Researchers read sealed 17th-century letter without opening it
In a world first for the study of historic documents, an unopened letter written in 1697 has been read by researchers without breaking the seal. The letter, dated 31 July 1697 and sent from French merchant Jacques Sennacques in Lille to his cousin Pierre Le Pers in The Hague, had been closed using “letterlocking”, a process in which the letter is folded to become its own envelope, in effect locking it to keep it private. It is part of a collection of some 2,600 undelivered letters sent from all over Europe to The Hague between 1689 and 1706, 600 of which have never been opened.
The international team of researchers from universities including MIT, King’s College London, Queen
Mary University London, Utrecht and Leiden, worked with X-ray microtomography scans of the letter, which use X-rays to see inside the document, slice by slice, and create a 3D image. They applied computational flattening algorithms to the scans to enable them to virtually unfold the letter without ever opening it, and discovered that Sennacques had been asking his cousin for a certified copy of a death notice of one Daniel Le Pers.
“It has been a few weeks since I wrote to you in order to ask you to have drawn up for me a legalised excerpt of the death of sieur Daniel Le Pers, which took place in The Hague in the month of December 1695, without hearing from you,” runs the letter. “I am writing to you a second time in order to remind you of the pains that I took on your behalf. It is important to me to have this extract & you willdo me a great pleasure to procure it for me & to send me at the same time news of your health & of all the family.”
The Unlocking History research group, which includes historians, conservators and scientists, published their findings on Tuesday in an article in Nature Communications. They say this is the first time an unopened letter from Renaissance Europe has been read without breaking its seal or damaging it in any way. It is a breakthrough for the study of historic documents because the papers’ folds, tucks, and slits provide valuable evidence for historians and conservators.
“This algorithm takes us right into the heart of a locked letter,” write the research team in the paper, led by Jana Dambrogio and Amanda Ghas