Viewing ceramic and technological change through sub-traditions in the Western Maya Lowlands

Traditions are generally used to describe the recurring presence of some grouping of attributes shared by spatially contiguous social groups over relatively long periods of time general patterns of which are applicable to material remains Western Maya Lowlands.  These are large scale, nomothetic entities that can serve to emphasize comparability among certain classes of pottery.  Sub-traditions, based on detailed analysis of formal variation and paste composition, although another nomothetic heuristic, can be seen to reflect the specifics of local histories that situate ceramic products within a variably long context of social group interaction.  These sub-traditions must be gleaned from ceramic data that goes well beyond general notions of ceramic form or surface finish, as used in Type-variety, requiring the increased resolving power of instrumental analytical techniques and appropriate numerical approaches to extract information from assembled multistate data sets.  I illustrate the role of sub-traditions to monitor shifting expressions of ceramic manufacture at the Western Maya Lowland site of Palenque, Chiapas, that lean themselves to the creation of more robust narratives concerning social, political and economic changes at this important Classic site and in its immediate sustaining area.

Ronald L. Bishop received his doctorate in Anthropology in 1975 from southern Illinois University and is presently the Curator for Mexican and Central American Archaeology in the Smithsonian Institution's National Museum of Natural History.  In 1973 he began the first of what would be several years in the Department of Chemistry at Brookhaven National Laboratory, carrying out research with Edward V. Sayre and Garman Harbottle, applying neutron activation analysis to archaeological problems.  He has spent 40 years analyzing ceramics and jade from Mesoamerica (especially Maya), Lower Central America, the greater U.S. Southwest, and more recently, Hispanic and Mexican Colonial pottery in California, Texas and Mexico.  He has written extensively on the compositional analysis of cultural materials, integrating the analytical data obtained from the study of museum objects with analyses of artifacts from recent excavation and surveys.  He has published extensively on subjects of ceramic manufacture and distribution, especially as these are aided through the use of chemical and petrographic analyses of pottery.  His mathematical modeling of compositional data incorporates both geological and social aspects of material production, use and exchange.

Use of White Pigment in Pottery: An Ancient Tradition in the Central Highlands of Mexico

In Mesoamerican pottery traditions, the use of dyes or pigments to decorate ceramic pieces dates back to, at least, the Early Formative period. The origins and characteristics of these dyes differ across temporal and spatial contexts, and evident variation depends on many factors (tradition, preferred style, availability of materials, processing technique, etc.). From among a wide range of slips, two colors predominate: white and red. The application of slips of these colors began at an early stage of the early Formative and endured throughout pre-Hispanic history.

This paper focuses primarily on the use of white slips in ceramic materials from various sites located in the Central Highlands of Mexico. Through the application of a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), we have analyzed the white slips of ceramic fragments that correspond to the Middle Formative and Epiclassic chronology, specifically Coyotlatelco red on white. The results of these analyzes permit a fuller understanding of the long tradition of using white coloring of various origins. In the case of the materials tested, from the Toluca Valley, it is argued that the application of diatomite, widely available in the lacustrine region as a pigment, has a long tradition since at least the Middle Formative.

Dr. Sugiura received her doctorate in Anthropology from the UNAM in Mexico City, where she is now a Full-time Researcher in the Institute for Anthropological Research and has received several distinctions, including membership in Mexico's National System of Researchers (SNI-Level III) and PRIDE. For the past four decades she has worked in the Toluca Valley conducting surface surveys and archaeological research at several sites and extensive excavations at Santa Cruz Atizapán. She has also carried out ethnoarchaeological research on pottery production and lakeside lifeways in the High Lerma. She has directed or participated in more than 20 archaeological projects and prepared posters, papers and keynote conferences for 158 national and international congresses. Her publications include over 90 scholarly articles and books. Dr. Sugiura has imparted several courses at the Colegio de México, the Escuela Nacional de Antropología e Historia and the Universidad Nacional Autónoma de México at both the undergraduate and graduate levels, and is responsible for designing the curriculum for the undergraduate program in Intercultural Development and Management in the Faculty of Philosophy and Letters at the UNAM. In addition, she has directed 44 Bachelor's, Master's and Doctoral theses, and participated in the Tutorial or Advisory Committees of another 29 students at different levels.

Demetrio Mendoza earned his Doctorate in Materials Engineering at the Autonomous University of Querétaro, and is now a researcher in the Materials Science Department of the National Institute for Nuclear Research (ININ). He has directed, or collaborated in, over 15 archaeological projects, and participated through papers or conferences in more than one hundred national and international congresses. He has over 70 academic publications, 35 of which were edited internationally. Dr. Mendoza has been active in teaching in the Faculty of Chemistry at the UAEMex, the Center for Archaeological Studies at the Colegio de Michoacán, the Faculty of Chemical Engineering at the BUAP, the Mexican Association of Microscopy, and the University Liaison Center at the BUAP. Also, he has served as a thesis supervisor at the B.Sc. and M.Sc. levels as a member of 7 Thesis Committees: 3 Bachelor theses, 3 Master's theses, and 1 Doctoral thesis.

A graduate of the undergraduate program in archaeology at the Escuela Nacional de Antropología e Historia, Mr. Sánchez has fieldwork experience in Taretan, Michoacán, Metzquititlan, Hidalgo, Xochicalco, Morelos, and the Balsas River Valley, Guerrero. He has collaborated in archaeological excavation projects in northern Portugal, San Mateo Atenco and Santa María del Rayón, State of Mexico, and at Stonehenge in Britain. At the UNAM, he was named Assistant Researcher in the "Coyotlatelco Pottery in the Basin of Mexico and the Toluca Valley" project, while at the ININ he participated as an Auxiliary Operator of Basic MEB Functions. He has written 6 papers and prepared 2 posters for presentation at national and international events.

Negative-painted Ceramics in the Lacustrine Region of Michoacan: A Millenarian Ceramic Tradition

In the tombs at the El Opeño site (1500 B.C.) in Michoacán the biography of a decorative technique began. Called negative-painted ceramics, it would endure into the Post-Classic with its Tarascan polychrome ceramics. Though broadly distributed in culturally distinct sites in Mesoamerica, it was in the lacustrine region of Michoacán that this technique presented a millenarian cultural and ritual persistence that underlines its importance for pre-Hispanic societies. Archaeometric analyses conducted at the LADIPA laboratory at El Colegio de Michoacán on a series of samples from different periods and archaeological sites reveal a high level of technological knowledge. Discussions of artisanal specialization, the operative chain of pottery manufacturing, and some brief comments on iconography will lead us to ponder key questions concerning the ritual and symbolic value of this ceramic tradition.

Agapi Filini received her Doctorate in Anthropological Archaeology from University College London (England). She has authored books and articles on the Teotihuacan world-system, the development of social complexity in the Cuitzeo Basin, Michoacán, and studies of ceramics, among other topics.

Lime production in Mesoamerica

For millennia, lime has been used in construction and the elaboration of architectural facings, such that it constitutes an important aspect of the historical development of many social groups around the world, but especially of the inherited culture of Mesoamerica.

This paper discusses the geology, energy and physical-chemical aspects of lime production, beginning with a bibliographical review that traces the possible origin of this important technology to the Petén zone of Guatemala and northern Belize. It emphasizes that lime technology was invented independently in Mesoamerica, and that its use spread to the public architecture of many other zones, primarily in the Mayan area, Oaxaca and Mexico’s high Central Plain. Lime also had an impact on the urban development of ancient settlements by enabling construction of public architecture with masonry that produced tall, thin buildings.

Also, it played an important role in the development of mural painting, as it allowed the cultures that used it to elaborate surfaces where artists’ creative abilities could take flight and, thanks to its chemical and mechanic stability, permits us to appreciate these works of art hundreds of years later.

But perhaps it was in alimentation that lime played its most significant role in Mesoamerica, for it made possible the most distinctive characteristic of Mesoamerican culture: the technique of boiling corn kernels with lime to produce the dough used to make tortillas, tamales and other foods (nixtamalización). We have no evidence to suggest that this technique was known in any other area of the world.

Finally, the hygienic properties of floors made with lime, compared to compacted dirt or clay, have had enormous repercussions on the health of populations and propitiated the study of activities from the distant past.

Ph.D. in Anthropology, Graduate Program, Faculty of Philosophy and Letters, UNAM (1995).

Founder (1983) and now Coordinator of the Archaeological Prospection Laboratory, Institute for Anthropological Research, UNAM. Dr. Barba has published 109 articles (50 in international publications), 14 book chapters, 4 books, a manual, and 82 technical reports.

He has given 32 courses at different educational institutions and been Guest Professor at the Universidad de Barcelona, the Universidad Autónoma de Barcelona and the Universidad de Cádiz in Spain, and the Universidad Nacional Mayor in San Marcos, Peru.

He has directed 17 theses, advised 35 students and is now on 7 thesis committees. He has presented 178 papers at scientific meetings, 99 of them international events.

Dr. Barba has been a member of Mexico’s National System of Researchers since 1984 (Level II) and of stimulus programs at the UNAM since 1990 (now Level D). He became a Member of the Mexican Academy of Sciences in 2012.

His research areas include the field of archaeometry and the application of the techniques of aerial photography and geophysical and geochemical prospection to archaeology. He is active in the study of chemical residues at archaeological sites and in ceramic vessels as a means of interpreting their uses and functions. Recently, he has been studying the materials and energy involved in the construction of pre-Hispanic architectural structures.

Clay, lime, and economic security in Formative Period Valley of Puebla, Mexico

The central part of the Valley of Puebla, Mexico, has been an important source of lime in the Mexican highlands going back at least to the early 16th century when the town of Tepeaca was a seat of local political authority in the Aztec Empire.  Archaeological evidence indicates that lime processing was part of the local inhabitants' activities by the Middle Formative Period.  Furthermore, the available data suggest that pottery-making for exchange, at least on a regional level, was taking place by the Late Formative Period.  Both lime processing and ceramic manufacturing were performed on the same hillside, presumably by the same families, although the technologies involved were distinct.  Lime processing was done in open, shallow subhemispherical concavities, the bases of which lay in the underlying tepetate.  Ceramic firing facilities were more labor-intensive constructions, truncoconical in form.  These pits were dug through earth and into the underlying tepetate to depths of 34 to 90 cm, widening from apertures of perhaps 70 cm to floor diameters of as much as 198 cm.  Much greater control over firing temperatures was possible, and significantly higher temperatures were achieved, in the pottery facilities as compared to the lime processing pits.  The floors of the ceramic firing facilities were dark gray to black, similar to the floors of the lime pits, but the walls (both the fire-hardened earth above and the tepetate below) were orange to red in color to thicknesses of several centimeters.  Since little evidence exists of subsistence stress in this area during Middle and Late Formative times, these households were likely using these activities as a way to trade for necessary or desired items and as a subsistence risk reduction mechanism.

Ron Castanzo has conducted archaeological research, with a focus on Mesoamerica, since 1994.  After graduating from Penn State University (University Park, Pennsylvania, USA) in 2002, he began postdoctoral studies at the Smithsonian Institution (Washington, District of Columbia, USA), where he was introduced to the chemical characterization of ceramic pastes using neutron activation analysis.  In 2007, Ron joined the faculty of the University of Baltimore (Baltimore, Maryland, USA), a small public liberal arts institution, where he has built the anthropology curriculum.  His scholarly interests lie mainly in the archaeology of prehispanic Mexico and include the evolution of economic institutions, ceramic manufacturing, and population dynamics and change.  He has published papers on such topics as Formative Period settlement in the Valley of Puebla, ceramic manufacturing and kiln technology, and obsidian production.  He also has interests in historical archaeology in the City of Baltimore and State of Maryland.  In the near future Ron intends to continue his work involving the Formative Period in the Tepeaca area and to embark on a study of broad changes in settlement in the Puebla-Tlaxcala Region, while continuing to strengthen the anthropology and archaeology capability of his home institution.

Social Agreement versus Technological Agreement: The Beginnings of Metal Production in Iberia

The state of affairs regarding the origins of copper metallurgy in Europe was laid bare by Heather Lechtman some years ago with her usual perspicacity: "these metals did not have the same impact on Andean civilization that they had among peoples of Europe and the Ancient Near East" (Lechtman 1984:1). Currently in Europe, the debate surrounding the social impact of metallurgical technology on prehistoric societies continues to rule the agenda. However, comparative studies between the Old and New Worlds were not a priority then; nor are they now. This meeting is an excellent opportunity to stake a larger theoretical and methodological union between the two.

The Iberian Peninsula is in the eye of the storm surrounding the discussion on innovation and technological change. Scientific debate is currently focused on the possible existence of distinct areas of technological invention, as opposed to Childean neo-diffusionism from a single nucleus in the Near East. Apparently, this situation is similar to that of a few decades ago; however, the perspective has changed completely because other theoretical models are now utilized, mainly due to conceptual redefinitions in technological, economic, social, and symbolic fields. This allows us to plant new questions and challenges: Is metallurgical technology a homogeneous block? When, how, and why do different forms of specialization arise? At what scale in the archaeological record can one trace the social agreement that allows or prevents a new technology taking root? As Andrew Feenberg (2003:79) states, "technical development is not an arrow seeking its target, but a tree branching out in many directions."

This paper attempts to explain these conceptual and methodological changes in the context of early European metallurgy, with particular emphasis on the metallurgy of gold, and on what remains to be done.

Dr. Perea is currently a Scientific Researcher at the Center for Human and Social Sciences (CCHS, CSIC), where she leads the Archaeometal Research Group in the area of Archaeology and Social Processes. She graduated in Prehistory and Archaeology from the Universidad Complutense in Madrid and later earned her Doctorate there (1989). Her interests center on the archaeo-metallurgy of gold, and she has specialized in archaeometrics applied to research on technological and social change. She was a founder and Scientific Director of the Laboratory of Electronic Microscopy and Microanalysis (MicroLab) at the CCHS, CSIC, and has published numerous articles in national and international scientific journals. Her series of monographs includes outstanding volumes on the Fíbula de Braganza and the Visigoth treasures of Guarrazar and Torredonjimeno. Her latest book, published with O. García-Vuelta and C. Fernández-Freire is: El Proyecto Au. Estudio arqueométrico de la producción de oro en la Península Ibérica, BPH, vol. XXVII, CSIC, Madrid 2010.

Questioning the Status Quo: From a Western Archaeometallurgy to a Mesoamerican Archaeometallurgy

Metallurgy developed relatively late in Mesoamerica (approximately post-650 A.D.). The existing consensus holds that this technology originated in the south and was most likely brought to western Mexico along maritime routes that followed the Pacific coast. The ancient tradition of copper-based metallurgy in the west and the high degree of development that it achieved, especially in the Tarascan culture during the Post-Classic period in Michoacán, seem to support this theory, as this zone has come to be considered the center of metallurgical production in Mesoamerica. However, while the importance of metallurgy in western Mexico is an unquestioned reality, this area does not seem to have been the only productive region in the Late Post-Classic. Recent studies of a collection of copper bells from Templo Mayor using portable X-ray fluorescence equipment (XRF for its initials in English) succeeded in demonstrating that significant production of metal objects in Central Mexico was highly probable. In this paper I discuss some aspects of the history of archaeometallurgical research in western Mexico to explore this possibility or even, perhaps, question the status quo of the “Ex Occidente Lux” theory of Mesoamerican metallurgy. I also examine the Western Mexican Metalworking Zone and varying opinions on the introduction of metallurgy into this region, as well as the established explanation of its development. Some salient points are then contrasted to the data that is emerging from Central Mexico, before returning to evaluate the question, Ex Occidente Lux? Regional comparisons help us to better our knowledge of change and persistence as they relate to copper metallurgy in Mesoamerica, and allow us to posit new questions.

Dr. Schulze studied Pre-Colombian Prehistory, Languages and Cultures, Journalism and Analytical Methods in Archaeology in Hamburg, Germany and Bradford, England. Recently, he obtained his Ph.D. in Anthropology at the UNAM, Mexico. He worked as an Expert Associate at the Center for World Patrimony at the UNESCO in Paris, France, on the cultural patrimony of Latin America and the Caribbean, and has collaborated as a consultant in the UNESCO offices in Paris, Montevideo and Mexico. Currently, he is a Professor/Researcher in the Coordination of Social Sciences and Humanities at the Autonomous University of San Luis Potosí. His research areas include the analysis of archaeological materials with a special focus on pre-Hispanic archaeo-metallurgy and the administration and protection of cultural patrimony.

Dr. Ruvalcaba received his B.Sc. in Physics at the Faculty of Science at the UNAM with the thesis "Análisis elemental cuantitativo mediante técnicas nucleares de piezas arqueológicas". He obtained his Doctorate inScience (Physics) from the Faculté des Sciences, Facultés Universitaires Notre-Dame de la Paix, in Namur, Belgium, with the thesis "Analyse non destructive par faisceaux d’ions de bijoux anciens d’Amérique", which won highest honors. Today, he is a Full-time Researcher at the Institute for Physics at the UNAM and a member of the SNI (Level II). His research interests include:non-destructive methods using ion beams applied to archaeology, history and art(archaeometry), radiation interaction with materials, ionization and ionoluminiscence, analytical techniques based on particle accelerators, and the characterization of multilayer systems and materials.

Analysis of the Different Regions of Metallurgical Work in Oaxaca in the Late Post-Classic: Origin and Change

Metal objects made a late appearance in the cultural area of Mesoamerica, especially in the western and southern regions of Mexico and on the Yucatán peninsula. Arriving around 800 A.D., these objects were introduced from other cultural areas, such as Central America and the Andean region. But their arrival in Mesoamerica marked a key moment that eventually resulted in certain places in this zone undertaking the development of their own methods for working metals. In this regard, western Mexico and the area of Oaxaca stand out. Today, the state of Oaxaca is divided into eight regions, some of which, during the Late Post-Classic period, were characterized by the manufacture of a variety of artifacts rich in gold. While around eighty per cent of the gold artifacts extant today are associated with the Mixtec culture, other groups were also active in creating metal objects in distinct regions of Oaxaca. The objective of this study is to identify the different manufacturing areas of metal objects in Oaxaca, and to demonstrate the different metallurgical traditions adopted by the metalworkers in the elaboration of their pieces. Thus, our interest centers, first, on associating each group or region with the metallurgical tradition to which it gave rise, and then establishing the subsequent development in each region, in an attempt to explain why and how this phenomenon occurred. To fulfill this objective our study is based on non-destructive analyses that have been conducted with diverse collections of metal objects from Oaxaca, on historical and geological data associated with this state, earlier material studies, and comparisons with objects that are considered similar, such as those from Mexica collections.

Dr. Díaz obtained her B.A. in Archaeology at the Escuela Nacional de Antropología e Historia and an M.A. in Art History at the Faculty of Philosophy and Letters of the UNAM. She has an M.A. and Ph.D. in History from El Colegio de México, and is now a Full-time Researcher at the Institute for Anthropological Research (UNAM) and a member of the SNI (Level I). Her areas of interest are communication and exchange routes in Mesoamerica (pre-Hispanic and Colonial periods), archaeometric studies of pre-Hispanic metallurgy (raw material sources and evidence from archaeological remains), the history and archaeology of the Northern Sierra of Oaxaca, and settlement and resettlement of Indian peoples in the 16th century in the Papaloapan region.

Dr. Ruvalcaba received his B.Sc. in Physics at the Faculty of Science at the UNAM with the thesis "Análisis elemental cuantitativo mediante técnicas nucleares de piezas arqueológicas". He obtained his Doctorate inScience (Physics) from the Faculté des Sciences, Facultés Universitaires Notre-Dame de la Paix, in Namur, Belgium, with the thesis "Analyse non destructive par faisceaux d’ions de bijoux anciens d’Amérique", which won highest honors. Today, he is a Full-time Researcher at the Institute for Physics at the UNAM and a member of the SNI (Level II). His research interests include:non-destructive methods using ion beams applied to archaeology, history and art(archaeometry), radiation interaction with materials, ionization and ionoluminiscence, analytical techniques based on particle accelerators, and the characterization of multilayer systems and materials.

The Constructive/Destructive Flame: Fire in Colonial-Period Mexican Mining Communities

Mesoamerican mining communities during the Colonial period employed fire to extract and transform natural resources, fulfilling obligations to the Spanish crown. At the same time, they depended on fire for light, heat, and food. What kinds of knowledge were brought from one fire to the next? How did fire mediate daily life in these mining communities? Drawing on written reports and visual representations of Mesoamerican mining communities held in the Bancroft Library of UC Berkeley, this presentation proposes that fire helped to unify these potentially transient communities; the creation, maintenance, and enjoyment of fire were and still are inherently social acts.

Is a PhD candidate in Anthropology at the University of California, Berkeley where, for his dissertation, he is exploring the technological styles of the metal objects deposited in the Cenote Sagrado at Chichén Itzá. He earned his B.A. in Art and Archaeology at Princeton University and his M.Sc. at the Institute of Archaeology at University College London, where he analyzed metal ornaments from the Colonial occupation of Tipu, Belize. Besides teaching courses at Berkeley, he has taught several courses in Mesoamerican archaeology and in Spanish in the education program at San Quentin State Prison in California.

Glass Manufacturing Technologies in Post-Medieval Europe

Glass has been manufactured in Europe for several millennia. In the post-medieval period (16th to 20th centuries) glass has been produced and applied in three main sectors: tableware (drinking cups, etc), flat glass (windows and mirrors) and containers (mainly bottles). Each sector has, at various times, had different requirements and found different technological solutions, although each has tended to borrow solutions developed in other sectors.

In post-medieval Europe almost all glass was made using a silica base with the use of a suitable flux (usually an alkali) to reduce the melting temperature. The use of different materials as the source of these fluxes is discussed in many historical sources for the period but can also been uncovered through the chemical analysis of surviving glass. Until the end of the 18th century, almost all fluxes used in glass making were obtained from plants. Many different types of plants could be (and were) harvested and burnt to produce an alkali-rich ash. Most of these may be divided into two broad groups: soda-rich plant ash derived from coastal and/or arid environments around the Mediterranean sea and potash-rich plant ash derived from temperature forests of central and northern Europe. Some contemporary glassmakers were aware that these plant ashes contained only a proportion of alkali and developed processes to purify plant ashes and so increase their alkali content. There was no real appreciation that sodium and potassium were separate alkalis until the late 18th century. The identification and isolation of these elements and the developments of techniques to allow their industrial production revolutionised the glass industry. Traditional plant ashes usually contained sufficient calcium to ensure that the finished glass was chemically durable. The role of calcium as a glass stabiliser and its deliberate addition for this purpose only developed from the late 18th century.

A significant driver for the post-medieval glass industry has been the production of colourless glass for drinking vessels; the goal seems to have been for a glass which would resemble rock crystal. Avoiding the production of any colour or tint in glass depends mainly on the use of raw materials which contain little or no iron. Most plant ashes contain sufficient iron to give resulting glass a colour. The use of lixiviation and other techniques to purify the flux largely removed this iron. The careful selection of suitable sources of silica ensured that glassmakers could produce truly colourless glass. Much of the early work to achieve this end took place in Venice but the late 17th century saw important developments in both Bohemia and England.

While tablewares had high status and have attracted most attention from later scholars, the production of utilitarian containers were a much larger sector of the industry. The post-medieval period saw the emergence of the ‘English' bottle which came to dominate container glass production. While bottles had existed before, the ‘English' bottle was thick-walled and narrow-necked allowing bottles to be effectively sealed and so allow their use for storage and transport. The nature of the glass employed in the production of bottles in England was for many years constrained by a system of taxation which allowed the use of only the cheapest raw materials. The progressive increase in the use of low-quality ingredients can be seen in the chemical composition of surviving glass bottles.

I hold a degree in Ancient History and Archaeology from the University of Birmingham and a PhD (Iron Age and Roman Copper Alloys from Northern Britain) from Durham University (1995). I worked for the University of Sheffield in their Department of Archaeology for five years before starting to work for English Heritage. English Heritage is a state agency with statutory responsibilities for the historic environment of England. I have worked in the English Heritage laboratory providing expertise in the investigation of early metal and glass production and now head the Archaeological Conservation and Technology section. I co-directed the excavation of a 17th-century glass production site in 2002 and have since developed a keen interest in many aspects of post-medieval glass production.

Colonial Period Glass Production

Unlike other activities, glass production in Mexico City showed gradual progress over time, due just as much to the social circumstances of the colonial period context as to economic conditions. Doubt has been cast on its existence in the city, despite the fact that Mexico City was the political and economic center of New Spain. Nonetheless, the presence of glassmakers since the sixteenth century and facilities dedicated to this type of production, evidenced in written sources, reveal its presence.

From an early stage, glass production was linked to metallurgical activities, specifically to the Casa del Apartado (associated with monetary production), which set the tone of its establishment and also promoted the development of luxury items and containers used by physicians and apothecaries. The tendency to replace barilla (soda ash) with tequesquite and salitre (lime and saltpeter), led to difficulties in the manufacture of glass, since the latter was used by the Gunpowder Factory, and both were subject to individual leases until the late eighteenth century, which conditioned developing glass production.

The production process was similar to that practiced in Spain; nevertheless, glass makers were restricted by the available mineral resources and had to adapt the industry to the natural and geological conditions of the areas where the raw materials were obtained. This, however, affected the quality of the glass produced, a factor that favored the importation of European glass.

Dr. Peralta earned his Master's in Science at Mexico's National Polytechnical Institute (I.P.N.), and his Doctorate at the UNAM. He has published several scientific articles and popular works in national and international journals related to the topics of visual health and glass production. In 2007, the Mexican Committee of Historical Sciences awarded him Honorable Mention for his study "Desarrollo de la óptica oftálmica y uso de anteojos en la Cd. de México, siglos XVI-XVII". In 2011, he published the book El vidrio en la Ciudad de México. Productores y Productos Novohispanos, siglos XVI-XVII. Today, he is active in two lines of research focusing on the historical development of attention to visual health in Mexico, and of ophthalmic glass and optics. He is a professor/researcher in the Section of Graduate Studies at the Escuela Superior de Medicina at the I.P.N., and a Fellow of the Stimulus for Teaching Performance and Exclusivity System programs, also at the I.P.N.

Izumi Shimada is Distinguished Professor of Anthropology at Southern Illinois University, Carbondale, with research interests in the archaeology of complex pre-Hispanic cultures in the Andes, the technology and organization of craft production (particularly ceramics, metals and shells), mortuary analysis, and ecology-culture interaction, among other topics. He has excavated at many sites including Pampa Grande, Pachacamac and Sicán and continues to direct two archaeological projects in Peru. He has authored or edited 16 books including Pampa Grande and the Mochica Culture (1994), Craft Production in Complex Societies (2007), andCultura Sicán: Esplendor Preinca de la Costa Norte (2013).