SAN DIEGO. — In the department of special collections on the top floor of the at the library of the University of California, San Diego, a visitor can move his hands over soft vellum binding, the untanned skin of calves who lived hundreds of years ago. Here and there, you can see small holes were insects dined long ago.
Opening these books, a Latin Bible printed in 1486 and ''Pliny's Natural History,'' printed in 1483, one would expect the pages to be brown and brittle, but they are as astonishingly white as the day Columbus left port. Today, we know the world is round. Yet, on the next floor down, the pages of 2-year-old hardbacks are crumbling from age.
''Until the mid-19th century, most paper was made of recycled rags, often old linen or cotton clothing,'' explains Lynda Claasen, UCSD's special collections director. ''Then paper manufacturers switched to high-acid wood pulp. As a result, an average hard-back book may last only 10 or 20 years on a library shelf.''
The Library of Congress says about 77,000 more of its books become endangered every year. In the near future, 40 percent of the books in America's largest research collections will be too fragile to handle.
One solution might be to switch media -- copy the culture's memory onto computer tape, videotape, optical disks. But that would be like fighting fire with gasoline.
Floppy disks will last five or 10 years in, say, an air-conditioned office, says John Mallinson, UCSD's magnetic recording research chief, who sits on the Ad Hoc Committee on Preservation at the National Archives. ''Computer-tape drives first used seven track tapes, then came nine-track tapes,'' he says. ''Currently the tapes hold 18 tracks. Of course, none of these is compatible with the others.''
Since 1956, there have been 32 videotape formats, each unplayable by the succeeding technology. Each day, television networks send the National Archives videotapes of the day's prime-time news programs.
''These tapes, in a Sony three-quarter-inch U-matic format, have been piling up since 1974,'' says Mr. Mallinson. ''You don't have to be an electronics marvel to understand that one day Sony will declare that format obsolete. When they do that, hundreds of tapes will become unusable.''
Because of this rolling obsolescence, every decade or so archivists will have to make a massive transfer of information to whatever new format has become popular. That soon will be an unwiedy proposition.
The Defense Department, Mr. Mallinson says, stores Korean war records on old seven-track computer tapes. These records, which may contain fascinating historical information, could be transferred to newer, readable formats, but only at enormous cost.
Six years ago, Mr. Mallinson and his associates recommended that information not be stored in machine-readable records unless the National Archives was prepared to make extraordinary budgetary outlays -- 10 years or more in advance -- to transfer it to whatever new recording form comes in vogue.
''Our advice has not been taken,'' says Mr. Mallinson.
In lieu of such a budgetary commitment, Mr. Mallinson recommended that the National Archives not accept any machine-readable information that hasn't also been copied to a human readable form, such as good paper or microfilm.
That advice was not taken, either.
The National Archives do periodically transfer information to new media, including a massive project to copy crumbling books to microfilm.
''But we don't budget for this 10 years in advance,'' says Alan Calmes, Archives preservation officer. ''We're lucky to project three years in advance.''
As for the recommendation that the National Archives keep backups of computer-readable information on microfilm, Mr. Calmes says, ''some people don't feel it would be very useful; they're not as interested in long-term preservation as they are in immediate user access.''
Maybe the disappearance of some information is a hidden blessing. Maybe God's just playing editor. But it does make BTC sense, considering the perils of techno-fixes, to put more effort into improving paper.
One expensive approach is to de-acidify existing books. France and Canada devised one process that makes old books more youthful, but also releases ozone-depleting chlorofluorocarbons. The Library of Congress, NASA and a Houston company have pursued another technique.
Unfortunately, the first books tested blew tested blew up.
So the most important long-term goal, according to Terry Allison , UCSD library preservation officer, will be to reverse the production of high-acid wood pulp in paper. ''When paper manufacturers ran out of rags in the last century, they turned to wood pulp,'' says Mr. Allison. ''Using a new chemical process, long-life, acid-free paper can now be produced from wood pulp for not much more expense than the present cost of high-acid paper.'' And the process produces far less pollution.''
The chief hurdle: encouraging the paper industry to retool. That will take place only with considerable consumer pressure. So the American Library Association is encouraging authors to pressure their publishers to use acid-free paper. Some publishers are doing so.
What can a consumer do? Next time you're at the bookstore, vote with your wallet for acid-free paper.
Richard Louv is a columnist for the San Diego Union.