JAIC 2004, Volume 43, Number 3, Article 5 (pp. 273 to 290)
BOOK REVIEWS
BOOK REVIEWSD.H. SOXHLET (FOREWORD BY RICHARD O. BYRNE), THE ART OF DYEING AND STAINING MARBLE, ARTIFICIAL STONE, BONE, HORN, IVORY AND WOOD. Staunton, Va.: D�j� Lu Press, 2003. 168 pages, hardcover, spiral bound, $25. Available from Richard O. Byrne, 114 Fayette St., Staunton Va. 24401. This book is a reprint of a 1902 English translation (The Art of Dyeing and Staining Marble, Artificial Stone, Bone, Horn, Ivory and Wood and of Imitating All Sorts of Wood: A Practical Handbook for the Use of Joiners, Turners, Manufacturers of Fancy Goods, Stick and Umbrella Makers, Comb Makers, etc. [London: Scott, Greenwood Son]) of an 1899 work in German by D.H. Soxhlet (Vienna: A. Hartleben). The publisher of the translation lists its premises as the offices of “The Oil and Color Trades Journal,” indicating the practical relevance of this book to its original intended audience. As the complete title makes clear, it is directed at the small-shop craft manufacturer, particularly those engaged in some part of the carriage trade in luxury goods. D. H. Soxhlet appears to have been a professional chemist. I was interested to know if he was the inventor of the “Soxhlet Extractor,” a kind of recondensing coffee percolator device still used for chemical extraction, but this did not prove to be the case. He was, however, the author of other works on dyes besides this one. The translators of the book list academic degrees in science, so we might assume they used up-to-date English terminology. The publisher and translators would have been well aware that Germany at the time was in the forefront of organic chemistry and dye manufactures, so they knew that they were going to the source. The chapter topics include mordants and stains; natural dyes; artificial pigments; coaltar dyes; staining marble and artificial stone; dyeing, bleaching, and imitation of bone, horn, and ivory; wood dyeing; varnishes and polishes. There is a great deal of detail describing contemporary practice and knowledge in these areas, and works such as this one are an invaluable aid to the historian of technology and period craft practices. Soxhlet covered the origins (as he understood them) of various materials, methods of manufacturing chemicals and pigments, trade and marketing, and the now largely obsolete but then serious concern about commercial adulteration. All this material is a fascinating window on the times. It is true, as publisher Richard O. Byrne writes in the foreword, that this reprint will make “a real contribution to those working in museums, architectural conservation and many craft fields,” but we must be clear on what that contribution is. Byrne sees this book as a work that has current applicability, as suggested by his choice of a spiral binding, which “allows it to lie flat on the worktable.” Further, “Those of us concerned with dyeing and staining wood will find enough information to transform the most common looking wood into the most exotic and then ask why has it taken so long for us to have this information so clearly presented.” It is these claims to practicality that provoke a need to caution the modern reader, particularly the craftsperson, about concerns such as obsolete terminology, availability of materials, and safety. The problem of obsolete terminology is immediately encountered in period works. It is somewhat less of a problem here than in contemporaneous craft-recipe books, since Soxhlet and his translators were technical men. The term “ammonia” (ammonium hydroxide), for instance, is used instead of “spirit of hartshorn” (which one would expect to see in a period craftsman's manual), but understanding the meaning of “sulfureted hydrogen” (hydrogen sulfide) and similar terms might require a little help from a modern reference such as the Merck Index cross-reference. Even more obscure are such expressions as “pyrolignite of iron,” which sent me to The Incompleat Chymist by Jon Ecklund (online at dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Obsolete-Chem-TermsTOC.Html). As best as I can make out, this concoction was iron dissolved in crude vinegar made from the distillation of wood (and therefore similar to the iron-and-rice-vinegar solution formerly used by fashionable Japanese ladies to dye their teeth black—a bit of information gleaned from Chemical knowledge was less complete in 1899. So while Soxhlet reports that “verdigris dissolved in wax is used for dyeing marble” (p. 17), he discusses the debate about what verdigris actually is. He tells us that it should be “bluish green, have a slight smell of vinegar and a nauseous metallic taste.” Nausea is the least of one's problems, as later on he says, “The bichromates … have a sharp unpleasant taste and are poisonous” (p. 22). And that brings us to safety. Many of the reagents commonly used at the turn of the last century are now known to be toxic, or at least more toxic than was appreciated at the time. So we might be concerned to read that “The only lead salt which concerns us is sugar of lead” (p. 25). Merck says it best:“Poisonous!”“Sugar of lead” (lead acetate), so called because of its sweet taste, is water soluble and so a hazard through the possibility of both skin absorption and inhalation. By the same token, the directions for making cinnabar (red mercuric sulfide) might cause the hair of a reader knowledgeable about chemical hazards to stand on end, involving as it does open pots of glowing sulfur and mercury and the risk of “violent explosion which would shatter the apparatus” (p. 52). Shattered nerves would be the best outcome for the operator. Almost equally frightening are directions for coloring horn white by means of a surface precipitation of lead chloride. A conservator should know that white horn in a collection might have once been treated this way, but a craftsperson might actually try to do it. Those most attracted to “traditional” and historic ways of doing things are often least informed about the hazards involved. I am aware of one traditional restorer who was seriously poisoned with cinnabar, for example, and I myself engaged in some pretty dodgy craft practices in younger days. There are potential dangers to the object as well. Chromic acid, used for “black dyeing” wood, bone, and ivory, is corrosive, “easily injures the material to be dyed, more especially if it be wood,” and “quickly destroys brushes and makes them useless” (p. 23). Surely there is a safer alternative at Home Depot. This book is interesting on the subject of the natural dyes, but it is not the best period source for a few reasons: accuracy is one, and the period during which it was written another. Soxhlet reports that lac dye was “first made by Stevens in India,” that it was first known in Europe in 1796, and that Bancroft published the earliest practical recipes. This account seems authoritative in its detail unless the reader knows that lac is an ancient dye of India, published in the Plictho of Gioanventura Rosetti in 1548 and so well known in Europe that lac lent its name to all pigments made from dyes (“lakes”). In another place Soxhlet writes that “Ptero-carpus santalinus is said to be the tree from which red sandalwood is obtained. Cuts in the bark of the same tree yield dragon's blood” (p. 30). In fact, during most of the period in which dragon's blood was widely used, it came from Dracaena cinnabari, a completely unrelated tree growing in the Socotra Islands south of Yemen. Red sandalwood (also called “sanders,”“saunders,” and “padauk”) does provide an alcohol-soluble dye used historically in varnish manufacture, as was dragon's blood—hence the confusion. Much of this information is reasonably accurate, however, and Soxhlet can be forgiven for using outdated botanical nomenclature since taxonomy is not fixed in time. Morus tinctoria (fustic) is now Chlorophora tinctoria (L. Gaudich), having been reas-signed to a different genus. Note the “authority” in parentheses—the only way to know if the name is in fact current. The truth is that Soxhlet, a man of his times, is not particularly interested in natural dyes, and he says as much:“The colorist cannot fail to be amused” (by literature focusing on vegetable colorants) when “it is known that anilines give best results” (p. 112). This dismissal is certainly a weakness for someone interested in these traditional dye materials. Madder, one of the more important dyes, “is thus of historical interest only” (since the synthesis of alizarin),“and we need say no more about it” (p. 31). Orchil and cudbear (dyes from lichens) “have also been almost driven off the field by the aniline colors and will soon be disused altogether” (p. 31). So what of the aniline dyes? Here Soxhlet believed himself to be on terra firma, but historically, even this terra is shifting. These anilines are the synthetics, of course. Extracted and synthesized from the black, toxic goo left over from coal gasification (coal tar), they were sometimes, but not always, derived from one particular fraction and precursor for synthesis (aniline). It is not quite accurate to state, as Byrne does, that the coal tar dyes were newly emerging, having been commercially pounced on soon after the first synthesis by Henry Perkin in 1856. At the time Soxhlet was writing, synthetic dyes had seen almost a half-century of intensive research and rapid development. They were understood both theoretically and structurally, and by 1910 virtually all the chemical families of these dyes were already in production. Many of those described by Soxhlet are still used, but many are not. Commercial names such as “Victoria Blue” have almost all changed, so the modern craftsperson can forget about availability based on those particular descriptors. It is all right, though, that the reader will be unable to obtain many of the dyes he mentions, since Soxhlet was correct in his belief that synthetics as a rule are more durable and fast than the natural dyes. The winnowing process has left us with those that are more durable still than many of those he describes, and they are available in the form of commercial dyes and stains. Some of the material in this publication could indeed be safely used by the traditionalist. The black stains based on ferrotannin complexes are excellent and have a venerable history of use. Iron salts and oak galls, for instance, produce iron-gall ink within the structure of the wood. I have experimented with them, and been informed by the experience, but I would probably reach for a tin of either oil or water-soluble synthetic stain crystals to “ebonize” a current woodworking project. The dyed-in-the-wool tradi-tionalist would also be able to make and use some of the varnish recipes, though not without the risk of studio-(or life-) threatening fires. Period treatises such as this reprint are fascinating and useful to the historian when compared against other period works. Their utility can even be extended to the craftsperson when he or she is informed by modern practice and literature. This volume should certainly be added to any library of historic technology, and Richard Byrne is to be commended for making this very interesting book easily available to a modern audience.
PATRICIA SHERWIN GARLAND, ED., EARLY ITALIAN PAINTINGS: APPROACHES TO CONSERVATION. Proceedings of a Symposium at the Yale University Art Gallery, April 2002. New Haven: Yale University Art Gallery, 2003. 300 pages, hardcover, $60. Available from Yale University Press, P.O. Box 209040, New Haven, Conn. 06520-9040; (800) 405-1619; fax: (800) 406-9145; customer.care@triliteral.org. ISBN 0-300-10078-7. For those of us who attended the symposium on early Italian painting conservation held at the Yale University Art Gallery in April 2002, the welcome, prompt appearance of this attractively produced compendium of the 24 symposium papers and panel discussions confirmed the excellence of that event. What a stimulating, intellectually challenging, and well-organized three-day conference it was! American and European experts from the art-historical and conservation fields considered issues relating to the conservation of Italian paintings of the 12th through 15th centuries, including, but not limited to, the philosophy, history, techniques, and aesthetics of conservation (I will use the term in the American sense throughout as encompassing the slightly more limited meaning of “restoration”). The book provides what we always hope for following an exciting conference: a well-edited, well-illustrated, and relatively speedily appearing record of the conference contents. The Yale symposium was organized at a point approximately five years into a courageous collaborative conservation project between the Yale University Art Gallery's conservation and curatorial staff and the conservation staff of the J. Paul Getty Museum. This project involved revisiting the conservation questions The first nine papers cover topics ranging from the history of conservation of the Jarvis Collection, the history of conservation of early Italian art in Europe, the role of the art historian in the conservation process, and the role of science and new, related technical findings. These papers are followed by papers from speakers on three panels focusing on specific topics: four papers on “Approaches to Retouching and Restoration”; five papers on “Artist/Conservator Materials”; and five on “Issues in Presentation.” The first paper in each panel group is intended to be an introduction by the panel moderator to the theme. A brief review of these 23 papers follows, with some commentary on their significance to the field and their interconnecting themes. Michel Laclotte, in his broad-ranging keynote speech, introduced many issues that are revisited steadily throughout the book. Most notable among them are the importance of the art historian in the decision-making process during conservation planning and treatments, and the importance of preserving later, nonoriginal additions during cleaning. For Laclotte, the art historian brings an especially nuanced view to the complex decision-making processes surrounding treatments and can bring considerable knowledge of the “successive pasts” of the painting not available to the conservator. His pleas that the painting not be “purified” of all later changes, that the marks of time be allowed to stay, include the preservation of later framing solutions as part of the historical record. These issues take on interesting significance in the Yale context: it was the strong leadership of an art historian, the product of the aesthetic of the time, that resulted in the Jarvis Collection's pared-down appearance after the 1950s–60s conservation campaign. Another interesting issue introduced here is where the responsibility for conservation decisions lies: from the United States through northern to southern Europe, the control shifts from conservators to art historians, each group ideally working in close collaboration with the other. Different training and different traditions prepare each for the responsibility, and the shifting effects of these different arrangements are touched on throughout the book. Mark Aronson presents the Jarvis Collection's history, with emphasis on its conservation history, and is followed by Patricia Sherwin Garland describing the present conservation project. In his balanced and thoughtful review, Aronson touches on questions that have long intrigued interested colleagues: What were the respective roles of museum director Charles Seymour and conservator Andrew Petryn in the 1950s conservation campaign? How badly damaged was the collection prior to that campaign, and did damage occur during it through ignorance and overly purist goals? Patricia Garland outlines the philoso-phies and methodologies of the present project. She brings us the overriding conclusions of so many papers in the book: a rigid approach must be avoided, painting treatments must be considered on a case-by-case basis, and collegial collaboration is essential in all the decision-making processes on treatment goals. These are seemingly obvious assumptions, but they are shown by the book to be anything but simple. These papers provide a history of conservation in various European countries: the thoughtful reviews by Giorgio Bonsanti and later by Marco Ciatti on Italian conservation history and one by Elizabeth Mognetti on the history of French restoration of the early Italian paintings now at the Petit Palais in Avignon and on the general evolution of French policies on the restoration of early Italian panels. The reader becomes aware that the centuries-old Italian philosophical and method-ological theories detailed by Bonsanti and Ciatti are still preeminent issues in our field. They have had a far-reaching influence over the years and would have had much more internationally if more Italian treatises, especially Cesare Brandi's work, had been translated. Issues such as the stability and reversibility of conservation materials, minimalist intervention, visible compensation, neutral toning of losses, patination, establishing unity of appearance by respecting both historical and aesthetic values, etc., are the essence of conservation discussions and controversies today, but they were written about in the 18th century, evidence of their much earlier roots. These papers give insights into the historical development of these theories and how they have evolved into practical, official, often bureaucratic conservation policy in countries like France and Italy. Bonsanti's statements that Brandi established a “coherent philosophical approach” (p. 90) and a “theory/system to forever erase all empiricism and improvisation from conservation” (p. 90) suggest a cultural need for such an all-encompassing approach that may be somewhat foreign to us but is the result of centuries of dealing with conservation questions. The three papers that complete the first section of the book illustrate some of the issues raised previously and review broader histories of the impact of analytical science. Yvonne Szafran and Narayan Khandekar use two examples from the Yale project supported by other illustrations and related documentation to show that early Italian panels were varnished with a vernice liquida (sandarac resin/linseed oil type), but only over the paint layer, not the gilding. Fascinating evidence for this kind of varnish has been building as more recent findings have been published. This information is invaluable for conservators and curators trying to decide on a final appearance for paintings: the present era is strongly influenced by modern art and the subtlety of the unvarnished surface, until recently the accepted look for these early panel paintings. Ashok Roy and Jill Dunkerton provide an informative review of advances in the scientific analysis of artist's materials at the National Gallery, London, which continues its outstanding publications on its pioneering research on artist's materials and techniques. They add a wealth of information on the binding media of the early Italian period that erodes long-held traditions. Improved analytical capabilities have made possible discoveries, such as the use of oil as a medium much earlier than traditionally thought and the use of different media in the same paintings. In her summary at the book's end, Cristina Acidini Luchinat mentions how the conference highlighted the need to treat traditional sources on technique with caution; recent analytical findings reveal a much greater complexity of painting techniques in the period than, for example, Cennino Cennini would indicate. The benefits of the close team-work between conservator and conservation scientist described by Roy and Dunkerton are reinforced by Carl Brendon Strehlke, who adds the art historian to the team. Strehlke's examples of cases where technical and scientific findings have aided the art historian epitomize the repeated message of this book on the immeasurable benefits of collaboration. The papers from the panel on “Retouching and Restoration” constitute for the practicing painting conservator such as myself an extremely useful and interesting compilation of information on approaches to compensation and the unification of a painting's appearance. Andrea Rothe explains his philosophy on compensation through examples from his work on the Yale Collection: patination,“negative inpainting” (leaving old dirt and varnish accumulations on damaged areas during a cleaning because they will harmonize better than a repatination), and “minimalist” approaches. The themes of avoiding rigid theories and treating paintings in a highly individual way are omnipresent. Underlined here is the need for the specially talented, sensitive conservator who may be responsible for all the subjective choices recommended by these writers. Teresa Lignelli's paper gives the clearest, most thorough, and practical descriptions of Italian visible retouching techniques that I have seen in English. The gradual nature of the tratteggio process, “tratteggio allows me to incrementally ‘knit’ … an area of damage back together” (p. 183) is beautifully explained. Marco Ciatti's previously mentioned review adds more information on the Florentine contributions, especially those of Umberto Baldini and the Opificio delle Pietre Dure, to the development and practice of theory and application of pictorial restoration in Italy. Moving to “the opposite camp,” Diane Dwyer Modestini in the next paper quotes Sydney Freed-berg—“In this country we do not believe that a painting should be required to wear its history on its face” (p. 208)—and presents a thoughtful explanation of the process of “imitative” inpainting based on Mario Modestini's teachings and experience of 50 years. This technique is used in variants by most American and other non-Italian-trained conservators, and possible historical reasons for its preferred use in certain types of American collections, most specifically here the Samuel H. Kress Collection, are described. The effects of separation of these paintings from their original social and cultural milieu are discussed, as well as the nature of the demands of the generally artistically unsophisticated American businessman collecting them. Dwyer Modestini's detailed examples from her and Modestini's work illustrate the rationale behind their aesthetic choices. She also includes a wealth of practical detail, with interesting techniques for restoring gold grounds and gilding. There are some thoughtful insights on the characteristics needed by a conservator that lead to a brief mention of training, a welcome topic for a future conference like this one. In the next panel, the papers take up the mutual influence of artists' and conservation materials on each other, with examples of individual treatments and of how scientific findings can influence these treatments. Mark Leonard uses one treatment from the Yale project to show the evolutionary nature of some treatment decisions: a treatment's direction can be changed as the changing appearance of the painting during treatment dictates. “The works of art themselves have guided the dialogs and decisions” (p. 225) of treatment. He shows the essential role of the engaged frame for paintings of this period and thereby introduces themes from the final panel on the presentation of the finished treated painting. Cathy Metzger's treatment of a Botticelli/Fra Filippino Lippi portrait and Jill Dunkerton's treatment of a Dead Christ Supported by Two Angels by Carlo Criv-elli underline Leonard's message: the painting itself, its own materials, its own condition, its past history, the history of the collection in which it hangs/will hang— all guide the treatment choices facing the conservator. Roberto Bellucci shows how scientific advances can be helpful to the conservator not only by improving treatment techniques but also by checking treatment progress. And Frank Zuccari recounts the history of conservation at the Art Institute of Chicago with specific reference to the materials characterizing each conservation era, using examples of treatments from the collection. In a clear parallel to the international trends shown in this book, he describes the development of the museum's conservation work from invasive to minimalist structural interventions, from the belief that “the moral imperative” was “to recover the painting's true state” (p. 252) below all nonoriginal additions, to the tailoring of treatments to the condition problems at hand. He agrees that this aim is possible to a much greater extent than previously with the ever-increasing, exciting new “matrix of knowledge” available. The last panel consists of the thoughts of five art historians—Carl Brandon Strehlke, Laurence B. Early Italian Paintings will serve as an encyclopedic reference for years to come. Although much of the material will be familiar to the specialist reader, the juxtaposition of so many parallel lines of information stimulates connections and deepens understanding of the issues. The book is dense with information. Its format mirrors that of the conference accurately, so any questions as to why some papers are under certain panels must be answered by the conference organizers' logic. Although the book is well illustrated, with color-plates in the middle and black-and-white photographs throughout, the occasional lack of needed illustrations suggests that the writers could not or chose not to produce more for the editors. The Italian translations are outstanding, whereas the French are occasionally confusing. But these are minor issues in a very well produced book. Conservator Patricia Sherwin Garland of the Yale University Art Museum and all her colleagues should be thanked for their outstanding work putting together the book and the conference. The greatest boon will be to the works of art benefiting from the type of collaboration presented here.
JAN VUORI, ED., TALES IN THE TEXTILE: THE CONSERVATION OF FLAGS AND OTHER SYMBOLIC TEXTILES. Albany, N.Y.: North American Textile Conservation Conference, 2003. 199 pages, softcover, $45. Available from University Products, 517 Main St., P.O. Box 101, Holyoke, Mass. 01041-1010. ISBN: 0-9746438-0-7. The North American Textile Conservation Conference (NATCC) held its fourth meeting in Albany, New York, on November 6–8, 2003. The location of the meeting was partially chosen to highlight the ongoing project to preserve the New York State Battle Flag Collection. Correspondingly, about two-thirds of the papers presented at the conference concerned the conservation of North American and Western European flags and standards, with the balance discussing a broad range of symbolic textiles drawn from diverse geographies and cultures. Tales in the Textile: The Conservation of Flags and Other Symbolic Textiles contains the preprints of these 23 papers as well as brief summaries of the 10 posters displayed at the conference, all copiously illustrated with black-and-white photographs. The authors of these papers primarily work in the conservation field, and the publication's contents show this bias. While some papers are concerned with framing historical and philosophical back-grounds, most go into great detail about specific treatment materials and procedures and display methods, making this an invaluable book for someone charged with the conservation of a flag or banner, but less so for a casual or general reader outside the immediate conservation field. The papers concerning symbolic nonflag textiles are of interest for providing a complement and contrast to the flags portion of the proceedings, but because of their disparate subject matter, which touches only briefly on a wide array of topics, they should not be considered a primary reason for consulting this volume. Deborah Lee Trupin's overview,“Flag Conservation Then and Now,” introduces the section on flag conservation. Her discussion of the when, where, why, and how of flag treatments, starting from the early 20th century, is of interest to both the researcher and the conservator and puts current treatment Of the remaining papers addressing flag conservation, particularly the dreaded painted banner, a few are of particular note. Frances Lennard and Vivian Lochhead compare and contrast treatment and display methods used at the National Museum of Labour History (now the People's History Museum, or PHM) in Manchester, England, and the Textile Conservation Centre (TCC), also in England. Lennard and Lochhead discuss the two institutions' methodologies, giving the rationalization behind their steps and noting and discussing differences. One example of the differences was illustrated by the PHM's preference for wet-cleaning painted banners, a practice that only rarely occurs at the TCC. Because of the detailed explanations of the two approaches, this paper is an excellent starting point for anyone thinking about performing treatment on a painted textile. Another valuable contribution is from Nancy Pollack, giving the perspective of a paintings conservator who treats painted textiles. Pollack's writing demonstrates the importance of an interdisciplinary approach to these problematic pieces. Her discussion of the composition of a painted object and her numerous tips on structural support at the painted/unpainted interface, consolidation of the paint layer, and choice of inpainting materials give additional options to the textile specialist. More tips are given in Joanne Hackett and Beth Szuhay's description of the challenging treatment of a painted silk flag. The authors' successful use of remoistenable adhesive-coated tissue paper as a temporary facing for flaking paint, and cyclododecane as a protective barrier against the tidelines resulting from the application of this facing, adds another possibility to the repertoire of treatment options for these objects. The discussion of the thinking and testing behind Hack-ett and Szuhay's treatment choices is also welcome. Reflecting the strong presence of painted silk banners in collections within the United Kingdom, other contributions from British authors also detail treatments of these objects. Ann French and Nicola Gentle describe the incredible efforts required to conserve and display an extremely large banner belonging to a very small village. Lynn McClean and Elizabeth-Anne Haldane recount their treatment of a Scottish painted banner. The more interesting aspects of their account involve the employment of digital imaging to explore various compensation options and the use of the “Albertina-Kompresse” enzyme poultice to reduce the starch adhesive on the banner. Three poster submissions round out this group. Contributions to the publication from outside of the United Kingdom have a greater variety in subject matter and style. Fanny Espinoza's overview of the evolution of treatments for banners and flags at the Museo Hist�rico Nacional in Chile is a reminder of how many textile laboratories work under constraints of available materials and knowledge, not just time, space, and budget. Mary Westerman Bulgarella and Susanna Conti present a solution to the desire for viewing a textile from both sides in their discussion of the treatment and display of a 15th-century religious banner. The discussion of displaying a collection of Texas flags is only the jumping-off point in Fonda Ghiardi Thomsen's paper, as Thomsen vehemently argues against both treating flags and approaching them with the idea of “wrong” and “right” sides. The two most science-oriented papers in the preprints, Fenella G. France and Suzanne While the majority of papers concerning the conservation of flags and banners examined in-depth procedures for a single or small group of objects, the nonflag papers in Tales in the Textile often cut a wide swath through their respective subject matter, as the authors each realized they would be the only speaker covering their particular topic. T. Rose Holdcraft's documentation of a collection of Native North American objects associated with the Lewis and Clark expedition goes into painstaking detail about the materials, construction, and condition of pipe bowls and pipe stems. Anyone interested in these objects will find Holdcraft's meticulous observations useful. Ann Shaftel's account of the religious textiles used at Himalayan monasteries includes thangkas large enough to cover mountains and prayer flags small enough to be strung together and waved in the wind. Shaftel raises interesting questions about mounting and restoration versus replacement, but the organization of her paper is unclear, and unfortunately she never ties together or concludes the many threads of discussion she begins. Other papers in this section include Dorothy Alig's description of Egun-gun costumes and a dynamic way to mount them; Sarah Clayton et al.'s discussion of the challenges of preserving the collection of the Australian War Memorial; a paper highlighting the difficulties of displaying controversial symbols such as swastika-bearing Nazi banners, as well as identification of forgeries and treatment of prisoner uniforms in the collection of the U.S. Holocaust Memorial Museum, by Lizou Fenyvesi; and Virginia Jarvis Whelan's discovery of the only known extant painting by Amos Bad Heart Bull. One paper of particular note is Dinah Eastop and Charlotte Dew's introduction of the Deliberately Concealed Garments Project (DCGP), which documents objects and garments hidden in buildings. The DCGP's database is intended not only to identify these objects but also to help understand why they were secreted in these structures. An interesting side note for the textile field is that the concealed pieces are often the “everyday” garments, shoes, and objects which are otherwise rare survivals from previous centuries. Symbolic textiles are challenging textiles to conserve, not only because they can be large or made of problematic materials (or both), but also because they carry with them a charge to respect the intent and interpretation of the people, places, and ideas they represent. The authors included in Tales in the Textile have taken this responsibility seriously. While the treatment options presented for painted silk objects will probably be the most widely consulted part of this volume, the ethical discussions surrounding the treatment and display of the diverse group of objects in this publication should not be ignored, as they provide a window into current thinking at various institutions, in numerous countries, and on several continents on the conservator's responsibility to these objects as their caretaker.
JEANNE MARIE TEUTONICO AND GAETANO PALUMBO, EDS., MANAGEMENT PLANNING FOR ARCHAEOLOGICAL SITES. Los Angeles: Getty Conservation Institute, 2002. 158 pages, softcover, $35. Available from the Getty Conservation Institute, 1200 Getty Center Dr., Los Angeles, Calif. 90049; www.getty.edu/bookstore. ISBN 0-89236-691-5. This book represents the proceedings of an international workshop organized by the Getty Conservation Institute and Loyola Marymount University that took place in Corinth, Greece, in May 2000. It follows the excellent publication by the Getty Conservation Institute in 1997 of The Conservation of Archaeological Sites in the Mediterranean Region, but instead of being broad in scope, it focuses on the issue of management of the archaeological heritage. The book is organized in two parts. The first part covers the theoretical concepts of archaeological site management. The second part presents five case studies. These are followed by a summary of discussions and an extremely useful annotated bibliography of publications on the subject. Part 1 begins with a paper by Gaetano Palumbo that gives a good overview of the problems facing the preservation of archaeological sites. It points out that typically the concern is for arresting material decay, yet without integration in development and management planning, damage to archaeological heritage cannot be successfully mitigated. Palumbo lists the many negative factors affecting archaeological sites, including natural threats, development and urbanization, the nonsustainability of salvage archaeology, and environmental factors such as pollution. Other threats facing archaeological sites include increased tourism, which can lead to overreconstruction, vandalism, and inappropriate behavior. Social unrest is also identified as a potential hazard, resulting in looting, occupation, damage due to acts of war, deliberate destruction of cultural symbols, and conflicting values. Palumbo declares archaeological excavation without conservation to be damaging, and he refers to poor conservation, reconstruction, and lack of maintenance as additional factors. He also observes the difficulty of following international guidelines while maintaining cultural diversity. In the next paper, Randall Mason and Erica Avrami provide a discussion of values, noting that conservation professionals are generally comfortable with technical solutions but have more difficulty with decisions about what gets conserved and why. In this context, values-based decision making becomes an “analytical tool.” The Burra Charter of Australia International Council on Monuments and Sites (ICOMOS) (1979, revised 1999), an evolution from the Venice Charter (1964), is the reference document used to establish cultural significance through identification of site values. Mason and Avrami explore various types of values, including historical and artistic, social, spiritual, symbolic, research, natural, and economic values. They describe values as subjective, depending on who is performing the assessment, and subject to change. The writers express the opinion that it can be more important to focus on the conservation of heritage values than on that of the material fabric. They indicate that a greater comprehension of the balance needed between competing concerns can be achieved by undertaking “decisions in the context of who cares, who values and why” (p. 25). Martha Demas's paper presents a values-based approach to archaeological site conservation and management, pointing out that “‘good’ decisions are the result of careful planning” (p. 27). Referring to the Burra Charter, Demas notes that values and stakeholder participation are “at the core of the decision-making process” (p. 29). There is a helpful chart graphically illustrating a three-part methodology for developing a management plan, beginning with identification and documentation. Identification includes members of the planning team as well as stakeholders, and we are reminded that interested parties who are not “part of the solution, will make themselves part of the problem” (p. 32). Documentation synthesizes knowledge about a site and identifies gaps, ultimately leading to policies for research and interpretation. The second step is assessment and analysis of significance, conditions, and management. The assessment of significance involves the identification of values (along with possible conflicts), which are described in a statement of significance. Condition assessment reveals the degree of intervention necessary for preservation, as well as appropriate use. Christopher Young begins the case studies with Hadrian's Wall in the United Kingdom. In its time, Hadrian's Wall represented the northernmost frontier of the Roman Empire and consisted of a series of linked fortifications stretching across Britain from sea to sea. A designated World Heritage Site, Hadrian's Wall is a large, complex site with multiple and diverse owners, many of whom are private. Tourism and agriculture, two of the main activities at the site, were considered potential sources of negative impact. A management plan was developed and published in 1996 after stakeholder review. A committee was established to implement the management plan, and much has been accomplished. The plan has provided the framework for funding of individual projects. Various components of the wall have been conserved, and a new museum has opened at Tyneside. The establishment of the Hadrian's Wall Tourism Partnership has led to “sustainable access” in the form of a National Trail. The impact of tourism has proven less harmful than initially thought. The plan is undergoing a five-year review and revision. Young emphasizes that the definition of values, as well as the consensus of stakeholders, is critical to the success of a management plan. The second case study is presented by Carolina Castellanos. Chan Chan is an earthen architecture site on the outskirts of the city of Trujillo in northern Peru. Chan Chan was the center of the Chim� Kingdom from 850 A.D. through 1470. Also a designated World Heritage Site, Chan Chan is plagued with seemingly insurmountable problems, such as periodic flooding from El Ni�o, urban encroachment, agricultural activities, and lack of money and resources. Identified as World Heritage in Danger, Chan Chan has a management plan developed in 1998. The plan's purpose was to provide a means for a participatory approach to interventions at the site and a “phased action plan” that would enhance and preserve the significance of Chan Chan. Initially, an interdisciplinary team with local experience was created, stake-holders were identified, and the reasons for a management plan were established. Meetings were held to present and discuss values. Policies were developed to help prioritize values based on the “physical, social and economic context” (p. 78). Zoning was established with the participation of the municipality. “Inter-institutional agreements and committees” (p. 76) were formulated and given assignments. Conservation projects were designed to also try to give meaning to heritage for different stakeholders. Esti Ben Haim takes a look at Masada, a well-known archaeological site in Israel designated a World Heritage Site since 2001. The remains at Masada repre-sent three periods: Herod's, the period of revolt and massacre, and early Byzantine. One of Masada's important values is its ability to offer archaeological evidence to support a 1st-century A.D. historical source. Other values include the site as an example of a water system designed in Herod's time (37–4 B.C.), its Roman construction and siege system, as well as its natural and aesthetic considerations. The social and symbolic significance of the site have led to the “Masada myth,” which the Zionist movement adopted. The site also attracts religious pilgrims for its early synagogue and Byzantine church. Masada became a national park in 1966, a period when most of the site's reconstructions were undertaken. A cable car was installed in 1972, greatly increasing visitation. From 1995 to 2000, the Masada Project oversaw expansion, repair, and redevelopment of visitor facilities and infrastructure. Another cable car was added, which permitted the site to be handicapped-accessible. A conservation master plan has been developed and is being implemented by a local team that underwent specialized training, some of whom will remain at the site as maintenance personnel. Visitors'paths have been installed, and all new interventions are reversible. The Israeli government has been the main funding source, but all the work is reviewed and approved by a steering committee. Aysar Akrawi discusses Petra, Jordan, a World Heritage Site since 1985. Petra has been inhabited for Guy Sanders writes about Corinth, Greece, a site of continuous occupation since 3000 B.C. Ancient Corinth consists of several sites, including the Classical and Roman sites, Isthmia on the Saronic Gulf, and Acrocorinth, an abandoned medieval site, to name a few. Corinth is identified as the third most important Byzantine site after Constantinople and Thessaloniki. The list of problems at the site includes the need for conservation of the monuments, the fact that no paths are defined for visitors, the lack of a modern guide-book and explanatory signage, inadequate toilet facilities, and the outdated and inadequate nature of the Corinth museum (although the Archaeological Museum of Isthmia is considered one of the best in the Peloponnese). Traffic congestion during tourist season in the local village, a small settlement with a population of 2,000, is also noted as problematic. A proposal for “emergency” enhancement of the site was accepted by the Greek authorities in 2002. A management plan is needed and is considered the next step. Jeanne Marie Teutonico and Gaetano Palumbo summarize the workshop's discussions in a final paper. They note that values are often “taken for granted.” Economic values are considered paramount, particularly where tourism is an income source, so education of the public and officials about other values is important. There is a need for the participation of local stakeholders. Conflicting values require negotiation and may result in compromise and prioritization. Values and their acceptance are impeded by the “lack of administrative infrastructure and education in conservation and management planning” (p. 127). There are benefits to the process of management planning. A well-thought-out process can result in the collaboration of various government entities, education and training opportunities for local people, heightened public awareness, and economic development. Management planning requires an “interdisciplinary and participatory” approach. The book ends with an annotated bibliography separated into three categories: archaeological heritage management, site management, and assessment of significance. As the product of an international workshop, this publication goes well beyond a collection of papers and offers a truly insightful look at the management process for archaeological sites. It provides a methodology that has been proven in practice. The book is nicely illustrated and will be most helpful to site managers, conservators, and authorities who are responsible for archaeological sites. It is a welcome addition to the relatively sparse bibliography on the subject. Pamela Jerome Registered Architect and Architectural Conservator Adjunct Associate Professor, Columbia University Graduate School of Architecture, Planning and Preservation
JEAN H. LANGENHEIM, PLANT RESINS: CHEMISTRY, EVOLUTION, ECOLOGY, AND ETHNOBOTANY. Portland, Oreg., and Cambridge: Timber Press, 2003. 586 pages, hardcover, $49.95. Available from Timber Press, 133 S.W. Second Ave., Suite 450, Portland, Oreg. 97204; www.timber-press.com. ISBN 0-88192-574-8. The author notes that plant resins are casually understood to be “any sticky plant exudate” and slightly more tightly understood to “include substances that are mainly insoluble in water and that ultimately harden when exposed to air” (p. 23). Given the chemical and behavioral variety of plant exudates that can fall within these definitions, the author uses a more biologically and chemically concise definition of plant resin as “primarily a lipid-soluble mixture of volatile and nonvolatile terpenoid and/or phenolic secondary compounds that are (1) usually secreted in specialized structures located either internally or on the surface of the plant and (2) of potential significance in ecological interactions” (p. 24). This definition reflects aspects of the conservator's understanding of natural resins and also highlights the basis of the book's approach to resins. It is a book written by a biologist-ethnobotanist for biologists and others with a strong interest in plants and the ways they have been utilized by people. The first half of the book presents resins from a botanical and ecological perspective—anatomy, composition, and function. The second half reviews the use of fossil and fresh plant resins by people. The author is Professor Emeritus of Biology and Research Professor in the Department of Ecology and Evolutionary Biology, University of California–Santa Cruz. For more than 40 years she has researched and published extensively about resin-producing plants, particularly those of the New World tropics. Her many years of experience mentoring students are reflected in the clarity of her presentation. Please note that the reviewers are conservators writing for conservators and other cultural history professionals. Their comments are directed specifically to this audience and are not intended to address the relevance of the book to its biological audience. The text is divided into three sections: “The Production of Resin by Plants” (120 pages), “The Geologic History and Ecology of Resins” (110 pages), and “The Ethnobotany of Resins” (220 pages). The chapters in “The Production of Resin by Plants” section detail anatomical, biochemical, and taxonomic aspects of resin production. These are of interest as they add to our understanding of the context of the origin of resins found in collections, but much is likely to be beyond the interest of readers with minimal background in botany. The introduction to and reviews of biochemical studies in resin composition are of obvious application to analytical studies, always bearing in mind that the focus of the book is on the biological origin and production of resins and plant exudates, not on their modification in manufacture and aging. Some passages, such as the descriptions of the nonresinous plant exudates (latex, gum, mucilage, oils, waxes) offering succinct, easily understandable definitions, are very useful to the layperson. Discussion of modes and locations of resin production also adds to our understanding of the complex composition of the resins and resin cements (particularly those that are unrefined or only slightly refined) found in artifacts. Similar comments apply to the section on “The Geologic History and Ecology of Resins.” Langen-heim's primary area of research is amber, and the 50-page chapter on geologic history is almost exclusively devoted to amber—sources of amber through the geological ages, analytical studies of amber composition, and paleoecological studies based on evidence found in amber. The ecological roles of resins are discussed in the succeeding chapter—primarily defense against micro-and macro-organism pests and grazers but also removal of metabolic waste products and moisture content regulation. The secondary roles of pharmaceutical and hormonal use of resins by insects and adjustment of soil nutrients by resins are not of immediate application to cultural heritage preservation, but the possibilities raised are interesting to consider. “The Ethnobotany of Resins” section is of most immediate application to cultural history and conservation. As would be reasonably expected of a biology text, there is extensive information on plant sources, methods of cultivation and harvesting, and preliminary processing. Manufacture and use of artifacts are Specific ethnobotany chapters comprise the historical and cultural importance of amber and resins, oleoresins, fragrant and medicinal balsams, varnish and lacquer resins, miscellaneous resins, and future use of resins. The first chapter features the use and trade of amber but also includes hashish, Mayan copal, indigenous Malay resins, New Zealand kauri resin, and African copal. Naval stores (pine oleoresins) production worldwide constitutes most of the chapter on oleoresins, with some mention of ancient use and more detailed discussion of more recent historical use. Other oleoresins included are production of the legume resin copaiba in South America and the tapping and use of dipterocarp resins (e.g., keruing, bal�u) in Asia. The chapter on fragrant and medicinal balsams was interesting for the coincidence that those so widely prized for their fragrance are also those with wide medicinal application and for the seeming contradictions in their medicinal effects. They are described as irritants and stimulants, yet are used externally as antiseptic salves for wounds and burns and internally for colds, coughs, consumption, cramps, constipation, and diarrhea. The 35-page chapter on varnish and lacquer resins addresses the use of resins as varnishes, with only slight mention of picture varnishes. The author relies heavily on a few sources for this chapter, with C. L. Mantell et al., The Technology of Natural Resins (1942), and Mantell, The Natural Hard Resins: Their Botany, Sources and Utilization (1950), providing the most salient facts. The first section discusses the multiple genera of resins known collectively as damar, complementing and expanding the familiar observations made by J. S. Mills and R. White and R. J. Gettens and G. L. Stout. The details of the collecting method for damar are brought to life through careful description and various illustrations. The reader is left with a better appreciation for the extensive manual labor and personal risk associated with resin collecting in remote tropical forests. Sandarac, mastic, copal resins, lacquers, and even shellac are given varying degrees of focus. The description of mastic resin and the alternate uses for it (and related species) are given equal treatment. It is the supplemental information here that makes for fascinating reading, since the core facts are already known in the conservation literature. In particular, the antimicrobial effect of mastic resin has led to wide-ranging uses in food preservation and medicine from perhaps as early as 5000 B.C. to the present. Today mastic is used as a wound adhesive and on surgical tapes after dermatologic and plastic surgeries due to its superior adhesion and a lowered incidence of contact dermatitis. The author clarifies the confusing historical uses of the term “copal” as applied to many New and Old World resins derived from various sources. Part of the confusion derives from the compositional variability that often occurred when local collectors mixed resins from trees belonging to different genera (as is true of damars). Hard copals from the Congo have been used after cracking (heating) to make hard varnishes, printing inks, and polishes. The history of New Zealand Agathis australis (kauri copal) collecting and shipment to North America and England in the late 19th and early 20th centuries is a fascinating story of market development and natural resource exploitation. We are told that by the early 20th century kauri was considered the premier varnish resin for furniture as well as an important constituent of linoleum. For high-quality furniture, more durable French polish could be obtained by mixing shellac and kauri, with the result of improved water resistance. Many of the resins discussed in the 45-page chapter on miscellaneous resins are unlikely to find their way into collections, but their effect on humans will not seem trivial to anyone who has suffered a severe reaction to poison ivy or the urushi lacquer The numerous black-and-white photographs and line drawings include both botanical and ethnobotanical information. About two-thirds of the 47 color photograph plates illustrate the plant and habitat of resin sources. The remaining third include interesting illustrations of collection techniques. The appendices include a list by family and genus of resin-producing conifers and their distribution, a list by family and genus of resin-producing angiosperms and their distribution, diagrams of the chemical structure of characteristic components of fossil resins, and a list of amber deposits by age, location, and botanical source. The list of resins by common resin name, plant source, and primary uses is most helpful for the nonbotanist. As would be expected of a book intended for an audience of very mixed professions, the seven-page glossary is a mixture of technical terms like “schizolysigeny,” relevant primarily to the botanist and ecologist, and highly general terms like “natural product.” In fact, the concise, easily comprehensible definitions for many terms used or encountered by conservators are very useful. For example, that for “latex” (“milky or clear plant exudates composed of a complex mixture of substances such as terpenoids, proteins, carbohydrates, phenolics, etc.,” p. 496) is one of the clearest introductions the reviewers have seen. The extensive 68-page references section comprises major studies and review articles, primarily botanical, biochemical, and analytical. The references for the resins included in the ethnobotany chapters provide a good starting place for further research. Some standard art history and conservation texts (e.g., Mills and White, C.W. Beck, and H. T. Barry) and several newer publications (e.g., White and J. Kirby) are referenced; however, a quick search of the Bibliographic Database of the Conservation Information Network (BCIN) yields a number of research articles on resin composition and aging, and one wonders why they were not consulted. A plant index including common and botanical names and a subject index conclude the book. Is this a must-have for every conservator's book-shelf? It is a good introduction to natural resins from a biological and ethnobotanical perspective. Mills and White, Gettens and Stout, and the historical technology texts like E. J. Parry present more information directly applicable to resin processing, use in artifacts, and durability. But Langenheim offers a wider context for access to research on resins, and the information on collection and processing of a number of resins worldwide is a great starting place—not comprehensive (use of plant exudates is far too extensive for any one author or publication to cover it comprehensively) but providing ready access to information on a wide range of geographical areas. Information on such a large number of historical and noncommercial resins is otherwise not found in a single source. Wandering through their copies again one recent afternoon, the reviewers' general summary was that, for most conservators, this was probably a browser— interesting detail to be gleaned from a text for a biology audience. But then, three hours later we were still enthusiastically browsing with a chorus of, Hey, this is fun:“Turpentine was the most important naval stores product in the early to mid-1800s, but the price of rosin was so low that it was often discarded in streams, lakes, and holes in the ground. However, one of the soldiers on Sherman's march through North Carolina in 1865 recognized the potential of the buried rosin and returned after the Civil War to begin a rosin-mining venture. By the 1900s, demand for rosin had increased enough that streams and lakes were mined for the discarded material”(p. 314). Need a little some-thing to fill an awkward conversational pause? “Sticky monkey flower resins are composed primarily of five So, in fact, whether on a private or an institutional conservation bookshelf, Plant Resins may not be a primary general reference, but it is an excellent complement to the conservation, art technology, and cultural history literature and one that can offer great enrichment and enjoyment. So, a must-have browser!
SANDRA DAVISON, CONSERVATION AND RESTORATION OF GLASS. Oxford: Butter-worth-Heinemann, 2003. 380 pages, hardcover, $120. ISBN 0-7506-43412. Conservation and Restoration of Glass is written and intended as a comprehensive introduction to the background required by conservators and restorers who work with glass. The book includes recent developments and changes in the conservation of glass and adds a focus for conservators who are involved with glass in historic homes and public settings. The book begins with a preface explaining the objectives of the book and how it has changed from the earlier edition, Conservation of Glass, coau-thored by Roy Newton. Most significant is the removal of the section on painted glass window restoration, which was Roy Newton's area of specialization. The information regarding the technology and history of glass windows has been kept “as background for conservators preserving panels of glass” (preface). The preface continues with an outline of the book, detailing its layout and providing short descriptions of each of the chapters. Without question, the author offers a useful and thorough reference on glass as a material, its historical development, and the mechanisms of deterioration and preservation. This background is then used to introduce how glass deteriorates and, finally, what materials and techniques are available to carry out conservation (active or passive) and restoration. Almost half the book is devoted to the nature, technology, and historical development of glass. This extensive introduction is most valuable to both students and conservation professionals for understanding glass as a material, both physically and chemically. The chemical structure is clearly explained in chapter 1 and clarified with schematic diagrams. This explanation is followed by a discussion of the materials that can be added to alter the appearance of glass, from colorants and opacifiers to decolorizers. The history of glassmaking in chapter 2 offers insight into the progression of techniques of glass manufacture, beginning with Egyptian and western Asian core-forming and followed by perhaps the most significant change in technology, glassblowing. Individual locales such as Britain, Ireland, Bohemia, and Venice all influenced changes in glass manufacture and shaped the history of the material right up to the present. Chapter 3 builds firmly on the two previous chapters and presents an in-depth look at the methods and materials used in the production of glass. The technology of glassmaking varied in different regions, and experimentation continued from Egyptian times right Chapter 4 introduces the basic need for conservation, in that glass is far from indestructible and suffers not only from the risks of cracking, chipping, and breaking, but from chemical deterioration as well. Water is the primary cause of deterioration, and the rates and mechanisms are directly related to the chemical composition of the glass. This thorough examination and discussion of the causes, symptoms, and effects of glass weathering or “corrosion” is an excellent and informative summary. Davison explains that she does not like to use the word “corrosion” but, in the end, does use it, as the word “weathering” does not always seem to be appropriate. The practicing conservator will find chapter 5 most useful as it outlines the materials used in glass conservation, from adhesives to packing materials. The importance of the shorter chapter 6 on examination and documentation cannot be overstated, as the many techniques and pieces of equipment described are critical to understanding and recording the condition and history of a glass object. Simple or complex examination not only will provide valuable information that might affect one's choice of treatment, but also may provide insights into the technology and origin of the glass. The book finishes with the long chapter for which it is titled, and the next 100 pages (or so, if one adds appendix 1 on materials and equipment) are an up-to-date resource that is comprehensive, objective, and balanced. Certainly not all glass requires many of the types of intervention described, such as desalination or consolidation, but a practical knowledge of all approaches is necessary and offered here. The conservator needs to assess the value of a restoration and its long-term consequences, whether the restoration is for nostalgic reasons or museum display. Not all the materials and techniques described are easily reversible and may have a lasting effect on the appearance of a glass object. Sandra Davison has again provided the field of conservation with a thorough and up-to-date text-book. The book is more devoted to glass objects than the previous version, and topics have been expanded to reflect the significant developments in the field of glass conservation. The sections on architectural glass have been removed but replaced with useful information on chandeliers, installations, and reverse paintings on glass. One noticeable change between the previous book and this one is not as successful— in general, the photographic reproductions are not as clear or as sharp as in the previous volume, owing to a less fine printing quality, but this detriment is not a fault of the author. Several editing comments should be noted, one of which is significant to the use of the very popular adhesive Hxtal NYL-1. Table 5.2, on page 210, reports the Refractive Index (RI) of Hxtal as being 1.549. This is incorrect and may simply have been a typographical error. The RI of Hxtal is usually reported as 1.51 or 1.52, but I have seen it as 1.519, and possibly the “19” was miscopied as “49.” This discrepancy can be easily checked in figure 5.1, which lists the RIs of various resins, including Hxtal. Unfortunately, this three-page figure (or “table,” as it was originally published by N. Tennent and J. H. Townsend, 1984,“The Significance of the Refractive Index of Adhesives for Glass Repair,” Adhesives and Consolidants, pp. 205–12), complete with resins, manufacturers, and glass analyses, has been improperly referenced in the text. The reference comes after paragraph two, under “Refractive index,” page 207, whereas it should follow “Figure 5.1” at the end of the previous paragraph. A missing “g” from “Tg,” in the same chapter, page 219, line 21, is also confusing. The refractive index of PVAC, mentioned in the same paragraph (line five), is not really “similar to glass.” Rather, this low a refractive index only matches “fused silica” or “96% silica” glass. Almost all other glasses, from Roman times to modern, have a refractive index above 1.50. Finally, in this reviewer's Sandra Davison is an enthusiastic, extremely talented glass conservator who enjoys sharing her knowledge and hands-on skills widely. She has lectured, taught courses, and given demonstrations of techniques throughout the world, and she actively continues to improve our understanding and capabilities in the conservation of glass. The drawings that she provides in the book are lessons in themselves. The field of glass conservation is fortunate to have her commitment and authoritative expertise. Conservation and Restoration of Glass is a valuable resource for students, conservators, restorers, and anyone else who is interested in the complex nature and behavior of glass. The additions and improvements to the previous edition add significantly to all its original strengths. It is an excellent resource, but not to be used on its own. The author rightfully cautions near the end of the preface that even conservators should not undertake complicated treatments for which they have not been trained or in which they have no experience. The temptation is always there, but as H. J. Plenderleith stated in his introduction to glass in 1956 (The Conservation of Antiquities and Works of Art [London: Oxford University Press], p. 339), “Broken glass is one of the most difficult materials to repair.”
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