Thomas Jefferson’s pocket notebooks, composed of erasable ivory plates on which he would write scientific observations and memoranda before copying them into notebooks in the evening. At Monticello. Jefferson made use of a practice that was a thousand years old: replace the ivory with parchment scraps (leftovers) and you end up with the medieval version of this handy “fan” notebook.

Thomas Jefferson’s pocket notebooks, composed of erasable ivory plates on which he would write scientific observations and memoranda before copying them into notebooks in the evening. At Monticello. Jefferson made use of a practice that was a thousand years old: replace the ivory with parchment scraps (leftovers) and you end up with the medieval version of this handy “fan” notebook.