LETTER FROM MICHAEL TAYLOR, CHAIRMAN
US/ICOMOS SPECIALIZED COMMITTEE ON EARTHEN ARCHITECTURE

As Chairman, I have represented the Specialized Committee at various meetings and events since last reported in the September 1993 newsletter. At the 7th International Conference on the Study and Conservation of Earthen Architecture (TERRA 93), held in Portugal in October 1993, I presented a paper titled "The Effectiveness of the US/ICOMOS Specialized Committee on Earthen Architecture," which describes the goals, accomplishments and challenges of the committee. If any of you would like a copy of the paper, please write and I will be happy to send you one. At the conference approximately eight of us from the States had an informal meeting at which we reviewed past accomplishments and discussed future goals and objectives. At the same conference, I represented the United States at the Second Annual Plenary Meeting of the ICOMOS International Committee for the Study and the Conservation of Earthen Architecture.

Last February in Washington DC, I presented a report describing the Specialized Committee's 1993 accomplishments and 1994 goals to the US/ICOMOS Annual Meeting, and met immediately after with four members of the Specialized Committee. I also represented the Specialized Committee at the Third Annual Plenary Meeting of ICOMOS International Committee for the Study and the Conservation of Earthen Architecture held in Grenoble, France in October 1994, in conjunction with the 4th International Course on the Preservation of the Earthen Architectural Heritage, which our Specialized Committee helped to implement. Minutes from the international meeting will be available from me in February.

One of the primary responsibilities of the Specialized Committee is to facilitate the transfer of information between colleagues working in the field of earthen architecture conservation, both in the United States and abroad. This newsletter, which is made possible by US/ICOMOS, is instrumental in fulfilling that role. If you are not a member of the US/ICOMOS Specialized Committee on Earthen Architecture, please consider joining. It is through membership dues that many of the goals of the committee can be accomplished. Please see the box inset below for instructions on how to join today. Members will receive updated news of committee activities, and will be invited to be a part of the working objectives and tasks that we are in process of implementing. Please let me know your thoughts, suggestions, or questions by writing: Michael Taylor, State Historic Preservation Officer, Historic Preservation Division, 288 East Palace Avenue, Santa Fe, New Mexico 87503.

INTERNATIONAL UPDATE

Keeping abreast of the results of TERRA 93 is a main concern of the ICOMOS International Committee on the Study and the Conservation of Earthen Architecture.

A remarkable number of initiatives derived from the event. First among these, and directly related to the immediate concern of the host national authorities of the D.G.E.M.N. (Direccao Geral dos Edificios e Monumentos Nationais, Portugal) and related governmental agencies, is the establishment of a three-year program for master masons in earthen constructions at the Escola Nacional de Artes e Oficios Tradicionais de Serpa, the first interministerial initiative of this kind worldwide.

The D.G.E.M.N. will soon make available a publication, in addition to the TERRA 93 Conference Proceedings, which will include the Recommendations of the 7th International Conference on the Study and the Conservation of Earthen Architecture.

In other countries also there are significant initiatives encouraged by TERRA 93. A first step toward the establishment of the Danubian Earth Structures Network, by the Technical University of Brno in the Czech Republic, was taken in the meeting organized by The University of Brno from May 16-21, 1994, in Prykazy, Czech Republic, with funding from the Tempus European Union programme.

In England, the joint efforts of the University of Plymouth, the Plymouth School of Architecture, the Centre for Earthen Architecture, in association with English Heritage, the newly formed ICOMOS UK Earth Structures Committee, the CRATerre-EAG/ICCROM Gaia Project and the Royal Institute of British Architects resulted in the organization of the first national conference on earthen architecture. In Spain, an initiative has been promoted by our newly coopted associate institution, Inter-Accion/Centro Navapalos, with the organization of an Iberoamerican Exhibition of Earthen Construction.

In France, steps are being taken by members of the ICOMOS French National Committee to form the National French Sub-Committee on the Study and the Conservation of Earthen Architecture. With the creation of this Committee, ICOMOS will have four established National Specialized Committees on Earthen Architecture (France, UK, USA, Zambia). In addition, steps have been taken for the organization of activities in the Americas. Further news on this matter will be available as initial discussions develop.

The dynamic character of the earthen architecture community is unquestionably expressed in these events, together with the initiatives of an active professional network and the renewed commitment of the ICOMOS International Committee on the Study and the Conservation of Earthen Architecture to follow-up with its ideas and objectives.

THE CONSERVATION OF THE BAS-RELIEFS OF THE ROYAL PALACES OF ABOMEY: THE GETTY CONSERVATION INSTITUTE AND THE BENIN GOVERNMENT

The bas-reliefs of the Royal Palaces of Abomey, one of the most famous and historically significant sites in the West African Republic of Benin, will undergo scientific study and conservation treatment by the Getty Conservation Institute and the Benin government. The project aim is to conserve 50 polychrome earthen bas-reliefs that once adorned one of the palace buildings known now as the Salle des Bijoux.

The approximately three-foot square bas-reliefs, depicting royal symbols and human and animal figures in allegorical scenes, are thought to be the oldest surviving elements of the Royal Palaces of Abomey. The palaces are a group of earthen structures built by the Fon people between the mid-17th and late 19th centuries. The restored ruins of these palaces, now the Historical Museum of Abomey, are among the endangered sites on UNESCO's World Heritage List.

An international team of scientists and wall-painting conservators is addressing the problems afflicting the bas-reliefs. The Getty Conservation Institute team consists of: Neville Agnew, Special Projects Director, and Francesca Piqué, Research Fellow (chemist and wall-painting conser- vator trained at the Courtauld Institute of Art), who are leading the project; and Valerie Dorge, Training Program Coordinator, who is supervising the training component. Leslie Rainer, consultant (wall-painting conservator specializing in earthen materials), and Francesca Piqué are under- taking the conservation, documentation and training activities. An important aspect of the project is the on-site training of Benin Ministry of Culture staff: Léonard Ahonon, Curator of the Musée Historique d'Abomey; Justin Alaro, Curator of the Musée Historique de Kétou; and Dorothé Ayadokoun, Department of Cultural Heritage, Cotonou. They will be trained in documentation, conservation, care and maintenance of the bas-reliefs.

The bas-reliefs are in extremely fragile condition. Exposure to the weather and termite and insect attack caused serious erosion and deterioration of the bas-reliefs while they were on the façade of the Salle des Bijoux. In 1988 they were cut out and removed from the building walls in heavy blocks which were subsequently framed with a cement-earth mixture. The Salle des Bijoux itself has since been torn down and is currently being rebuilt.

The Getty Conservation Institute has conducted years of extensive research on the preservation of earthen structures and materials. The project to conserve the bas-reliefs, which is expected to last four years with field campaigns each spring and fall, will follow the basic approach developed by the Getty Conservation Institute in its other field projects around the world. After thorough review of existing documentation on the bas-reliefs' history and condition, and scientific analysis of their constituent materials and causes of deterioration, the joint project team will then develop and implement a conservation treatment plan. The final phase of the project will involve the planning of a site protection and monitoring program to ensure the long term survival of the bas-reliefs.

The West African kingdom of Abomey (formerly Dahomey), founded in 1625 by the Fon people, was an exceptionally powerful and wealthy center of trade and culture. The first royal palace of Abomey was constructed in 1645. Thereafter, each king had his palace built near that of his predecessors, the last being built for King Glélé (1858-1889). Earthen bas- reliefs were used as an integral decorative feature of the palaces. Their function was to represent and communicate the significant events marking the evolution of the Fon and their dominion over a vast territory. Although most of Abomey was burned in 1892 as the French prepared to occupy the city, the Salle des Bijoux is thought to be one of the few structures to survive, making its bas-reliefs of particular importance as a historic record of the Fon's rich culture, complex mythology, customs and rituals.

The Getty Conservation Institute is an operating program of the J. Paul Getty Trust. Committed to the preservation of cultural heritage worldwide, the Institute seeks to further scientific knowledge and professional practice in the field of conservation and to raise public awareness of the importance of conservation. Through field work, research, training and the exchange of information, the Institute addresses the conservation needs of museum objects and archival collections, archaeological monuments and sites and historic buildings and cities.

OUT OF EARTH

Out of Earth, the first national conference on earth buildings in the United Kingdom was held in Devon at the medieval Dartington Hall from May 4 - 7, 1994. The Conference was organized by the Plymouth School of Architecture in collaboration with the ICOMOS-UK Earth Structures Committee, and the ICCROM/CRATerre-EAG Gaia Project with the financial support and guidance of English Heritage.

After an entertaining evening lecture by Jochen Guntzel on the destruction of earth buildings by saltpeter scrapers, John Fidler (English Heritage) opened the first day's proceedings explaining that Out of Earth launched several new initiatives including:

• The formation of the National Centre for Earthen Architecture at Plymouth School of Architecture, University of Plymouth for studies and training in earth construction and its repair; and for research into the history, decay, conservation and contemporary use of the material;
• The formation of the ICOMOS-UK Earth Structures Committee to foster awareness, interest and study of historic earthen architecture and its conservation;
• An English Heritage travelling exhibition on the Out of Earth theme which highlights the wealth of earthen buildings in the British Isles, the issues threatening their survival and actions being taken to ensure the conservation and continued use of this important building material.

Peter Child gave a well-illustrated talk on the history of cob buildings in Devon where structures are known to survive from the 13th century. Both the number and diversity of earth building types in the region are exceptional. Earth has been used for buildings ranging from humble barns to middle-size gentry houses, thus demonstrating the flexibility and appeal of the material. This diversity in typology continues through Dorset and Hampshire. Robert Nother, speaking of Dorset, described similar building techniques to Devon, while Gordon Pearson illustrated a wide range of techniques using the chalk occurring in Hampshire. Precast chalk blocks were used extensively in domestic walling during the 1920s and 1930s, in addition to the earlier examples, particularly from the 18th century.

The use of clay blocks (lump) characterizes the building of East Anglia presented by Dirk Bouwens. In this region, the earth walling is often clad with other materials, making it particularly difficult to identify. Bouwens paper described his experience in repairing clay lump, giving sound advice on conservation methodology. Moving north into Lincolnshire, John Hurd spoke of the regional construction techniques known as "mud and stud" in which a timber armature is used to improve the structural performance of the walling. Sadly, only 200 examples of these buildings survive, thousands having been destroyed by agricultural reformers of the early 20th century.

Travelling northwest, Peter Messenger presented a paper on the clay dabbins of Cumbria. In this region, walls are erected from shallow lifts of clay with straw sandwiched between. Messenger explored the reasons for this unusual technique, illustrating the few examples which have survived.

Bruce Walker had the unenviable task of providing an overview of Scotland and Ireland, an enormous geographical area rich in earth building. Several construction techniques are found, each described in Walker's paper complete with variations on the regional terminology used by the Scots and the Irish. Walker also emphasized the extensive use of earth mortars and renders to be found in Scotland as well as other parts of the British Isles.

The final paper on regional techniques was delivered by Geralt Nash who spoke of Welsh "clom" buildings, a technique similar to cob.

Turning to conservation, Ray Harrison spoke about Bow Hill, a medieval manor house in Exeter under the care of English Heritage. Built partly of cob and daub, Bow Hill has provided a test site for investigation of materials and technique. A second conservation project, Town Farmhouse, Gittsham, Devon, was presented by the architect Paul Bedford. Both demonstrated the consideration given to the repair of earth buildings in Devon.

The first day of the conference concluded with some presentations from outside the UK. Milos Cseri presented the earthen architecture of Hungary where earth was a primary building material up to the middle of the 20th century. Cseri described construction techniques similar to those found in the British Isles as well as recent success in the reintroduction of earth for contemporary buildings. John Sargent concluded the proceedings with some illustrations of defensive earth villages in China.

The intention of the second day was to explore the contemporary use of earth as a building material. Since there has been relatively limited new earth construction in the UK, the day relied heavily on overseas speakers. Hugo Houben (CRATerre, Grenoble, France) began the proceedings with a comprehensive overview of worldwide developments in earth construction. Gernot Minke provided a more personal illustration of recent projects utilizing earth construction. Both experts made a convincing case for the contemporary use of earth with its associated environmental benefit and exciting design possibilities. Other talks included Leticia Achcar's illustration of the "ECO house" constructed by a student group in Sweden and Sumita Sinha's presentation of various projects utilizing earth blocks in France. Jackie Wilkinson spoke of Australia's continued use of earth building techniques while Kevin Drayton illustrated recent examples of earth- sheltered building in England.

The second half of the day was devoted to a discussion of recent initiatives in earthen architecture both in Britain and abroad. Alejandro Alva and Jeanne Marie Teutonico presented the ICCROM/CRATerre-EAG: Gaia Project including a discussion of the Gaia Project Research Index. Hugo Houben described the work of CRATerre, the International Centre for Earth Construction in Grenoble, France, which has been active in the field for more than 20 years. Closer to home, Larry Keefe spoke about the Devon Earth Building Association; Linda Watson outlined the objectives of the newly formed Centre for Earthen Architecture at the Plymouth School of Architecture; and Gordon Pearson and John Hurd introduced the ICOMOS-UK Earth Structures Committee.

At the end of the afternoon, speakers and delegates broke into small workshop groups to discuss future strategies in various sectors. These sessions resulted in a set of conference recommendations under the thematic headings of Research, Training, Documentation, Consultancy and Communications which will help to guide the activities of both the Centre for Earthen Architecture and the ICOMOS-UK Earth Structures Committee. A post-conference tour visited significant earth buildings in Devon including a stop for afternoon tea with Alfred Howard, a master cob builder who has recently constructed an impressive extension to his own house in cob.

Delegates agreed that the conference had been of immense value, both in terms of content and of developing a network of colleagues involved in the conservation and construction of earth buildings. A second national confer- ence will be held in 1995. Conference papers are available from: Linda Watson, Centre for Earthen Architecture, University of Plymouth, Hoe Centre, Notte Street, Plymouth PL1 2AR, England, UK. tel: 44-752-233630 to whom enquiries should be addressed for details of price and shipping.

RUINS AND PLASTER STABILIZATION PROGRAM: FORT UNION NATIONAL MONUMENT AND FORT DAVIS NATIONAL HISTORIC SITE

Southwest Region, National Park Service, U.S.Department of the Interior, Project Director: Jake Barrow, Senior Exhibit Specialist

The Architectural Conservation Laboratory of the University of Pennsylvania and the Southwest Region of the National Park Service are currently completing a three-year program of laboratory and field research focused on the conservation of lime plasters in earthen ruins at two National Park Service sites in the American southwest: Fort Union National Monument and Fort Davis National Historic Site. Based on the promising results of the past two years of this program and the emergency work still required at these sites, the field program will continue in 1994. This project has resulted in the long-term stabilization and presentation of the wall plasters within these ruins, and has provided training for National Park Service staff and graduate students from the University of Pennsylvania as per the established Cooperative Agreement.

Based on the completion of the first phase of laboratory testing on the design and performance of various hydraulic lime-based grouts and the experiences from the 1992-93 field work, the following coordinated stabilization program has been developed for the plain and painted plasters at Fort Davis and Fort Union.

1. Documentation of extant surface materials, i.e., paints and plasters, and graphic conditions survey using acetate overlays on 8 x 10 black and white prints. All treatments, temporary and permanent, have been recorded using this system.
2. Temporary emergency stabilization of plasters and paints using tissue and textile-facings with polyvinyl alcohol in water as the adhesive and wet- strength tissue and cotton gauze for added strength.
3. Reattachment and compensation:
   • Dry and wet cleaning to remove surface dirt and biological growth using scalpels and 1% Triton detergent;
   • injection grouting and reattachment of detached plasters with hydraulic lime, fine silica sand, ceramic microspheres and an acrylic emulsion admixture with defoaming agent (see below);
   • crack filling and edging of plasters with hydraulic lime, sand and a small amount of earth for color matching to exposed scratch or finish coat;
   • reattachment of flaking paint on plaster and wood and consolidation of powdering paint with Acryloid B72 (3-5% in xylene/toluene 1:1) applied through tissue facings.

A condensed description of the technical program recently was published in CRM (Volume 17, No. 4) 1994 and will appear in full in the new journal, Conservation and Management of Archaeological Sites.

AN EVALUATION OF GEOTEXTILE SHELTERS: FORT SELDEN, NEW MEXICO

In the last newsletter of the US/ICOMOS Committee on Earthen Architecture ("GEOTEXTILE SHELTERS: FORT SELDEN, NEW MEXICO," Number 9/10, 1993), the author described geotextile shelters which were installed at Fort Selden State Monument to protect the adobe wall remnants at that site. In summary, two decades of stabilization efforts have offered only marginal solutions to the preservation of the walls which have remained exposed in the 100 years since the abandonment of the desert outpost. It was predicted that unless an effective form of intervention is employed little will remain of the standing architecture within half a century.

Based upon successful experiments with geotextile wall covers by the Getty Conservation Institute and the National Park Service, 592 linear feet of walls at Fort Selden were covered with woven polypropylene geotextiles to protect them until a long-range plan for site interpretation and preservation is developed. In addition a visitor survey determined the public's acceptance level of the wall covering.

A three-person crew installed the geotextile shelters in December-February 1992-1993 at a cost of $15,000, including materials. Two types of geotextile were utilized: Mirafi 600X and 700X (Products of Mirafi Inc., Charlotte, North Carolina, USA). The sheltering systems were designed by the Fort Selden State Monument staff. After a year and a half of exposure to the harsh desert environment, the 700X product has begun to deteriorate, and some sections of it have been removed. The 600X product, which is a tighter weave than the 700X geotextile, is still intact. The fabrics contain carbon black to retard solar degradation.

Protective systems include wrapping the fabric around wall segments.

Wall Wraps: Smaller segments of walls were wrapped with the protec- tive fabrics and stretching the fabric over wooden frameworks.

Fasteners designed for use with geotextiles attached nylon lines to the polypropylene fabric to hold it in place (Grifflyn Clips manufactured by Reef Industries, Houston, Texas).

In limited cases the fabric has abraded protruding areas of the walls. However, the abrasion is minimal and wall loss is most likely less than could be expected by natural erosion.

While moisture penetrates the walls wrapped with geotextiles, apparently there is little damage to the historic adobes. When the walls dry out, they are seemingly unchanged. The fabric alleviates problems associated with damage from the physical impact of rainfall upon the fragile historic walls.

Rigid Frameworks: Because frameworks were constructed over some of the larger sections of walls, and the geotextiles were stretched over the framework to form a tent-like structure, the fabric does not come in contact with the walls. In these cases, water that penetrates the polypropylene fabrics runs down the inside of the shelter in a similar manner to moisture on the rainfly of a tent. Virtually no moisture gets to the walls.

The fabrics also protect the walls from windborne abrasives which blast the historic fort during the spring sandstorms.

Visitor Acceptance: The perception that such a radical initiative would be totally unacceptable to visitors has prevented the utilization of this form of site protection. To ameliorate the striking visual alteration to the site the following sign was installed to explain the preservation attempts for the public:

FORT SELDEN PRESERVATION PROJECT
It's no small thing to outwit time.

Fort Selden was abandoned on January 20, 1891, after 25 years of service. The fragile adobe walls then began to return to the earth. For almost a decade the Museum of New Mexico and the Getty Conservation Institute have been conducting extensive experiments in an attempt to preserve the exposed adobe walls of the historic post. To date, the search for the magic elixir of adobe immortality has proven to be as illusive as the fountain of youth. The experimental procedures will continue, but right now we are faced with the reality of the loss of the post.

Based upon the present erosion rate, there will be virtually nothing of Fort Selden in 50 years. The only known way to preserve the walls is to isolate them from the deleterious effects of the environment, some of the walls are covered with synthetic fabrics to provide temporary protection until a long- term solution is reached.

Your comments and suggestions are welcome. Please see the ranger for more information.

1. Allow the ruins to follow their natural path of deterioration (21 responses).
2. Deposit the fort in the bank for future generations by covering it with earth (10 responses).
3. Establish a permanent maintenance crew and plaster the walls on an annual basis (54 responses).
4. Save the fort at any cost! Construct structures over the ruins (80 responses).
5. Selectively implement all of the above (83 responses).

REFERENCES
Agnew, Neville. "The Getty Adobe Research Project at Fort Selden I. Experimental Design for a Test Wall Project", 6th International Conference on the Conservation of Earthen Architecture, Adobe 90 Preprints. The Getty Conservation Institute, Los Angeles, 1990.

Barney, Joseph. Sales Representative for Contech Construction Products, Inc. National Manager, Green Industry Sales, Belle Vernon, Pennsylvania. Letter to Thomas Caperton dated: July 18, 1992.

Caperton, Thomas J., "Fort Selden Ruins Conservation", 6th International Conference on the Conservation of Earthen Architecture, Adobe 90 Preprints. The Getty Conservation Institute, Los Angeles, 1990.

Caperton, Thomas J., "Geotextile Wall Shelters: Fort Selden, New Mexico", International Council on Monuments and Sites, United States Committee on Earthen Architecture (US/ICOMOS) Newsletter Number 9/10, 1993. Washington, DC

Caperton, Thomas J., "Long Term Preservation Issues Related to Earthen Archaeological Sites", 7th International Conference on the Study and Conservation of Earthen Architecture, Direcao Geral Dos Edificios E Monumentos Nacionais, Silves, Portugal, 1993.

Caperton, Thomas J., "Cultural Heritage and Exploitation In the Land of Enchantment, Visitors Studies: Theory, Research, and Practice." Vol. VI. Collected Papers from the 1993 Visitor Studies Conference, Albuquerque, NM. Jackson, AL: Visitor Studies Association Publishing.

Coffman, Richard, and Selwitz, Charles, and Agnew, Neville, "The Getty Adobe Research Project at Fort Selden - II. A Study of the Interaction of Chemical Consolidants with Adobe and Adobe Constituents," 6th International Conference of the Conservation of Earthen Architecture, Adobe 90 Preprints. The Getty Conservation Institute, Los Angeles, 1990.

Cohrs, Timothy and Caperton, Thomas J., Fort Selden, New Mexico. Museum of New Mexico Press, Santa Fe, 1993.

Selwitz, Charles and Coffman, Richard and Agnew, Neville, "The Getty Conservation Institute Adobe Research Project at Fort Selden III: An Evaluation of Chemical Consolidants to Test Walls", 6th International Conference of the Conservation of Earthen Architecture, Adobe 90 Preprints. The Getty Conservation Institute, Los Angeles, 1990.

TOWARDS A WORKABLE PRESENTATION THEORY FOR VERNACULAR ARCHITECTURE

Despite the poetic appeal, the romantic sentiment and a tendency towards philosophic conservatism, the principles of preservation theory outlined by Ruskin, Philippot, the Secretary of Interior's Standards and the Venice Charter all ring a bit hollow and anachronistic when read with vernacular architecture in mind. We in the preservation community need desperately to provide ourselves with a set of conservation guidelines, one that may be applied to the unfathomable huge, diverse and serviceable inventory of historic buildings which must, in order to maintain their importance and viability, remain in the use of whatever constituency they serve. We need to distinguish them from the erudite, and judge them by a new set of standards that allows preservation through change. The alternative is to watch as they are turned into static reminders of communities whose demise has been accelerated by a misdirected effort to preserve the built environment.

We in New Mexico have for eight years been designing, and for the last five implementing, a program which helps our rural communities save their historic churches. We have tried to conform to the most conservative of preservation standards, but have failed on two levels: first, because we found that we cannot force compliance of living, vital structures to a litany of standards that were not written with them in mind; second, and more poignant, we have verged on betrayal of our stated goal of helping preserve the culture and thus maintain the viability of the communities which inherited the buildings and use them every day. For these communities the buildings are meaningless if stripped either of their ability to function according to community needs, or to reflect the character of the living population.

Historic churches in New Mexico serve a multiplicity of functions and reflect a broad spectrum of values. They are used regularly as houses of worship and exemplify the spiritual lives and values of their parishioners. As community centers they shelter the gathering of villagers to assess, discuss and ratify issues of common interest, such as the maintenance of acequia systems and common lands. In this light, their value is economic. In some cases, the churches historically doubled as fortresses; in the precedent Latin culture, they were sanctuaries for fugitives, and the concomitant value is the protection of life. Ultimately, the churches stand as monuments to a whole cultural experience; they are the visible symbols of the history, the corporate values, the lives of the people who use them. In this case the overweening value is associative; they represent a living heritage.

We have found it untenable to apply, for example, the Philippot Criteria to such a range of uses and values without embalming one or more of the uses and values themselves. For these buildings, the Venice Charter's "message from the past" is spoken in every word, thought and deed that occurs in a building which is a cultural vehicle for a living people.

New Mexico is not unusual in harboring a unique and beautiful assemblage of historic, vernacular, functioning buildings. Every corner of the occupied globe is dotted with historic churches, mosques, schools, synagogues, shrines, homes, factories and taverns. They not only define the character of the culture surrounding them, they are vital components in its preservation. This class of buildings have historically reflected change in the community and should continue to do so without being denied the recognition and economic assistance that is vital to their survival. That assistance should not be based on one uniform policy of compliance.

I propose to US/ICOMOS that we convene all interested parties to discuss the formulation of a new philosophy of preservation which will embrace the vernacular. As topics for discussion, I suggest that we work:

• To reach clear definitions that distinguish between erudite and vernacular architecture;
• To acknowledge that standards written for erudite architecture are problematic when applied to vernacular buildings;
• To accept that the preservation of a living culture, surrounding and using the buildings, is fundamentally more important than the buildings themselves;
• To acknowledge that all periods of use of historic vernacular buildings are inherently important, including present and future ones;
• To outline a charter setting forth standards for the preservation of vernacular architecture.

EL CUARTEL, PRESIDIO DE SANTA BARBARA (CALIFORNIA)

The Presidio of Santa Barbara in Alta California was founded in 1782. However, the original, rough version of the presidio was rebuilt as a sound adobe brick-walled structure in 1788. Its construction was based on a plan drawn up on the orders of the commandant, Felipe de Goycoechea. This plan, dated September 16, 1788, showed the Presidio in the state of construction, with the fourth side (or lienzo) still to be completed. This fourth side was the portion that housed the families of the soldiers of the Presidio. Of this line of one-room dwellings, only one dwelling and about a half of the adjoining one remain intact. This structure is believed to be the second oldest one remaining in Alta California.

Following the military abandonment of the Presidio in the mid-1840s, the houses were given over to various old soldiers and their families. In the case of the structure that came to be called El Cuartel, it came into the ownership of José Jésus Valenzuela. It subsequently remained in the Valenzuela family until 1925 when it was sold to others and became an artist's studio, a Boy Scout headquarters and a bookstore.

El Cuartel is 41'4" (12.6 m) long by 18'2" (5.54 m) wide. The walls are approximately 3/4 of a vara (24.75 inches or 0.63 m) thick. They are supported by a foundation of sandstone boulders that extends above ground surface. It is composed of two rooms. The larger, complete room has interior measurements of 24'7«" (7.51 m) long by 14'4" (4.37 m) wide. This is a close approximation of the dimensions of 9 varas (7.54 m) by 5 varas (4.19 m) stated on the Goycoechea plan.

In the course of its 206 years of existence the adobe has undergone at least four major earthquakes (1806, 1812, 1857 and 1925), plus a number of renovations that involved cutting out and filling in various doors and win- dows. In addition, it has suffered from cosmetic treatments such as covering the adobe walls with chicken wire and painting over with latex. Concrete has been used to patch up some portions of the walls. In other cases, stabilized adobe bricks have been inserted to replace earlier bricks that had turned to loose earth under the latex. The floor of the structure has been removed and replaced twice by concrete. Plans for this floor removal indicate that the original floor has been dug out to a depth of 13 inches (0.33 m), effectively destroying the original. In addition, the concrete floor has undoubtedly contributed to a destructive rising damp in the walls. A shed addition was added to the west side of the structure sometime before 1886. It was taken down and replaced with a larger attached addition c. 1925.

Despite all of the above, it is assumed that there is much integrity left in the building and that a careful architectural and archaeological examination of the building and the surrounding grounds will provide invaluable informa- tion to be applied to the ultimate plan for reconstruction of the Presidio de Santa Barbara. So far, in addition to archival research on the Presidio, and particularly, El Cuartel, a detailed photographic study of the building has been seconded by a set of architectural elevation drawings of all the interior walls. A limited amount of archaeological excavation has revealed information about the foundation and the historical level of the Plaza de Armas.

CHRONOLOGY OF HISTORIC ADOBES AT PECOS NATIONAL HISTORICAL PARK

Through a partnership of ruins preservation, archaeological and historical investigation in the 17th and 18th-century Spanish church and convento at Pecos National Historical Park, near Santa Fe, New Mexico, a typology of original adobes and mortar has been established. Although based primarily on visual and compositional differentiation, the typology has been refined to the point where specific adobe types can be attached to the Pecos chronology, thus enabling researchers to gain a clearer picture of the architectural construction sequence.

Since 1992 archaeological documentation of historic adobes and mortar in the church/convento complex at Pecos has been conducted as an integral function of the park's annual ruins preservation program. In the early 1970s much of the original Spanish fabric was encased in stabilized material. As maintenance on this material proceeds, documentation of exposed original fabric takes place. This documentation, completed primarily in hand-maps and still photography, has proceeded on a room-by-room, wall-by-wall basis according to the priorities set by the Park Archaeologist.

Observations of original fabric have led to a basic dichotomy of adobe and mortar types in the complex: black bricks and associated mortar are tied to the first phase of construction, while red adobes and mortar are tied to the next three major phases of construction. While the initial dichotomy was made on the basis of visual differentiation, pollen and flotation analyses have confirmed it. The source, they indicate, of the black bricks is in the prehistoric trash deposits of the nearby pueblo, while the source of the red bricks is not.

In addition to the basic dichotomy, the red adobe typology has been broken down into six subtypes, each corresponding to a construction phase in the complex. For example, the presence of white plaster bits in the mortar of a wall known to be built during a period of remodeling might indicate the recycling or reuse of plastered adobes from an earlier phase of construction, a supposition that is being borne out by compositional analyses.

During the Spanish period four churches were built at Pecos. The first was apparently constructed of yellow adobe, though it has not been sampled yet. The second church was built of the same black adobe that was used to construct the convento. The third and fourth churches were built of red adobe, though mostly of a type unassociated with any red brick observed so far in the convento.

Of the three phases of historic construction in the church/convento complex that utilized red adobes and associated mortars, the first directly followed the cessation of black adobe use, the second followed the reoccupation of Pecos by the Spanish in 1694, and the third involved the raising of the fourth, or last, church at the site. Each adobe type related to this chronological sequence is distinguishable from one another.

A summary of the relationship between adobe typology and chronology at Pecos looks like this:

Yellow adobe                pre-1620       First Church

Adobe Types Ia and Ib black
and Mortar Type 1-3         1620-1640(?)   Second Church

Adobe Types IIa-b red                      2nd Story of
and Mortar Types 4-5        1640(?)-1680   Convento

Adobe Types IIc-e red
and Mortar Type 6           1694-1704      Third Church

Adobe Type III red
and Mortar Type 7           1705-1800(?)   Fourth Church

RECENT ACTIVITIES IN EARTHEN ARCHITECTURE AT THE UNIVERSITY OF NEW MEXICO

The grant from the National Endowment for the Arts, Design Arts Program, for the study of the Durability of Adobe Plasters, was completed the end of June 1994. This demonstration study was a combination of laboratory analysis in the Department of Earth and Planetary Sciences of The University of New Mexico and fieldwork with the Churches, Symbols of Community! program of the New Mexico Community Foundation. The fieldwork included oral history interviews and working on plastering at the program's sites. Ed Crocker and Dr. M. Susan Barger did six oral history interviews and Barger analyzed ten plasters during the project period. The findings of the study indicate that there are two general types of mud plasters within the sample set analyzed: ones that have natural limes added to the mix and those that have a large amount of organic material (with particle sizes of two micrometers or less) added to the mix. Both of these types of plasters have cement-like hydration products that form in the plasters during aging. This project was described in the Australian Broadcasting Corporation's science magazine program Quantum in October 1993. Currently, additional funding is being sought to carry on a more in-depth study of the materials chemistry of mud plasters of Northern New Mexico.

In addition, the School of Architecture and Planning will be opening the Arid Americas Research and Design Center during the academic year 1994-1995. This new interdisciplinary center will coordinate all research in the University of New Mexico that is concerned with the built environment and the arid regions of the Southwestern United States and Northern Mexico. A part of the mission of the Arid Americas Center will be related to earthen architecture for this region and also to preservation issues. The organizers of the Center are Dr. Barger and Chris Wilson.

THE ARCHAEOLOGICAL APPLICATION OF INVESTIGATIVE METHODS AT CAHOKIA MOUNDS

More than 100 earthen mounds have been documented at the Cahokia Mounds State Historic site, a Mississippian period (ca. AD. 1000-1400) mound center located in southwestern Illinois, yet the site bears few visible traces of this construction process. Its impressive arrangement of mounds and plazas presents a finished facade, largely concealing the extensive earth moving efforts involved in creating this paramount Mississippian center.

As part of current research at the site (Dalan 1993), a unique approach for investigating earthen architecture and anthropogenic earth moving efforts has been developed. This approach involves several complementary methods, including the use of surface electromagnetic conductivity and electrical resistivity surveys and the application of environmental magnetic techniques to collected soil samples. Supplemented by topographic mapping, soil- chemical analyses and limited test excavations, the geophysical methods can be used to investigate not only surface expressions of earth moving activities (i.e., the mounds and open borrow pits), but to also examine subsurface evidence for borrowing, leveling and reclaiming. At Cahokia, this suite of methods has been employed to locate and document the depth and character of refilled borrows and reclaimed ground, to investigate mound structure and pre-mound preparation activities, and to determine source materials used in mound building and in the filling of off-mound areas.

Though these methods have been developed and applied in diverse fields, they have not been combined previously in an integrated study to deal with this important archaeological problem. They comprise a powerful package, and one that is relatively rapid, non-destructive, and cost-effective, for investigating the process of earthen construction and landscape change.

Dalan, Rinita A., 1993. Landscape Modification at the Cahokia Mounds Site: Geophysical Evidence of Culture Change. Ph.D. dissertation, Center for Ancient Studies, University of Minnesota. University Microfilms, Ann Arbor.

Early aspects of this research may also be found in the following publications:

Dalan, Rinita A., 1991. Defining Archaeological Features with Electromagnetic Surveys at the Cahokia Mounds State Historic Site. Geophysics 56:1280- 1287.

Dalan, Rinita A., In Press. Issues of Scale in Archaeogeophysical Research. In Effects of Scale in Archaeological and Geoscientific Perspectives, ed. by J.K. Stein and A. Linse. Geological Society of America Special Paper 283.

Holley, George R., Rinita A. Dalan, and Phillip A. Smith, In Press. Investigations in the Cahokia Site Grand Plaza. American Antiquity 58.

CONTINUING RESEARCH ON THE DEVELOPMENT OF A COMPOSITE TREATMENT FOR PRESERVING HISTORIC ADOBE

The field work at Fort Selden, directed to finding ways to stabilize its historic walls, has continued. In the last Newsletter (9/10, 1993), we described a four-step composite procedure for stabilizing historic ruins walls while retaining the natural appearance of the structure. In this set of steps, the wall is first brushed free of loose material and then spray- impregnated with ProSoCo's Stone Strengthener H (SSH) which is a mixture of monomeric alkoxysilanes. The next two steps involve aqueous systems, muds made from sand, clayey soil and a water-based acrylic emulsion instead of water. The emulsion is based on Rohm and Haas RE330, an amine containing acrylic terpolymer. The polymer modified mud is used to build a water- shedding crest running along the top of the consolidated wall. When this is dried a thinner version of the mud is applied over the entire structure, using a stucco type sprayer to provide a veneer that retains the color and the pattern of the original wall. Finally, this product is treated with a spray of a poly(methylhydrosiloxane) in mineral spirits to impart water repellency. The four test sections treated in this manner have come through a second winter in Southern New Mexico without observable deterioration and in good condition.

Over the past year, we have examined the use of poly(ethyl silicate)s instead of SSH for the initial consolidation because the polysilicates are much lower in cost. Our studies were based on the work of Giacomo Chiari, who has had more than 20 years of successful results using this material for stabilizing adobe (Adobe 90 Preprints, page 267). Silbond-40, a product of the Silbond Corporation, is 70% poly(ethyl silicate), 27% ethyl silicate and 3ø/O ethanol. This relatively nonvolatile and nontoxic liquid has a viscosity of 3.9 centistokes at 25øC, which is significantly higher than the 0.8 centistokes of SSH. Nevertheless, when Silbond-40 is dribble-sprayed over Fort Selden adobe ruins, 300 ml is readily absorbed in a one-square foot area without runoff to provide penetration to a depth of 20-25 millimeters. Curing, which moves gradually inward from the surface, is slow without a catalyst. With daytime highs ranging from 80-90 F, only about 5 millimeters of hardening were found after 3 weeks. Methyl borate is an effective catalyst and at an optimum level of 2%, curing is complete in two days. A second application of 300 ml of Silbond-40 containing 2% methyl borate over a previously treated one-square foot area gave further penetration to depths of 40-45 millimeters but curing at these inner levels was slower. The use of higher concentrations of methyl borate, 5-10>Mo, led to cracking. The walls were subjected to an intense hail storm and chipping occurred in an area that had been treated with Silbond-40 without catalyst, which had only started to harden. This did not happen to treated sections where curing was complete. Further wall tests with these new systems are planned.

REPORT FROM CALIFORNIA POLYTECHNIC STATE UNIVERSITY

Mission San Antonio de Padua, California
California Polytechnic State University conducted its 18th annual archaeological field school at Mission San Antonio de Padua (1771-1834) under the direction of Dr. Robert L. Hoover. Previous research had been conducted on the adobe brick architecture of the married Indian dormitories (1976-78), the soldiers' barracks (1979-83), the vineyardist's house (1984-86) and the communal kitchen (1987-90). From 1991 until 1994, the team has been excavating the shops wing of the mission and, from 1993-94, the orchard wall and neophyte quarters. Samples of adobe bricks from the dormitory and vineyardist's house were collected for floatation and seed analysis.

Today a group of interested citizens would like to create a 5,500 acre national historic park commemorating the encounter and blending of four cultures -- Salinan, Spanish, Mexican and Anglo-American. The proposed park would include prehistoric villages and rock art, the mission complex, various adobe ranchos and the Anglo-American village of Jolon. With the continuing shift in control of many military bases in recent years, the surrounding area of Fort Hunter Liggett may be threatened by development in the form of housing or petroleum prospecting. The virtually pristine historic landscape, the preserved archaeological resources and the important historic role of Mission San Antonio should place it in top priority for preservation.

Mission San Miguel Arcangel, California.
A $5,000 grant from the Stauffer Foundation of Los Angeles has been received by the Friends of Historic Mission San Antonio for a seismic and vibration study of Mission San Miguel (1797). The study will be conducted by Kenneth King, a geophysicist formerly of the U.S. Geological Survey, to determine the effects of adjacent railway traffic and military activities on the church, which contains the best preserved examples of original interior mural decoration of any California mission.

BIBLIOGRAPHY AVAILABLE