Britannica for Sale

MANY people can remember when their school assignments reached a critical mass of difficulty that pushed them away from lighter-weight research materials toward that most massive of references -- the Encyclopaedia Britannica. The prose was a little thicker, but the layers of detail and learning were rich, a new frontier for the budding scholar.

That experience, apparently, has become rarer in recent years, if you judge by Britannica's sales, which dropped from 117,000 sets of encyclopedias in 1990 to 51,000 last year. The private foundation that publishes them has been losing money on the books for a number of years and recently decided to sell Britannica, hoping for a buyer with the capital to transport the encyclopedia into the information age.

There's irony here, since if any enterprise has a grip on vast amounts of information, it's Britannica. It's all there, right at the fingertips, with all the familiarity and convenience of print. (Or at least it was until the shift, a few years ago, to a confounding system involving ''Macropaedia'' and ''Micropaedia'' -- a move that may have precipitated some of the sales slide.)

Not that Britannica hasn't tried to move into the digital future. Like many of its competitors, Britannica has published a CD-ROM version of itself. But that came out later than other electronic encyclopedias, and it cost about 10 times as much. There's a limit to what computer users will spend to brag they've committed the Britannica to memory, so to speak.

Meanwhile, an on-line service from Britannica is winning belated praise from college users of the Internet. For those able to navigate electronically layered reference works, there's probably no text more hyper than a digitized Britannica.

Perhaps future young scholars will have the same experience as past generations, just in a different medium, with that familiar trade name -- almost synonymous with learning -- still intact. And it is expected that for a very long time to come, they will also have the option of leafing through the leather and paper artifact too, if the on-screen version feels too confining.