By Jeffrey Levin

"Knowledge," said 18th-century English lexicographer and critic Samuel Johnson, "is of two kinds. We know a subject ourselves, or we know where we can get information upon it."

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If he were with us today, doubtless Dr. Johnson would agree that there is no greater single source of information than libraries—particularly our large public and university research libraries. Within their walls is a cornucopia of material, documenting the history and culture of living societies and peoples long vanished. In addition to printed books, everything from illuminated medieval manuscripts and ancient maps to gramophone recordings and early cinema form a part of library collections around the world. Each of these items is a piece of information in the puzzle of civilization.

Unfortunately, as we near the end of the 20th century, a time dubbed by some as "the information age," our major repositories of information are grappling with the substantial problem of preserving enormous collections that continue to grow. The staggering accumulation of items, the range of materials used, and the diverse methods needed to maintain those materials have complicated the task of preserving information. New and developing technologies may ultimately preserve the intellectual content of vast amounts of materials, yet no technology is likely to prove to be the one solution to the multiplicity of problems. In addition, the new technologies themselves raise their own preservation issues, broadening the responsibilities for those charged with their safekeeping.

A Mountain of Material

The sheer quality of materials makes the preservation task daunting. Less than a century and a half ago, the number of volumes in the libraries of U.S. colleges totaled little more than 270,000. The Library of Congress acquired well over that amount in new volumes last year alone.

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The kinds of material housed in libraries goes well beyond books. Indeed, at the Library of Congress books constitute perhaps only a quarter of the collections. Manuscripts, maps, periodicals, microfilm, motion pictures, photographic prints and negatives, video tapes, and audio materials are housed not only in the Library of Congress, but in major public and research libraries around the country, adding to the massive custodial responsibilities of these institutions. As of 1989, for example, the New York Public Library had over 34 million cataloged items.

The storage of materials in environmentally controlled conditions remains a prime concern for library preservation officers, according to Carolyn Morrow, who heads preservation efforts at the Harvard University Library. "I would say that our major challenges are the same as they've always been—to provide a proper environment for our collections, which is a constant struggle, and to decide on our priorities for the preservation of materials since everything that we'd like to be done cannot be done."

Among the priorities for many U.S. libraries is finding ways to cope with brittle books. The problem is the result of changes in manufacturing that occurred back in the mid-19th century when paper began being mass produced on machines that used wood pulp rather than rags. Wood pulp paper has chemical constituents that acidify over time when exposed to oxygen and other elements, and it becomes brittle much more quickly than rag paper.

"You can take two documents—one created 20 years ago and one created 200 years ago—and the chances are the one that's 20 years old is in worse condition," says Kenneth Harris, Director for Preservation at the Library of Congress. "From the late 19th century to the present, the volume of printing increased so greatly that we're faced with a paper mountain, so to speak, of acidic materials, not just in the United States but throughout the world." This unfathomable amount of paper is undergoing inexorable deterioration, a phenomenon commonly described as "slow fires."

Because of U.S. Environmental Protection Agency regulations and certain other changes in the paper industry, the percentage of alkaline paper today manufactured by U.S. mills has risen dramatically. Ellen McCrady, Editor of the Alkaline Paper Advocate (a publication for users and makers of alkaline paper), reports that about 75% of all printing and writing paper now produced in the United States is alkaline, over three times what it was less than 10 years ago.

However, worldwide the production of poor quality acid paper remains prevalent. For example, according to Ms. McCrady, none of the paper presently produced in Russia is alkaline. The pervasive use of acidic paper poses a continuing problem for libraries around the world, including U.S. institutions like the Library of Congress, where over half the book acquisitions are foreign publications. This combined with existing collections of books and other paper material produced in the last 150 years forms a significant deacidification challenge.

If the deterioration of wood pulp paper materials constitutes a "slow fire," the degeneration of collections of other more modern materials such as film and magnetic-based media is considered by some to be a "fast fire." Many of these materials are degrading more quickly than paper, yet the issue has gotten less attention than brittle books.

"It's a big, expensive problem," says Mr. Harris of the Library of Congress. "Right now motion pictures and video recordings have to be recopied every 10 or 15 years. Institutions like this one that have massive collections of these things are not going to be able to afford to copy them [that frequently]. A decade or two from now we're going to have a major cultural crisis on our hands."

Chris Coleman, Library Preservation Officer for the University of California, Los Angeles (UCLA), agrees that not enough attention has been paid to the preservation of nonpaper media. "The major effort has been on printed material," he observes. "Certainly the preservation of sound recordings and photographic material has not been given the attention it should have." The range of materials, he points out, complicates the preservation task.

A concern for motion picture preservation is high in Latin America, according to Susan Benson, Coordinator of Multinational Projects of Libraries, Information & Communication for the Department of Cultural Affairs of the Organization of American States (OAS). The OAS has a film archive project under way in Latin America devoted in part to film conservation training.

"The Latin Americans really care a great deal about films they've produced," says Ms. Benson. "Films may be less taken for granted there than they are here [in the United States]." Cinematecas, or film libraries, can be found throughout the region, and the sophistication of the film conservation effort is proportional to the size of the country's film industry. In Mexico and Argentina much attention is paid to preservation of film. While storage facilities are improving, throughout the region poor storage in the past has resulted in the loss of films.

The issue of storage transcends cinematecas. "The biggest problem in conservation [for Latin American libraries] is poor storage," Ms. Benson reports. A number of national libraries are housed in historic structures that lack environmental controls, and even many newer facilities have not been designed with the needs of collections in mind.

Allert Brown-Gort, Program Coordinator of the Preservation and Conservation Studies programs at the University of Texas in Austin, considers library design to be an important issue for Latin America. "There needs to be some very serious research done on appropriate architecture," he says.

A Mexican by birth who has traveled extensively in Latin America, Mr. Brown-Gort perceives an emphasis in preservation in the region that differs from that in the United States. Latin America is the repository of countless historical documents from the Spanish colonial period dating back to the 16th century. "In so far as institutions think about preservation of their collections," he explains, "they tend to think about that material....The issue [in the United States] is the disintegration of modern research collections." Modern research collections in Latin America receive less attention, he continues, in part because their size is typically less than that found in the United States, and in part because the poor quality of paper used in Latin America has rendered the preservation of books produced during this century extremely problematic at best.

Preservation Options

One approach to the problem of large numbers of brittle books is a mass treatment system called mass deacidification. The process retards deterioration by neutralizing the acid contained in the paper. During the 1970s, the Preservation Research and Testing Office of the Library of Congress developed and patented a mass deacidification method using diethyl zinc (DEZ). Since that time other mass deacidification techniques have been developed not only in the United States, but also in Europe and Japan.

The Library of Congress licensed the DEZ mass deacidification process to Akzo Chemicals, a Houston-based company which in 1987 designed and built a pilot Book Preservation Facility in Texas. Since then over two dozen institutions throughout the United States have sent items to the facility to be treated with the DEZ process.

Among them is the Harry Ransom Humanities Research Center, a scholarly research institution with 19th-and 20th- century Western materials, located at the University of Texas. The Center was the recipient of a grant from the National Endowment for the Humanities (NEH) to evaluate the use of the process on archive and manuscript collections. James Stroud, Head of Conservation at the Center, considers the process to be very applicable to paper records and manuscripts, but more problematic for bound materials which are "much more complex objects."

"We are talking about a process that starts right out dehydrating the materials to about 2% moisture content, which is bringing it down 6% to 8%," says Mr. Stroud. "You set up all kinds of tensions just in the dehydration phase: adhesive bonds can separate, covers can pull loose from boards, boards can warp. Without the binding you just don't have as many problems. I find it eminently more applicable to paper records."

Other university libraries, including those at Johns Hopkins and Harvard, have also made extensive use of the DEZ process at Akzo's Texas facility. During 1992 and 1993, the Harvard University Library mass deacidified approximately 16,000 maps and 10,000 books.

"We're very pleased with the process," says Harvard's Carolyn Morrow. "It's not perfect, but we're very pleased with it."

While use of the Akzo's Texas facility by major research libraries has been growing, that growth apparently failed to meet the company's expectations. In December 1993 Akzo notified the Library of Congress that because of "limited prospects for the adoption of DEZ in the near future," it would be closing the facility in early 1994. The facility's closure would have an extremely serious impact on the ability of research libraries nationwide to deacidify large amounts of material. Discussions are now under way with the company to help them identify a subcontractor willing to continue the facility's operation.

Neither mass deacidification nor any single procedure can be considered the ultimate solution to the problem of brittle books. Because of the monumental number of endangered volumes now housed in the largest libraries of the United States (estimates range as high as 77 million), a multiplicity of approaches will be necessary.

Mass deacidification is designed to preserve both the object and the information it contains. But technology now makes it possible to preserve information apart from the original object. For many librarians today, "preservation" has come to mean saving the intellectual content of an object as opposed to the object itself. In practice this means copying or "reformatting" the material.

The most established and standardized method of reformatting, both in the United States and elsewhere, is microfilming. First used in the 1930s, microfilming was originally utilized to increase access to materials that were not widely held. Only more recently has it been employed as a preservation tool. Today, for example, a book too brittle to sustain frequent handling can be microfilmed, thereby preserving the book's content as well as affording broader access to the information it contains.

Retrieval and handling of microfilm can be more cumbersome than books, and while considered archival, microfilm itself is subject to wear and tear. In addition, it is not a reformatting option for many other media.

One reformatting option of increasing interest to libraries is digital technology. A wide range of materials, from printed pages and photographs to sound recordings and motion pictures, can be translated into laser-readable information and stored on optical disks where material can be copied electronically with no loss of quality. Optical disks provide easy access to the material and unlike other media do not suffer perceptible damage from frequent use. The technology permits originals to be removed from handling and to be preserved in environmentally controlled storage conditions. Among the storage devices utilizing digital technology are CD-ROMs (Compact Disk Read Only Memory) and WORM (Write Once, Read Many) optical disks, which can be recorded on once by the user and cannot be erased.

The potential of digital technology for vastly increased information access and preservation is significant, but problems remain. Equipment costs are expensive, and archival standards for optical disks have yet to be established.

Ironically, in the long term the life span of an optical disk may end up being far greater than the equipment that can read it. Today, the pace of technological change is so swift that machine obsolescence is a regular occurrence. Kenneth Harris, who spent over 20 years at the National Archives before coming to the Library of Congress, says that large institutions with materials on outdated media have to maintain obsolete equipment to retain access to items not reformatted on the latest technology. "At the National Archives and Library of Congress we have literally museums of audio, video, and imaging equipment to reformat materials that have been produced in the last 150 years," he adds. Some experts have suggested that librarians and archivists using digital technology should be prepared to make reformatting digital material onto newer technology a regular part of collections management.

Another solution for books and other paper materials may be doing no reformatting at all, or at least waiting until demand or condition justifies the copying. Improved storage conditions and microhousing of materials can lengthen the life of even brittle books and help postpone the day when reformatting becomes essential for preserving intellectual content. Called "phased conservation" by the Library of Congress, a maintenance program that targets deteriorating material for a variety of microhousing options can "buy time" for items in a way that efficiently utilizes limited resources. (See Phased Conservation Revisited)

Libraries are also seeking to cope with financial constraints by exploring ways to share the burden of responsibility for preservation. For example, by coordinating reformatting programs to avoid excessive duplication of efforts, a broad range of material can be preserved and costs spread.

Making Choices

Ultimately, it seems, library preservation officers will have to astutely employ a multisystem preservation approach that is flexible and relies on a diversity of methods and technologies. An important component of this approach appears to be an expanded use of passive, preventive conservation measures that can preserve objects collectively.

However, even with increasing technological and administrative options for information preservation, major libraries will remain faced with tough decisions as they confront immense and expanding collections.

"Sometimes I feel that a large part of our job is presiding over decay, rather than doing preservation or anything more active," observes Carolyn Morrow of Harvard. "The job is too large, and we have not yet admitted to ourselves the constraints. We're still acting under the assumption that we're going to be able to do it all. We're not making hard choices."

UCLA's Chris Coleman, who worked for many years in public libraries in Britain, sees "a long tradition" of librarians making judicious decisions regarding what should be kept and what should be discarded. This generation, he believes, must be prepared to do the same.

"There's no real need to preserve everything," he asserts. "No one has done that for any of the past high points of civilization. There's no reason to suppose that the 20th century is so absolutely marvelous that everything we've produced should be kept. I don't think we'll be able to, simply because of the largeness of the job and the inadequacy of the funds." That being the case, he says, the losses should be planned and not the result of circumstance. "I would prefer to lose things by making decisions rather than by accident."

Jeffrey Levin is the editor of Conservation, The GCI Newsletter.