{"id":5177,"date":"2026-10-30T06:00:00","date_gmt":"2026-10-30T13:00:00","guid":{"rendered":"https:\/\/bartbaggett.com\/blog\/?p=5177"},"modified":"2026-10-27T11:29:23","modified_gmt":"2026-10-27T18:29:23","slug":"galileo-manuscript-forgery-watermark","status":"publish","type":"post","link":"https:\/\/bartbaggett.com\/blog\/galileo-manuscript-forgery-watermark\/","title":{"rendered":"Galileo\u2019s Manuscript Forgery: How a Watermark Exposed the Truth"},"content":{"rendered":"

Imagine holding a piece of history\u2014a manuscript believed to be written by Galileo himself, describing his first observations of Jupiter\u2019s moons. For decades, the University of Michigan Library treasured such a document, displaying it as a rare artifact from the dawn of modern science. But in 2022, the truth emerged: the manuscript was a modern forgery, its secret betrayed not by ink or handwriting, but by the paper beneath it.<\/p>\n

The University of Michigan\u2019s prized Galileo manuscript, thought to date from 1609, was revealed in 2022 as a 20th-century forgery. A historian spotted a watermark on the paper\u2014used decades after Galileo\u2019s time\u2014which proved it could not be authentic.<\/p>\n

\"Illustration
Illustration: A forger’s workshop with Galileo’s manuscript and a magnifying glass revealing the BMO watermark. Not a reproduction of the original document.<\/figcaption><\/figure>\n

The Galileo Manuscript: A Treasure with a Hidden Past<\/h2>\n

The document at the center of this story was a single sheet, with the top half appearing to be a draft letter from Galileo Galilei to the Doge of Venice in August 1609, and the bottom half a set of notes from his January 1610 observations of Jupiter\u2019s moons. This manuscript surfaced publicly at a 1934 auction and was soon acquired by collector Tracy McGregor, who later bequeathed it to the University of Michigan in 1938.<\/p>\n

For nearly a century, the manuscript was celebrated as a genuine artifact, surviving the scrutiny of collectors, curators, and even supposed authentication by Cardinal Pietro Maffi\u2014though, as later investigation revealed, Maffi had died years before the auction and the letter attesting to his opinion was missing.<\/p>\n

The Forger\u2019s Craft: How Experts Were Fooled<\/h2>\n

Forgers know that the allure of a famous name can distract even the sharpest eyes. In this case, the forger\u2014believed to be Tobia Nicotra, a prolific 20th-century Italian forger\u2014crafted a document that fit the expectations of scholars and collectors alike. The handwriting, the ink, the style of the text all seemed plausible for Galileo\u2019s era.<\/p>\n

In 1934, the manuscript was compared to other documents, including some that were later revealed to be Nicotra\u2019s forgeries as well. Despite these comparisons, the document\u2019s authenticity went largely unquestioned for decades, a testament to the forger\u2019s skill and the challenges of authenticating historical artifacts.<\/p>\n

The Watermark That Broke the Case<\/h2>\n

The turning point came in 2022 when historian Nick Wilding took a closer look at the manuscript\u2019s paper. Using a light table, he identified a watermark: \u201cAS\/BMO.\u201d The \u201cBMO\u201d stood for Bergamo, a mark not found on any paper dated before 1770\u2014long after Galileo\u2019s death in 1642. Two paper experts confirmed that the sheet was made no earlier than the late 18th century.<\/p>\n

This single detail unraveled the entire story. No matter how convincing the handwriting or ink, the paper itself was an anachronism\u2014an impossibility for a document supposedly written in 1609. The library reexamined the manuscript and, based on the new evidence, concluded it was a 20th-century forgery, likely one of Nicotra\u2019s many clever fakes.<\/p>\n

How Document Examiners Approach Cases Like This<\/h2>\n

Cases like the Galileo manuscript show why forensic document examination goes far beyond handwriting. When authenticating a historical document, examiners consider:<\/p>\n