Cyclotron unlocks secrets surrounding Gutenberg

Gutenberg meets the cyclotron. ''Sounds like the title of a late-night horror show, doesn't it,'' jokes Thomas Cahill, the energetic, owlish director of the Crocker Nuclear Laboratory at the University of California here. Actually, the phrase conveys the essence of a unique collaboration that would bring a smile to C. P. Snow, one of the first to decry the schism between the humanities and the sciences. For the drama of Gutenberg and the cyclotron is the story of a research effort that is employing a machine designed for probing the mysteries of the atom to shed light on the origins of printing in the 15th century.

''So little is known about the early days of printing that there is even debate about the exact role that Gutenberg played,'' explains Richard Schwab, the silver-haired historian who, with Dr. Cahill, leads the multi-disciplinary research effort.

The use of the cyclotron to analyze the ink of the Gutenberg Bible has revealed the step-by-step process of printing and why the ink has mysteriously remained so sharp and clear. The research also helped corroborate what is known of Gutenberg's economic and personal difficulties in printing his Bible. And there is some evidence that the cyclotron could be used to detect fraud in antiquities.

This scientific detective story began in 1977.At a faculty party, Professor Schwab mentioned to Doctor Cahill the difficulty he was having in authenticating old documents. Cahill concluded that a little nuclear physics might help.

As director of an atom smasher that had lost all its government funding, Cahill was open to unusual ways to put his cyclotron to work. The machine produces a beam of protons which can be used to analyze the elemental composition of various materials.

To see if there was any potential for doing this with historic documents, Dr. Schwab sacrificed an 18th-century book. They found that, unlike modern paper, the older rag paper had a distinct elemental profile that varied enough between makers to be useful.

To measure the elemental makeup of a material with the cyclotron, the object is placed in the cyclotron beam. When the particles in the beam strike the target, its atoms give off X-rays of a characteristic energy, which can be identified with a sophisticated detector. By designing this detector so it rests against the paper, the researchers managed to get meaningful measurements when using a beam with a power equivalent to the light from a 100-watt bulb 2 feet away, Dr. Cahill explains.

The process was adapted so that it wouldn't destroy the very books it sought to analyze. The discovery that the cyclotron's beam could be extended out into the air instead of in a vacuum helped. So did putting an X-ray detector as close as possible to the page of the document and pulsing the cyclotron so it generated a beam only when required, rather than steadily.

About the time they were working the bugs out of this system, the interests of the scientist and scholar were piqued by Adrian Wilson, a San Francisco craftsman who still prints books using traditional methods. He asked them if they had analyzed any documents from the early days of printing. They hadn't, but they were intrigued enough to borrow a page from a Gutenberg Bible to put under their ''cyclotronic eye.''

When they did, they discovered something remarkable. Whereas earlier inks were chemically bland, Gutenberg's stood out in sharp relief: It was rich in lead and copper. Perhaps this is why the print on the Gutenberg Bible, which some feel is not only the first but the most beautiful book ever typeset, has remained sharp and clear to this day while the ink on many other old books has faded, the researchers speculate.

Excitedly, the professors began scouring the state for other early typescripts. As they tested a page here and another there, an intriguing pattern began to emerge. Pages from Gutenberg Bibles had a metal-rich ink unlike any other, even from the same period. ''What extraordinary luck; it is almost as if he left a signature,'' Cahill says. It appears that Gutenberg guarded his formula for ink jealously. Apparently not even his associate, a man named Schoeffer, knew; one of his known books was analyzed, and it shows a much lower lead content.

Not only did the analysis detect differences between the ink Gutenberg used and that of other early printers, but findings clearly show even the variation between individual batches of ink which the early inventor mixed. This capability has led to some new insights into exactly how the Gutenberg Bible was printed.

''It clearly shows the organizational genius which Gutenberg, or whoever he was, possessed,'' Dr. Schwab comments.

About a year ago, the Edward Lawrence Doheny Memorial Library in Camarillo, Calif., made the entire first volume of a Gutenberg Bible available for analysis. The researchers measured the chemical composition of the paper and ink on both sides of every page.

The fact that the first several pages and the same number of pages near the center of the volume have only 40 lines per page, while the rest hold 42 lines has led scholars to the conclusion that Gutenberg began the unprecedented printing process with two presses. There is general agreement that he later added more of the hand presses, but there is disagreement on the number of additional presses he employed.

While the Cahill and Schwab analysis of ink patterns is not conclusive, it suggests the following historical reconstruction:

Gutenberg began work with two presses. He was forced to print page by page - rather than printing an entire, four-page sheet at once as is now commonly done - because he could not calculate where the page breaks would appear. Well into the three-year project, the printer got a loan from a financier. With this money he added three, maybe four, new presses.

Near the end of the book, the pattern of printing grows erratic, apparently reflecting the famous printer's growing financial problems. His note fell due before he was finished, so Gutenberg couldn't pay it.

As a result, the financier sued the printer and won. (A description of this suit is one of the few sources of information about Gutenberg's life.) As a result, Gutenberg lost control of the printing project. He apparently departed, taking his recipe for ink with him, because the last several pages of the Bible are printed with a different ink. Perhaps by Schoeffer, who became the financier's partner. Thereafter, Gutenberg faded into obscurity while his ex-associate became the most successful printer of the period.

In addition to the famous 42-line Bible, Schwab and Cahill have found the distinctive metallic ink on several other early doc-uments: the 36-line Bamberg Bible and the first printed forms, the so-called letters of indulgence that granted the recipients direct passage to heaven.

Indeed, reports on the cyclotron analysis are stirring considerable interest in the antiquities world, for it could prove a powerful new tool for detecting frauds. This has created a unique problem for Dr. Cahill. He has people trying to force valuable art works on him. For instance, taped on a file drawer in his Spartan office is a message from a man who wants him to run an analysis on a valuable Rubens painting.

''We've got to be awfully careful, the physicist says, shaking his head. ''There's a tremendous amount of money at stake in this kind of work: What if we say something is genuine, and it's not - or vice versa. Think of the size of the lawsuits!'' The Rubens project will be turned down, he says.

Instead, the pair is concentrating on the early days of printing, known as the incunabula period. They have interested a chemistry student in trying to duplicate Guten-berg's ink, using materials known to be available at the time. And they are trying to interest European nuclear laboratories in using the new method to analyze the many early printed works stored in European museums.

Moreover the efforts of Professors Schwab and Cahill demonstrate how productive the collaboration between the sciences and the humanities can be. Even further, the story of Gutenberg and the cyclotron can serve as a valuable reminder of how much we have slighted our roots while pursuing our future - and how far the use of scientific techniques can go to rectify this situation, if only we desire it enough to break down the barriers that have grown up between the scientist and the scholar.