Three hundred years ago, before envelopes, passwords, and security codes, writers often struggled to keep thoughts, worries, and dreams private.
One popular way was to use a technique called letter blocking: intricately folding a flat sheet of paper to make your own envelope. This security strategy presented a challenge when 577 blocked letters delivered to The Hague in the Netherlands between 1689 and 1706 were found in an undelivered mail trunk.
The cards held they never reached their final recipients and the conservationists did not want to open and damage them. Instead, a team has found a way to read one of the letters without breaking the stamp or unfolding it in any way. Using a highly sensitive X-ray scanner and computer algorithms, the researchers deployed the letter virtually unopened.
It is a computer-generated display sequence of a sealed letter from seventeenth-century Europe. The virtual display was used to read the contents of the letter without physically opening it. Credit: Courtesy of the Unlocking History Research Group archive
“This algorithm takes us directly to the heart of a blocked letter,” the research team said in a statement.
“Sometimes the past resists scrutiny. We might just have cut out those open letters, but instead we’ve devoted ourselves to studying them for their hidden, secret, and inaccessible qualities. We’ve learned that letters can be much more revealing when left unopened. ”
The technique revealed the contents of a letter dated 31 July 1697. It contains a request from Jacques Sennacques to his cousin Pierre Le Pers, a French merchant from The Hague, for a certified copy of a notice of death of Daniel Le Pers.
The details may seem prosaic, but the researchers said the letter provides a fascinating insight into the lives of ordinary people, a snapshot of the first modern world while engaged in their business.
This trunk of undelivered letters from the 17th century was bequeathed to the Dutch Postal Museum in The Hague in 1926. A letter from this trunk was scanned by X-ray microtomography and practically unfolded to reveal its contents for the first time. in centuries. Credit: Courtesy of the Unlocking History Research Group archive
In addition to the unopened letters, it contains 2,571 open letters and fragments that for one reason or another never reached their destination.
At that time, there was no postage stamp and the recipients, not the senders, were responsible for the postage and shipping costs. If the addressee died or the letter was rejected, no charges could be charged and the letters were not delivered.
A new way to extract historical documents
X-ray scanners were originally designed to map the mineral content of teeth and have been used so far in dental research.
“We have been able to use our scanners for X-ray history,” study author David Mills, a researcher at Queen Mary University in London, said in a statement.
“The scanning technology is similar to medical CT scanners, but with much more intense X-rays that allow us to see the small traces of metal in the ink used to write these letters. The rest of the team was able to do our scan. images and turn them into letters that could virtually open and read for the first time in over 300 years “.
The letter contains a message from Jacques Sennacques dated 31 July 1697 to his cousin Pierre Le Pers, a French merchant. A watermark in the center containing an image of a bird is also visible. Credit: Courtesy of the Unlocking History Research Group archive
The new technique has the potential to unlock new historical evidence from Brienne’s trunk and other collections of unopened letters and documents, according to the study.
“Using the virtual deployment to read an intimate story that has never seen the light of day – and that has not even reached its recipient – is truly extraordinary,” the researchers said in the statement.
The research was published Tuesday in the journal Nature Communications.