are alter- nated. These green strips accentuate the arch and envelop the scalloped brick, as well as other details of the porch. They also strengthen the edges of the composition. The principle of the frame is derived from Byzantine design. However, for Muslim art- ists, the frame could cut an endless network of patterns. Paccard [18] designates this M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

36 (France), theMédiathèquedel’architectureetdupatrimoine,Paris). (a): Figure de laculture by ©Ministère (authorized 1872 by Duthoi (b): watercolor Authors, Figure geometricdesignof the arch(a), Figure 10.Underside in1872(b). and asdocumented Source: ing ontheirdirection,appearstomaketheminterlockwitheachother. shape. identical depend- of thediamonds, and geometric characteristic The resulting weft. intrados (Figure10),thereisanoblique of The lattercreates browndiamonds context, this geometric motifs are combinedwithvegetalpatterns. Indeed, on the surface of the In [27]. nature static and stable its to contrary mobile, and lowing free unlimited world. that opensontoan framework, whichcutsthepatternsinrandomplaces,asawindow

emphasizing the emphasizing design of geometric leaves. In the adornment of the intrados, the shape. a spearhead determines lines outline, byawhite The motifsarehighlighted step is thesmallrightanglethat succeeds it (Figure 10). The intersection of broken are called “shoulder and step”, ( and “shoulder are called of lightandshadowsthatanimateenliventhearc. of thegrids,withaplay a graphic the whiteplastercoating.Itgenerates and enriches enhances colors of panoply This [31]. continuity and happiness inluenced it color,as vides itwiththebrillianteffect of thegoldcolor. The Marinidsyearnedforthegolden with theblack. and pro- of theocher-yellow the brightness This furtheraccentuates ocher and thedullbrown,becauseofitsmixture the contrastbetweenbrightyellow a contrastofquality.designates of tones time, thiscombination the same The latteris According to Itten [20], light colorstendto recoil, whiledarkcolorsmoveforward. At contrast. on aclear/obscure is based and relief. This resultsinaplayoflight,shadow and a Within an architectural context, color changes its appearance. It becomes rather It becomes its appearance. changes context, color architectural Within an 4.1.3. Polychromyofthestaveboworintrados On the intrados, the combined diamond-patterns are geometrized vine leaves. vine are geometrized diamond-patterns On theintrados,combined They These blacksurfaces stripes. are surroundedby ocher-yellow Their arrangement a darj grid is essential. It serves as a structure for the loral decoration. The strip The decoration. loral the for structure a as serves It essential. is grid ktaf oudarj) b [18]. the is thecurveand The shoulder b ktaf

37

CONSERVATION SCIENCE IN CULTURAL HERITAGE frieze on the leaves acts as a counterpart. It is accentuated by the use of contrasting colors. It creates an effect referred to as a ‘counterbalance of values’ [16], in the same ceramic mosaic panel. The yellow palm leaf, placed near the brown one (almost black), is added to the loral composition of the intrados. It afirms the clear/obscure contrast in addition to the quality contrast. It is the opposition between the saturated bright yellow ocher and the dark brown, considered as a dull color [20]. In this case, the yellow color illuminates the chromatic ensemble. It replaces gold, gild and spark. It represents the energy and the wealth of the Marinid dynasty. In this case study, yellow is similar to the color of the brick and consequently creates harmony. In this composition, the complementarity of shapes is associated with an opposi- tion between two values or two colors; black and white (the white on black highlights the lines of the pattern), raw brick and glazed brick. The function of this opposition is to disrupt the relationship between form and background. This combination of shapes and colors allows the transformation of the architectural context into a lively and sig- niicant space.

4.2. The stairs

A staircase, allowing access to the mosque, leads to the monumental door. Eleven steps provide this arcade with a majestic base (Figure 2). The stair risers are decorat- ed with a mosaic of small multicolored diamonds. The patterns are totally different from the rest of the porch decor, but their tones are identical. This chromatic unit enables a visually pleasing continuity with the architectural elements [18]. The colored fragments in diamond shapes are smaller than those that adorn the courtyard of the mosque. Framed by a green ceramic surround, they are the unique decoration of the staircase. The green, black (dark brown) and ocher-yellow colors enhance and contrast with the white marble steps. The latter illuminates the space through its high level of light relectance. Similarly, the polychrome decoration contrasts with the neutral tones of the sidewalls that lank the stairs. These colored arrangements break the monotony of the long white walls.

4.3. The courtyard paving of the Mosque

The subtle ornamentation of the porch and the stair risers mark the threshold to an inward focused interior space: the square courtyard of the mosque. The decorated facades are introverted, inwardly facing. They surround the faithful on all sides, to form a “box of dreams”, in which everything is wealth and poetry [16]. The courtyard is covered with mosaics on a square grid (Figure 5). Much less com- plex than the ornate porch, the loor inserts are composed of small diamonds of vari - ous colors, organized in 45° diagonals. They are multiplied to ininity, interrupted only by the walls. Tiles are assembled side by side and arranged diagonally in rows of diamonds with the same nuance. They are also set in bands, through an arrangement of tones: manganese brown, copper green, iron yellow, and white. The diagonal bands, joined to each other, form a checkerboard design, thus highlighting a grid loor plan. The square is a basic geometrical element that can be multiplied ininitely and forms a grid. The extension of motifs is interrupted by frames or friezes, beyond which they appear to pursue their invisible repetitions. M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

38 nomena of vibration, because the eye is often undecided between clear and dark forms. nomena ofvibration,becausetheeyeisoftenundecidedbetweenclearanddarkforms. and yellow)accentuatethedesignofbothframespatterns. The resultsareopticalphe centuating theperspectivewithinthisarchitecturalspace.Contrastingcolors(black,white geometry. The combinational logicofcolorsinsidethisframecreatesvisualeffects, ac between afinity colored surfacesandthecontactbetweentonesmakescoloraplasticworkofart. The movement. of impression an provides colors between relation The membrane. enveloping an like surface, loor entire the encases decor The shine. effectan optical form cause make theocher-yellow rotations, which ofscintillating similarities foundinthetextilearts[16]. tone. principle, withinteresting on theweaving of variations range There isawhole to another a valueasopposed Each toneacquires their trailonawhitebackground. effect.white) anddark(black)tonescreateaweaving print The stripsofdarkdiamonds with color,the fountaininmiddleofpatio. plays acontrastingroleandhighlights another.” [30,p.7]. geometry isassociated of thepavement,where The formaldesign way to unify theinteriorwithexteriorandcanvisuallyconnectonespaceto this unity.thetic unityandcolorisoneoftheitemsthatensures palettes offer “Color a continuity. a harmonious duces aes- shapes, thereisan and Inthisassortmentofgrids pro This porch. the of those and patio the of loor the covering ceramics the of those

architectural elements,suchastheembrasuresandpillars, tobetraced. the of contours the allows sides lanking its and ground the between difference color space, accentuates for landmark its visitors. stability andprovidesarecognizable The darker thanits monochromatic surroundings.Principally, it highlights the central patio its roleistoilluminatethisspace[21]. Yellow is a color that gives a feeling of it warmth andwell-being; is an activecolorand [21]. to thespace of belonging a sense engenders and a warmambience, atmosphere, bright a procures It daylight. relects and shines it sun, the Under color. warmest the and expressthesenuances. black servestoemphasize Yellowto be isconsidered and punctuatedbygreen. by yellow bywhite,illuminated latter isenlightened The Fortheviewer,work combination. motion. result isaspaceindynamic thevisual The viewer tocomecloser. mosaic decoratesitstop. encrusted multicolored The minaret appears toinvitethe sections. Finally,variety ofitsintermediate from afar,to beperceived inorder arichly the and of itsproportions in thebalance resides [5]. Itselegance of itskind specimens dominates themonument.It is considered tobeoneofthemostattractivestill-standing it isvisiblewithinandbeyondthecity. The svelteformofthisarchitecturalelement to thefaithful[32].Hence, the way to show set up indicator as itisseenan role zin northwest corner (Figure 6). The main vocationof this pinnacle is to provide the The frameisalineargeometricdistributionof these compositions,creatinganet- At the pavement level, color creates a uniform frame effect, a lattice that enhances the of patternsandtheincessantrepetitionsame theaccumulation In addition, As discussedearlier,light (ocher-yellow,between colorcombinations greenand tobothsurfaces; It is importanttonotehowcolorsarethecommondenominator Wellof ensemble above thearchitectural 4.4. TheMinaret The colored loor is open to the sky. It decorates the sparsely furnished space and is with a higher point for the ive daily prayer calls. It also has a symbolic and political Sidi Boumediene Sidi rises the minaret at its risestheminaret muez- - - - 39

CONSERVATION SCIENCE IN CULTURAL HERITAGE The minaret is built and decorated in adorned and scalloped brick, where light and shade play a distinct role. The tile mosaic that adorns this pinnacle is com- posed on each side by a frieze of four rosettes of elaborate geometrical construc- tion. Two half-rosettes appear on the other faces (Figure 6). A tangle of white threads limits the surfaces. The black is enclosed within the yellow. It forms a star with twenty-four points surrounded by broken lines. The green ceramic band frames the ensemble. The polychromic rosettes of the minaret create a double contrast. First, the clear- obscure one and second, the contrast of value or quality “bright, dull” [20, p. 37]. The latter emphasizes the spark of the yellow color and forms a bright spot in the “dark and dull” [20, p. 37] surface that surrounds it. In the unfolding of the friezes, the whole is punctuated by yellow dots which add luminous touches throughout. A row of crenellations crowns the main body of the tower. They carry a mosaic decoration that unfortunately has been badly impacted over time. This adornment is composed of white star-shaped polygons on a black background. The different colors assigned to the different forms, allow them to be distinguished from each other. In- terpretation of the forms can also be accentuated by alternating clear shapes with dark ones [16]. The pattern stands out as a white active form on a dark background, allowing it to highlight the geometrical forms. Bands of green tones underline the ce- ramic panel. With the clear-obscure contrast, the entire surface takes on a plastically animated character. The pattern is highlighted and stands out as a dark active form on a white background. Color contrasts reinforce the principle of counterbalance. The latter resides in the ambiguity of forms and colors: black and white, full and empty, presence and absence. Indeed, the reading of some igures varies, depending on the eye, which eliminates either the clear or dark shapes. This alternate reading gives rhythm to the composition and fascinates the viewer [33].

Table 1. Visual and spatial effects of the polychrome patterns based on color contrast as perceived from a distance and close up. View from a distance

Hue contrast Clear/obscure contrast Temperature contrast The colored spots, placed side-by- Color combinations between light Foreshortening effects side, provide a multicolored and tones (ocher-yellow, green and and attractiveness. The optical pointillist effect. white), and dark (black) create a mixture draws its liveliness from The optical mixture reinforces weaving effect. the temperature change in the the repeated colors and their The color combination of the green (cool color) and the ocher afterimages, in order to synthesize checkerboard paving emphasizes yellow (warm color). an overall picture of warm hues. the perspective. It is highlighted - Illusion of relief of the ocher The contrast of hues achieves a by the monochromatic yellow and depth of the green. colorful patio paving that creates environment (white color). The - Appeal and attraction of movement and animation. colored loor decorates the the object highlighted by the sparsely furnished space. brightness of the ocher yellow, a shimmering color. M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

40 ing paletteofhigh-qualitydecorations thatarerichandvaried. mixture and lickering effects. Although small in number, the four tints provide a surpris effect,and background of lightanddarkness,ofoptical together withanimpression trasts in hue,qualityandtemperature. The latterprovidethe impressionof relief, form composition. it anidentityandasensetoitsgeometric and theatmospherethatemerges,giving building a of appearance the on inluence decisive a has It space. architectural the of ceramics transformthelook which coversthem.Indeed, thepolychrome ing adorning oppositions, relectingamoregraphicunderstandingofthe form. by aplayofcontrasting Color gradients,thatsuggestthevolumes,havebeenreplaced background. white a on mostly designs loral and geometric interlacing of composed tural lines and facilitating formalreading. They are alsocombinedintocompletepanels that surroundthem. architec- tone highlighting in stripsofasingle They areassembled surfaces dark or matt the in spots bright are tones The inish. exterior an as paratus, of thispaper. is a representative heritageof that period andits color ceramicshavebeenthe focus and courtyardsof the mosquesandmajorpublicbuildings. minarets, portals, the to ixed are colors Permanent exteriors. for coating preeminent of eval Islamicarchitecture made ita to theelements resistance Tlemcen. Itsproven

ocher-yellow andprovidesitwitha accentuates thebrightnessof chromatic ensemble.Itreplaces the gold,gildandspark. The yellowcolorilluminatesthe The ceramics adorn the lat surfaces, with colors in chiaroscuro, producing con producing chiaroscuro, in colors with surfaces, lat the adorn ceramics The The visualimpactofthesedecoratedspacesisintimately related totheoutstand- and encrustedinabrickap- fragments orsmallgroups are usedinisolated Colors The mosaics of faience played an important role in the decorations of The mosaicsof the medi- faience playedanimportantroleinthedecorations 5. Conclusion shape smaller, whilethetone- The blackonwhitemakesthe background makesitappear on-tone ofthecolorwithits The blackasadullcolor brilliant goldeneffect. ult otatTmeauecnrs Clear/obscurecontrast Temperature contrast Quality contrast ininite. Close-up view-colorsofferbetterperceptionofdetails lighter one. The lighttones;white the blackleaves(thuscreatinga dark background),appearlarger and ocher-yellow, inproximityto colors appearbrighteronadark The blackgraphicleafdesign is accentuatedbecauseclear background anddarkerona and radiateoutwards. while thedarkcolorsmoveto highlights thecoloursandmakes and shadowaplayofrelief. colors andmakesthemappear background weakenstheclear Sidi Boumediene contrast createsaplayoflight Light colorstendtowithdraw, them appearbrighter. This dull; whiletheblackcolor Visual balance:thewhite The calligraphyappears to emergefromitswhite background. foreground. Mosque - - 41

CONSERVATION SCIENCE IN CULTURAL HERITAGE The image of this architecture, its aesthetics and polychromy is a visual memory that enhances the built heritage. Documenting it enables the conservation of the chro- matic authenticity of this architectural heritage. It also provides the necessary data for prospective conservation, as well as forming a basis for its integration as a potential expression of contemporary cultural identity.

Notes

1 Speciically in relation to his last chapter. 2 Leo Africanus was born in Granada around 1486-1488 and died in Tunis around 1535. He was a diplomat and explorer of North Africa, during the ifteenth and sixteenth centuries.

References

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42 2] Itten,J.(1961). [20] 1] Barnet,S.(2008). [19] 2] Goethe,J.W. (1840). [21] 2] Banks, A. andFraser, T. (2004). [22] [18] Paccard, A. (1981). Paccard,A. [18] 2] Barges,J.L (1859). [24] R.(1997). Chalavous, [23] 2] Albers,J.(1963). [29] [17] Stierlin, H. (2005). Stierlin, [17]

2] Katz,D.(1935). [26] T. Bendaoud, (2011). [25] [28] Hornung, D. (2005). Hornung, [28] 2] Servantie,M.P. (2007). [27] 3] Portillo,M.(2009). [30] environment ingeneralwithafocusonIslamic Architectural heritageintheMaghreb. Technologyof Oran, in thebuilt in colortheory andapplication Algeria. Shespecializes art inthe plastic andgraphic and of Science Program attheUniversity Architectural P. Ringgenberg, (2009). [33] 3] Bloom,J.(1989). [32] [31] Martínez de Castilla, N. (2010) MartínezdeCastilla, [31] ings, sustainableheritageconservationandhumanfactors inthebuiltenvironment. in experience Algeria, theUSA andMiddleEast. Her researchfocusesongreenbuild- versity,and professional academic UAE.Shedraws fromover25yearsofinternational Kheira TabetKheira Aoul Meriem Benkhedda Biographical notes son, PrenticeHall,p.66. ture. to ColorTheoryand Application Gründ. & Challamel Ainé. Challamel & rence KingPublishingLtd. Paris: Alternatives. Ltd. in DesignedSpaces L’Harmattan. Oxford: OxfordUniversityPress. Investigaciones CientiicasCSIC. QVCTVS. Coleccion medieval, musulmán Vol. 1. Annecy: Atelier 74. The Art ofColor The WorldofColour is aProfessor of Architecture at the United Arab Emirates Uni- Interaction ofcolor is an architect and is and PhDcandidate currently teaching A ShortGuidetoWritingabout Art Minaret: SymbolofIslam(OxfordStudiesinIslamic Art VII). L’artd’Istanbul àCordoue en Méditerranée, del’Islam Color Planning for Interiors: anIntegrated Color Planning Approach toColor Le Maroc et islamique dansl’architec- l’artisanat traditionnel . NewJersey:HobokenJohnWiley&Sons. Colour: Colour: A Workshopfor Artists ansDesigners Tlemcen, Ville d’Artetd’histoire Theory ofColors Souvenir d’un voyageàTlemcen Souvenir Le nouveloutildescouleurs Chromo-Architecture, l’artdeconstruireencouleurs. L’universdes arts islamiques symbolique . Documentos y manuscritos árabes del occidente del árabes y manuscritos . Documentos . Chicago:ChronicleBooks. . New York: Van Company. NostrandReinhold Designer’s Color Manuel: The Complete Guide Complete The Manuel: Color Designer’s . London: Kegan Paul, . London: Trench, Trubner &Co . NewHaven: Yale press. University . London:JohnMurray. Vol.de Superior Consejo 2.Madrid: . Paris:Désiris. . 9thed.NewJersey:Pear- . Alger: Atoucha. . Paris: Benjamin Duprat . Paris:Benjamin . London: Lau- . London: . Paris: . Paris:

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CONSERVATION SCIENCE IN CULTURAL HERITAGE Summary The study and research described in this paper aims to reveal the unexplored aes- thetical role of colors used for the ceramics in a mosque from the Marinid dynasty in Tlemcen, Algeria. The methodological approach consists irstly, of a formal analysis of the mosque’s artwork by describing its elements and composition and related princi- ples. Secondly, the patterns and geometries are analyzed in-depth using artistic color concepts and laws of color contrast. The analysis demonstrates that the contrasts between bright, pure and dynamic colors provide luminosity, dynamism, rhythm, bright- ness and an optical mix. The color contrasts are also found to provide visual illusions of mass, volume or movement, as well as depth and relief that ultimately result in inluencing the overall ambience of the mosque. The study thus enables the chromatic authenticity of this architectural heritage to be preserved by providing the necessary data for potential conservation, as well as providing a basis for innovative principles in expressing contemporary architecture.

Riassunto La ricerca è rivolta alla conoscenza dei colori impiegati nelle ceramiche presenti nella moschea della dinastia Marinid a Tlemcen, in Algeria. L’approccio metodologico consiste, innanzitutto, nella trattazione degli aspetti artistici della moschea, descriv- endo i principi ai quali essi si riferiscono. In secondo luogo, i modelli e le geometrie dei colori vengono presi in esame dal punto di vista estetico e nel contrasto dei col- ori. L’analisi dimostra che i contrasti tra colori luminosi, colori puri e dinamici fornis- cono luminosità, dinamismo, ritmo. Tali contrasti danno luogo anche a illusioni visive di massa, volume e movimento, nonché profonditàμ in ultima analisi essi inluiscono particolarmente sull’ambiente della Moschea. D’altra parte, questa ricerca consente di preservare l’autenticità cromatica di questo patrimonio architettonico fornendo i dati necessari per la conservazione, nonché alcuni principi innovativi sull’architettura con- temporanea. M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque M. Benkhedda, K. Tabet Aoul - Polychrome ceramics, artistic diagnosis and resulting ambiences in a Marinid mosque

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