Jason Olson, Deseret Morning News
John F. Hall, left, a professor of Roman history and ancient languages, explains to Randy Olsen, BYU library director, the text engraved on two bronze plates displayed at the Harold B. Lee Library at BYU.

PROVO — They're surprisingly heavy.

The replicas of two 2nd-century, Roman, bronze metal plates that date back to A.D. 109 on display in the Harold B. Lee Library on the BYU campus are thin, so one would think they're fragile and lightweight.

But pick one up, and it's hard not to drop it.

And even though the original plates weighed only 2.5 ounces each, holding just the two of them makes it difficult to imagine how heavy the set of 4th-century, golden plates — like those LDS Prophet Joseph Smith is believed to have unearthed from the Hill Cumorah — would have been.

And according to the literature supplied by BYU professor of law/Editor-in-Chief of BYU Studies John W. Welch, which accompanies the campus display, the two sets of plates would have been very similar in construction and physical appearance.

The comparable size and thickness, the use of alloyed metal and binding rings, the fact that one part is open and another sealed, the fact that the plates bear the names of witnesses, the combination of all of these factors in a pattern, make the Roman plates relevant to the Book of Mormon plates.

"We are extremely fortunate to have this exhibit at BYU," Welch said. "This may be the best example of ancient writing on metal plates anywhere in the world."

The 2,000-year-old plates behind the glass case at BYU were issued by imperial decree to a retiring Roman soldier — Marcus Herennius Polymita — on Oct. 14, A.D. 109 during the rule of Emperor Trajan in Rome. Similar plates were posted on a temple wall in Rome to announce his honorable discharge as well as his right to move freely about the Roman empire wearing the toga of a Roman citizen. His family was listed, providing valuable genealogical information.

The plates have a natural place in the Lee library because they are a historical record of ancient writing and record keeping, said Shaun McMurdie, chair of exhibition services and exhibit art director.

The imperial artifacts illuminate important and ancient documentation practice, said Welch.

The ingeniously designed plates feature an open presentation of the text and a sealed interior portion, a double copy that protects the document from those who might tamper with the contents.

"We refer to such records as doubled, sealed, witnessed documents," Welch said.

The plates, discovered near Dacia or modern-day Romania in 1986, have undergone extensive testing by BYU professor of geology Mike Dorais and found to contain the metals known to be available (and used in Trajan coins) in the region at the time, and their construction matches the technology of the period.

Included with the exhibit is an informational video that helps immerse visitors into the culture and story behind the plates.

For more detailed information see: byustudies.byu.edu.

If you go

What: Two ancient Roman plates: bronze military diplomas and other sealed documents

Where: Harold B. Lee Library, BYU, Provo campus

When: throughout 2007

Cost: free

E-mail: haddoc@desnews.com