If, as Argentine author Jorge-Luis Borges wrote, time "is a fire that consumes me, but I am the fire", audio-visual archivists are the firemen, constantly trying to douse a process of decay that is, because of the laws of the universe, unstoppable. "You can slow down this process or speed it up" says George Boston, a former British Broadcasting Corporation (BBC) engineer and consultant to UNESCO, " but you can't stop it or reverse it."
This image of time as a fire is no longer merely metaphorical for the tens of thousands of hours of silent movies and early talkies shot on cellulose nitrate film. As it ages, nitrate film gives off a toxic gas that spontaneously combusts, creating fires that are impossible to put out -- as a trail of burned out cinemas in the early days of film showed. And even if it does not catch fire, poorly conserved nitrate film gradually turns into a crumbling, brittle block. According to Dietrich Schüller, Managing Director of the Austrian Research Sound Archive, some 80% of nitrate silent movies and half of the "talkies" have been lost already.
So-called "safety film", with its non-inflammable, cellulose acetate base, may not be the salvation it was heralded as being, either. Used almost exclusively since then 1950s instead of nitrate film, and still in use, it also suffers the ravages of time. A chemical reaction called "vinegar syndrome" is already eating into screen classics of the past 50 years.
Even so, acetate film -- and the more recent polyester-based film -- is still the only feasible medium for archives. Digitization of cinema archives will not be a realistic option for several years -- a one-hour feature film needs storage space equivalent to about 1,000 hard disks of an average personal computer. The immediate challenge now is to copy films shot on nitrate before they either explode or turn to dust, at a cost of upwards of $5 per metre for black and white film. Colour classics on safety film from the 1960s and 1970s also need to be copied onto fresh stock. But, at a cost of $40,000 to copy a full-length feature, all but Hollywood blockbusters are probably destined to oblivion, no matter what historical pearls they may conceal.
Although audio and video tapes also deteriorate, like film, there is a further complication -- the machines used to play back the recorded material are becoming obsolete even before the "carrier" (i.e. tape, disk, CD, etc.) deteriorates. "UNESCO carried out a survey in 1995," says Boston. "There used to be 25 manufacturers of 1/4 inch audio tape recorders, each making several models. Now there are only five manufacturers, each with one or two models." Yet most archives recordings can only be played on these fast-disappearing machines.
And digital media, like CDs, are going out of date even more quickly than the older, analogue media. "It's the big headache of our times," says Joie Springer of UNESCO's Information Society Division. "The CD was the archive format of the future, but it is now almost obsolete and is being replaced by the DVD. And even that is not permanent. Every carrier that has been developed is now on its way to obsolescence." So, in 1995, says Boston, "UNESCO held a meeting with audio-visual equipment manufacturers to discuss a "phased pullout", so that we are not left without any machines." The idea is that manufacturers would preserve enough working machines to make sure recordings are not lost because they simply cannot be read any longer. But, adds Boston, "there is an estimated 40 million hours of 1/4 inch audio tape, including the master tapes of most recorded music. It would take about 80 million man-hours to copy. And we have about 15 years before the supply of parts for the machines dries up.
"The situation for TV output recorded on video, he says is "the same, but worse, as far more formats were used". UNESCO's Memory of the World programme nevertheless stresses that the future lies in digitization. Once audio-visual material has been digitized, explains Schüller, it can be stored in digital mass storage systems -- giant juke boxes that can automatically make back-up copies, either as the original deteriorates or as new carriers appear. And with digitization, the content of a recording is divorced from the medium on which it is stored. It doesn't matter if a film is replayed from a hard disk, a CD or a DVD.
For George Boston, though, digitization raises other questions for archivists -- and for the society. "Once we have digitized a work, do we need to keep the original? What if anyone can access any copy of a recorded work anywhere in the world, any time? How many repositories are needed? Does every country need a library of all the world's music?" Which brings us back to the land of Borges, for whom the Universe is just a huge library and its people the librarians.