[1] His works include Delicia Physico-Mathematicae (Nuremberg, 1636) and Geometriae practicae novae et auctae tractatus I-IV (published posthumously in 1641).
As a linguist, Schwenter was familiar with Greek, Hebrew, Arabic, Syriac, and Aramaic.
This is a universal joint that allows a microscope, mounted on the ball, to be swiveled into any position.
[2] One part served as a reservoir for ink and included the writing point.
Squeezing the pen forced ink to flow through a small hole in one of the first part's quill fragments and from there to the writing point.