Mary, Queen of Scots used a "spiral locking" technique to seal the last letter she wrote before her execution, indicating that she wanted the contents to remain secret, according to research published in the Electronic British Library Journal.
원문출처 : https://www.cnn.com/style/article/mary-queen-scots-letterlocking-execution-intl-scli-gbr/index.html
원문출처 : https://www.cnn.com/style/article/mary-queen-scots-letterlocking-execution-intl-scli-gbr/index.html