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galileo demonstrating telescope illustration

Standards Sniff Out Fakes: Galileo Manuscript Revealed as a Forgery


A prized manuscript thought to be drafted by Galileo Galilei has been uncovered as a forgery. The document contains sketches and a letter signed with Galileo’s name that describe a telescope – the very telescope Galileo was using when he saw moons orbiting Jupiter and realized that the universe does not revolve around Earth – and plot the positions of the moons around Jupiter.

For decades, the University of Michigan Library held the manuscript as one of the most treasured items in its collection – until Nick Wilding, a historian at Georgia State University, investigated the piece and found evidence that it is the work of a 20th-century forger. Standards helped keep the document safe for many years when it was thought to be real, and they helped to uncover it as a fake, too.

Valuable library materials are archived in exacting conditions in order to preserve them as cultural artifacts and reference materials, and protect them from the elements. ISO 11799, Information and Documentation – Document Storage Requirements for Archive and Library Materials, is an international standard that covers long-term storage of these materials. It was developed by the International Organization for Standardization (ISO) Technical Committee (TC) 46, Information and documentation, Subcommittee (SC) 10, Requirements for document storage and conditions for preservation. The National Information Standards Organization (NISO) is the administrator to the American National Standards Institute (ANSI)-accredited U.S. Technical Advisory Group (TAG) to TC 46.

Beyond everyday storage conditions, rare documents must be protected against the threat of fires and natural disasters that could compromise their condition or destroy them completely. NFPA 232A, Guide for Fire Protection for Archives and Records Centers, developed by the National Fire Protection Association (NFPA), offers guidelines to preserve archive materials in the event of a fire.

While the document thought to be drafted by Galileo was perfectly preserved for many years, Wilding had his suspicions that it was not authentic. Supposedly, the letter and sketches were written at two different times on the same sheet of paper, but the ink color was exactly the same throughout the page. Some letter forms and word choices seemed strange to him, as well. Wilding searched for answers by examining the manuscript’s watermark – a circle with a three-leafed clover and the monogram “AS/BMO.”

Wilding was able to photograph the watermark for analysis, but many watermarks on antique papers are more difficult to discern with the naked eye, especially if there is printing over the watermark. One technique used for these watermarks is producing an X-ray image of the paper. X-rays pass more easily through thinner areas of the paper – like where a watermark was pressed – so the resulting image shows the paper in black and the watermark in white, while any printing does not show up at all in the image. X-ray technology has long been supported by standards such as ASTM E94/E94M, Standard Guide for Radiographic Examination Using Industrial Radiographic Film, developed by ASTM International.

Once the watermark was copied, Wilding did extensive research to compare it to other watermarks of its supposed provenance. He found this information in a reference work called “The Ancient Paper-Mills of the Former Austro-Hungarian Empire and Their Watermarks.” He was able to track the book down to a library and access it thanks to standards for library records, such as ANSI/NISO Z39.71, Holdings Statements for Bibliographic Items, an American National Standard developed by NISO.

With all of this information in hand, Wilding determined that the “AS/BMO” watermark (which in part referenced the Italian city of Bergamo) had not been used prior to around 1770. He concluded it was highly unlikely that Galileo had used the watermark more than 150 years earlier, making the document a forgery.

Librarians at the University of Michigan Library have accepted Wilding’s findings, and will update records to note that the document is “formerly attributed to Galileo.” In the meantime, the manuscript now holds other importance as it offers insights into the methods and stories behind forgeries.

Read the full story in The New York Times: A Watermark, and ‘Spidey Sense,’ Unmask a Forged Galileo Treasure.