jaic 1997, volume 36, number 1, article 5 (pp. 59 to 81)

8/8/2019 JAIC 1997, Volume 36, Number 1, Article 5 (Pp. 59 to 81)

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JAIC 1997, Volume 36, Number 1, Article 5 (pp. 59 to 81)

PUVIS DE CHAVANNES'S ALLEGORICAL MURALS INTHE BOSTON PUBLIC LIBRARY: HISTORY,

TECHNIQUE, AND CONSERVATION

TERI HENSICK, KATE OLIVIER, & GIANFRANCO POCOBENE

ABSTRACTPuvis de Chavannes's allegorical murals, installed in the Boston Public Librarybetween 1895 and 1896, were recently conserved by the staff of the Straus Center forConservation as part of an ongoing major renovation of the building. The treatment of the murals

included the consolidation of large areas of flaking paint, the reattachment of detached canvassections, and the removal of tenacious surface grime. The opportunity to examine and analyzethe Boston murals and to study archival material in France, as well as other murals there, hasyielded interesting information about the materials and techniques Puvis used to create hishighly individual and influential murals. The authors combine information about the BostonPublic Library commission with the methods and materials used in the murals, the conservationtreatment, and additional materials analysis.

TITRELes peintures murales allgoriques de Puvis de Chavanne la bibliothque municipalede Boston: Histoire, technique et restauration. RSUMLes peintures murales allgoriques dePuvis de Chavanne, intalles dans la bibliothque municipale de Boston entre 1895 et 1896,furent rcemment restaures par le personnel du Straus Center for Conservation. Le traitementde ces peintures murales s'inscrit dans le cadre d'une rnovation gnrale du btiment, toujoursen cours, et comprend la consolidation de zones importantes de soulvements, la remise en placedes sections o la toile s'tait dtache et le nettoyage de la surface couverte d'une salet tenace.L'examen et l'analyse de ces peintures murales, ainsi que l'tude de documents d'archives et decertaines autres peintures murales conserves en France, ont permis la mise jour derenseignements intressants concernant les techniques utilises par Puvis pour crer ses peinturesmurales, si originales et si influentes. Les auteurs prsentent des informations sur la commandede la bibliothque municipale de Boston, les mthodes de travail et les matriaux employs dansles peintures murales, la restauration de ces peintures et les rsultats de l'analyse d'autres

matriaux.

TITULOLos murales alegricos de Puvis de Chavannes de la Biblioteca Publica de Boston:historia, tcnica y conservacin. RESUMENLos murales alegricos de Puvis de Chavannesque fueron montados en la Biblioteca Publica de Boston entre los aos 1895 y 1896, fueronrecientemente conservados por el equipo del Centro Straus para la Conservacin, como parte de

http://cool.conservation-us.org/jaic/articles/jaic36-01-005

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la gran remodelacin que se esta llevando a cabo en el edificio. El tratamiento de los muralesincluyo la consolidacin de grandes reas de pintura que se habia escamado, la unin desecciones de lienzo desprendidas y la remocin de tenaz suciedad superficial. La oportunidad deexaminar y analizar los murales de Boston, y de estudiar documentos pertinentes ubicados enarchivos franceses, tanto como otros murales en Francia, produjo interesante informacin acerca

de los materiales y las tcnicas utilizadas por Puvis en la creacin de estos murales muyparticulares y trascendentales. Los autores combinaron informacin sobre la Comisin de laBiblioteca Publica de Boston con los mtodos y materiales utilizados en los murales, eltratamiento de conservacin y el anlisis adicional de materiales.

1 INTRODUCTION

The Boston Public Library (fig. 1) is one of the great Renaissance Revival buildings of America.Designed and built between 1888 and 1895 by the distinguished architectural firm of McKim,

Mead, and White, the library remains an impressive testimony to the late-19th-century fashionfor buildings both monumental in scale and eclectic in their architectural and artistic sources.The building embodies the impulse toward a cultural continuity that brought Europeancivilization and the classical world to America. Its architects sought to unite the most celebratedartists of the day to accomplish this goal.

Fig. 1. The facade of the Boston Public Library, 1904.Courtesy of the Boston Public Library, Print Department

Pierre Puvis de Chavannes (182498), widely considered the greatest European muralist of thetime, was the ideal candidate to decorate the grandest and most complicated space in the new

library. By the 1890s he had painted most of his major mural decorations, including projects forthe Pantheon and the Sorbonne in Paris, and for museums and municipal buildings in Lyon,Rouen, Amiens, Poitiers, and Marseille. Although in his youth he studied for brief periods in thestudios of Eugene Delacroix, Thomas Couture, and Theodore Chasseriau, Puvis's individualstyle and technique were developed largely independently. Combining idealized classicism withsimple flat designs and pale colors, his murals were in great demand.


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From the beginning, the intention was that the library's imposing grand staircase and loggia bedecorated with murals. Thus it was that in 1891 Charles Follen McKim traveled to Paris toengage Puvis's services. Convincing the aged painter to undertake the commission proved noeasy task, but McKim was initially successful. Soon after, however, Puvis was awarded a

commission for the Paris City Hall and had second thoughts about the American project.Another emissary was sent to Paris in 1892, and as a further inducement the artist was given aplaster scale model of the library's interior. Finally, on July 7, 1893, Puvis signed a contract forthe murals that guaranteed him 250,000 francs, the equivalent of the then-unparalleled sum of$50,000. A year later, after completing the Paris City Hall project, the painter began working onthe Boston murals and asked for more detailed measurements. He also requested, and was sent, asample of the marble to be used in the staircase so that he might harmonize his palette with thesurrounding architecture.

Puvis's oversized murals were executed on canvas in a specially designed studio at Neuilly,which included a two-story door (fig. 2)(Milner 1988). The Inspiring Muses was the first mural

to be painted. It was exhibited at the Salon du Champs-de-Mars, then rolled and transported toBoston in October 1895, and finally mounted on the east wall of the loggia a month later (fig. 3).During the following year, the other eight panels were completed, exhibited in Paris, shipped,and installed (fig. 4). In fact, the artist himself never saw his works in situ. Their installationusing a marouflage technique was overseen by Puvis's trusted collaborator Victor Koos. Thearrival of the murals in Boston was met with much fanfare and celebration. In France, on theother hand, the art critic Gustave Geffroy expressed the feelings of many Frenchmen when hewrote:

It is a great shame to see these works go to the Boston Public Library, to farawayAmerica. It is certain that many among us will never see them again. But, on

reflection their going is to be admired: art crossing the globe, braving the waves ofthe ocean, to a new people, is a confirmation of one of its roles (Geffroy 1897,14849).


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Fig. 2. The interior of Puvis's studio at Neuilly showing The Inspiring Muses before it was sentto Boston in 1895. Courtesy of the Trustees of the Public Library of the City of Boston

Fig. 3. The Grand Staircase of the Boston Public Library showing the loggia with The InspiringMuses Acclaim Genius, Messenger of Lighton the east wall


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divisions of literature and the arts (Esch 1982), float above the landscape, draped in white andholding lyres and laurel branches. On either side of the door Puvis painted stone statuesrepresenting Study and Meditation in grisaille.

For the eight paintings in the staircase, each 4.37 m (14 ft. 4 in.) high by 2.18 m (7 ft. 2 in.)

wide, Puvis chose subjects that represent the various spheres of human knowledge. On the southwall he painted Philosophy, Astronomy, andHistory, on the north Pastoral Poetry (Virgil),Dramatic Poetry (Aeschylus) andEpic Poetry (Homer)(fig. 4), and on the west wall, on eitherside of the windows that open out onto the courtyard, he painted Chemistry and Physics.

3 MATERIALS AND TECHNIQUE

Firsthand accounts of the materials and techniques Puvis used for the murals come primarilyfrom the writings of his students and contemporaries as Puvis himself revealed very little. The

observations of conservators and art historians, combined with recent scientific analysis, provideadditional information that corroborates much of what was written during Puvis's time.

The preparatory studies and sketches Puvis created for the murals were an indispensable part ofthe final product; indeed, the sketches tell us most about his creative process. Prized in Puvis'sday, many of the sketches for the Boston Public Library project were exhibited in the Salon of1896. Geffroy reported that

the entire room behind the frescoes [murals] for the Boston Library is filled on allfour walls with a series of drawings, an assemblage of research and studies. Thereare pencil, pen, and pastel sketches; detailed studies showing patient draftsmanship,

balanced panels which are as beautiful as paintings: powerful sketches, harmonizedby the rhythm of the lines (Geffroy 1897, 167).

Today, sketches for the library murals are preserved in numerous private and public collections.The Cabinet des Dessins at the Louvre houses five related works. Two of the smallcompositional studies, both about 10 x 33 cm (4 x 13 in.), are in ink over pencil on tracing paper.They reveal that Puvis did not at first conceive of the Muses as figures floating over thelandscape but as figures standing firmly on the ground. In a third study at the Louvre (RF23070),Puvis raised the Muses as in the final design. This change was made so that the figures would notbe truncated by the solid balustrade when seen from halfway up the staircase (Price 1994, 230).

Puvis drew hundreds of life drawings from models in his studio. He used distillations of thesesketches, squared up and transferred, for the figures in the murals. A drawing for one of theBoston Public Library Muses (the second figure from the left in The Inspiring Muses) revealsthat Puvis carefully worked out the pose of the figure in a nude sketch (Petit Palais, P.P.D 274.1)before draping her in a robe in another sketch of the same size (Lyon Inv. B60728). Puvis alsomade numerous small color studies for each mural project. He rendered his color ideas for the


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deadened his oils by adding spirits of turpentine. Paul Baudouin (1935) writes that Puvis drainedhis oils by placing them onpapier buvard(blotting paper). Baudouin also states emphaticallythat Puvis never added anything to his paints (no siccatives, copal, varnish, or any otheringredient). Each of these techniques, combined with thefond maigre (absorbent ground), wouldobviously produce a lean, matte paint with little if any excess oil.

According to one contemporary observation, Puvis painted in common oil-paints(Crowninshield 1887). This fact was confirmed by the discovery of some of Puvis's leftoverpaint tubes in a paint box preserved by the artist's heirs at Le Brouchy (fig. 5). A list of thevarious colors found in the paint box is included in table 1. Puvis purchased paint from severaldifferent colormen and paint manufacturers in Paris. The tubes are tin with metal screw caps,which would date them after 1865 when screw caps began to replace the corks previously in use(Lefranc and Bourgeois 1990)(fig. 6). A box of six tubes is labeled Exposition Universelle de1889 Grand Prix. Some of the tubes (from Gay and Lefranc) are labeled ground in oil whilethose from Bourgeois Aine are a new preparation for painting in gouache.

Fig. 5. Puvis de Chavannes's paint box at Le Brouchy.Courtesy of the Straus Center for Conservation


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Fig. 6. Paint tubes from Puvis's paint box at Le Brouchy. Courtesy of the StrausCenter forConservation

TABLE 1. TUBES OF PAINT FOUND IN PUVIS'S PAINT BOX AT LE BROUCHY

Numerous authors have also suggested that Puvis achieved a matte appearance by adding wax tohis painting medium. By the late 1840s, the use of wax was commonplace in French muralpainting. Delacroix (at St. Sulpice), Hippolyte Flandrin (at St. Germain-des-Prs), andChasseriau (at St. Roch) all painted la cire(Baudouin 1914). In this technique, wax was either

saponified with lime or dissolved in mineral spirits, making it usable without heat (Bguin1981). According to his student Lasalle-Bordes, Delacroix added small amounts of wax to theoils on his palette as he worked at L'Assemble Nationale (Srullaz 1995). There is nodocumentary evidence that Puvis mixed wax with his oils in this manner. Indeed, no wax wasdetected in the two samples from Puvis's Boston murals analyzed with gas chromatography (seeappendix 1). Furthermore, solubility problems were not encountered during the conservationtreatment of the murals. Wax was also not detected in samples taken from Puvis's murals atRouen. Other works by Puvis have, however, been found by analysis to contain a waxcomponent (Galinier 1995). This inconsistency in the use of wax has at least two possibleexplanations. Either Puvis added wax to his medium in some works (perhaps especially hisearlier paintings) but not others, and/or wax was present as a component in some of the paint he

purchased commercially. Analysis of four samples from the paint found in Puvis's paint boxconfirms that the latter theory is possible. Two of the samples contained wax, while the other twodid not (see appendix 1).

Puvis may or may not have been aware of the wax component in the tubes of paint he purchased.One of the samples that contained wax is from a tube labeled ground in oils and gives no


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indication of any wax additive. Carpentier (1875), among others, warned against mixing waxand oil because the wax stops the oil from drying and the oil stops the wax from hardening. By1897, Lefranc advertised an oil paint that was completely solid containing not an atom ofwax (Lefranc and Cie 1897). We can assume, therefore, that by the end of the 19th century,fewer and fewer color manufacturers added wax to their oils.

To imitate the pale colors of fresco in his murals, Puvis painted in a very light key within anarrow tonal range, renouncing all the effects of depth belonging properly to oil (Hamerton1882, 336). Puvis was accused in his own day of starting a contagion of white (quoted in Price1977, 25). Lead white was found as a major component in every layer of paint sampled at theBoston Public Library (see appendix 2). Puvis kept the range of colors simple, limiting thenumber of pigments used in each work and using them consistently within each painting. Helikely achieved this harmony in a process, described by his student Baudouin, of mixing largeamounts of mother tones (tons mres) in bowls (assiettes creuses) that he kept submerged inwater so that they would not dry out (Baudouin 1935, 302).

Puvis applied paint in a direct manner, often using just one or two layers. No glazes wereobserved in the murals, and only one of the numerous cross sections taken revealed a third layer.He textured his paint by various means: thick, dry impastos; thin, lean layers revealing thecoarse texture of the canvas; passages of thick paint scraped flat; and incisions and scratchesinscribed with various pointed tools or spatulas. Puvis also left some areas of canvas uncovered,especially outlining figures and trees, which often reveal what appears to be a charcoalunderdrawing. The very few pentimenti visible in the Boston murals may well be explained byhis thorough preparation or by his practice of scraping off unwanted passages rather thanpainting over them. Puvis recommended this practice to his followers: Be fearful of uselessimpastos which darken, turn bluish and heavy. When you have painted a passage that youdislike, wait until it is possible to remove it. Judge it and if it is condemned, scrape it off firmly

with a palette knife. Excess paint is an abomination. In twenty four hours the gold will changeto lead (quoted in Vachon 1895, 57).

It is highly unlikely that Puvis applied a varnish to his mural works. Ultraviolet lightexamination of his first mural cycle located at Le Brouchy has revealed that as early as the1850s, Puvis chose not to apply a final varnish coating. The recent treatment and analysis of theBoston murals detected no original resin coating. As with many other questions of technique,Puvis appears to have written nothing at all about varnishing his paintings. His studentBaudouin, who notes that Puvis never added varnish to his paint mixtures, also makes nomention of varnishing and adds that Puvis's Childhood of St. Genevieve (1876) in the Pantheongives the total illusion of frescoes (Baudouin 1935, 300).

The use of all these techniques produced the frescolike appearance so sought after by Puvis. Hefirmly believed that murals should not dominate an architectural space. To that end, he createdpaintings with minimal illusionistic depth by using light colors with unsaturated and unvarnishedsurfaces. Puvis chose colors that would harmonize with the library's marble staircase, and heflattened the figures and other elements to emphasize the two-dimensional nature of the wall.


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In Boston, as in France, Puvis's gigantic canvases were mounted to the wall using marouflage.The technique of affixing oil paintings on canvas to a wall or ceiling originated in 17th-centuryFrance (Mora et al. 1984). Thus the artist could work in the comfort and privacy of his studio,surrounded by his own paraphernalia. When the painting was finished it was usually rolled and

delivered to the site for installation by a mural hanger. In French, maroufle refers to the stickyremnants of paint left in an artist's pots. The adhesive typically consisted of oils, resins, andfillers mixed into a thick paste. By the beginning of the 19th century, cruse (lead carbonate) wasadded to speed up the drying process (Mora et al. 1984, 157). For Puvis's murals at the library,lead white was a major component in the mounting adhesive. Although Puvis was not involvedin the Boston installation, he did personally supervise the marouflaging of many of his murals inFrance. Paintings marouflaged with lead white paste are extremely durable and often show nosigns of cracking.

Puvis's murals in Amiens and in the Boston Public Library were attached by first priming thewall with an isolating layer of lead white in oil (d'Argencourt 1973, 253). When the primer had

dried, both the wall and the back of the canvas were coated with a layer of the marouflage paste.The canvas was then attached using hand rollers to work out wrinkles, air pockets, and excesspaste (Mayer 1957, 34). The task of mounting an immense canvas such as The Inspiring Museswas obviously not without problems. Although very close, the huge canvas did not registerexactly, especially in the arches where portions of the tacking margin were used to extend thecanvas. Air pockets that formed during the installation were slit open and additional adhesivewas inserted. Along some of the canvas edges, metal tacks were driven through the painting toensure contact while the adhesive dried. These edges, together with the extended edges in thearches, were repainted in oils, most likely by Victor Koos after the installation.

4 CONSERVATION

Documentary evidence indicates that Puvis's murals were restored on at least three previousoccasions. The first documented treatment occurred in 1930 when they were cleaned and coatedby Charles Durham. Commenting on that early restoration, Edward Forbes wrote that theprotective surface that was put on was a mixture of the white of egg combined with someother ingredients, which makes a sort of varnish and has given the paintings a slight gloss(Forbes 1940). In 1940, the restorer R. Arcadius Lyon cleaned the murals with a weak solutionof castile soap (sodium carbonate and olive oil) and water. At that time he found that thepreviously applied egg white coating was tough and well adhered and that it did not respond wellto his cleaning efforts. Fearing possible damage to the paint layers, he chose not to try strongercleaning solutions and decided to leave the coating on the surface (Forbes 1940). Finally,Finlayson Brothers restored the murals in 1953, but they do not appear to have left anydocumentation of the treatment.

As part of a major restoration program for the library, the murals were scheduled for


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conservation in 1994. They were generally in a very good state of preservation but did requiresurface cleaning, consolidation of minor flaking, and retouching of minor abrasions. During theearly phase of the renovation, however, an unfortunate event necessitated the immediateconservation treatment ofThe Inspiring Muses. In the early morning hours of February 3, 1992,the painting was badly damaged by water condensing on its surface as a result of an accidental

steam valve release. Fortunately, the other eight murals on the staircase were not damaged, asthey had been covered with multilayer barriers to protect them from the renovation work. KateOlivier, who was the first conservator from the Straus Center for Conservation to arrive at thescene, found the area still full of hot, white steam and described it as like being in a Turkishbath. The first RH reading, taken that morning shortly after 9:00 a.m. was 87%, but it surelymust have been very near 100% earlier that morning. Fans were installed in the staircasewindows to extract the damp air. By midafternoon the RH had dropped to 77%, and by the nextmorning it had dropped to 55%. Later, a protective polyethylene barrier was draped around thescaffolding in front of the mural, and humidifiers were placed in the enclosure to control thehumidity level.

The steam caused three specific types of damage. The most serious was extensive lifting andtenting of the paint layers that affected approximately 40% of the painting (fig. 7). Most of thedamage occurred on the right half of the mural; fewer and smaller sections were affected on theleft half. Why this occurred is not entirely clear, but a likely explanation is that variations in aircurrents increased the amount of water condensation on the right. Fortunately, the canvas did notshrink very much because of its strong attachment to the wall. The areas of lifting varied inseverity over the surface of the painting. The worst damage occurred along the bottom edge,where most of the water collected, and in the blue areas on the right side of the mural. There wasmoderate flaking in the middle section and minor flaking in the upper section. Generally, thewhite paint layers exhibited less damage because of their greater thickness and the slowabsorption of water by lead white. In spite of their critical condition, the paint layers remainedsurprisingly intact with very few visible losses. A second serious consequence of the watercondensation was overall blanching and the formation of dark vertical stains over much of thepaint surface. As the warm water ran down the mural, it dissolved surface material that wasre-deposited and dried in the form of disfiguring drip marks (fig. 9). The third problemencountered was the detachment of small areas of canvas from the wall (fig. 11). These areaswere located near the bottom of the mural where the water had collected and in six of the cutsmade by the mural installation crew in 1895.


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Fig. 7. Detail of an area of tented cleavage caused bysteam damage in The Inspiring Muses. Courtesy of the

Boston Public Library. Before treatment

Fig. 9. Detail of stains and drip marks on The Inspiring Muses. Beforetreatment


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Fig. 11. Detail of detached canvas around an originalinstallation slit in the arm of one of the Muses, beforetreatment. Also visible is the extensive cleavage in the

surrounding paint layers.

Given the urgency of the situation, consolidation tests were begun immediately. Access to theentire surface of the mural was provided by the fixed scaffolding that had been installed for otherrenovation activities. Of the many adhesives considered, the two adhesives finally selected fortesting on the mural were sturgeon glue and BEVA 371. Both were effective in readhering thepaint layers. The BEVA 371, however, held the flaking paint more effectively during the removalof the excess adhesive. In addition, it would not be affected by water-based cleaning solutionsthat would later be required to remove the surface grime and stains; it would not cause furthercanvas shrinkage during application; and it would be less affected by fluctuations in temperatureand relative humidity.

The BEVA 371 adhesive, diluted (1:1) in benzine and heated to increase its flow and penetratingproperties, was applied to the affected areas with sable brushes. Because of the vertical surface,the adhesive did not always flow easily under all of the flaking paint. To assist penetration intodifficult areas, benzine was lightly sprayed onto the paint surface to wet it out before applyingthe BEVA 371. Two or three applications of the adhesive were required in most areas to ensure


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adequate consolidation. The BEVA 371 was allowed to dry at least 24 hours prior to paintreattachment using Willard heated spatulas. The severity and extent of the flaking over the muralmade this a difficult and lengthy procedure, but in the end the paint layers were successfullyreadhered (fig. 8). Then a xylenes/water emulsion was applied by brush to remove the excessBEVA 371 adhesive (for the formula, see appendix 3). The emulsion and the gelled and partially

dissolved BEVA 371 were then lifted from the paint surface with dry cotton wads. Thisprocedure reduced the amount of solvent penetrating into the paint layers that might otherwisehave dissolved the adhesive. The emulsion had the added advantage of removing some of theless tenacious grime layers. To eliminate the possibility of continued solvent action on the paintlayers, the emulsion residues were rinsed several times with water-moistened cotton wads. Oncedry, the paint surface was rinsed with benzine and cotton wads.

Fig. 8. Detail ofThe Inspiring Muses. Scale is 1:1 with fig.7. After treatment

After the consolidation was complete, the fixed staging was replaced in favor of rollingscaffolding, which allowed more flexibility and the ability to view the work as a whole. Thesteam had completely disrupted the grime layers and surface coating (fig. 9). Even before thesteam damage occurred, the surface grime was known to be difficult to remove, t attempts toclean the mural were further complicated by the redeposited drips. Coating samples were


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Fig. 12. Catherine Rogers applying the diammonium citrate gel solution onthe surface ofThe Inspiring Muses

Fig. 13. Detail ofThe Inspiring Muses during the removalof surface grime and stains


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A number of conservators and conservation scientists have expressed concerns about the use ofsome of Wolbers's cleaning solutions. They question the solubility effects of various componentson the paint layers, the difficulties of clearing surface residues, and the long-term effects ofresidues that might remain on the paint layers. These issues led to repeated, painstaking rinsing

of the mural surface. Given its size and the quantities of cleaning solution used, it is still possiblethat some residues remain. However, no other cleaning solution was found to remove theaccumulated grime and staining.

In the white drapery of the Muses the redeposited accretions and streaks were also removed, butit became evident after cleaning that the paint layers had been darkened slightly by thecondensing steam. While the nature of this darkening effect was not determined, possible causesinclude: (1) the conversion of lead carbonate into lead sulfide, which is typically seen in frescopaintings, (2) the much rarer conversion of lead carbonate into lead dioxide (Gettens et al. 1967),and (3) the recrystallization of the lead carbonate, which would give it a darkened appearance.Attempts were made to convert what was thought to be darkened lead sulfide into lead sulfate

(white form) using hydrogen peroxide. The very limited success of this procedure suggested thatlead sulfide was not present, and this conclusion was later confirmed by analysis.

The detached canvas areas were plasticized by the application of local moisture and pressure. Toapply the necessary pressure, a jig made from a veneer press was secured to the scaffoldingusing C-clamps (fig. 14). Dampened blotters, sections of foam (to allow the blotter to conform tothe distortion), and a Masonite board were placed against the delaminated canvas, and gentlepressure was exerted. After some 40 minutes the paint and canvas were sufficiently plasticized,and the dampened blotters and foam were removed. They were replaced with dry blotters, a 1/4in. thick Ethafoam section, and a Masonite board and left in place overnight to allow the canvasto dry flat. The detached canvas was then readhered to the wall with Jade 403 (polyvinyl acetate

emulsion), and the adhesive was allowed to set under the pressure of Mylar, blotters, andMasonite board for 24 hours. Although Jade 403 is basically an irreversible adhesive, it issufficiently weaker than the lead white paste and was chosen for its strength and flexibility.


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Fig. 14. Pressure jig applied to the arm of a Muse toreadhere a pocket of detached canvas (see fig. 11 for

detail)

In comparison to the scale of the mural, the losses were small and relatively few. Filling of thelosses was not necessary since they occurred in the thinnest paint layers and thus would not benoticeable from a normal viewing distance. The losses and irreversible remnants of the dripmarks were inpainted with Bocour Magna Colors (fig. 15). These paints were chosen for theirreversibility and appropriate degree of opacity to match the original colors. Although the colorshave been discontinued, the Straus Center for Conservation still has a full complement.Retouchings that dried too matte were glazed and adjusted with Acryloid B-72 in xylenes.


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Fig. 15. Detail of one of the nine Muses after inpainting

Once conservation ofThe Inspiring Muses was completed, treatment proceeded on the othereight murals in the staircase. Apart from Philosophy, which has had a history of structuralproblems, these murals were in good condition and required very little consolidation. Surfacegrime was thick throughout, but especially obscuring in the murals nearest the windows (fig. 16).The consolidation, cleaning, and retouching of these murals was carried out using the samemethods and materials described for the treatment ofThe Inspiring Muses.


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Fig. 16.Aeschylus during the removal of surface grime

Although the Boston murals were not originally varnished, consideration was given to thepossibility of applying a protective coating. Issues of public accessibility, vandalism (thus far nota problem), and the redeposition of grime were the main concerns. Natural resins and mostsynthetics were considered but rejected because of their high saturating properties and pooraging characteristics. Acryloid B-72 was chosen for testing because of its stability and lowersaturating properties. It was applied by brush in concentrations ranging from 2 to 6% in xylenes.It was clear to conservators and art historians who were consulted that varnishing would impartfar too much saturation and gloss to be aesthetically acceptable. Another concern was thesolubility effect that aromatic hydrocarbon solvents would have on the BEVA 371 that was usedto consolidate the paint layers should it become necessary to remove the varnish in futuretreatments. Furthermore, Puvis's clear desire for a matte surface dictated that the murals should

remain unvarnished. After the grand staircase was reopened to the public, low display cases wereplaced against the dado below The Inspiring Muses to create a partial barrier between the muraland visitors to the library.


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5 CONCLUSIONS

The conservation decisions that were reached were based on the scale and urgency of theproblems faced. Using the citrate and detergent gel solution proved to be the safest and most

effective way of removing the surface grime and the worst effects of the stains and drip marks.Although concerns about the effect of this solution on paint layers should not be ignored, in thisinstance its positive attributes were decisive. An important factor was that it caused noblanching, thus eliminating the need for varnish.

Puvis's skillful and remarkable integration of a mural cycle into a complex space for a buildinghe never saw is a testament to his unusual abilities. While it is recognized that Puvis's imageshad a significant influence on 20th-century painting, the impact of his highly individual paintingtechnique has not been adequately acknowledged. Painting in oils on canvas, he combinedvarious methods and materials to imitate the matte appearance of frescoes. He used coarsecanvases, absorbent grounds, drained oils, pigments mixed with large amounts of white, and a

variety of texturing techniques. Contrary to common practice in the first half of 19th-centuryFrance, he did not add varnish and other ingredients to his medium, nor did he apply a finalvarnish coating to his murals. His role in the introduction of these innovative techniques, whichbecame common practice in this century, warrants further investigation.

ACKNOWLEDGEMENTS

ACKNOWLEDGMENTS The authors are greatly indebted to Richard Newman, who analyzedthe binding media and compiled appendix 1, and to Richard Wolbers, who produced appendix 3and without whose research the treatment of the murals would not have been so successful. Weare also extremely grateful to David Bomford, Yvonne Hoppenot, Hayden Maginnis, AnneRoquebert, Hubert de Truchis de Lays, Amy Snodgrass, and especially Aime Brown Price fortheir invaluable support and assistance. For their tireless work, enthusiasm, and efficiency wewould like to thank our conservation colleagues Nancy Buschini, Lenora Rosenfield, DanicaStojkovikova, Lydia Vagts, Nancy Garrison, and particularly Catherine Rogers, who wasindispensable throughout the entire project. Finally, we would like to acknowledge the support ofthe Boston Public Library and the architectural firm Shepley, Bulfinch, Richardson, and Abbott,and to thank the National Endowment for the Arts for funding the professional developmentgrant.

Photographs are reproduced courtesy of the Trustees of the Public Library of the City of Bostonand the Boston Public Library, Print Department.

APPENDIX


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1 APPENDIX 1

1.1 BINDING MEDIA OF THE MURALS

1.1.1 Ground

A sample of the ground was hydrolyzed, derivatized with phenylisothiocyanate, and analyzed foramino acids by high-performance liquid chromatography (HPLC) following WatersChromatography Pico Tag method. Analyses were carried out on a Waters instrument thatconsisted of two 510 pumps, a manual injector, and 991M photo diode array detector. The amino

pattern closely matched that of collagen, with the exception of considerably reduced glutamicand aspartic acid levels; these amino acids are typically lost during sample preparation whencalcium carbonate is present, as was the case in the ground sample (Halpine 1992). Anotherportion of the ground was saponified in 10% KOH in methanol, the solution neutralized and thenextracted twice with ether. Ether extracts were combined, evaporated to dryness, redissolved in asmall amount of methylene chloride, and methylated with 10 l dimethylformamide dimethylacetal (Pierce Chemical Co.). Analysis was carried out by gas chromatographymassspectrometry (GC-MS) on a Hewlett Packard 5890 capillary gas chromatograph equipped withan HP 5971A mass selective detector. The sample was found to contain traces of palmitic andstearic acids, which are typical contaminants in animal glues. It is also possible that these fatty

acids came from the overlying oil paint layer.

1.1.2 Paint Binder

Two samples were saponified and analyzed by GC-MS as described above. While traces ofhydrocarbons were detected, such as those characteristic of hydrocarbon waxes such as ceresin,the very low levels suggest that they may simply be contaminants in the oil and not indicative ofwax intentionally added by the paint manufacturer. Traces of methyl dehydroabietate, anoxidation product commonly found in aged pine resins, were also detected in the two samples.

The level was extremely low, so it cannot be concluded that pine resin was an intentionalcomponent of the paint. Ratios of the C9 and C8 dicarboxylic acids (diC9/C8) suggest that theoil was not heat-bodied. The palmitic/stearic acid ratios (P/S) are somewhat high for linseed oil;possibly the oil was walnut or a mixture of linseed and poppyseed. Poppyseed was identified inall four samples from the tubes of paint (see next section).


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1.1.3 Tube Paints

Four partially dried samples from tubes preserved from Puvis's studio by his heirs were analyzed

by GC-MS as described above. The oil in each appears to be poppyseed, based on the highpalmitic/stearic acid ratios (P/S). Two samples contained substantial amounts of straight-chainhydrocarbons in the C22-C32 range, maximizing at C26. This hydrocarbon pattern is typical ofceresin wax. The results were as follows (when two analyses were carried out, P/S ratios fromboth are given):

2 APPENDIX 2

2.1 ANALYSIS OF THE PIGMENTS, MAROUFLAGE ADHESIVE, ANDSTAINS

2.1.1 Pigments

Nine paint samples were selected for analysis, including two greens, one red, four blues, and twowhites. Cross sections of the paint samples were examined using a Leitz Laborlux biologicalmicroscope fitted with visible and ultraviolet light sources. The cross sections were prepared byimbedding the paint samples in cubes of bioplastic polyester resin, which were subsequently cutand polished with micromesh polishing cloths to reveal the structure of the paint layers. Thecross sections were analyzed for their elemental composition using a JEOL 6400 scanningelectron microscope with a Noran Instruments Z Max 30 Series light x-ray energy dispersivex-ray spectrometer (SEM-EDX). Sample sites were analyzed for 100 counts at an acceleratingvoltage of 20 kilo electron volts (keV). Standardless quantitative analysis was performed by thecalibrated voyager quantitative microanalysis system using ZAF matrix corrections. Fouriertransform infrared microspectroscopy (FTIR) was performed using a Spectra-Tech IR-Planmicroscope attached to a Nicolet 510M spectrometer with an auxiliary MCT detector. Sampleswere mounted for analysis on a Spectra-Tech Micro Sample Plan fitted with a diamond window,

and data were collected for 200 scans at a spectral resolution of 8 cm1. The resulting spectrawere viewed in absorbance mode between 625 and 4000 wave numbers, and for consistency theCO2 peak was removed and the spectra were baseline corrected.

Pigments were identified by microscopy and SEM-EDX (see table). Analyses showed that leadwhite was used throughout the painting as highlights and aa matrix for the colors. For example,


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the highlight from The Inspiring Muses is lead white over a gray layer composed of lead whitemodified with ultramarine, red oxide, emerald green, and carbon black. The principal greenpigments used were emerald green (copper aceto-arsenite) and green earth (hydrous iron,magnesium, and aluminum potassium silicate). Emerald green was found in the grass ofPhilosophy and in the initial green layer of the foreground of theMuses, together with green

earth. The upper layer of the foreground of theMuses contains particles of green earth in a leadwhite matrix. The principal blues found were cobalt blue (cobalt aluminate) and syntheticultramarine (sodium aluminum silicate). The water for theMuses was ultramarine mixed withlead white, black, and red in one simple layer. The blue sky in both Chemistry andAeschylus iscobalt blue mixed with lead white. The blue water ofAeschylus was applied in two layers:ultramarine blue and lead white overlaid by cobalt blue and lead white. Four reds wereidentified: vermilion (mercuric sulfide), red lake on an aluminum substrate, red ochre, and redlead. History's red robe is built up from a layer of lead white and red ochre followed by a layercontaining lead white, calcite, and vermilion. Red lake was found as a minor component of thegreen grass in theMuses.

The yellowish white ground was identified by SEM-EDX and FTIR as chalk with aproteinaceous binding medium. A small amount of oil was also identified in the ground, whichcould account for the yellow color of the ground.

2.1.2 Marouflage Adhesive

The marouflage adhesive, which holds the canvas onto the wall, was analyzed by SEM-EDX andFTIR. The sample showed absorbances for lead white, oil, and lead carboxylate (a byproduct ofthe aging of lead white in the presence of oil).

2.1.3 Drip from Surface of The Inspiring Muses

A drip stain was sampled from the surface of the Muses. FTIR analysis showed majorabsorbances for protein and lead white. There was a minor absorbance at 1076 wavenumbersthat was unidentified.

3 APPENDIX 3

3.1 UV FLUORESCENCE STAINING ANALYSIS OF PAINT SAMPLESFROM THE INSPIRING MUSES AND CLEANING FORMULAS


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Samples ofThe Inspiring Muses were taken in an attempt to characterize the drip and stains andthe accumulation of grime on the surface of the paint. Samples were also taken from similarareas before and after grime and accretion removal tests to evaluate the effects of the cleaningsolution. These were mounted in Ward's Bioplast and sent to Richard Wolbers for ultraviolet

fluorescence analysis and photomicrography. Twelve samples were viewed and photographed inthe following sequence: normal light, UV only, UV stained with 4% triphenyl tetrazoliumchloride in methanol (TTC), UV stained with .25% rhodamine isothiocyanate in acetone (RITC),and UV stained with .20% rhodamine 123 in acetone (RHO 123).

The results of the examination can be summarized as follows:

3.1.1 Samples of Paint with Surface Bloom but No Deposit from Steam Drips

Boston Public Library (BPL) 1. Green paint. The green paint stained with RHO 123 (for oils)and with TTC (carbohydrates), signaling both materials and therefore potentially water solublecomponents in the binder. Apart from a single droplet of a noncharacterized material (negativestaining with the stains listed above) and a substantial and continuous grime layer, no othersurface-accumulated materials were observed.

BPL 3. White paint. The white paint stained only lightly with RHO 123. Little accumulation ofgrime was noted on the surface, which was slightly autofluorescent, indicating normal aging onthe surface.

BPL 5. Blue paint. The blue paint stained RHO 123 positive (oil), but, as in sample BPL 1, there

was a slight reaction with TTC (carbohydrate) as well. The surface is obviously aged(autofluorescent) and grime-laden, but no additional deposits were noted on the paint surface.

3.1.2 Samples of Paint with Deposits from Steam Drips

Three samples of the green, white, and blue paint (BPL 2,4, and 6) all exhibited obviousautofluorescent deposits along the surface and above the grime layer under UV light. Themorphology of the deposited materials was noncrystalline (organic) in nature and may havesignaled the extraction and redeposition of a discrete layer of polar organic material. However,

this material was negative for all of the applied stains.

3.1.3 Samples of Paint After Cleaning with Wolbers Diammonium citrate-chelating/ionic strength solution


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Three samples of the green, blue, and white paint (BPL 7, 8, and 9) all showed undisruptedsurfaces after cleaning with Wolbers's diammonium citrate-chelating/ionic strength solution.

4 FORMULAS

Xylenes/water emulsion formula (for the removal of BEVA 371 adhesive and less tenaciousgrime layers):

50 ml xylenes, 20 ml Triton X-100, 30 ml water, 2 ml triethanolamine (the aqueousphase was adjusted with dilute HCl acid to a pH of 8.5 prior to emulsification)

Diammonium citrate-chelating/ionic strength solution (for the removal of surface grime andstains):

100 ml water, .5 g deoxycholic acid, 5 ml triethanolamine, 1 g ammonium chloride,1 g diammonium citrate, .05 g Triton X-100, 1.5 g hydroxypropyl-methyl-cellulose(adjusted with HCl acid to a pH of 8.5)

REFERENCES

Baudouin, P.1914.La fresque: Sa technique, ses applications. Paris: Librairie Centrale des

Beaux-Arts.Baudouin, P.1935. Souvenirs sur Puvis de Chavannes. Gazette des Beaux Arts(Paris)13:295314.

Bguin, A.1981.Dictionnaire technique de la peinture. Paris: Audr Bguin.

Carpentier, P.1875.Notes sur la peinture la cire cautrise ou procd encaustique, d'prs leslaborieuses recherches de Paillot de Montabert. Paris: Librairie Renouard, Rue de Tournon.

Crowninshield, F.1887.Mural painting. Boston: Ticknor and Co.

d'Argencourt, L.1973. Les peintures murales de Puvis de Chavannes au Muse de Picardie.Thesis, Universit de Paris, Sorbonne.

d'Argencourt, L., M.-C.Boucher, D.Druick, and J.Foucart, eds.1977. Puvis de Chavannes.Exhibition catalog. Ottawa: National Gallery of Canada.


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Esch, E.1982. The decorative program of the Boston Public Library. Honors thesis, HarvardUniversity.

Forbes, E. W.1940. Letter to Robert Bellows, February 1. Cambridge, Mass.: Harvard UniversityArt Museums.

Galinier, C.1995. La dcoration de l'escalier du Muse des Beaux-Arts de Lyon. Unpublishedmonograph. Service de Restauration des Muses de France, Versailles.

Gautier, T.1861.Abcdaire du salon de 1861. Paris.

Geffroy, G.1897.La vie artistique, vol. 5, ed.H.Floury. Paris.

Gettens, R.J., H.Kuhn, and W. T.Chase. 1967. Lead white. Studies in Conservation12: 12539.

Halpine, S. M.1992. Amino acid analysis of proteinaceous media from Cosimo Tura'sThe

Annunciation with Saint Frances and Saint Louis of Toulouse. Studies in Conservation37:2238.

Hamerton, P. G.1882. The graphic arts: A treatise on the varieties of drawing, painting, andengraving in comparison with each other and with nature. Boston: Roberts Brothers.

Lefranc and Bourgeois. 1990.Le livre des couleurs. Le Mans: Lefranc and Bourgeois.

Lefranc and Cie. 1897. Les couleurs et lesvernis de J-G Vibert.Notes et renseignements sur lesproduits prpars pour la peinture artistique d'aprs les procds de J-G Vibert. Paris: Lefrancand Cie.

Mayer, R.1970. The artist's handbook of materials and techniques. New York: Viking Press.

Milner, J.1988. The studios of Paris: The capital of art in the late nineteenth century . NewHaven and London: Yale University Press.

Mora, P., Mora, L., and Philippot, P.1994. The conservation of wall paintings. London.

Price, A. B.1977. The decorative aesthetic in the Work of Pierre Puvis de Chavannes. In PierrePuvis de Chavannes, ed.L.d'Argencourt et al. Ottawa: National Gallery of Canada.

Price, A. B.1994. Pierre Puvis de Chavannes. Amsterdam: Van Gogh Museum.

Srullaz, A.1995.Delacroix l'Assemble Nationale.Paris: Assemble Nationale.


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FURTHER READING

Cartwright, J.1896. Puvis de Chavannes.Art Journal. 19092.

Farell, E., and A.Snodgrass. 199294. Analytical reports on the Boston Public Library murals.Straus Center for Conservation, Cambridge, Mass.

Moore, C.1929. The life and times of Charles Follen McKim. Boston and New York: HoughtonMifflin Co.

Newman, R.1993. Analytical reports on the Boston Public Library murals. Research Laboratory,Museum of Fine Arts, Boston.

Puvisde, Chavannes. 1896.Description of the decorative paintings of Puvis de Chavans. BostonPublic Library.

Sharp, W.1898. Puvis de Chavannes: An appreciation.Art Journal. 377378.

Vachon, M.1895. Puvis de Chavannes. Paris.

Wattenmaker, R.1975. Puvis de Chavannes and the modern tradition. Toronto: Art Gallery ofOntario.

SOURCES OF MATERIALS

BEVA 371

Conservator's Products, P.O. Box 411, Chatham, N.J. 07928

Acryloid B-72

Rohm and Haas Co., Philadelphia, Pa. Supplied by Conservation Materials, 1165 Marietta WaySparks, Nev. 89431

Deoxycholic acid Triethanolamine Citric acid-diammonium salt Triton X-100 Hydroxypropyl-

methyl-cellulose Triphenyl tetrazolium chloride (TTC) Rhodamine isothiocyanate (RITC)

Sigma Chemical, P.O. Box 14508, St. Louis, Mo. 63178

Ammonium chloride


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Mallinckrodt Specialty Chemicals, Paris, Ky. 40361

Hydrochloric acid (reagent A.C.S.)

Fisher Scientific, Springfield, N.J. 07081

Mylar (.0005 in.)

Talas, 213 West 35th St., New York, N.Y. 10001

Magna Colors

Bocour Artists Colors, New York, N.Y. 10019

Willard heated spatula

Willard Developments, Leigh Road, Chichester, West Sussex P019 2T3, U.K.Rhodamine 123 (RHO123)

Kodak Laboratory and Research Products, Rochester, N.Y. 14650

AUTHOR INFORMATION

TERI HENSICK has been a paintings conservator at the Straus Center for Conservation,

Harvard University Art Museums, since 1980. She holds a B.A. (Phi Beta Kappa) in art historyfrom Wellesley College and trained in paintings conservation in Florence (UniversitaInternationale dell'Arte), Zurich (Swiss Institute for Art Research), and Nuremberg(Germanisches Nationalmuseum). She interned in paintings conservation at the HarvardUniversity Art Museums in 197677 and was assistant and subsequently associate conservator ofpaintings at the Detroit Institute of Arts from 1977 to 1980. In 1995 she spent two months inFrance researching Puvis de Chavannes's materials and techniques with the support of a NationalEndowment for the Arts professional development grant. Address: Straus Center forConservation, Harvard University Art Museums, 32 Quincy St., Cambridge, Mass. 02138.

KATE OLIVIER received her training at the Courtauld Institute of Art from 1962 to 1965. She

worked for six months in Florence following the flood in 1966 and one year in Venice onpaintings by Tintoretto. As a private conservator in London she worked regularly for theDepartment of the Environment, the Royal College of Music, and private conservator PatrickLindsay. From 1974 to 1976 she was assistant painting conservator at the Winterthur Museum,Delaware. She has been a conservator at the Fogg Art Museum since 1977. Address: Fogg ArtMuseum, Harvard University, Cambridge, Mass. 02138.


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GIANFRANCO POCOBENE received his master of arts in conservation from the ArtConservation Program, Queen's University, in 1984. He was assistant conservator at the ArtConservation Laboratory in Raymond, New Hampshire, from 1984 to 1985. He returned toQueen's to conserve paintings from the university collection from 1985 to 1988. During that time

he also worked on paintings from the Alfred Bader Collection and on several mural projects inCanada. From 1988 to 1989 he was a paintings conservation intern at the Center forConservation, Fogg Art Museum. Upon completion of his internship he became assistantpaintings conservator. He is currently associate conservator of paintings at the Straus Center forConservation, Harvard University Art Museums. Address: Straus Center for Conservation,Harvard University Art Museums, 32 Quincy St., Cambridge, Mass. 02138.

Section Index

Copyright 1997 American Institute for Conservation of Historic and Artistic Works


jaic 1997, volume 36, number 1, article 5 (pp. 59 to 81)

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