An ancient documents expert working for Brigham Young University microfilmed the pages of the earliest complete book of Psalms - a 1,600-year-old manuscript believed to be the oldest book of any kind.

Except he didn't know it at the time.Steve Baldridge of Murray said he was surprised to read in the newspaper Thursday that scholars have dated the book to the second half of the fourth century A.D. - making it the oldest complete book of Psalms and possibly the world's oldest book.

"I knew it was important. I knew it was valuable. But I never expected to read about it on the front page of the newspaper," he said, noting that manuscript discoveries seldom receive that kind of attention.

The book, discovered four years ago in an Egyptian cemetery, is handwritten on about 490 parchment pages bound between leather-covered wood in a dialect of Coptic - a now-dead language of Old Greek and Egyptian hieroglyphs, that includes words never before seen.

Baldridge said he was on an assignment in Egypt for the BYU department of ancient scripture when he got the opportunity to photograph the book last fall for the director of the Coptic Museum of Cairo.

The job of putting the pages on microfilm posed specialproblems for Baldridge, who had recorded genealogical information from all types of documents in remote corners of the world for The Church of Jesus Christ of Latter-day Saints.

"Most manuscripts, you can microfilm in under an hour," he said. "This took just under a week." The pages, bound by threads, had to be carefully held down by hand for the camera instead of using the usual metal clamps.

Parchment, which is made from animal hide, is so delicate that too much pressure would cause it to break, Baldridge said. Many of the pictures taken show the hands of his assistants.

While working, he said, his thoughts were often of the young girl whose body was buried with the book. It was found under her head in a shallow grave in a cemetery for the poor located about 85 miles south of Cairo.

"I kept thinking of the person who had been lying on it for 1,600 years," Baldridge said. Several apparent bookmarks were found tucked into the manuscript, including reeds and a "Key of Life" carved from bone.

The 21/2-inch long symbol, known as an ankh, was imprinted on one side with five circles in a pattern that reminded him of a cross. It was attached to a leather thong.

An abstract design that Baldridge described as "zig-zag" was imprinted on the leather attached to the wooden covers of the book. The wood was more than a half-inch thick, he said, and, other than having a crack, was in good condition.

Some of the words on the ancient pages were corrected or written over for other reasons. Scholars are trying to translate the original text by studying the impressions made in the parchment, Baldridge said.

While this book might get the most attention of all the projects he's worked on, Baldridge said his greatest professional satisfaction comes from discoveries he has made on his own.

One of those occurred while he was in Egypt. He said he found that a small parish had records dating back hundreds of years. The microfilm records he made of those documents are now used by genealogical researchers.