Mary, Queen of Scots, sealed her final missive with an intricate spiral letterlock

Enlarge / Four vector drawings show the five-slit spiral lock mechanism used by Mary, Queen of Scots; the front and back of a locked letter packet using this method; and an unfolded lock. Sections are numbered 1-20 to show the different areas created by folding. (credit: Unlocking History Research Group) On the eve of her […]