Housed in a box with letters of Brahe, Newton and Robert Hooke.
Watermark: Rampant lion in shield with initials "V4B" above and "S T" below; presumably German or Dutch paper per Paul Needham, 2010. Watermark, beta radiograph. Shield, rampant lion, "V4B"
Written on the wrapper of a letter addressed to Galileo.
Being astronomical observations recording data on the satellites of Jupiter.