Cornell Magazine (01/96): A Slow Burn

Cornell's book doctors fight to save the
University Libraries' collections from self-destruction.
by Hillel J. Hoffmann '85

The McGraw Tower bells toll the lunch hour as Catherine Murray-Rust, associate university librarian, leaves her desk at Olin Library and crosses the concourse to Uris. She walks purposefully through the stacks, in search of books for her teenage son's Western civilization term paper. Recognizing the diminutive spines of the Loeb Classical Library series, Murray-Rust stops and pulls a volume from the shelf. The pages crackle as she turns them. Yellow and brown fragments of Cicero fall to the floor. Virgil, Ovid, Pliny-all brittle, too fragile to bear the hands of many more readers. The words of the authors have survived centuries. The printed pages are less than 50 years old.

If written and printed words form our collective memory, then we're losing brain cells by the second. Millions of books, manuscripts and other paper artifacts are destroyed every year, burned slowly, literally, to a crisp-not by fire, but by acidic paper. Almost all paper used in books, periodicals, newspapers, manuscripts and correspondence from the middle of the 19th century to the present day carries the seeds of its own ruin. Acids, chemical leftovers from a flawed manufacturing process, inevitably break down the microscopic structure that gives paper its flexibility and durability.

Across the nation, and now here at Cornell, libraries have mobilized to fight what may be a losing battle against the destruction of paper-based materials. Combining craftsmanship and science, the University Library's Department of Preservation and Conservation is struggling to save the endangered bound and unbound papers of the tenth-largest research library collection in North America.

Library administrators don't expect their collections to live forever. Books begin to deteriorate from the moment of their creation. We think of printed matter as inert, but books and paper are no less perishable than the food in your refrigerator. They just decay less rapidly. Heat, humidity, mold, insects-books and paper share enemies with yesterday's uneaten dinner.

Unlike works of art in a museum, books in libraries are meant to be handled, copied and occasionally checked out. There were 2,017,889 recorded on-campus "uses" of Cornell's library materials in 1993. "Next to the Library of Congress, Cornell is the largest net lender in the nation," says John F. Dean, the preservation and conservation department's director. "You have to be realistic," he admits with a shrug. "You have to remember that books don't stay in libraries. People take them home and subject them to the tender mercies of their breakfasts." Even under ideal environmental conditions, in the gentlest of hands, books and paper are fundamentally impermanent.

But now, thanks to paper's built-in acidity-or what Dean and his colleagues call its "inherent vice"-the preservation and conservation of books and paper artifacts has become an urgent mission. Recent studies of the collections of the Library of Congress suggest that at least one-quarter of its printed volumes are brittle, potentially doomed with one more use. Over 77,000 books per year at the Library of Congress are downgraded from "acidic" to "brittle." Half the books in the New York Public Library and 40 percent of the books in the Harvard University Library are terminally brittle. Dean estimates that between one-quarter and one-third of Cornell's library books and papers would not pass the conservationist's simple embrittlement test: fold a corner of a page once or twice. If the corner breaks off, the paper's next handling may be its last.

The sad story of the tiny, broken, yellowed triangles of acidic paper littering the library floor began 5,000 years ago. The first portable writing surfaces were Mesopotamian clay tablets and Egyptian papyrus rolls. Both were eventually replaced by parchment-thin sheets of sheep, goat or calf skin. Durable and able to hold up to erasures, parchment remained the West's handwriting surface of choice for centuries (3,500- year-old parchment scrolls survive today). Although paper had been made in Asia since AD 105, it did not reach Europe until the Moors brought it to Spain in the 1200s.

Paper is a felted sheet of long, intertwined fibers, created by passing a soupy suspension of fibrous material through a fine screen. After draining away the liquid and removing the screen, a thin mat is left to dry. Hold a magnifying glass up to almost any sheet of paper-the tangles of hair-like strands are easy to see, almost absurdly coarse. The longer the fiber, the stronger the paper. In order to increase the absorbency of paper and prevent the spreading of ink, the tiny holes and valleys between the fibers are filled in with a variety of chemicals in a process called sizing.

The earliest papers were all made by hand and remain marvels of durability. The shelves of the rare book vault in the new Kroch Library are covered with 300- to 400-year-old books printed on beautifully preserved paper, whiter and stronger than paperback books published only 30 years ago. "In my studies of French literature, I find that primary source material from the 17th century is in far better shape than books on the topic from this century," says Carl Kroch University Librarian and Professor of Romance Studies Alain Seznec.

The fibrous building blocks of paper, then as now, are long molecules of cellulose, the basic structural component of the walls of plant cells. Cellulose is a polymer, a large molecule made up of many simple, repeating subunits, like a pearl necklace. Cellulose's "pearls" are molecules of glucose, a sugar; they combine with each other with the loss of one water molecule per sugar subunit to form a linear chain. In plants, cellulose chains are 7,000-10,000 units long.

With the invention of the moveable-type printing press by Johannes Gutenberg in 1450, the demand for more books forced paper makers to seek production shortcuts. Step by step, the quality of paper began to decline. For centuries, the source of cellulose fiber in most papers was pulp made from macerated linen or cotton rags. Improved rag-chewing machines began to shorten cellulose fiber lengths in middle of the 17th century. At around the same time, paper makers began to add alum to the sizing. A chain of chemical reactions facilitated by heat and moisture turns alum into hydrochloric acid. Alum sizings remain in widespread use today, and cheaper contemporary alums are even more acidic than sizing additives of the past.

The disastrous climax of the story of paper's decline began in the mid-1800s with the advent of chemical and mechanical processes for reducing wood into a fibrous pulp. Wood was cheaper and more plentiful than rags, but chemical wood digestion and wood pulverization drastically reduced the average length of paper fibers. Approximately 95 percent of paper-making pulps produced in the United States today are wood-derived. Mechanical wood grinding also leaves lignin, a naturally occurring, acidic chemical, in the pulp. You can see the effects of lignin-rich, machine-ground wood pulp in crumbling newsprint. It's also used to make book paper in the third world.

The short fiber length in paper made from wood pulp is bad enough, and acid from alum sizing, lignin and other sources makes it worse. Acids degrade paper by chemically cutting cellulose molecules; just a few snips here and there along the chain reduces strength and flexibility. Paper weakened by acidity fractures when it folds, like a fresh Triscuit. Eighty percent of the bound volumes in America's research libraries were printed after 1850. That makes four out of every five Cornell library books acidic time bombs, ticking toward self- destruction.

"That deterioration is greatly accelerated by poor environment," adds Dean. "Food putrefies at high temperature and high levels of relative humidity, and so does everything else-and very quickly. For example, for every increase of ten degrees Fahrenheit over normal room temperature, the life of paper is shortened by a factor of five."

Heat, humidity, air pollution and exposure to light all hasten the embrittlement of books printed on acidic paper. High levels of nitric oxide and sulfur dioxide (the chemical precursors of nitric and sulfuric acids) in the air of our major cities may explain the higher proportion of brittle volumes in urban research libraries. But even in clean, rural Ithaca, environmental conditions are seldom ideal. The bursting of water pipes in winter has become as predictable as the flight of geese in the fall. Last winter, broken pipes in Martha van Rensselaer Hall and Carpenter Hall's Engineering Library brought preservation and conservation staffers out of their homes for emergency drying work, fanning wet books on drying racks before mold could begin to grow.

Unlike museum storage rooms, libraries need to be as comfortable for patrons as they are for books and paper. "Mann Library is very hot and dry in the winter, and humid in the summer. Olin is muggy year-round-we have a problem with condensation on the windows," laments Book Conservator Peter Verheyen. "If we wanted to create ideal conditions for the collections, we'd suck out all the air, turn down the thermostat, turn off the lights and lock it up. But that's not our mission."

Books from warm, humid parts of the world are particularly vulnerable, as conservators discovered when they reviewed the Echols collection, Cornell's outstanding and recently conserved collection of Southeast Asian books. "When we surveyed material printed in Vietnam, we found the paper to be extremely deteriorated," Dean recalls. "The paper was very, very brittle. Some was printed as late as 1972, but it would fall into dust when just turning the page."

Not all paper is acidic. Some paper makers make paper with an alkaline reserve. By definition, anything that a chemist would call "acidic" has a pH below seven (the value assigned to a neutral solution). Alkaline chemicals (also called bases) buffer acids, neutralizing their ability to corrode cellulose. An alkaline paper, with a pH over seven, has enough buffering reserves to fight off environmental acidity for centuries.

Believe it or not, alkaline paper costs no more to produce than acid paper. "Unfortunately, most paper manufacturers would have to spend considerable amounts of money to retool their plants," Dean explains. "When only 2 percent of their output is for books, they have little economic incentive." A scarce few publishers, notably university presses (Cornell University Press included), print on alkaline paper-look for the infinity symbol [show one] on the copyright page.

Even for Cornell's Department of Preservation and Conservation, one of the biggest and most comprehensive in the world, the task of saving the university collections from the acid paper holocaust seems almost hopeless. As of June 30, 1994, 5,697,525 books could be found in Cornell's 19 libraries or in nearby storage facilities, along with 211,872 maps and 53,526 cubic feet of manuscripts. Add non-paper materials, and that's a library shelf more than 167 miles long.

Like field doctors at war, Cornell conservators practice triage, sorting patients and allocating treatments to items most in need of care. With limited resources and over a million brittle patients, who gets attention first? Dean has mobilized the department to heal on two fronts: the most precious collections and the most frequently used items.

Cornell has 102 collections that earn the Association of Research Libraries' "conspectus five" status, a rank reserved for collections of the greatest importance to the national bibliography. Most libraries have only a handful. Three floors underground, just beyond the hidden observation cameras in the rare-book reading room, is the entrance to the rare-book vault in Kroch Library. Here, in climate-controlled conditions and almost constant darkness, lie Cornell's special collections: the Echols collection, the only remaining home of many Southeast Asian books; the French Revolution collection, including 45,000 books, 15,000 pamphlets and the manuscripts of Lafayette and Lavoisier; the Icelandic collection, thousands of primitively bound 16th-century volumes; the Anti-slavery collection; the University Archives; the Witchcraft collection; the History of Science collection; the Human Sexuality collection; the Petrarch collection; the Dante collection; the Wordsworth collection-every aisle with ceiling-high shelves of priceless, unique resources for researchers.

Although the staff rejects the notion of any items in the collections being treated as the university's crown jewels ("I think that connotes a certain museum preciousness that is not what we're about," bristles Curator of Rare Books Mark Dimunation), special pieces earn special attention. When the University Library's flagship books and papers need care, they're sent to the department's top artisans, Book Conservator Peter Verheyen and Paper Conservator Tatyana Petukhova.

Verheyen works in a small office in the basement of Olin Library, surrounded by the timeless tools of his craft: bone folders, thick needles, scalpels, wash basins, drying racks, a compression press and boxes of brass type. When books from Cornell's special collections arrive on his desk, Verheyen takes them apart, cleans each page, and then reassembles them with the efficient care of an experienced parent bathing a child. Pages are soaked one by one in warm water, supported by a polyester mesh. Rinse and repeat: "It's like washing a fine silk shirt," he explains. After  cleansing, potentially brittle sheets are bathed in a de-acidifying alkaline solution. Damaged pages are mended with durable, long-fibered Japanese paper. The renewed pages are then pressed to remove excess moisture, dried, resewn onto linen tapes, and, if necessary, rebound. Verheyen makes elegant, custom-fitted cloth boxes for material in need of careful handling.

Trained on Rembrandts, Matisses and Delaunays at the Hermitage in St. Petersburg, Tatyana Petukhova is the department's art-on-paper expert. Her spotless lab at the Library Annex is a short drive from Olin, an apple's toss from the Cornell Orchards. Here Petukhova uses all of her art-restoration and paper-chemistry experience to conserve what seem like irreparably degraded artifacts: fractured 19th-century engravings, weakened by acidic paper; yellowed, hand-colored French caricatures; cloth-backed maps from the 1800s, coated with decaying varnish.

After analyzing paper and pigment under a polarized-light microscope, she must decide whether treatment is appropriate- conservators, like doctors, live by a rigid "do no harm" code. Petukhova can relax paper artifacts in a humidification chamber, moistening objects without touching them. Pieces are often washed on a special table, where suction from below gently pulls a cleansing aqueous solution through an artifact. An alkaline bath neutralizes the acidic paper substrate, and acidic boards and mattes are replaced by new alkaline supports.

The satisfactions of conservation work are not unlike those of a surgeon. "Sometimes I feel in a way like a doctor," says Petukhova. "You create these miracles. You see a piece in very poor condition, badly damaged, and sometimes you think, 'I can't do anything.' Look at this one-it's moldy, brown, deteriorated. And then after conservation, it's alive again."

Verheyen, Petukhova and their assistants work as fast as they can, but conservation treatment of a badly damaged book or paper artifact can take up to a day or two. Although appropriate for special collections and flagship pieces, unit- by-unit cleaning and de-acidification can't keep pace with demand when it comes to the libraries' meat and potatoes: books in the circulating collection. Dean and his staff know that they cannot conserve all the brittle books and papers in the general collection. They also know that they don't have to. Very few of the libraries' materials are in circulation at any one time, and the popularity of books, like courses and hemlines, rises and falls with changing times. Most go untouched for decades.

"The average rate of use for an item in a research library is about once every 50 or 60 years," Dean explains. "Statistically, we know that the only reliable indicator of future use is past use. If something has just been returned, the chances are that someone's going to want to borrow it again. So by directing our efforts at dealing with those materials that are actually used, we feel that we're serving the readers very well."

Every book that crosses the circulation desk is checked for brittleness. Tens of thousands fail the corner-folding test every year. Some new copies are purchased, some are placed back on the shelf to die a natural death, some lucky volumes buy a few more decades of use by getting de-acidified by hand. The preservation and conservation department is also monitoring the potential of mass de-acidification-the chemical buffering of thousands of books and papers at one time in large chambers. But de-acidification cannot cure a brittle book. An alkaline bath stabilizes acidic paper, preventing it from reaching terminal embrittlement, but paper that's weak and crumbling before treatment remains weak after treatment. Books and papers that have reached the point of no return need to be reborn in another form. A Buddhist might call it reincarnation. Preservationists call it "reformatting." For now, most reformatted materials take one of two shapes. Neither is much loved.

A few hundred brittle items each year are made into "preservation photocopies," replaced on the shelf by a carefully photocopied facsimile on acid-free paper. The rest are microfilmed. Although preservation microfilming remains the only reformatting technique that earns the approval of the mainstream library preservation community (film has proven to be extremely durable and cheap), no technology is more reviled by users. Who hasn't cursed, weeping from eyestrain, at microfilm reading machines?

"Microfilm is not a user-friendly medium," admits Anne R. Kenney, associate director of the Department of Preservation and Conservation. "You have to get up and go to a different place to use a machine; typically, offices do not have microfilm readers. The printed version coming off of most of these readers is not very high quality. And the film does not lend itself to research in a number of disciplines-you wouldn't use the microfilm of music scores to play." Kenney realizes that libraries need to find more sympathetic, accessible reformatting technologies. She leads the preservation and conservation department's most innovative exploratory project: in cooperation with Xerox, Cornell preservationists have reformatted more than 2,000 books by transforming their words from deteriorating pages into digital computer files.

On the third floor of Olin, in a room overlooking Uris and West Hill, Michael Friedman and Susan Poucher of the scanning and digitization unit are placing acidic and brittle books from the circulating collections of Mann Library and the Math Library on high-speed scanners. They scan 300 pages, or about one volume, per hour-as fast as a photocopier. Six hundred dots per inch of scanned image are captured and printed (the more dots per inch, the finer and more accurate the reproduction; a normal FAX machine resolves only 200 to 300 dots per inch).

Once the initial scan is complete, preservationists can create a number of different products: a readable, on-screen image for browsing; duplicate books printed on acid-free paper, nearly indistinguishable from the originals; and microfilm. But the end-product that excites librarians the most is one that can't be touched-a digital facsimile that may be accessed, downloaded and printed out over computer networks. Kenney imagines a not-so-distant future when users will search digital research libraries all over the world, pulling material from electronic shelves far from Ithaca, no longer thwarted by closed stacks or limited hours. However, preservationists must first resolve the thorny issues of technological standardization and the relatively short life- span of optical discs, magnetic tapes and other electronic storage media. Is the book dead? Corrupted from within by acidic paper, perhaps soon to be replaced by digital textÉ[insert brilliant, pithy concluding quote from Dean describing lasting value and cultural importance of the book-why they must be saved. A new quote has been solicited, but I'm tired of waiting for it, so I'm sending this to you anyway.]

[SIDEBAR 1:]

HOW TO SAVE YOUR PERSONAL RECORD

Libraries are not the only battlegrounds in the war against the self-destruction of the human record. Many people save the physical manifestations of their memories, their roots: letters, photographs, certificates. Even fairly recent graduates may have noticed that their yearbooks have started to become yellow and brittle. The ravages of acidic paper, compounded by poor environmental conditions, are seldom reversible, but here are a few tips to ensure that your personal and family records live to the millennium and beyond:

Not too hot, not too cold. Books and papers last longest when storage temperatures never exceed 75 degrees Fahrenheit. That means that human preferences for heat in the winter and air conditioning in the summer make the inhabited parts of your home the best place for your personal artifacts. Attics can be too hot. Keep temperatures constant: an unheated room is great, but avoid big temperature fluctuations.

Keep 'em dry. Moisture promotes mold growth and accelerates acid damage. Ideal preservation conditions require relative humidity to stay below 65 percent. Keep books and papers out of the basement, and avoid placing bookshelves too near a shower stall.

Make copies. Some ephemera-photos and newspaper clippings, for example-have such a short life expectancy that you may want to prepare for the worst by taking them to a professional photocopier. Demand archival paper-many establishments carry the good stuff for students' dissertations and other important documents.

Storage technology: shop smart. Many suppliers (Conservation Resources International, Gaylord Brothers, Light Impressions, University Products) make archival containers. Some will fulfill small orders. When shopping for papers, boards, folders or boxes, ask for products that are made from cotton or sulfite wood pulp (not ground wood); are lignin-free; and are marked as "alkaline" or "buffered." Plastic sleeves should be made from polyester film, polypropylene or polyethylene.

Photo care. Use photo corners to hold pictures in albums. Stay away from glue, tape or albums with adhesive under plastic sleeves. Don't put pictures face-to-face, on both sides of an open spread: color photos can stick together if their surfaces touch. Do not let alkaline or buffered paper touch color photographs-use neutral paper.