source https://www.cnn.com/style/article/opening-sealed-letters-study-scn/index.html
'Locked' letter sealed 300 years ago is finally opened
Three hundred years ago, before envelopes, passwords and security codes, writers often struggled to keep thoughts, cares and dreams expressed in their letters private.
source https://www.cnn.com/style/article/opening-sealed-letters-study-scn/index.html
source https://www.cnn.com/style/article/opening-sealed-letters-study-scn/index.html